- 1. Neuropsychological assessment (NPA) in practice
- 2. Primary concepts
- 3. Brain and Behavior
- 4. Measuring deficits
- 5. Procedures in an NPA
- 6. Interpreting an Neuropsychological Examination
- 7. Neuropathology
- 8. Neurobehavioral Variables and Diagnostics
- 9. Awareness
- 10. Perceptual tests
- 11. Testing memory
- 12. Batteries, Paired Memory Tests and Questionnaires of memory
- 13. Verbal and language skills
- 14. Constructional functions
- 15. Performance in executive functioning and motor skills
1. Neuropsychological assessment (NPA) in practice
Clinical neuropsychological is an applied science concerned with the behavioral expression of brain dysfunction. It owes its concepts to those who puzzled about what people made people do what they did and how. These people first called attention to what seemed to be linkages between body structures and people’s common response to common situations and behavioral anomalies. In the 19th century the idea of controlled observations became generally accepted. The beginning of the basis schema of brain behavioral relationships. In the first half of the 20th century, war-damaged brains gave the chief impetus to the development of clinical neuropsychology. Neuropsychological programs were created for the First World War for screening and diagnosis of brain injured and behavioral disturbed servicemen and for their rehabilitation afterwards. The Second World War promoted the development of many talented neuropsychologists and of increasingly sophisticated examination and treatment techniques.
Clinical neuropsychology can trace its lineage directly to the clinical neurosciences. Psychology contributed to the two other domains of knowledge and skills that are integral to the scientific discipline and clinical practices of neuropsychology today.
-‘Intelligence’, by educational psychologists (Binet, Spearman) for screening recruits. (Raven’s Progressive Matrices, the Wechsler Intelligence Scales ed.) -Experimental studies of cognitive functions in both humans and other animals. |
The practice of neuropsychology calls for flexibility, curiosity, inventiveness, and empathy even in seemingly most routine situations. Any of six different purposes may prompt a neuropsychological examination:
1. Diagnosis: accurate diagnosis, including localization of a lesion, is often achieved by means of the neurologist’s examination and laboratory devices. Still conditions may not be diagnostically enlightening (f.e. Alzheimer). Here is neuropsychological assessment needed. Despite general similarities in the pattern of brain function sites, these patterns will differ more ore less between patients and thus the outcome will be different. Screening is another aspect of diagnosis.
2. Patient’s care and planning: Many patients are referred for detailed information about their cognitive status, behavioral alterations, and personality characteristics – often with questions about their adjustment to their disabilities – so that they and the people responsible for their wellbeing may know how the neurological condition has affected their behavior. When all the data of a comprehensive neuropsychological examination – the patient’s history, background, and present situation; the qualitative observations; and the quantitative scores – are taken together, the examiner should have a realistic appreciation of how the patient reacts to deficits and can best compensate for them, and whether and how retraining could be profitably undertaken. Deterioration on repeated testing can identify a dementing process early in its course. Repeated testing may also be used to measure the effects of surgical procedures, medical treatment, or retraining. Brain impaired patients must have factual information about their functioning to understand themselves and to set realistic goals, yet their need for this information is often overlooked. The family needs to know about their patient’s condition in order to respond appropriately.
3. Treatment -1: Treatment planning and remediation Sensitive, broad gauged, and accurate neuropsychological assessment is necessary for determining the most appropriate treatment for each rehabilitation candidate with brain dysfunction. This includes delineation of problem areas and evaluation of the patient’s strengths and potential for rehabilitation.
4. Treatment -2: Treatment evaluating
Consumers and referring clinicians need to ask whether a given service promises more than can be delivered, or whether what is produced in terms of the patient’s behavioral changes has psychological or social value and is maintained long enough to warrant the costs.
5.Research Neuropsychological assessment has been used to study the organization of brain activity and its translation into behavior, and to investigate specific brain disorders and behavioral disabilities. Research with neuropsychological assessment techniques also involves their development, standardization and evaluation.
6.Forensic Neuropsychology Legal proceedings -claims of bodily injury and loss of function Criminal cases -misbehavior, question about mental capacity to stand trail. The neuropsychologist may uncover vocational or family problems, or patient care needs that have been overlooked, or the patient may prove to be suitable candidate for research.
The validity of neuropsychological assessment. Ecological validity typically refers to how well the neuropsychological assessment data predict future behavior or behavioral outcomes.
What can we expect of neuropsychological assessment at the beginning of this new century?
-More and more varied applications of neuropsychological assessment in both clinical and theoretical research in medicine, the neurosciences, education, and the social sciences as well. |
-Wider variety of tests |
-Computerizes assessment a dominant place |
-Older age groups, aspect of the aging brain, its competencies, and its vicissitudes. |
-Neuropsychologist in the future would have at their disposal a set of test modules and perhaps structured interviews that can be upgraded as knowledge increases and that can be applied in various combinations to answer particular questions and meet specific patient’s needs. |
2. Primary concepts
Brain examination
Neuropsychological assessment is another method of examining the brain by studying its behavioral product. Because the subject matter is behavior, there are much similarity’s between neuropsychological and psychological assessment, it is both based on the same techniques, assumptions and theories. Both types of assessment involves the intensive study of behavior by means of interviews and standardized scaled tests and questionnaires that provide relatively precise and sensitive indices of behavior. The distinctive character of neuropsychological assessment lies in a conceptual frame of reference that takes brain function as its point of departure.
The earliest instruments for studying brain function that continue to be in use are electrophysiological (EEG, EP, ERP). Some of these techniques are not only useful to detect brain diseases, but can be used also to study aspects of cognition. Elektrodermal activity -autonomic nervous systems functioning -emotional response Brain mapping: large volumes of data generated by these techniques displayed on a stylized head (brain image). Whether EEG/EP brain mapping should be employed in routine assessments has become a controversial issue because of the many technological and methodological problems in this practice that lead to a high rate of erroneous interpretations.
Functional brain imaging: non-invasive methods that permit the study of ongoing brain activity useful for exploring both normal brain functioning and the nature of specific brain disorders. In studies of cognition and other forms of behavior, these procedures (rCBF, PET, SPECT) compared data obtained during an activation task of interest to data from a resting / control state.
fMRI will, more than others procedures discussed, greatly affect neuropsychology as well as cognitive neuroscience in general, in part due to its widespread use. In addition to the many current clinical applications of motor and language mapping, fMRI has become a popular method for investigating traditional psychological processes such as time perception, semantic processing, emotional processing, response inhibition, and many others.
Procedures like WADA test and electrical cortical stimulation mapping have not only significantly reduced cortical morbidity following epilepsy chirurgy, but they have also greatly enhanced our knowledge of brain-behavior relations. These procedures have drawbacks in that they are invasive and afford only a limited range of assessable behavior due to restrictions on patient response and the short durations of medication effects. Generalizability of data obtained by this technique is further limited by the atypical functioning of these patients diseased brain.
‘Damage of the brain’ and ‘organicity’
Organicity: viewpoint of brain damage as a unitary phenomenon (’30, ’40). Although it was well recognized that brain damage result from different conditions and had different effect, much of the work with brain damaged patients was based on the assumption that organicity was characterized by one central behavioral defect. In neuropsychology’s next evolutionary stage, ‘brain damage’ was still treated as a unitary phenomenon but was given measurable extension. The theoretical basis for this position had been provided by Karl Lashley (localisation of function). Later on, Chapman and Wolff (1959) reviewed the literature on localization, presented data on their patients and concluded, with Lashley, that sheer extent of cortical loss played a greater role in determining the amount of cognitive impairment than did the site of the lesion. Advances in diagnostic medicine have changed the typical referral question to the neuropsychologist from one that attempts to determine if the patient has neurologic disease or not. In most cases the presence of ‘brain damage’ has been clinically established, however, the behavioral repercussions of brain damage vary with nature, extent, location and duration of the lesions, age, sex, status en many other individual characteristics. Not only does the pattern of deficits vary with different lesion characteristics, but two persons with similar pathology and lesion site may have distinctively different neuropsychological profiles.
Terminology
Behavior dimensions
Behavior may be conceptualized in terms of three functional (dimensional) systems: -cognition: the information-handling aspect of behavior -emotionality: feelings and motivation -executive functions: how behavior is expressed.
Although brain damage rarely effects just one of these systems, the cognitive functions have received more attentions than does the emotional and control systems. This is because:
-the cognitive defects can figure so prominently in a brain damaged patient;
-these systems can easily be conceptualized, measured and correlated with neuro-anatomical systems;
-and it is more difficult to detect such subtle changes in emotion and control Behavioral problems can also be secondary reactions to the specific problems created by the brain injury. Additional repercussions en reactions may occur as the patient attempts to cope with succeeding sets of reactions and the problems they bring.
Cognitive functions
The four major classes of cognitive functions are:
1. Receptive functions (select, acquire, classify and integrate information)
2. Memory and learning (information storage and retrieval)
3. Thinking (mental organization and reorganization of information)
4. Expressive functions (means trough which communicated or acted upon) although each function constitutes a distinct class of behaviors, normally they work in close interdependent concert. Generally speaking, within each class of cognitive functions a division may be made between those functions that mediate verbal/symbolic information and those that deal with data that cannot be communicated in words or symbols, such as complex visual or sound patterns. These subclasses differ from another in their neuroanatomical organization and in their behavioral expression while sharing other basic neuro-anatomical and psychometric relationships within the functional system. These functional divisions are conceptual constructions that can help the clinician to understand what goes into the typically very complex behaviors and test responses of their brain damaged patients.
Cognitive activity was originally attributed to a single function, intelligence. As refinements n testing and data-handling techniques became more precise, it became evident that the behavior measured by ‘intelligence’ tests involves specific cognitive and executive functions. Neuropsychological studies have not found a general cognitive or intellectual function, but rather many discrete ones that work together so smoothly in the intact brain that cognition is experienced as a single seamless attribute. Although IQ can be a good predictor of academic performance, it is not always useful in describing cognitive test performances. They represent so many different kinds of more or less confounded functions as to be conceptually meaningless. In neuropsychology, IQ scores are often unreliable indices of neuropathic deterioration.
Cognitive functions
Receptive functions
Entry of information into the central processing system proceeds from sensory stimulation, i.e., sensation, through perception, which involves the integration of sensory impressions into psychologically meaningful data and thence into memory. The components can be splintered into ever smaller receptive units. Sensory reception involves an arousal process that triggers central registration leading to analysis, encoding, and integrative activities. Neuropsychological assessment and research focus primarily on the five traditionally recognized senses: sight, hearing, touch, taste and smell. Perception involves active processing of the continuous torrent of sensations as well as their inhibition or filtering from consciousness. Normal perception in the healthy organism is a complex process engaging many different aspects of brain functioning. The extensive cortical distribution and complexity of perceptual activities make them highly vulnerable to brain injury. The perceptual functions include such activities as awareness, recognition, discrimination, patterning and orientation. Agnosia: disorders of recognition, impairments in perceptual integration. The fine degree to which brain organization is specialized becomes apparent in patients with similarly placed lesions who van identify inanimate objects but not animated ones, or comprehend words tat are abstract, better than those that are concrete.
The agnosia can be divided into two major categories:
-Associative agnosia: breakdown in one ore more aspects of the patient’s information store or generic’ knowledge |
-Apperceptive agnosia are due to higher level perceptual disturbances |
Types and stages of memory
Central to all cognitive functions and probably to all that is characteristically human in a person’s behavior is the capacity for memory, learning and intentional access to this knowledge store. Although there are many named types of memory, for clinical purposes, the dual system conceptualization – into declarative (explicit) and nondeclarative (implicit) memory with its major subsystems – provides a useful framework for observing and understanding patterns of memory competence and deficits presented by our patients.
When complaining about memory problems, most patients are referring to problems with remembering information, objects and events (explicit memory).
Stages of memory processing
1. Registration or sensory memory Holds large amounts of incoming information briefly (seconds) in sensory store. It is a selecting and recording process by which perceptions enter the memory system. Either the information is further processed as short-term memory or it quickly decays.
2a. Immediate memory (first stage of short-term memory) Temporarily holds information retained from the registration process. It serves as a limited capacity store from which information is transferred to a more permanent store. It typically lasts from about 30 seconds up to several minutes
2b. Rehearsal is any repetitive mental process that serves to lengthen the duration of a memory trace, with rehearsal a memory trace may be maintained for hours. 2c. Another kind of short term memory may be distinguished from immediate memory in that is lasts from an hour or so to one or two days.
3. Longterm memory (LTM) or secondary memory – i.e. learning, the acquisition of new information – refers to the organism’s ability to store information. Long-term memory is most readily distinguishable from short term memory in amnesic patients. Amnesic conditions all have in common that there is a relatively intact short term memory capacity with significant long term memory impairments Consolidation: process of storing information as long-term memory. Long term memory storage involves a number of processes occurring at the cellular level. These include neurochemical alterations in the neuron en in the synapse, and perhaps pruning. There is no single local site for stored memories.
Anterograde amnesia: inability to remember one’s life events beginning with the onset of a condition. Patients are unable to learn and have defective recent memory. Retrograde amnesia: Loss of memory for events preceding the onset of brain injury, most often due to trauma. When retrograde amnesia occurs with brain disease, loss of one’s own history and events may go back years and even decades, in which newer memories are more vulnerable than the older ones. Remembering: retrieval of information, this may occur through recall involving active, complex search process.
Nondeclarative memory. The knowledge and skills in nondeclarative memory have been defined as ‘knowledge that is expressed in performance without subjects’ phenomenal awareness that they possess it. Two subsystems are clinically relevant: -Procedural memory (motor and cognitive skill learning)
-Priming/perceptual learning (form of recall in which, without the subjects’ awareness, prior exposure facilitates the response (classical conditioning is also considered a form of nondeclarative memory
Two elements common to these different aspects of memory: -their preservation in most amnesic patients -they are acquired or used without awareness of deliberate effort
Forgetting: some loss or diminished access to information – both recently acquired and stored in past. Normal forgetting differs from amnesic conditions in that only amnesia involves the inaccessibility or nonrecording of large chunks of personal memories. What the process of normal forgetting might be is still unclear.
Thinking
Thinking may be defined as any mental operation that relates two or more bits of information explicitly (in making arithmetic computation) or implicitly (as in judging that this is bad, i.e., relative to that). Lots of complex cognitive functions are subsumed under the rubric of thinking, such as computation, reasoning and judgment, e.d. The nature of the information being mentally manipulated and the operation define the category of thinking. The higher cognitive functions of abstraction, reasoning, judgment, analysis and synthesis tend to be relatively sensitive to diffuse brain injury, even when most specific receptive, expressive or memory functions remain essentially intact. The higher cognitive functions tend to be more fragile than the lower, more discrete functions. Problem solving involves executive functions as well as thinking, since a problem first has to be identified. As with other cognitive functions, the quality of any complex operation will depend in part on the extent to which its sensory and motor components are intact at the central integrative (cortical) level.
Expressive functions
Expressive functions, such as speaking, drawing or writing, manipulating, physical gestures, facial expressions or movements, make up the sum of observable behavior. Mental activity is inferred from them. Apraxia: disturbance of purposeful expressive functions.
Given the complexity of purposeful activity it is not surprising that apraxia occurs with disruption of pathways at different stages. Apraxic disorders may appear when pathways have been disrupted that connect the processing of information with centers for motor integration and executive functions integral to the performance of complex learned acts. Apraxias tend to occur in clusters of disabilities that share a common anatomical pattern of brain damage.
Constructional disorders, often classified as paraxial, are actually not paraxial in the strict sense of the concept. Rather, they are disturbances ‘in formulative activities such as assembling, building and drawing, in which the spatial form of the product proves to be unsuccessful without there being an apraxia of single movements’. More often associated with lesions of the nonspeech hemisphere of the brain.
Aphasia
Defects of symbol formulation Although there are many types en subtypes of aphasia described, the presentation of aphasic symptoms also varies enough from patient to patient and in individual patients over time that clear distinctions do not hold up in many cases.
Aphasia type | Fluency | Comprehension | Repetition | Naming |
Broca’s | Poor | Good | Poor | Poor |
Wernicke’s | Good | Poor | Poor | Poor |
Global | Poor | Poor | Poor | Poor |
Conduction | Good | Good | Poor | Good |
Anomic | Good | Good | Good | Poor |
Transcortical motor | Poor | Good | Good | Poor |
Transcortical | Good | Poor | Good | Poor |
Subcortical | Fair to good | Variable | Variable | Variable |
Mental Activity Variables
These are behavior characteristics that concern the efficiency of mental processes. They are intimately involved in cognitive operations but do not have a unique behavioral end product. They can be classified into three categories:
-Level of consciousness
Consciousness generally concerns the level at which the organism is receptive to stimulation, or is awake. Level of consciousness ranges over a continuum from full alertness through drowsiness, somnolence, stupor and coma. Levels of alertness can vary in response to organismic changes as in metabolism, circadian rhythms, fatigue level or organic states.
-Attention Attention refers to several different capacities of processes that are related aspects of how the organism becomes receptive to stimuli and how it may begin processing incoming or attended-to excitation. Most investigators conceive of attention as a system in which processing occurs sequentially in a series of stages within different brain systems involved in attention. This system appears to be organized in a hierarchical manner and disorders of attention may arise from lesions involving different points in this system. A salient characteristic of the attentional system is its limited capacity. Attentional capacity varies not only between individuals but also within each person at different times and under different conditions. Brain injury may reduce attentional capacity more lastingly. Simple immediate span of attention – how much information can be grasped at once – is a relatively effortless process that tends to be resistant to the effects of aging and many brain disorders. The more fragile aspects of attention are:
• Focused or selective attention (concentration)
• Sustained attention
• Divided attention
• Alternating attention
Underlying many patients’ attentional disorders is slowed processing, which can have broad ranging effects on attentional activities.
-Activity rate Activity rate refers to the speed at which mental activities are performed and to speed of motor responses. Behavioral slowing is a common characteristic of both aging and brain damage.
Executive functions
The executive functions consist of those capacities that enable a person to engage successfully in independent, purposive, self-serving behavior. As long as the executive functions are intact, a person can sustain considerable cognitive loss and still continue to be independent, constructively self-serving and productive. Cognitive deficits usually involve specific functions or functional areas; impairments in executive functions tend to show up globally, affecting all aspects of behavior. Many of the behavior problems arising from impaired executive functions are apparent even to casual observers, but other defects, however, are not so obvious. Perhaps the most serious of these problems, from a psychological standpoint, are impaired capacity to initiate activity, decreased or absent motivation, and defects in planning and carrying out the activity sequences that make up goal-directed behaviors.
Personality / emotionality variables some personality or emotional change usually follows brain injury. Among the most common effects of brain injury on personality are:
-Emotional dulling -Disinhibition -Diminution of anxiety -Heightened anxiety -Depressed mood –Hypersensitivity.
Some brain injured patients display emotional instability characterized by rapid, often exaggerated affective swings, a condition called emotional lability. Three kinds of lability can associated with brain damage can be distinguished.
1 The emotional ups and downs of some labile patients result from weakened controls and lowered frustration tolerance. Often pronounced in the acute stages of their illness and when they are stressed or fatigued.
2 A second group of labile patients have lost emotional sensitivity and the capacity for modulating emotionally charged behavior.
3 A third group of labile patients differs from the others in that their feelings are generally appropriate, but brief episodes of strong affective expression – usually tearful crying, sometimes laughter – can be triggered by even quite mild stimulation. This is the pseudobulbar state. This condition is most usually observerd with left-sided anterior damage.
One significantly and relatively common concomitant of brain injury is a changed sexual drive. Sometimes they become (much) more sexually driven, but more frequently the patient loses sexual interest of capability.
3. Brain and Behavior
Brain Pathology and Psychological Functions
Lesion is a localized abnormal tissue change. Syndrome is a cluster of deficits that occur together with some regularity. Knowledge of localization of dysfunction gives an educated guess of the site of the lesion based on behavior. But the same lesion van have a different outcome, there is no push-button relationship because behaviors take place at multiple levels.
The Cellular Substrate
Nervous system does reception, processing, storage and transmission of information. 2 types of cells: 1) neurons : conduct nerve impulses that transmit information, there are 10neurons. 2) there are 10x 50 glia, support cells that can’t transmit info. Are thought to have nutritional and scavenger functions. Types: astrocytes (component blood-brain barrier) and oligodendroglia (form myelin). Nerve cells vary in shape and function, cell body, dendrites, axon, action potential. Synapse is point of interaction between nerve cells. Have an excitatory/inhibitory effect. Long lasting synaptic modification is a long term potentation/depression. Provide variability and flexibility in behavior. Neurons communicate through neurotransmitters, 100 different types. When a nerve cell is injured/diseased, the function stops, circuits are disrupted. Sometimes there is recovery, in general they are not replaced. Apoptosis kills neurons to enhance organization, this is called pruning.
The structure of the brain
The brain consists of a hind-, mid-and forebrain. The lowest is most simply organized. There are 4 ventricles filled with cerebrospinal fluid (CBF) to absorb shocks. Obstruction leads to normal pressure hydrocephalus. Cerebral blood comes from 3 major arterial distributions. Anterior and middle arteries feed the internal carotid artery.
Hindbrain
Medulla oblongata/bulb is the lowest part of the brainstem. Basic life maintaining centres. Injury leads to death. Has sensory nuclei for mouth and throat movements. Reticular formation (upper chord to diencephalons) connects all major neural tracts. Many nerve centres: mediates important and complex postural reflexes. Site RAS (Reticular Activating System): wakefulness and alertness, modulates attention through arousal of cortex. Lesions lead to sleep, consciousness and responsivity disturbances. Pons: pathway for fibres from cortex to cerebellum. Correlates with cerebellum postural and kinaesthetic info and refines and regulates motor impulses. Lesions lead to motor, sensory and coordination disorders. Cerebellum: contributes to motor control through programming and executing actions. Can affect cognition, personality changes and psychiatric disorders.
Midbrain (mesencephalon): conscious experience, sensory and motor correlation centres. Integration reflex and automatic responses. Lesions lead to movement disabilities, memory retrieval.
Forebrain, Diencephalic Structures Thalamus: has 11 nuclei or more, consists of 2 halves. Has extensive reciprocal connections with topographic organization of the cortex. Has a sensory relay centre for bodily sensations, tactile object agnosia. Relay for vision, hearing, taste, limbic system, motor. End of RAS and has therefore arousal and sleep production functions. Role higher level brain activity: The dorsomedial nucleus for memory gets input from the amygdale, the mammillothalamic tract connects mammilary bodies to the thalamus which sends through to prefrontal cortex and the medial temporal lobe. Memory impairments with thalamic lesions: 1) learning/anterograde 2) Recall in temporal gradient (older memories recalled better). Lack appreciation deficits. Left thalamus is verbal, right nonverbal. Only large lesions lead to language problems. Right also identification of shapes and location. Thalamic damage leads to apathy, loss spontaneity and drive, flat affect. Hypothalamus: regulates physical drives such as appetite, sex, arousal, thirst. Input from many regions, coordinates autonomic and endocrine functions, rage and fear reactions. Damage leads to obesity, temperature regulation, lower drive states, mood. Mammilary bodies at the end do memory processing.
Forebrain: Cerebrum
Basal Ganglia: consists of caudate, putamen and globus pallidus (sometimes also amygdale, subthalamic nucleus and substantia nigra called). Neostriatum is caudate and putamen, translates cognition into action. Damage leads to motor deficits, involuntary movements, problems acquisition habits and skills. Parkinson is degeneration of substantia nigra leading to lower dopamine levels. Huntington is caused by a loss of neurons in the caudate nucleus and leads to an excess of motor activity, personality change and cognitive problems. Neostriatum has a key function in the procedural memory system. Basal ganglia help with cognitive flexibility, many neuropsychological conditions show alterations in basal ganglia. Nucleus basalis of Meynert: lies in basal ganglia, is a source of cholinergic transmitters in learning.
Limbic System: includes amygdale, cingulate gyrus and hippocampus. Situated in brain stem and forebrain. Role in emotion, motivation and memory. Amygdala: lies in anterior part temporal lobe. Emotional processing and learning, modulation attention, drive states, movement patterns. Has a connection to olfaction centres. Damage causes hyper sexuality, diminished aggressive capacities, feeding, fear reaction. Removal has a taming effect, can’t make emotional discriminations between stimuli, apathy. Amygdala gives an emotional tag to memory traces, role in memory consolidation. Kluver-Bucy syndrome is a destruction of amygdale resulting in inability to learn, eat a lot, hyper sexuality. Cingulate gyrus: sited above corpus callosum. Influences attention, response selection and emotional behaviour. Anterior controls behaviour, posterior involved in memory. Hippocampus: normal learning and retention. Interaction between perception and memory systems, processes new memories; information about events and their context. Damage leads to anterograde and retrograde amnesia, mild Alzheimer. Left involved in verbal memory, right in recognition of patterns. In the white matter there are association, commissural and projection fibres. Lesions cause dementing disorders. The corpus callosum is a band of commissural fibres, it is larger in righthanded persons. Commissurectomy leads to discontinuities in perception, comprehension and response. Agenesis of the corpus callosum leads to slowed motor movements on bimanual tasks. Cerebral cortex is grey matter and synaptic connections, it is the most highly organised centre of the brain. Multiple (sub)cortical areas are involved in complex behaviours. The processing patterns have many forms.
The cerebral cortex and behavior
The functional patterns of the cerebral cortex are divided in 2 planes: lateral and longitudinal Lateral Organisation The hemispheres are nearly symmetrical, they mediate in the contralateral side of the body. In the primary motor area and the primary sensory area the amount of cortex is associated with a body part, proportional to the number of nerve endings in that body part. Visual: 1 half of each visual field is projected onto the contralateral visual cortex. There are two pathways for visual recognition (visuospatial analysis and pattern analysis & object recognition). Auditory: most fibres go contralateral, a few ipsilateral. Destruction of the primary sensory/motor area has little effect on higher cortical functions. The primary cortical area is responsible for sensory and non-functional movements. The secondary cortical area integrates and refines raw perceptions. The tertiary area combines more modalities. The posterior association cortex does supramodal integration of perceptual functions also called multimodal or heteromodal.
Asymmetry of the brain: Right: wider frontal area, larger Sylvian fissure. Left: wider occipital area (especially men), cells more integrated, more focal representation. Right-handed people have a larger planum temporale on the left. There are different neurotransmitters associated with each hemisphere. Functional specialization: Left: linear processing, detailed info, familiar info, speech, verbal, number symbols, sequences of movements. Right: configurational processing, global info, new info, non-verbal, intonation, voice recognition, prosody, discrimination, (spatial) attention. Cognitive alterations with lateral lesions: Left: sequence, aphasia, verbal memory/fluency, tendency to simplification. Right: illogical, bad judgement, organizing, impersistence, visuospatial perception. One hemisphere is enhanced when the other is impaired. Hippocampal damage: Left: verbal memory. Right: recall and recognition of complex visual and auditory patterns. Temporal lobe damage: left verbal, right non-verbal. Emotional alterations with lateral lesions: Right: multidimensional, emotional tone in face, self-evaluation, range and intensity affective intonation, unaware mistakes, indifferent reaction, euphoria. Left: emotional words, catastrophic reaction, anxiety. All is coloured by the premorbid personality. Advantages hemispheric interaction: mutually enhancing, ability to use hands together in many arts.
Longitudinal Organisation Structure: gyri (ridges) and sulci (clefts). 4 lobes. The central sulcus divides the hemispheres in anterior and posterior. In the front (precentral) lies the primary motor area. Behind (postcentral) lies the somatosensory projection area. The parieto-occipital sulcus is the border between visual and spatial functions. Posterior: analysis, coding, information storage. Anterior: formations of intentions, programs behaviour.
Posterior Cortex
The primary sensory area lies in the posterior cortex, the primary visual cortex in the occipital lobe posterior, the somatosensory area lies in the postcentral gyrus, the primary auditory cortex lies in the temporal lobe, kinaesthetic and vestibular functions are in the parietal lobe. There is no clear demarcation of functions.
Occipital lobes and their disorders Visual pathway: retina to lateral geniticulate nucleus to primary visual cortex. Damage of the primary visual cortex leads to cortical blindness (blind sight). Visual anosognosia is denial of blindness, seen in Antons syndrome, lesion in occipital lobe. Lesions of visual association cortex in areas of the occipital lobe leads to visual agnosias, aspect(s) of visual perception is defective. Apperceptive agnosia is when there is no ability to synthesize, they draw fragmented. In visual object agnosia stimuli can only be recognized through other senses than sight. Simultagnosia is Balints Syndrome, the inability to perceive more than 1 object, difficulty directing gaze and shifting from a fixation point. Colour agnosia: can’t appreciate differences between colours. Pantomime agnosia: can’t comprehend pantomime. Associative visual agnosia due to lesion of the left occipital lobe: defects recognition, organisation and scanning. Problems also due to damage left: acalculia, optic aphasia for colours. Visual inattention is the imperception of stimuli. Spatial neglect: stimuli from left are ignored, damage right parietal and occipital lobe. Other visuoperceptional anomalies: achromatopsia (loss colour), metamorphopsias (visual distortions). Prosopagnosia is the inability to recognize faces, either familiar or unfamiliar. Damage to undersides cortex of the occipital and temporal lobe bilaterally. Impairment is greater with a right sided lesion, most common in men. There are 2 visuoperceptional systems: 1) dorsal, the parieto-occipital pathway which does spatial analysis, “where”. 2) ventral, the tempero-occipital pathway for shapes and patterns, “what”.
The posterior association cortex and its disorders (often apraxias and agnosias) Defects caused by posterior lesions either hemisphere: constructional (parietal), short-term memory, serial ordening, tactile agnosia, guidance of movements. Left: programming. Right: disengagement attention. Lesions left posterior hemisphere: fluent aphasia, symbol processing, echolalia, impaired comprehension of semantic features of language, writing, apraxia for gestures, sequential hand movements, acalculia, agraphia, reading, finger agnosia. Lesions right posterior hemisphere: constructional ability, dyscalculia, apraxia for dressing, sensory neglect, inattention (all modalities), visual extinction, hemisomatognosia, anosognosia, visual imperception half side, spatial thought memory, perceptual fragmentation.
The temporal lobes and their disorders Temporal info processing and lesion associated defects: often hearing involved, cortical deafness, cocktail party-effect impaired, pure word deafness, auditory agnosia, phonagnosia (voices), Wernickes aphasia, dysnomia (left), right: organisation of complex data and formulating multifaceted plans, amusia, odour perception, visual discrimination/recognition. Memory: Left verbal, right nonverbal. Loss facts, knowledge of objects, meaning of words. Emotional: anxiety, delusions, mood. Temporal lobe epilepsy involves mood, hallucinations and perceptual distortions.
Damage of the frontal lobe
Responsible for cognitive and social behaviour, 3 parts: precentral, premotor and prefrontal Precentral: the primary motor cortex: mediates movement. Damage causes paresis, paralysis. The primary taste cortex lies in the Sylvian fissure. Premotor: the integration of motor skills and learned action sequences. Lesions cause uncoordinated movements, motor skills, limb strength, initiation. Left: disrupted speech production; oral apraxia.
Supplementary motor area mediates speech mechanisms and fine hand movements. Damage causes agraphia, Broca’s aphasia, avocalia (can’t sing), motor impersistence. Prefrontal: attends, integrates, formulates, executes, monitors, modifies, judges all nervous system activities. Damage leads to derangement of behavioural programming, affects ‘how’ things are done.
Prefrontal subdivions:
1) dorsolateral: control, regulation, integration of cognitive activities.
2) Medial (cingulated/limbic): drive, affective integration, emotional and social behaviour.
3) Orbital (basal/ventral): impulse control, regulation and maintenance of set and ongoing behaviour. Damage leads to disinhibitions and impulsivity. Left: prolonged unconsciousness. Odour detection, reasoning. Left: verbal fluency, spontaneous speech, organisation of language, gestural fluency, spatial analysis. Right: constructional design, fluency, adaptation to handicap, self-evaluation. Prefrontal and attention: controls shifts of attention, concentration new tasks, divided attention, working memory, short term memory. Prefrontal and memory: frontal amnesia is a problem with prospective memory. Stimulus encoding, source memory, criterion setting, monitoring retrieval, confabulation. Prefrontal and cognitive functions: perseveration, carelessness, apathy, poor judgment, adaptability, sensitivity new stimuli, stimulus boundedness, verbal cues, planning, problem solving, self monitoring, sense of time.
Behavioural problems with prefrontal damage: practical and social judgment.
1) starting: initiative, ambition, pathological inertia.
2) making mental and behavioural shifts: supramodal perseveration and rigidity.
3) stopping: impulsivity, disinhibition, loss control.
4) deficient self-awareness: self criticism.
5) concrete attitude: planning, goal-directed behaviour.
Clinical limitations of functional localization Functional localization has clinical limitations because the relationship between brain activity and human behaviour is uncertain.
4. Measuring deficits
Neuropsychological assessment is not only concerned with the documentation and description of deficits but also with preserved functions. Yet brain damage always implies behavioural impairment, even when psychological changes are viewed as improvement.
In some patients the deficit may be subtle, becoming apparent only on complex judgmental tasks or under emotional conditions. In others, behavioural evidence of impairment may be so slight or ill-defined as to be unobservable under ordinary conditions.
The assessment of psychological deficit has focused on cognitive impairment for a number of reasons:
(1) Some degree of cognitive impairment accompanies almost all brain dysfunction and is a diagnostically significant feature of many neurological disorders.
(2) Psychologists are better able to measure cognitive activity than any other kind of behaviour, except perhaps simple psychophysical reactions and sensorimotor responses. The deficit measurement paradigm can be used with other behavioural impairments, however these measurements have not yet achieved the community of agreement nor the levels or reliability or predictability that are now taken for granted when measuring cognitive functions.
Comparison standards
The concept of behavioural deficit presupposes some ideal level of functioning. This level, the comparison standard, may be normative (derived from an appropriate population) or individual (derived from the patient). Neuropsychological assessment uses both.
The normative comparison standard may be an average or middle (median) score. For many cognitive functions, variables of age and education or vocational achievement may significantly affect test performance. Because of the differential rate of development for boys and girls, children’s norms are best given separately for each sex. In neuropsychological assessment, population norms are most useful in evaluating basic cognitive functions that develop throughout childhood. They can be distinguished from complex mental abilities or academic skills when examined as relatively pure functions. Typically, performances of these capacities do not distribute normally. Functions most suited to evaluation by population norms also tend to be age dependent, particularly from the middle adult years onward. As the number of different kinds of variables contributing to a measure increases, the more likely will that measure’s distribution approach normality.
The norms for some psychological functions and traits are actually species-wide performance expectations for adults, although for infants or children they may be age or grade averages. Speech is a good example. These skills are learned, improve with practice and its mastery is taken for granted. They are independent of social learning, although training may enhance their expression and aging may dull it. They are so integral in normal behaviour, that these capacities are usually observed only by deliberate examination. Other species-wide normative standards involve components of behaviour so rudimentary that they are not generally thought of as psychological functions or abilities.
A number of assumed normative standards have been arbitrarily set. Verbal response latency – the amount of time a person takes to answer a simple question – is an example of a customary standard.
In the assessment of persons with known or suspected adult-onset brain pathology normative standards are appropriate only when the function or skill or capacity that is being measured is well within the capability of all intact adults and does not vary greatly with age, sex, education or general mental ability. A description of that patient’s functioning in terms of population norms will, it itself, shed no light on the extent of impairment unless there was documentation of premorbid cognitive levels. For those functions with species-wide norms, this task is easy. Only an individual comparison provides a meaningful basis for assessing deficit.
As a rule, individual comparison standards are called for whenever a psychological trait or function that is normally distributed in the intact adult population is evaluated for change. The use of individual comparison standards is probably most clearly exemplified in rate of change studies. Knowledge of the rate at which the patient’s performance is deteriorating can contribute to the accuracy of predictions of the course of a degenerative disease.
Deficit measurement
Much of clinical neuropsychological assessment involves intraindividual comparisons of the abilities and skills under consideration. Deficit can be assessed directly when there are normative comparison standards against which the behaviour in question can be compared. The direct method using individual comparison standard requires the availability of premorbid test scores. In many cases, these will be nonexistent or difficult to obtain. Therefore, more often than not, the examiner must use indirect methods of deficit assessment from which individual comparison standards can be inferred.
In indirect measurement, the examiner compares the present performance with an estimate of the patient’s original ability level. Historical and observational data are obvious soureces of information from which estimates of premorbid ability may be drawn directly. The need for accurate estimates has increasingly become apparent, especially in evaluating complaints of mental deterioration in older persons.
For many years a popular method for estimating premorbid ability level from test performance used a vocabulary score as the single best indicator of original intellectual endowment. Vocabulary correlates most highly with education. A well known example of this method is the Shipley Institute of Living Scale (SILS), which contains a multiple-choise (testing recognition rather than recall) vocabulary section and verbal reasoning items. Vocabulary and related verbal skill scores sometimes do provide the best estimates of the general premorbid ability level. However, vocabularly tests such as Wechsler’s, which require oral definitions, tend to be more vulnarable to brain damage than verbal tests that can be answered in a word or two, require only recognition, or call on practical experience. Further, many patients with left hemisphere lesions suffer deterioration of verbal skills which shows up in relatively lower scores on more than one test of verbal function. Aphasic patients have the most obvious verbal disabilities.
The National Adult Reading Test (NART) can reliably estimate the comparison standard. It requires oral reading of 50 phonetically irregular words. This technique can only be used with languages in which the spelling of many words is phonetically irregular. In essence, these word reading test provide an estimate of vocabulary size. There is also the North American Adult Reading Test (NAART). It is of interest that for this verbal skill test the mean number of words correctly pronounced steadily increased with age. The American National Reading Test (ANART) proved sensitive to the developing semantic deficits of patients with early Alzheimer-type dementia. It was developed to be more approperiate for the ethnically heterogeneous U.S. population. A short form of the NART (Short NART) was recommended for subjects who fail more than five of the first twenty-five items. For subjects who pronounced between twelve and twenty of the first 25 NART words correctly, a procedure enables the examiner to estimate a full NART score; lower scores are assumed to be no different from what the total score would be if the entire word list had been given. A technique developed to be sensitive to anterior lesions, the Homophone Meaning Generation Test (HMGT), has been applied to the problem of estimating the degree to which a patient is impaired. The task, which requires a shift in cognitive set, asks the subject for other meanings for a set of eight homophones (e.g. pear-pair, pare; sight-site, cite) The Reading test of the Wide Range Ability Test (WRAT-READ) was developed on the same principle as the NART tests, using more to less frequently appearing words – although not all WRAT-READ words are phonetically irregular – to evaluate reading level. When subjects’ age range extends across several age cohorts into old age, age effects emerge on the NART/ NAART. Although age effects reached significance for a wide range subject sample, when the much stronger correlations for education and social class were partialled out, the very small age effects were nullified. The findings of studies on this technique have shown that when attempting to predict VSIQ and FSIQ scores of cognitively intact persons from their reading level, these tests are fairly accurate. The greater the actual IQ score deviation from 100, the more discrepant estimates by the NART or one of its variants. Reading test scores do tend to decline when given to dementing patients, but typically less than IQ scores. This method has been questioned as underastimating the premorbid ability of dementia patients
The degree of underestimation being fairly directly related to the severity of dementia of mildly demented patients with linguistic deficits and of those more severely demented. There is suggested that a language test standardized on one population may not work as well with another in which small differences in language have developed over time.
One problem with word-reading scores is their vulnerability to brain disorders, especially those involving verbal abilities; one advantage of demographic variables is their independence from the patient’s neuropsychological status at the time of examination. R.S. Wilson, Rosenbaum and Brown devised the first formula using demographic variables (age, sex, race, education, and occupation) to make this estimation. This formula predicted only two-third within a ten-point error range. It overpredicted high scores and underpredicted low ones. Barona elaborated on Wilson’s work by incorporating the variables of geographic region, urban-rural residence and handedness into the estimation formula. This demographic formula joins word reading tests in not predicting PSIQ effectively.
Further efforts to improve estimates of premorbid ability have generated formulas that combine word recognition test scores with demographic variables. In studies of normal subjects, while demographic variables accounted for 50% of the FSIQ score variance, and NART scores alone predcted 66% of the variance, the FSIQ score variance based on a combination of these variables was 73%. Krull and his colleagues devised the Oklahoma Premorbid Intelligence Estimation (OPIE), using Vocabulary and Picture Completion scores of the WAIS-R standardization population along with age, education, occupation, and race data. Not surprisingly, the predicted and actual correlations were high. OPIE formulas were then developed to predict FSIQ using raw scores for Vocabulary, Picture Completion both of these tests or the raw score for whichever of these two tests had the highest nonage corrected scaled score (BEST method) for subjects in the authors’ patient data base.
M.R. Basso, Bornstein and their colleagues, after testing the Barona, revised Barona, OPIE, and BEST3, concluded that none of these methods based on regression formulas were satisfactory. They pointed out that the phenomenon of regression to the mean affected all these methods. The authors concluded that each method “taps different aspects of variance”. The demographically based method produced the smallest discrepancy between the clinical sample and the matched control group. The Barona score had the lowest correlation by far with the subjects’actual FSIQ score. Data suggest that the BEST-10 may provide a better estimate of premorbid ability than BEST-2. The authors suggest that estimation procedures using best performances have higher predictive accuracy than those constructed on assumtions regarding “hold” tests.
Performance method
In the best performance method, the level of the best performance serves as the best estimate of premorbid ability. Once the highest level of functioning has been indentified, it becomes the standard against which all other aspects of the patient’s current performance are compared. Basic to this method is the assumption that, given reasonably normal conditions of physical and mental development, there is one performance level that best represents each person’s cognitive abilities and skills generally. This assumption follows from the well-documented phenomenon of the transituational consistency of cognitive behaviour. By and large, persons who perform well in one area perform well in others. This enables the neuropsychological examiner to use test performances to make as fair an estimate as possible of premorbid ability in neurologically impaired persons with undistinguished school or vocational careers. A corollary assumption is that marked discrepancies between the levels at which a person performs different cognitive functions or skills probably give evidence of disease, developmental anomalies, cultural deprivation, emotional disturbance, or some other condition that has interfered with the full expression of that person’s cognitive potential. Another assumption is that cognitive potential or capacity of adults can be either realized or reduced by external influences; it is not possible to function at a higher level than biological capacity will permit. An important corollary to this assumption is that, for cognitively impaired persons, the least depressed abilities may be the best remaining behavioural representatives of the original cognitive potential. The phenomenon of overachievement (people performing better than their general ability level would seem to warrant) appears to contradict this assumption; but in fact, overachievers do not exceed their biological limitations. Rather, they expand an inordinate amout of energy and effort on developing one or two special skills, usually to the neglect of others. A related assumption is that few persons consistently function at their maximum potential. A person’s performance on any task may be the best that can be done at that time but still only indicates a floor, not the ceiling, of the level of abilities involved in the task.
Another related assumption is that within the limits of chance variations, the ability to perform a task is at least as high as a person’s highest level of performance of that task. It cannot be less. The poor responses do not negate the good ones; the difference between them suggests the extent to which the patient has suffered cognitive deterioration. It is also assumed that a patient’s premorbid ability level can be reconstructed or estimated from many different kinds of behavioural observations or historical facts. The value of the best performance method depends on the appropriateness of the data on which estimates of premorbid ability are founded. A neuropsychologist should do enough testing to obtain an overview of the patient’s cognitive abilities in each major functional domain. The best performance method has very practical advantages.
Perhaps most important is that a broad range of the patient’s abilities is taken into account in identifying a comparison standard for evaluating deficit. For patients whose general functioning is too low or too spotty for them to complete a standardized adult test, or who suffer specific sensory or motor defects, children’s tests or specific skills provide opportunities to demonstrate reidual cognitive abilities. In general, the examiner should not rely on a single high test score for estimating premorbid ability unless history of observations provide supporting evidence. The examiner also needs to be alert to overachievers whose highest scores are generally on vocabulary, general information, or arithmetic tests, as these are the skills most commonly inflated by parental or school pressure on an ordinary student. Of all cognitive functions, memory is the least reliable indicator of general cognitive ability. The highest score among tests contributing to a summation score (e.g. IQ) is always higher than the IQ score since the IQ score is essentially a mean of all the scores, both higher en lower. Therefore, in cognitively intact subjects, the highest WIS-A test score is not an acceptable predictor of the WIS-A IQ score.
Paradigm
Once the comparison standard has been determined, the examiner may assess deficit. Discrepancies between expected level and present functioning are then evaluated for statistical significance. If significance discrepancies occur for more than one test score, a pattern of deficit may emerge. By comparing any given pattern of deficit with patterns known to be associated with specific neurological or psychological conditions, the examiner may be able to identify etiological and remedial possibilities for the patient’s problems. The deficit measurement approach is of use not only as an aid to neurological or psychiatric diagnosis but also in educational and rehabilitation planning.
5. Procedures in an NPA
People have to follow two rules for an neuropsychological examination.
1 you have to treat each patient as an individual
2 you have to think about what you are doing
An imaginative approach is the best approach. This should summed up the patient needs, abilities and limitations and to special examination requirements. The examination can be individual tailored in two ways. The examiner can use the information to diagnose the patient and to gain a full measure of information.
Conceptual framework
An examination may be undertaken for a lot of reasons. The main reason is to examine the patient. The examiner needs to evaluate its appropriateness. Mostly the neuropsychological assessment address to several issues, like neurological behaviour and functional behaviour. Other goals for an examination is to help with management, care and planning and to evaluate the effectiveness of a treatment technique The purpose of the examination determine the general questions that needed to be asked. The questions that will be asked fall into one of two categories, the diagnostic questions concern the nature of the patient’s symptoms and complaints in terms of their ethiology and prognosis. These questions are always questions of differential diagnosis. The second category contains the descriptive questions inquire into the characteristics of the patient’s condition. An examination with a full scale assessment is sometime called a baseline study. This study provides the first set of data against the data collect later on in the study.
Conducting the examination
The foundations of an examination contains the examiner background. The background of the examinator should include an understanding of the complex, multi-faced, and interactive nature of the cognitive functions. The examiner has to have a lot of clinical experience to collect this information about himself. The background of the patient may come from any of the four aspects of the patient backgrounds.
1 social history, information about the patient’s education and work-experience
2 present life circumstances, patient views and feeling about their live
3 medical history and current medical status
4 circumstances surrounding the examination. The test performance can be evaluated accurately only in the light of the reasons for referral and the relevance of the examination of the patient.
Procedures
The way patients learn of their referral for neuropsychological assessment can affect how they view the examination, thus setting the stage for such diverse responses as cooperation, anxiety, distrust, and other attitudes that modify test performance. You examine persons by sudden onset conditions, trauma, stroke. Within the first few weeks or months following a sudden onset event, a brief examination may be necessary then. Formal assessment should not be undertaken during the acute of post-acute stages. Because fatigues and awareness overtakes the patient quickly. Within the thirth to six month after the event an innitional comprehensive neuropsychological examination can be given. One or two year after the accident can the long term planning be given. Evolving conditions as disease and tumor, are situations were examination important is.
The neuropsychological examination proceeds in stages:
1 the examiner plans an overall approach to the problem
2 the initial interview and assessment, the examiner determines the range of functions to be examined, the extent to which psychological issues or emotional and personality factors should be explored
3 observation is the foundation of all psychological assessment (indirect and direct observations)
Test selection: Selection of test will depend on a number of considerations:
1. the examination goals
2. validity and reliability
3. sensitivity and specificity. The test sensitivity and specificity makes it more or less useful in a particular condition.
4. parallel forms, psychological assessment is designed for repeated measures
5. time and costs
6. non-standardized assessment techniques, occasionally a patient presents an assessment problem for which no well-standardized test is suitable.
Most examiners begin with a basic test battery. This battery measures the major dimensions of cognitive behaviour, attention, visuo-perception and visual reasoning, memory and learning, verbal functions, construction etc. They then drop some tests or choose additional tests as the examination proceeds. The patient strength, limitations and specific handicaps will determine how the test will be used. In deciding when to continuing testing with more assessment, we must keep in mind that a negative performance does not rule out brain pathology, it only demonstrates which functions are at least reasonably intact. However, when a patient’s test and intervieuw behaviour are within normal limits, the examiner cannot continue looking indefinitely for evidence of a lesion that may not be there.
Test selection in research
The examiner is not free to exercise in flexibility and inventiveness in the clinical situation. For research purpose, the prime consideration in selection examination techniques that test the hypotheses or demonstrate the phenomenon in question.
Fixed batteries
The popularity of ready made batteries attests to the need for neuropsychological testing and to a lack of knowledge among neuro-psychologically inexperienced psychologist about how to do it. These test extend barely minimal neuropsychological examination. If the ready made batteries are used as directed, most patient undergo more testing than is necessary but not enough to satisfy the examination questions specific enough to their problems. Also like most psychological tests, ready made batteries are not geared for patient’s with handicaps. However ready made batteries are useful as starting point for a inexperienced examiner. No battery can substitute for knowledge about patients, medical and psychological conditions, the nature of cognition and psychosocial conduct, and how to use test and measuring techniques.
Testing hypothesis
This stage of the examination begins with the answer to initial questions. The method of double dissociation identifies the components of complex cognitive activities are impaired and which are preserved. These procedures can lead to diagnostic impressions and to the identification of specific deficits.
The addition of specialized tests depends on continuing formulation and reformulation of hypotheses. The final stage is concluding the examination as hypotheses are supported or rejected. When it appears that assessment procedures are making patient aware of deficits patients, the examiner can end the examination with a relatively easy task.
Interpretative interview
A important part of the examination is the follow-up interview to provide patients an understanding of their problems. Feedback is most useful when patients bring close family.
Procedural considerations in assessment
The order of presentation of tests in a battery has not been shown affects on performance. In an examination tailored to the patient’s need, the examiner varies the testing sequence to ensure the patient’s maximum productivity.
Testing the limits can be done with any test. The limits should be tested whenever there is suspicion that an impairment of some function other than the one under consideration. Limit testing can provide a better understanding of the extend to which a function or functional system is impaired may have on related functional systems. The effects of repeated examination, named practice effects. Problem of practice effects is particularly important in memory testing since repeated testing with the same tests leads to learning of the material in patients. There are also benefits of the practice effects, the patient learns how to approach the task more effectively. With brain leasie patients , the patient is unlikely to improve with practice alone. Improvement to practice should be minimal. Absence of practice effects on tests when the effect is expected is also clinically meaningful. Large changes between test and retest are not normal, the date will not follow the group trend.
Analyses can be made on what the technician provides in terms of scores and observations. Most neuropsychologists who use technicians have them give the routine tests. The advances of using a technician are obvious, saving time and a technician is cheaper. The dis-advances are that the reports will be a blind analyses and the technician have minimal education and training requirement.
Examination of special populations
1 patients with sensory or motor deficits, defective visual acuity is common in elderly people and may be due to any number of problems (presbyopia). Visual disturbance are also common after head injury (double vision, diplobia). Persons over the age of 45 need to be checked for visual competency.
2 hearing problems, the patients keep this handicap often to themselves. Defective hearing increases with advancing age so that many patients with neurological disorders associated with aging will also have compromised hearing.
3 lateralized sensory deficits, these patients have homonymous field cuts. In their normal conversation you will notice nothing.
4 motor problems, patients with lateralized lesions will have use one hand, this will be slower than other patients.
5 meeting the challenge of sensory of motor deficits, there is a challenge for the patient as the examiner to take the test. Some of the tests have been devised specifically for physically handicapped people. The problems of these test are that these substitute tests present is normative comparable and the second problem is that alternative forms usually test many fewer and sometimes different functions than the original test.
6 the severely handicapped patient, it may be useful first to measure whether the patient has enough verbal comprehension for formal testing procedures.
7 the severely brain damaged patient. For patients with severe mental deficits you can best use a children’s test.
8 elderly people, healthy and active people in seventies and eighties do not differ greatly in skills or abilities from others. However they have age-related handicaps like motor strength and speed.
Common assessment problems:
1. attentional deficits, this can obscure in almost every area of cognitive functioning. Their effects tend to show up in those activities that provide little or no visual guidance and thus require the patient to perform most of the task’s operations mentally.
2. reduced auditory span, people hear then only a part of what was said, particularly if the message is very long, complex or unfamiliar.
3. mental tracking problems, people get confused or completely lost performing complex mental tracking tasks such as serial subtraction. These problems mostly show up in many repetitions on list-learning or list-generating tasks.
4. distractibility, some patient have difficulty shutting out or ignoring extraneous stimulation. That can increase fatigue en frustration. A record of the effects of interruptions due to distractibility on timed tasks gives valuable information about the patient’s efficiency. Comparisons between efficiency (performance under standard conditions) and ability (performance under optimal conditions) are important to understand both competencies and deficits.
5. memory disorders, faulty memory can reflect attentional deficits.
6. defective working memory,
7. defective retrieval, a not uncommon source of poor scores on memory tests is defective retrieval. The persons learn well but they cannot recall this information.
8. fatigue, this can be a an acute problem (brain disorder) or a chronic problem (multiple sclerosis)
9. pain, patients with pain often have reduced attentional capacity, processing speed and psychomotor speed
10. performance inconsistency, patient with cerebral impairments have good days en bad days. Performance variability may be most obvious in patients with seizure disorders.
11. motivation, the motivational capacity of some brain impaired patients , particularly those with damage to the limbic system or prefrontal areas may be diminished or lost. This conditions often reflects the inability for patients to formulate meaningful goals or to iniate and carry out plans.
12. anxiety, stress and distress. High anxiety levels may result in mental efficiency problems as slowing, scrambling or blocked thoughts and words, and memory failure. High levels of test anxiety have been shown to affect adversely performance on many different kinds of mental ability tests.
13. depression and frustration, depression is associated with many brain disorders and may be due to any combination of neuro-anatomic, neuro-chemical and psychosocial factors. It can interfere with the motivation aspects of memory in that the patient simply puts less effort into the necessary recall.
Making the best of the patient’s performance level
It is not difficult to get a brain damaged patient to do poorly on a psychological test. In the ideal testing situation, both optimal and standard conditions prevail. Optimal conditions are those that enable patients to do their best on the test. Standard conditions are prescribed by the test-maker to ensure that each administration are the same. Some patients who complain of significant problems attending, learning, and responding efficiently in their homes or at work perform well in the usual protective examination situation. The examiner can find a way to examine this. Examiners will communicate best by keeping their language simple. Exceptions tot this rule may be those brain damaged patients who were originally well endowed and highly accomplished.
Constructive assessment
Every psychological examination can be a personally useful experience for the patient. When the patients feel better at the end of the examination than they did at the beginning, the examiner had probably helped them to perform at their best Good assessment will contribute to each patient’s well-being.
6. Interpreting an Neuropsychological Examination
The Nature of Examination Data
In order to have a good image of a patient, the examiner needs to have information of many different kinds of observations.
Different Kinds of Data
Background Data Providing a context for understanding the observations, in most instances requires beside knowledge, also patient variables when evaluating test performances (such as sensory-, or motor status, medication regimen). Important background info:
• Developmental/medical history
• Family background
• Educational/occupational accomplishments/failures
• Current living situation
• Level of social functioning A particular performance level for someone, with high or low abilities, can be relatively high or relatively low in concordance with his/her abilities. Motivation can also play a big part, some people score lower because they don’t use their high abilities and some score higher than you would expect based on their abilities.
Behavioural observations These can be extremely useful because it offers extra information about how the patient functions outside the structured, intimidating examination setting. This is especially useful if a capability is overrated, this could happen when performance and ability are mistaken one for the other. Some people may score high on certain tests, but their everyday life still may be severely damaged. Patients can also score very low on tests but handle their everyday life far better than would be expected. Conduct at the moment of examination can also give you useful info about the subject.
Test data Testing elicits behaviour samples in a standardized, replicable, somewhat artificial, restrictive situation. Standardization enables the examiner to compare patients, but only to a limited area that is set in the test. Extrapolation: drawing inferences from a limited set of data; you can’t observe / test everything you actually want to. In order to be able to reliably generalize to every day life’s activities, the predictive and ecological validity should be examined.
Data: Quantitative and Qualitative
Quantitative: relies on scores, indices, often computer progressed. Qualitative: richly detailed observations without objective standardization. Together they provide the observational frames of reference and techniques for taking into account, documenting and communicating the complexity, variability, and subtleties of patient behaviour. When to choose the quantitative approach over the qualitative approach:
1. When there are only a small number of probable outcomes.
2. When the prediction variables are known.
3. When the data, from which the formula was derived, be relevant to the questions asked. This is often not the case; often a broad range of disorders is possible, there are individual variables that have an influence, or there is no formula present.
Quantitative data: Scores are summary statements about observed behaviour that fit a category and are placed on a numerical scale. Summary index scores: based on various combinations of scores on two or more (more or less similar) tests >>>> suffer the same problems as any other summed score in that they obscure the data. Seems not useful, if two tests produce the same scores, but when they differ they can be treated individually. The inclusion of test scores satisfies the need for objective, replicable data that permits reliable interpretation and meaningful interpretations (enabled by standardization) between very different patients and different behaviours.
Evaluation of quantitative data: Problems
1 The artificial/abstract nature; a test score approach that minimizes the importance of qualitative data can result in serious distortions in the interpretations, conclusions and recommendations drawn from such a one-sided data base.
2 Difficult to see what a score means (what functions contribute to a score). When a score is overinclusive (summed or averaged test battery scores) impossible to know what behavioural or cognitive characteristic it represents. Example: Memory Quotient scores of 2 groups of patients can be the same but is caused by two different brain impairments/disorders.
3 The range of observations an examiner can make is restricted by the test. With multiple-choice tests and automated tests, qualitative info is not recorded, the manner in which the answer is made is lost and sometimes important information is therefore not available.
4 The fine-grained scaling is not suited for the assessment of many of the behavioural symptoms of cerebral neuropathology. Using a finely scaled vocabulary test to examine an aphasic patient, is like trying to discover the shape of a flower with a microscope, the examiner will simply miss the point.
5 Patients can score the same on a test, but for very different reasons Example: the same scores on the WIS-A test; one has an inability to retain and juggle so much information at once in his immediate memory, another is unable to conceptualize or perform the operations needed. The pitfall of face-validity (Walsh): you don’t really always know what a test is measuring.
Qualitative data Direct observations, test-taking behaviour as test behaviour can provide a lot off useful info.
Qualitative data: Limitations In the case of a single observer all the problems with standardization, reliability and validity are a threat to objectivity and can lead to distortions or misinterpretations. Some important behaviour will not get noticed, some will be wrongly attributed and some unimportant behaviour will get noticed. It is difficult to appreciate the nature or extent of cognitive impairment without an objectively comparison technique. Clinical experience offers a sharpening of observational talent.
Quantitative and qualitative evaluation: Several hybrid techniques have been developed: the quantification of the qualitative aspects of test responses, by setting scores for the qualitative. Quantified qualitative errors provide information about lateralized deficits that scores alone cannot give.
Integrated data The integrated use of qual. and quant. examination data treats these two different kinds of information as different parts of the whole data base. Each is incomplete without the other.
Common Errors in interpretation
· If this then that: the problem of overgeneralizing
Two patients can have the same score on a test, but can have a different diagnosis.
· Failure to demonstrate a reduced performance: the problem of false negatives When brain damaged people show an absence of low scores, or other evidence of impaired performance.
· Confirmatory bias To seek and value supportive evidence at the expense of contrary evidence
· Misuse of salient data over-and underpretation. A single finding can be given too much weight (indicating a disorder) or be given too little (chance, mistake).
· Underutilization of base rates. Base rates are particularly relevant when evaluating signs or symptoms.When a diagnostic sign or symptom occurs; there can be different causes (slurred speech: MS or right hemisphere infarct or acute alcoholism). The cause can’t be made out of the sign or symptom.
Evaluation Qualitative Aspects of Examination behavior
Two kinds of behaviour of interest:
1 behaviour that differs from normal expectations for the circumstances, tell a lot about how patients think and how they perceive themselves, the world and it’s expectations.
2 Gratuitous responses: comments people make about their test performance or while they are taking the test, elaborations beyond the necessary requirements of a test reflect the patient’s mood, show preoccupations.
Test scores
Standard scores:
The usefulness of standard scores.
When using one test battery (WIS-A) the scores of each individual test’s are on the same scale, standardized on the same population so that test scores can be compared directly. No single test battery provides enough information to assess a patient’s situation. But different test’s can’t be compared directly.
Standard scores: kinds
There are different forms of standard scores but all are translations of the same scale, based on the mean and the standard deviation. Z-Score: in standard deviation units, the amount a score deviates from the mean of the population from which it is drawn. Derived scores: elaboration of z-scores. The score value is expressed in scale units that are more familiar to most test users. When standard populations are similar > standard scores become directly comparable
Estimation of standard scores from non-standard scores
Percentile or IQ scores can be standard score approximations when the population is normally distributed.
Exceptions to the use of standard scores:
Differences in standardization population
In evaluating a patient’s performance on a variety of tests, the examiner can only compare scores from different tests when the standardization populations of each of the test are identical or reasonably similar. For example: A test which was standardized on the general adult population versus a test which was standardized on college graduates: the college graduates would score on some tests much higher than the general adult population would do, because of their higher abilities. Test-makers usually describe their standardized populations in terms of sex, race, age, and/or education. These terms can be of great significance because of the differences they can produce.
Tests for Children
For testing children and adolescents, many good tests have been standardized for child or adolescent populations. An exception are children in their late teens, at 18, when they have received approximately 4 years of high school education, they do not really perform very differently than the adult population on tests of mental ability. Here adult norms can be applied without adjustments. Scores of children’s tests can be best scored and reports in terms of Mental Age (MA), it allows to compare between different tests and levels of impairment.
Small standardization populations
Studies of particular neuropsychological problems, where the groups can be small, sometimes there can’t be made norms for these patients. When there is a great difference between patient and control group scores, a patient’s score should be evaluated in terms of how closely it compares with the score ranges of either the patient or the control group.
Nonparametric distributions
Sometimes in neuropsychological tests score distributions, aren’t normally distributed but can be skewed (floor or ceiling effects) due to the nature of the test. Standard scores then are of a questionable value, as probable abnormal performances would then appear to be within normal limits.
Reporting of Scores
The practice of reporting test performances in terms of scores can be confusing and misleading, since recipients mostly are; teachers, physician’s and lawyers who lack training in this field. Difficulties issues are:
1 To notice the variability in the size of assigned standard deviations, (SD= 15, 75thpercentile, SD=10, 67thpercentile) you have to be knowledgeable about this.
2 The natural assumption that when one score is bigger than another, that this difference is attributed to a real difference in measured quantity. The possibilities of chance variations in the measurement of the same quantity are overlooked.
3 There is a tendency to reify test scores; children are sorted into different groups based on their scores. These test scores meanings are not standardized nor objective, but people will attach a personal/social meaning to it.
A recommendation to avoid difficulties is to write about test performances in terms of the commonly accepted classification of ability levels (average, high average etc.). The communication in terms of ability levels has relatively clear meanings, and when in doubt, percentile range could be added. Although some people confuse the meaning of percent and percentiles, which are not interchangeable constructs.
Interpreting the Examination Data
Different goals and approaches require different interpretation.
Issues in evaluation
Norms
Tests can have manifold sorts of norms, based on: local people, national sample, urban populations. It thus results in less perfect comparability between different tests, but an examiner doesn’t always has the opportunities to make norms for the group of people he would like (general population versus firstyears students). Different norms can produce quite different evaluations. Finding appropriate norms can be very difficult; there are even times when none of the norms apply to a particular person. Then the clinician should check several norm samples to look for consistency across norms, the final decision requires clinical judgment. An ongoing debate about the use of demographically based norms is happening. Age and education are related to performance, in the normal population, but not to age and barely for education in a brain damaged group. Without demographically appropriate norms, the false positive rate for older or poorly educated normal individuals tends to increase. Many tests however do not include all (or any) of the demographic variables that may be pertinent to measurement data on a particular ability or behavior.
Impairment Criteria
Neuropsychologists have to decide at which level of test scores performance is impaired. This is difficult because poor performance can entail many different things; a real impairment, poor abilities, a lack of motivation to take the test, or anxious, depressed or hostile to the test taking experience. Estimates of premorbid level of functioning can be of great significance when deciding if someone is actually impaired, but sometimes you only have the current test data to rely on. It is difficult to decide which impairment criterion to choose, because of the chance on ‘false positives’ and ‘false negatives’. When the impairment criterion is not so strict (-1SD) more intact performance will be called impaired (false positives) but when it is too strict (> -2 SD) you will call some impaired performance normal (false negatives). The neuropsychologist should therefore look at the pattern of performance, that should make diagnostic sense.
Someone’s background (history) is also of importance, what is considered a normal performance score for one person can be very low for someone with higher abilities. Therefore carefulness has to be taken when using a criterion for decision-making, in stead of looking at premorbid functioning.
Sensitivity / specificity and diagnostic accuracy
Sometimes tests are judged by the percentage of cases it correctly identifies (control patient vs. clinical patient). The accuracy of diagnostic classification depends to some degree on its sensitivity and specificity.
Sensitivity: the probability of correctly detecting abnormal functioning in an impaired individual. Specificity: the probability of correctly identifying a normal individual (or an individual with other clinical symptoms). The rate of correctly identified cases can be manipulated by the choice of population and so the outcome can be virtually predetermined. Therefore this standard should be looked at with precaution. In the end, you are dealing with individuals, with unique and general elements in every case, that should be dealt with sensitively.
Techniques in screening
Different screening techniques make use of different kinds of behavioral manifestations of brain damage. With such a variety of signs, symptoms, and behavioral alterations it is not reasonable to expect accurate detection of everything with one or few instruments. The accuracy of screening tests varies in a somewhat direct relationship to the narrowness of range or specificity of the behaviors assessed by them. Tests can be to narrow or too broad and produce ‘false negatives’ or ‘false positives’. When testing especially for screening purposes, be aware of the test’s limitations, and if possible, use a combination of tests to make the best diagnostic discriminations.
Signs
Characteristic signs of brain damage can be positive; indicating the presence of abnormal function, or negative; indicating that a function is lost.
Possible signs of brain dysfunction:
1. Isolated response deviations, may indicate the presence of an organic defect.
2. Specific test failures or test score discrepancies can be a sign of brain dysfunction.
3. The manner in which a patient responds to the task.
M. Williams (1979): 3 response characteristics associated with brain damage:
1. Stereotyping and perseveration
2. Concreteness of behavior (response to all stimuli as if they existed only in the setting in which they are presented).
3. Catastrophic reactions; of perplexity, acute anxiety and despair when the patient is
unable to perform the presented task. When someone presents with more than a few changes, the likelihood of a brain disorder runs very high.
Cutting scores
We use a cut-off score to separate patients in terms of the presence or absence of the condition under study. Sometimes cutting scores will not be effective, due to different causes. Cutting scores have to be adjusted for different populations and also the base rate of the predicted condition has to be accounted for.
Single tests for brain disorders identification
This idea is based on the assumption that brain damage can be treated like a single entity. But considering the diversity of brain disorders, single tests have proven to make much wrong classifications. It is not advisable to only look at one single test for decisive information.
Screening techniques: usefulness
Since we know about the diverse nature of brain pathology and of the quality of other neurodiagnostic techniques, the use of neuropsychological screening has become limited. But in some cases it still may be useful as an early warning system, with populations (like elderly or alcoholics) who tend to be at a high risk for neurological disorders.
Screening techniques: Evaluation
Each kind of test can be effectively used as a screening device as long as its limitations are known and the information it elicits is interpreted accordingly. Normal test scores cannot guarantee the absence of a brain disorder; it only means that the person scored within normal limits.
Analyzing patterns
When test procedures have been looked at carefully; a broad range of tests have been chosen, interpretation procedures that regard test and item discrepancies are considered, they can elicit the required amount of information needed for an adequate description and analysis of the patient’s deficit. After test data have been scored and appropriate norms have been chosen; the clinician must determine whether the pattern of performance is typical of individuals with a particular diagnosis. When the examiner comes across a pattern of discrepancies, he should take all other relevant information (history, observations, demographic and psychosocial data) in mind to come to a conclusion.
Intraindividual variability
Scatter = Discrepancy (or variability) in the pattern of successes and failures in a test performance.
Intratest scatter = scatter within a test.
Common answer patterns: -When the items are presented in order of difficulty, it is usual that the person passes almost all items, maybe up to the last ones (when they have reached their threshold).-When all the items in the test are of a similar level, there is usually a pattern in which people tend to do almost every item correctly (or fail at all, with maybe a few lucky ‘hits’). Some brain disorders or emotional disturbances may come out in intratest scatter patterns.
Intertest scatter = scatter between the scores of a set of tests.
The examiner attempts to relate variations between test scores to probable neuropsychological events, through comparison of the test score levels of different tests of a subject.
Consistency in the expression of cognitive functions is the key concept of pattern analysis When an estimate of premorbid level has been made, the examiner can identify impaired test score performances. The functions that are consistently associated with lower scores, when there is a returning pattern noticeable, will probably be the behavioural correlates of brain dysfunction. When the pattern is not consistently present, discrepant scores may be attributable to psychogenic, developmental, or chance deviations. Reliable assessment of impairment patterns requires a fairly broad review of functions. Wechsler batteries are very suitable for pattern analysis because of their obvious statistical comparability.
Integrated Interpretation
Pattern analysis isn’t always useful, as many neurological conditions are of a very complex nature, some conditions can’t be identified without an integration of all the data (malignant tumors are unlikely to follow a regular pattern of growth and spread, no consistence in their test patterns). The impact of emotional reactions (like depression, anxiety, euphoria and carelessness) on the patient’s cognitive functioning shouldn’t be overlooked. Also motivational and control (executive functioning) problems must be taken into account, because how well patients do on tests, if they cannot develop or carry out their own course of action they are incompetent for all practical purposes.
7. Neuropathology
CHI = closed head injury
DAI = diffuse axonal injury
OHI = open head injury
EDH = epidural hematomas
PHI = penetrated head injury
SDH = subdural hematomas
TBI = traumatic brain injury
ICH = intracerebral hematomas
GCS = glasgow coma scale
ICP = intracranial pressure
LOC = level of consciousness
CNS = central nervous system
QOL = quality of life
PNS = peripheral nervous system
PTSD = posttraumatic stress disorder
CVA = cerebrovascular accident
SIS = second impact syndrome
FTP = frontotemporal dementias
DLB = Dementia with Lewy Bodies
CBF = cerebral blood flow
DTICH = delayed traumatic intracerebral hematomas
MVA = moving vehicle accidents
QEEG = quantitative electroencephalography
To make diagnostic sense out of the behavioral patterns that emerge in neuropsychological assessment, the practitioner must be knowledgeable about the neuropsychological presentation of many kinds of neurological disorders and with their underlying pathology. This knowledge can give the examiner a diagnostic frame. The kind of information an examiner will need depends from patient to patient. A number of different kinds of disorders produce similar constellations of symptoms, which can be distinguished by differences in other neuropsychological dimensions. Other conditions are best identified in terms of: -The patient’s history -associated neurological symptoms -nature of the onset and course of the disorder The presence of one kinds of neurological disorder does not exclude others, nor does it exclude emotional reactions or psychiatric and personality disorders. The existence of several disorders in one patient van make the symptoms more complex. No single rule of thump will tell the examiner just what information about any particular patient is needed to make the most effective use of the examination data.
Traumatic brain injury
TBI (traumatic brain injury, head injury) can refer generally to injury involving the brain. Most of the TBI’s are closed (=skull remains intact, brain is not exposed), and is called Closed Head Injury (or: blund head injury). If the skull is broken or fractured it’s called an open head injury. The skull can be fractured and be a closed head injury as well. If the skull is by any object the injury is named: Penetrated Head Injury (PHI). TBI refers to the effects of closed head injury’s and penetrated head injury. TBI = the most common cause of brain damage in children and young adults. More modern medical techniques for the management of acute brain conditions are saving many accident victims and the numbers of survivors increases. Secondary or delayed injury to the brain may be more important than the immediate damage, (e.g. Hypoxia/ischemia, elevated intracranial pressure, coagulopathy and pyrexia). Prevalence studies of TBI differ in their conclusions, due to the different levels of TBI in severity. Urban centers account for a higher incidence of TBI than rural areas. The mortality studies vary greatly in their conclusions: there are late effects of TBI, lack of functional independence, age, and tube feeding. Risk factors of getting a TBI are: lower SES, unemployment, lower educational levels, transporting accidents and falls, assaults, alcoholism. Typically in young working class males, with limited educational attainment and who may not have had a stable work history.
The behavioral effects of all brain injury hinge upon a variety of factors: severity, age, site of lesion and premorbid personality. The psychological consequences vary a lot too, depending on the above risk factors and how the injury happened. You need to know: the kind of head injury, severity and the site of focal damage to outline the behavioral disabilities and to establish the psychological prognosis. As a baseline you will use the premorbid status of the patient.
Severity classifications and outcome predictions
Range of head trauma begins with almost no behavioral traces up to a coma or a vegetative status. Neuropsychological assessment is concerned with the patients between those extremes. To predict the outcome there is a generally accepted classification system based on the presence, degree and duration of coma: Glasgow Coma Scale. Which measures the depth and duration of altered consciousness. Coma duration = good predictor for more severe injuries. GCS alone is not appropriate for many cases, single GCS with no further indication can lead to an inaccurate assessment of the severity of injury. Patients with left lateralized PHI will suffer loss of consciousness more likely than right lateralized injuries. The duration of coma in patient with right-sided lesions tend to be shorter than in patients with left-hemisphere lesions.
Posttraumatic amnesia (PTA) is also used to measure the severity of the injury. Duration of PTA correlates with the GCS. It r remains difficult to define en determine the duration of PTA and therefore the test is difficult to use as a measurer for severity. PTA can be a psychologically painful issue (patients can become aware that they have no memory before or after the injury (antero-& retrograde amnesia (RA)). Retrograde amnesia is usually involving the period before the accident and frequently accompanies PTA, severe injury = severe amnesia. Other techniques for the measurement of severity of TBI are; auditory and brainstem (somatosensory) evoked potentials, visual field defects, anosmia, poor performance on olfactory tests. MRI is quite sensitive to traumatic damage (including brainstem lesions), but MRI in the acute stages may not predict the outcome reliably. Therefore CT scans are more often taken in the early stages of TBI whereas later (>5 months) imaging (= MRI) findings prove to be highly predictive. CT is also less expensive, are readily available, can even be given on the intensive care, and visualize the blood products and bone fractures better than MRI. A new promising method involves blood serum markers of neuronal damage; higher protein levels in the blood are positively related with mortality, brain death and increased intracranial pressure. According to the GCS there are 4 stages: Vegetative state = most severe state, almost no cortical functioning Severe disability = conscious patients who are more or less dependent on others for accomplishing much of the normal activities. Moderate disability = persons capable of independent living but who are restricted in one or more major activity area by their disabilities. Good recovery = person who are fully functional socially, although some may have minor residual deficits. Penetrating head injuries: Occurs accidently and intentionally with everyday objects. Some of these are embedded in the head, others cause through-and-through injury (entry and exit wounds; bullet). Can also derive from a tangential injury in which an object glances off the skull and bone fragments are driven into the brain. The amount of damage to the brain sustains in head injury is determined in large measure by the amount of energy translated to the brain in the course of the damaging event. Mortality is related to the type of projectile (puncture wounds, missile fragments and low velocity bullets are most likely to produce clean wounds. Surgical cleansing typically removes the damage along with debris; most of the brain remains intact.
Hypotension = abnormally low blood pressure, hypovolemia = abnormally low blood volume. Contusions are bruises that can be widespread with gunshot wounds. Intracranial hematomas (swelling filled with blood) develop most often three to eight hours after injury (subfrontal region). Prevention and treatment of infections (with antibiotics) are important in surviving PHI. Objects can also cause ischemia (absence of normal blood flow) and edema (normal physiological response to injury´s; tissue swelling), in the acute stages this may leave permanent tissue damage. Patients with PHI usually show impairment in memory, concentration, attentions, mental slowing (diffuse damage). Focal effects are more pronounced than diffuse ones, the larger the lesion, the more general the deficits. Patients tent to make relatively rapid gains in the first year or two following injury. Cognitive impairment (language, constructional disorders) may show significant improvement, sensory defects (visual blind spots) persist unchanged indefinitely. PHI is associated with a high rate of epilepsy (80% of the patients in first 24 hours). Lesions in left hippocampus are most susceptible to seizure development. Posttraumatic epilepsy is associated with premature death among survivors of PHI.
Closed head injuries 1:
The primary injury
In CHI brain damage occurs in two subtypes: primary injury (damage that occurs at the time of impact) & second injury (consists of the effect of the physiological processes set in motion by the primary injury). Several kinds of damaging forces have been identified; contact forces and inertial forces. Contact force is the predominant cause of brain damage in static injuries in which a relative still victim receives a blow to the head, leading to an inward molding of the skull. Or with enough stress, a fracture of the skull in which infection and additional tissue damage is possible. Inertial forces involve translational acceleration in which the brain rotates around its center of gravity. Movement of the head and neck on impact results in angular acceleration (combination of translational and rotational acceleration). Cerebral contusions consists of focal damage to brain tissue, called parenchyma, and vascular structure are most severe on gyral crests and may extend to the white matter. When the fine tissue covering the brain (pia-dura mater & arachnoid layer) are torn, the injury is referred to as laceration. The blow at the point of impact is called; the coup. Contrecoup lesions = lesions in which the brain sustains a contusion in an area opposite the blow and results from translational forces and direction of impact to the brain. Coup and Contrecoup lesions account for specific and localizable behavioral changes that accompany CHI. With contact or not, under conditions of rapid accelerations or deceleration, single or multiple contusions can occur in deep structures such as the basal ganglia, hypothalamus, brainstem and corpus callosum. The degree of corpus callosum injury on the MRI may be indicative of clinical severity of diffuse injury and the presence of midbrain injury. Focal deficits are much less likely to be seen if there is a great deal of momentum on impact, as in MVA. In MVA (moving vehicle accidents) damage tends to be widespread, so trauma can present a pattern of multifocal or bilateral damage without clear evidence of lateralization. Another important neuropsychologically important kind of brain damage in CHI derives from the combination of translational forces and rotational acceleration. The movement of the brain in the skull can cause shearing (microscopic lesions that occur throughout the brain). Shearing effects tend to be concentrated in the frontal and temporal lobes, interfaces between gray and white matter around the basal ganglia, periventricular zones, corpus callosum, brainstem fiber tracts and superior cerebellar peduncles. If a head experiences a fast movement as rapid acceleration and deceleration, damage to axons in white matter can occur. This kind of axonal damage is called diffuse axonal injury (DAI), which appears as torn axons, shearing of axons clusters, retraction balls and reactive swelling. Neural damage is accompanied by punctuate hemorrhages from ruptured blood vessels scattered throughout cerebral white matter and lower structures as well. Velocity, duration, acceleration and direction of head movement affect the severity of DAI. Diffuse axonal injury can occur without any direct impact on the head, as it requires only the condition of rapid acceleration such as takes place in whiplash injuries. The effect of these immediate disturbances in neurologic functions created by the mechanical forces of rapid acceleration is called concussion. Concussion does not require a direct impact to the head. There are two broad categories of concussion: mild concussion (without loss of consciousness) and classic concussion (reversible coma occurring at the instant of trauma: cardiovascular and pulmonary function changes and neurologic abnormalities). Concussion represent a continuum with varying severity of injury, neuropsychological impairments and neurobehavioral outcomes. If the confusion and disorientation solve in a few days it is called a mild TBI (but can have serious neurobehavioral consequences). Involvement in of brain stem reticular formation structures in the injury may not be necessary for a concussion. Besides the scattered tiny hemorrhages seen with diffuse axonal damage (shearing) larger blood vessels may be torn on impact. Epidural hematomas (EDHs) are formed when the brain´s outer layer; the dura mater, is stripped away from the skull by blood from lacerated blood vessels or bleeding from a fracture. EDH near the brainstem is particularly dangerous since the patient may be conscious until the end stage of development of t he blood-filled swelling and minutes from death. Subdural hematomas (SDH) form in the space between the dura and the brain, produces by torn veins on the brains surface and the inner side of the dura mater. SDHs will develop in the first 24 hours postinjury and might go unnoticed and grow slowly until they have mass effect. SDHs are most likely to appear in older individuals. Intracerebral hematomas (ICHs) from within the substance of the brain and may result from laceration. These hematomas probably result from direct rupture of blood vessels in the brain and are likely to be associated with DAI. Delayed traumatic intracerebral hematoma mostly occurs in the first 72 hours postinjury. These patients are conscious after the injury, and then deteriorate in a coma. They usually have a mass lesion that needs to be evacuated. When blood flows through the brain, the hematoma is a rapidly growing mass. As a hematoma grows, it exerts increasingly pressure on surrounding structures. Since the bony cranium does not give way, the air and liquid filled spaces surrounding and within the brain are first compressed. The swelling mass then pushes against the softer mass of the brain, deforming and damaging brain tissue pressed against the skull. Ultimately the build up pressure and swelling may force brain tissue through the base of the cranium (herniation). The high velocity of impact in a moving vehicle intensifies and severs the damage (shearing, shock waves etc). Therefore TBI-patients incurred in MVA are often treated separately from other head injuries. The second injury Secondary damage due to the ensuing physiological processes may be as destructive of brain tissue as the accident´s immediate effects, if not more destructive. Elevated intracranial pressure (ICP) can result from an increase in cerebral blood volume that produces cerebrovascular congestion; brain edema, and sometimes hydrocephalus (waterhoofd, mostly in patients with severe CHD). Brain swelling can be focal or generalized. Cerebral ischemia results from cerebral blood flow (CBF), which means that there is not enough metabolic transfer to the brain tissue. CBF is common in TBI: 91% of the patients with severe TBI. Pyrexia is likely to increase the metabolic demands of the brain when CBF is low and is associated with; brain congestion, edema, and elevated ICP. The most dangerous effects of swelling are on the brainstem. Along with edematous swelling (swelling tissue filled with blood), the cerebral blood volume may increase due to the loss of normal autoregulatory processes. Elevated ICP with hyperemia contributes to poorer outcomes in patients, hypotension (elevated blood pressure) and hypoxia (undersupply of oxygen). Reduced corpus callosum size, reductions in fornix and hippocampal volume (memory deficits), are common in severe CHI. Diffuse damage that accompanies much TBI consists of minute lesions and lacerations scattered throughout the brain substance that may become degenerative changes and scar tissue or little cavities. Diffuse damage can lead to slow reaction time and thinking, and lower capacity on timed tests. Patients with mental efficiency problem problems associated with diffuse damage frequently interpret their experiences of slowed processing and attentional deficits as memory problems. Coup and contrecoup lesions result in discrete impairment of those functions mediated by the cortex at the site of the lesion. The frontal an temporal lobes are most susceptible to the damaging effects against the brain, damage in that region affects social and personal adjustment as well. Few patients with TBI exhibit only one pattern of impairment. Many TBI patients sustain more or less subtle alterations in visual competency; diplopia (double vision), photophobia (aversion of bright light). But also, in 22% of the patients, dizziness, headaches, balance disorders and hearing effects (tinnitus (buzzing in the ear) & hyperacusis (intolerance of loud, sudden noises)).
Closed head injury 2:
Mild TBI; many different criteria: PTA + LOC. The main characteristic of mild TBI is concussion, due to DAI (axons destroyed or damaged by ac-deceleration forces). Concussion can occur without LOC or direct contact with the head. Most TBI patients with LOC are CT-scanned, MRI is more sensitive to measure lesions but is used in few patients (high costs, time, problems with patients, technical physical limitations, unable to visualize microscopic white matter lesions). EEG is also used to scan patients but standard EEG is unable to show abnormalities. Descriptions of the acute condition in mild TBI = attention deficits, impaired verbal retrieval, and forgetfulness. TBI may pass unnoticed by the patient if he restrains from doing his daily activities, when the patients goes back to work deficits can become obvious. 60% of the patients sustaining mild TBI will have returned to their premorbid occupations and usual personal activities, yet cognitive deficits (eg. Slow processing) remain. Mild TBI patients may suffer from the postconcussional syndrome (complex somatic, cognitive and emotional reactive symptoms experienced for months). Patients who seemed to be recovered were abnormally prone to mental efficiency when physiologically stressed by hypoxic conditions. Some scientists are pointing out that total recovery of mild TBI is impossible. The frequently complex interplay between behavioral alterations resulting from the brain injury itself emotional reactions to these alterations, emotional vulnerabilities predating the accident, and social pressures unique for each patient make it virtually impossible in many cases to clarify or partial out the contribution of each of these potentially contributing factors. The length of PTA (24 hours) and 7-10 day postinjury measures of life-event problems, emotional distress, processing speed, and mental status were predictive of postconcussion symptom complaints at three and six months. A key-variable in the persistence of postconcussion symptom is age. The chronic postconcussion symptom can be preceded by an implicated premorbid personality or psychiatric disorders, cognitive impairment, minor coping resources. Reports very greatly on the extent to which expectations for injury compensation contribute to the witting or unwitting exaggeration or persistence of postconcussional symptoms in mildly injured trauma patients. In whiplash injury the head receives no blow and there may not have been LOC. Patients with a whiplash (with or without pain) are significantly impaired on tests of attention, immediate recall, delayed recall, visuomotor tracking, cognitive flexibility and working memory deficits. Psychological problems are rather a consequence than a cause of somatic symptoms in whiplash. Most residual symptom patterns are similar to those for mild TBI occurring under conditions of rapid acceleration and with direct impact to the head. Post traumatic disorders (PTSD) had been considered to be a more or less severe anxiety reaction to a traumatic event. Many of the mild-TBI patients have some recall of the event itself or of circumstances, strengthening the agreement that PTSD and TBI (the triggering traumatic event) do coexist. The diagnosis of co-morbid PTSD is made difficult by the number of symptoms that overlap in PTSD and postconcussion symptom. The severe overlap includes; noise sensitivity, fatique, anxiety, insomnia, poor concentration, poor memory, irritability/anger, and depression. In the early stages following TBI, many patient have exhibit moderate to severe communication, perceptual, or conceptual disturbances that ultimately clear up but for others remain as subtle defects that are not always apparent to casual observers. The uniqueness of each patient makes a lot of interindividual variability in kinds of cognitive deficits. The most common cognitive deficits are attentional deficits; slow reaction times and slow mental processing (poor concentration, heightened distractibility, short term memory complaints). The common complaint of a memory problem in mild brain injury is usually the product of attentional and verbal retrieved deficits. Sluggish verbal retrieval is closely associated with slowed information processing. Most TBI patients show little deficit on verbal tests involving memory (Verbal retrieval problems; dysnomia). Sensory and perceptual problems are frequently reported following mild TBI, particularly in the acute and post-acute stages (symptoms; diplopia, photophobia, dizziness, deafness, headache which can take the form of chronic headache disorder). Many mild TBI patients experience dysphoric emotional alterations in which fatigue may be the chief culprit. Patient’s that can’t perform their automatic daily activities may be exhausted at noon. The activities that are normal in their functioning (concentrating, mental calculations, conversations) can suddenly cost a lot of energy and therefore patients experience fatigue and emotional distress (high irritability). The many symptoms that can interfere with daily life can lead to high anxiety and frustration. When the early symptoms persist, the patient becomes more prone to depression. Depression in TBI patients can lead to other somatic disorders. Fatigue, irritability and sleep disturbances, reduces libido (symptoms of depression) tend to further complicate depression in these patients. Of course, personality predispositions can affect how the patient deals with these symptoms and may contribute to some patients’ disablement. The diagnostic criteria for a moderate traumatic brain injury are a PTA with a duration of 1-24 hours, a GSC above 9, focal deficits, intracranial lesions, or depressed skull fracture with a dural tear. Moderate TBI patients are patients who can, and do, function independently. Temporal lobe damage makes its appearance as a true learning disorder that often reflects some lateralization of the damage in that the problems may predominantly involve verbal or visual material. Frontal lobe problems, in particular, tend to show up in subtle ways in the moderate impaired person who nonetheless lives independently works and maintains family relationships. Severe TBI continues to have significant effects on cognitive, emotional, psychosocial, vocational, and family functioning, as well as independence in living. This small group of patients (<10%) forms a growing group with major social problem because few return fully to independent living. Their disabilities tend to be interdependent, interactive and cumulative in their effect, and may result from a variety of impairments. Patients with severe TBI display the full range of severity of dysfunction in every aspect of cognition. Every patients impairment pattern will have at least some unique characteristics as certain functions continue at (near) premorbid levels while others have been more or less severely affected. Attentional deficits are common in patients with severe TBI (especially with rapid deceleration). Memory impairments usually consists of problems in the acquisition and retrieval of information: short term memory is less likely to be affected (discrimination of objects and recognition memory). Working memory deficits are often present when these patients attempt two tasks (operations) at the same time. This is important when patients return to driving, which involves considerable time pressure in carrying out different series of actions as well as making split second decisions. Psychomotor skill learning may be preserved despite impairment of semantic and event memory. Deficits associated with frontal lobe injury are often the most handicapping as they interfere with the ability to use knowledge and skills fluently, appropriately, or adaptively. The performance of patients with severe TBI may be compromised, they might even try to return to work, fly airplanes, or enter a profession despite the most obvious cognitive or motor deficits. Problems in emotional control and social interaction are most likely to be underestimated. Aphasia syndrome is relatively rare, but word retrieval, misnaming, auditory comprehension are common problems. Impaired pragmatics also takes in much of the nonverbal aspects of communication, such as gestures and loudness of speech. Breakdown in linguistic competence has been associated with severity of damage. Visuospatial, visuoperceptual and constructional deficits trouble some of these patients, but more often patients will have little or no difficulties in one or more of these areas. Basic motor functions such as primitive reflexes, protective reactions, muscle tone, range of motion, abnormal and voluntary movements, and motor skills involved in daily life (sitting, standing) may be impaired in the early stages. Executive functions also include aspects of cognition that are not cognitive abilities in themselves but rather concern whether or how they will be expressed. Treatments such as rehabilitation, orthotics, biofeedback, hydrotherapy, hippotherapy, medication and surgery may be needed at various times to improve motor function. The most crippling disorders associated with severe TBI involve capacities for self-determination, self-direction, and self-control and regulation which depend or intact awareness of one’s self and surroundings. Self awareness is important for social constructs such as empathy and insight. A patient may know that something is wrong or that a social situation may need a special approach but does nothing to correct himself. Automatic, unintended action errors occur more frequently in patient with severe TBI because of lapses in sustained attention and are very inflexible. Often what is needed to perform is available or within the patients capacity but it does not occur to them to use what is there or to anticipate future needs. They are in inadequate control of themselves or their destinies. Many kind of emotional alterations take place as a result of TBI. The emotional changes involve either exaggeration or muting of affective experience and response, both have their organic bases primarily in damage to the frontal lobes or underlying structures. Damage to temporal or limbic structures will also affect emotionality. Depression and anxiety are particularly common regardless of the severity of the injury. Mayor depression was more likely to remit than anxiety, generalized anxiety disorder for several weeks combined with depression appears to be associated with prolonged depression. Anxiety and depression can be a reaction to patients appreciation of their psychical and cognitive abilities. Other psychiatric problems are more common in these patients than in the population such as mania, paranoia, and schizophrenic-like symptoms. Increased risk of personality disorders such as borderline, avoidant, paranoid, obsessive compulsive and narcissistic types have been reported. PTSD can occur across the range of injury severity. The relative contribution of psychogenic reactions and organic dysfunction differ among patients and may differ for individual patients at different times. Social isolation is a common consequence of these emotional alterations, which is painful for families. Parents are also not always able to care for a severely injured family member at home. Therefore it is possible that a member of the family has to live in a nursing home, leading to feelings of shame and social withdrawal. Moreover, families with a TBI person tend to become increasingly isolated, which can only exacerbate tensions and dissatisfactions. Confusion is displayed in several patients who lost consciousness as a result of TBI. This confusion is characterized by motor restlessness, agitation, incomprehension, incoherence, resistive and assaultive behavior. Memory and learning are affected intensively in TBI-patients, memory seems to improve over years. Activities that have a large attentional component, such as immediate span, tend to improve quickly and reach a plateau within the first six months to a year after injury. Most of the times improvement comes gradually as a function of new learning and development. Irritability, restlessness and fatigability however are elements that take long time to recover fully, overall, the psychosocial functioning improves. In severe TBI patients mayor percentage of the patients will have to cope with several chronic problems, that is: problems that stay and which the patients did not have in the premorbid situation. 40 percent of the patients made a good recovery in a study of mason (p.184). TBI is a potential risk factor for Alzheimer disease, cognitive decline, psychotic disorders and delayed neurological deterioration. Thus in the long term, both good and bad outcomes have been reported for severe TBI patients.
Dysfunction in social activity
Problems in social activity are common neuropsychological deficits that occur amongst patients that survived severe TBI. Age at injury seems to be related to employment outcome, those with a severe injury in childhood and early teens having a poorer eventual vocational outcome. Characteristics most likely to distress family members, reflecting emotional disturbances, are aggression, increased temper and irritability, social withdrawal, emotional coldness, childishness, emotional lability and unreasonasbleness. Sexual difficulties are often involved in patients with severe TBI, due to physical, emotional, cognitive and hormonal changes. Cognitive problems can interfere with the imagery that induces sexual arousal. Discussion of sexual changes and problems in patients with severe TBI along with information about the many therapies should be part of any TBI rehabilitation program. Rehabilitation workers experience low levels of social interaction along with boredom and dissatisfaction in the treatment of the TBI patients. Severe TBI can reduce QOL.
Neurological Assessment in Traumatic Brain Injuries
In the acute and postacute stages of TBI the patient may be in coma or in a less-responsive stadium, therefore intensive neuropsychological examination is not usually undertaken. Clinicians that are assessing patients repeat most measures over an extended period, to get aware of the improvement and deterioration. Neuropsychological assessment is usually introduced when the patients is out of PTA or at specific time points (3 or 6 months postinjury). Some patients are hospitalized and can’t assist in a complex neurological examination. Testability has been shown to be predictive of outcome. When the patient enters acute or postacute rehabilitation, many of the same tests may be administered along with more detailed assessment of functional status. 2% or fewer of surviving severe TBI patients have a residual aphasic disorder. Most of t he test used for both general cognitive assessment and examination of brain dysfunction measure abilities likely to withstand TBI, many patients can perform on a conventional psychological examination or one of the prepackaged neuropsychological test batteries. Long after acute stages adults may perform normal (average) in the intelligence tests, yet these patients can continue to suffer frontal apathy, memory deficits, severly slowed thinking processes, or a mental tracking disability that makes them unable to resume working. Most patients seeking compensation for their injuries do not present more symptoms or deficits on testing than patients without that compensation seeking. The effect of compensation claims and pre-injury pathology is often secondary to organic factors.
Variables Affecting Severity of Traumatic Brain Injury
Advancing age is often associated with progressively higher mortality and morbidity. Not because they have more severe damage, but because the intrinsic characteristics of the aging brain (intracranial compliance, vasoelastic properties, response to mechanical stress, vulnerability to excitotoxic damage, alterations in neurotransmitter metabolism, microvasculature, dendritic spines and arborization, and blood-brain barrier). Older persons also tend to report more anxiety and depression. Age relates to 2 important predictors of severity; coma duration and PTA. Pre-existing medications also contribute to the problems thus the relationship between age and severity of injury is not entirely clear. On the contrary, patients who are younger might display more emotional and behavioral problems. Cost of rehabilitation is higher for older people as it is associated with longer hospitalization stays and slower rates of functional change. Repeated TBI’s tend to have a cumulative effect on cognition as a second concussion leaves the victim somewhat more compromised. A single TBI doubles the risk for a future head injury, two injuries raises the risk eightfold. Sport injuries have been a rich source of information about the effects of repeated TBIs and this can serve as models for the neuropsychological problems associated with repeated head injuries (Football most concussion for boys, Soccer causes the most concussions for woman). Most sports-related injuries fall into the category of mild TBI, young players examined immediately after possible concussion showed mild effects in slightly lower scores. Young and healthy athletes improve rapidly. However at least six months after their last concussion, youthful athletes performed as poorly on test of attention and response speed as did players concussed within the preceding week. Thus, most cognitive test performances of most athletes who have had few concussive injuries will be at or near normal levels. Few head injured athletes will suffer a long lasting postconcussion syndrome, but these have typically sustained a more severe concussion or possibility have a genetic predisposition to trauma vulnerability. Boxing (de sport; boksen) had served as an obvious model for the effects of cumulative blows to the head in that the goal in boxing is to give one’s opponent a sufficiently severe concussion as to render him unconscious. The most usual presentation of cumulative damage in boxers is the punch drunk syndrome, originally called: dementia pugilistica (chronic progressive encephalopathy of boxers). Dementing conditions (clumsiness, incoordination, intention tremor) occur in 20% of professional boxers. Acute effects of boxing were demonstrated by assessment before and immediately after a match, as these 38 amateur boxers displayed pronounced alterations on tests of conceptual reasoning, motor speed, sustained attention, and both verbal and visual recall. Clinicians working closely with athletes have identified the second impact syndrome (SIS), a somewhat rare event which is thought to occur when a second TBI is sustained before the physiological reactions to prior injury have dissipated. The hallmark of SIS is diffuse swelling of the brain (within hours of even mild injury and results from compromised cerebral autoregulation). Accidents causing head trauma frequently involve trauma to other systems and parts of the body that, in turn, tend to contribute to the severity of the neurobehavioral condition and cognitive deficits contribute to the status of polytrauma patients (no higher mortality rate). Severely head patients whose abilities to concentrate or perform mental operations are already compromised, they can greatly exacerbate the attentional difficulties, add to fatigue, and reduce mental functioning. It is not surprising to learn that TBI patients with prior histories of alcohol abuse tend to have poorer outcomes as measured by performances on neuropsychological tests. Alcohol appears to have a potentiating effect on head injury severity, neuropathological changes, event-related potentials, and outcome. The relationship between alcoholism and neuropsychological status after one year is not a simple one: those patients performing least well on tests tend to be poorly educated men whose premorbid lifestyle is more likely to have put them at risk for head injury than are the lifestyles of women or well-educated men.
Uncommon causes of Traumatic Brain Injury
Most cases of TBI involve blows to the head or penetration of the skull, other sources include lightning, electrical accidents and blast injuries. Lightning is one of the leading causes of death from natural disasters. The effects vary greatly, pathway through the body, associated injuries, victim characteristics and point of injury. Electrical injuries are divided into high voltage (> 1000 volts) injuries and low voltage (< 1000 volts) injuries. High voltage are likely to produce extensive burning and charring of tissues. Low voltage injuries can be deathly if victims can’t let go of the object (wanneer je onder stroom staat spannen je spieren aan als reflex, een gevolg van teveel spanning op de spieren en teveel actiepotentialen, dit heet: tetany en stopt als het contact met de bron wordt verbroken). Continued contact can cause sustained apnea, with hypoxemia and respiratory and/or cardiac arrest. The risk factors for electric shock are behavioral, environmental and geographic (often combination) of these three factors. Children and adolescent men are most likely to get electric burns or high voltage injuries due to their behavior (vingers in stopcontact, beklimmen electriciteitsmasten). Lightning has several ways to strike; a direct strike is particularly serious if it’s near the head. A side flash (splash) happens when the current is directed by an object with les resistance. A ground or stride current occurs when lightning strikes and then travels along the ground to a person. A weak upward streamer is an electric charge that surges up through any object projecting from the ground, induced when the tip of a branch of cloud to ground lightning gets within a few hundred meters of the ground. Neuroanatomy and pathophysiology. The central nervous system (CNS), heart and internal organs are included in head to foot conduction. Pathways involving the head should lead to higher rates of central nervous system disorders and neuropsychological deficits. CNS is not involved in electric shocks or lightning injuries. Over 70% of all lightning victims have a brief loss of consciousness and over 80 % have confusion with amnesia and brief periods of paresthesias and paresis. There are several neurological complications; intracranial and epidural hematomas, cerebral edema, hemorrhage, hemiparesis, infarct, myelopathy, concussion. A number of symptoms and syndromes may result, some of which can be delayed in onset. These include hypoxic encephalopathy, ataxia, bulbar palsy, polyneuropathy, Wilson’s disease, spinal atropy and autonomic failure (and seizures in first few days or later). In the peripheral nervous system (PNS) myelin sheaths and axons can suffer various injuries. Mild tingling or numbness may be reported or even a complete loss of sensory and motor function may occur. Damage in the autonomous nervous system can include cardiovascular, temperature, bladder and erectile dysfunctions. There are four categories of classification in the disease process; (1) immediate and transient symptoms, (2) immediate and prolonged or permanent problems, (3) delayed sequelae, (4) secondary lesions. Diagnosis of electric shock is based on the history, psychical surroundings at the time of the event, entrance and exit wounds, and burns. In cases where the patient was unconscious, paralyzed and disorientated one should consider another etiology. Cognitive deficits are difficult to report and is done by interviews and checklists as well as formal testing. Confusion and mental status alteration, together with decreased concentration and concentration seems to be normal in patients with TBI. Sensorimotor status changes include pain, paresthesias and dysesthesias. Memory and learning are often affected; retrograde and anterograde amnesia may be present actually. Verbal functions and academic skills are usually intact. Perceptual and constructional functions, mostly been measured by the WIS-A test, are generally normal. Executive functioning is not impaired. Personality and social behavior can change, mood and affective behavior is a key element in that change. Some patients may develop a PTSD, other may suffer from depression, changes in attitude, and problems with anger. Depression, emotional lability, increased anxiety and irritability, decreased stress tolerance, indecisiveness, immaturity, irrational violence, low self-esteem, etc.
Vascular disorders:
Stroke and related disorders: The most frequently encountered of the cerebrovascular diseases is the cerebrovascular accident (CVA) (once called; apoplexy, apoplectic attack, nowadays called; stroke). The incidence of stroke is actually higher than the patient count, silent strokes (without obvious motor or sensory alterations) may occur. Risk factors for stroke are well known. Atherogenic processes result in thickening lesions that grow with blood vessel walls; fatty substances are a significant component of these plaque like lesions. Hypertension, smoking, diabetes, and fatty acids are all risk factors for atherosclerosis. High oral intake of estrogen and smoking seems to be a high risk factor for stroke. Warning signs of impending stroke, such as transient ischemic attacks must be heeded for treatment to be initiated. A stroke is a focal neurological disorder of abrupt development due to pathological process in blood levels. The inability of nervous tissue of many parts of the brain to survive more than several minutes without oxygen, accounts for the rapidity with which irreversible brain damage takes place. The disruption of normal blood flow (infarction) created an area of damaged or dead tissue, an infarct. Cells around the place of the infarct are also at risk. Some parts of the brain may incorporate into a irreversible function unless medically treated. This area, called the ischemic penumbra, is the target of thrombolytic therapy do prevent the damage of following ischemic stroke. The two prominent mechanisms that can account for the tissue starvation of CVA’s are obstructions of blood vessels and hemorrhage. The symptoms differ and are considered separately.
Obstructive ischemic strokes
Cerebral thrombosis is the buildup of fat deposits within the artery walls (atheriosclerotic plaques) and causes 60-70% of the strokes. In thrombotic strokes, the infarction results from occlusion of a blood vessel by a clump of blood particles and tissue overgrowth (thrombus). Thrombotic strokes may occur suddenly with no further increase in symptoms and often they take half an hour to develop fully. Thrombotic strokes tend to arise from atherosclerotic lesions in the intracranial carotid or the vertebrobasilar arteries. More than 60% of the strokes is caused in the region of the middle cerebral artery. A stroke in that region enjoys significant spontaneous improvement as swelling and metabolic dysfunction resolve. When the middle cerebral artery is not involved, the most obvious cognitive disorders troubling those with right sided damage will involve visuospatial abilities. Left-sided disease will be more or less aphasic. Limb weakness, paralysis and somatosensory changes are common in all of these patients. Cognitive deficits involving visual and memory functions tend to occur with strokes due to occlusion of the posterior cerebral artery which branches of to the vertebrobasilar system. Cerebral embolism accounts for 20-30% of the strokes. In this form, stroke is caused by an embolus, a plug of thrombic material of fatty deposit broken away from blood vessel walls or of foreign matter such as clumps of bacteria or even obstuctive gas bubbles. Most emboli are fragments of thrombotic lesions that developed outside the intracranial vessels. The middle cerebral artery is the most common site of embolic strokes although they can occur elsewhere. Memory impairment is most common in this syndrome in which the medial thalamus is frequently infarcted.
Variables affecting presentation of obstructive strokes.
The effects of ischemic infarctions vary from patient to patient, or from time to time. Due to individual differences, in the anatomical organization, the capacity to develop and utilize brain circulation, and in cerebral blood pressure and blood flow. The extent, the size, the site, severity, the diabetes, blood conditions that affect its viscosity or clotting capacity. Age and sex can play a role in determining the presentation of a stroke. Emobolic strokes are often associated with heart disease and tend to occur at an earlier age than thrombotic strokes.
Cognitive changes with obstructive strokes.
Large artery infarctions tend to produce significant behavioral changes either by direct cortical injury of by disruption of large subcortical areas. Very small artery infarctions may have few behavioral consequences except when they occur cumulative with more and more little strokes producing an increasing volume of damaged tissue. Stroke tend to have one-sided effects. As strokes are acute in onset, there is no time for functional compensation. During the acute stages, secondary diffuse effects and diaschisis typically add symptoms of widespread brain pathology as edema and other physiological reactions take place. For aphasic stroke patients, speech fluency typically returns by one month if it returns at all; fewer than one-fourth of patients nonfluent at one month regain fluency by six months. At one months poststroke, most with hemiplegia had perceptual deficits as well. Most patients whose strokes were ischemic in nature have residual defects that are more or less obviously lateralized and display relatively minimal evidence of diffuse damage. For left-and right sides hemiplegics alike, the largest number of perceptual errors involve aspects of body image. Moreover, their focal deficits typically fit into a pattern of dysfunction associated with areas of the brain that share an artery or network of smaller arterial vessels. Emotional disturbances with stroke are normal, and differ in how patients with left or right hemisphere strokes react in terms of preponderance of depression and catastrophic reactions when the lesions is on the right. Patients with right hemisphere involvement have more restricted emotional expression, apathy and depression. Depressions are common, and the incidence is likely to increase over time. One or two year poststroke, severe depression in patients with right sided damaged was strongly correlated with posterior lesion sites, but depression in patients with left-sides lesions showed no anterior/posterior predilection. Reduction in activities and socializing are common life style alterations among stroke patients. Depression does not predict the quality of social functioning, but severity of the impairment does
Transient ischemic attacks (TIA)
These episodes of temporary obstruction of a blood vessel less than 24 hours by definition, and many last for only minutes, with fully half dissipating within an hour. Two types of TIA have been identified; those that last more than 45 minutes and leave no evidence of infarction on CT and those that last much longer and show radiological evidence of infarction. TIA´s are characterized by mild stroke-like symptoms that follow the same patterns of presentation as do full blown strokes. Furthermore, most TIA´s are associated with arteriosclerotic disease and have the same risk factors. Within the first months after TIA, evolves in 30% of the patients. The risk of stroke following a TIA depends on other clinical factors. Many patients who have had TIA, suffer mild residual cognitive impairment, the deficits becoming increasingly apparent with repeated attacks. Treatment of TIA or CITS typically involves chronic antiplatelet coagulation therapy; often aspirin suffices. Anticoagulation therapy may be initiated preventively if a potential embolic source is suspected
Hemorrhagic strokes
Is the primary and most significant agent of damage in 10-20% of all strokes. Hypertension is the chief risk factor. The two most common mechanisms causing arterial rupture are weakening of a vessel wall due to pathological alterations secondary to hypertension which is present in 78 to 88% of the cases and rupture associated with a vascular abnormality such as aneurysm, arteriovenus malformation, tumor, or deficient coagulation. Hypertensive hemorrhagic strokes occur most typically in persons from 60/80 year range. The risk of ruptured aneurysm depends more on aneurysm characteristics and the manifestations can be dramatic. Early warning symptoms rarely precede these subarachnoid hemorrhages. The patient may or may not lose consciousness depending on the severity of the bleed and the intensity and site of vasopasm (contraction of blood vessels in the region of the bleed). The condition can be fatal when massive bleeding or extensive vasopasm occurs but if the bleeding is arrested soon enough only little damage is caused. Patients who have had ruptured aneurysms of the anterior communicating artery are likely to suffer the kind of behavioral disturbances and frontal lobe lesions. Hemorrhages associated with hypertension tend to involve the blood vessels at the base of the cerebral hemispheres so that the damage is usually subcortical. Arteriovenous malformations are tangled masses of arteries and veins of congenital origin which grow much like a tumor. The cognitive of this may be relatively mild an not necessarily reflective or lateralized damage. Silent strokes are (small) strokes in which symptoms are not obvious and thus go unmarked. But me be present in up to 30% of patients with significant internal carotic disease. Silent strokes are five times as prevalent as symptomatic brain infarcts. Silent strokes become apparent upon CT or MRI scanning of later occurring, obvious strokes or when behavior changes bring the patient to medical attention.
Vascular Dementia
Is a decline in cognitive functioning that results from any of a number of vascular etiologies. Cerebrovascular disease has a lot of variety of treatments, some workers suggest staging by levels of severity beginning with vascular cognitive impairment. This procedure seems to be particularly relevant since memory loss, a prominent feature of Alzheimer´s disease and many other dementing conditions, is not necessarily a major symptom of cerebrovascular disease.
Multi-infarct Dementia (MID)
Ay blood also called arteriosclerotic dementia; arteriosclerotic psychosis, is an umbrella term for conditions in which widespread cognitive impairment takes place as a result of repeated infarctions, usually at many different sites. MID comes under the broader category of vascular dementia, treatment is done separately since this is probable the form of vascular dementia most frequently encountered by neuropsychologists. Two broad categories are distinguished: cortical atherosclerotic dementia (repeated infarctions of the large vessels which supply blood to the cerebral cortex) and subcortical atherosclerotic dementia (resulting from infarction and ischemia due to blockage or deterioration of the narrower arterioles that feed subcortical structures). Lacunar strokes occur as small infarcts in deep gray nuclei of the basal ganglia, internal capsule or pons, with a few appearing in cortical gray matter or in the major cerebral white matter pathways. These little strokes are mostly due to occlusion but occasionally emboli from a nearby lesioned area will plug up the arterioles. In 30% of the cases, the onset is gradual. Binswanger´s disease differs from the lacunar state in that the onset is slow and insidious. Moreover, the multiple infarcts are found mostly in periventricular areas and cerebral white matter with accompanying demyelinization. MRI is more sensitive than CT in revealing hyperintensities and abnormalities. Similarities in these two conditions include the common risk factors of hypertension, diabetes, abnormally high fatty content of the blood, and cigarette smoking. Leukoaraiosis is seen in large numbers of MID patients. Communication disorders have a distinctive pattern in which the content and organization of speech remain relatively unaffected but pitch, tone, and melodic qualities are deficient and rate of production is slow. Most of these patients become dysarthric and may ultimately deteriorate into a kinetic mutism. Writing is affected and auditory span may be diminished. Threatening delusions (let op: geen psychose) are likely to occur in half of these patients at some time in their course. MID has many similarities with Alzheimer´s disease, but differs in some ways. MID patients have better memory, both have a history of hypertension and stroke, better scores on verbal descriptions and on unstructured construction tasks. Early in its course, cognitive deficits are likely to predominate while personality deterioration lags behind, although eventually both aspects of behavior may become profoundly disordered. Motor abnormalities (gait disturbances and rigidity) are common but not necessarily predictive of MID.
Hypertension
Hypertension is the major precursor of most types of CVA. The major risk factors for hypertension include obesity, excessive use of salt, excessive alcohol intake, lack of exercise, and tobacco use. Patients with preceding hypertension have poorer performance on test of verbal and visuospatial learning and memory. The techniques for managing hypertension have been improved, and hypertensive encephalopathy (acute condition) has become quite rare. Hypertension has been associated with mild cognitive impairments which may worsen with the duration and severity of the hypertensive condition. Especially older patients with hypertension suffer from gradual cognitive deterioration over a ten-year period. Confusion, sexual dysfunction, general well-being, and work performance are also key-elements regarding to the cognitive effects of antihypertensive medication. Women with hypertensive periods also tend to score higher on depression and take more medication.
Migraine
The second most common neurological disorder, migraine, is a headache condition. And implies a lateralized headache (60% = unilateral). Classification of headaches has always been somewhat ambiguous: because patients can have more than type of headache, and their headaches may change in nature and frequency over time, and some headaches are not easily classified. There are several classification systems for a headache, one of the most used is developed by the headache classification committee of the international headache society. That classification system has the term; migraine without aura to replace common migraine, which is a clearly localizable to the cerebral cortex and/or brainstem. Risk factors for migraine are hereditary factors (chromosome 19p), comorbid mood disorders (depression, anxiety, panic attacks), and other triggers. These triggers can be personality characteristics such as neuroticism and neurotic signs. And consumption of foods such as cheese, chocolate, and alcohol. Lack of sleep, missing a meal, and stress can help in the induction of migraine. Migraines may be better, worse, or unchanged with oral contraceptives, menopause, and postmenopausal hormone replacement therapy. Pathophysiology; The vascular theory of migraine proposed that the aura of a migraine is associated with intracranial vascoconstriction and the headache with a sterile inflammatory reaction around the walls of dilated cephalic vessels. This theory supports the occurrence of headaches with other vascular disorders. In migraine with aura there appears to be a wave of oligemia (reduced blood flow). The neurogenic theory of migraine proposes that the headache is generated centrally and involves the serotonergic and adrenergic pain-modulating systems. Enhanced serotonin release increases the release of neuropeptides. White matter abnormalities are common in patients with migraine. The rates of white matter abnormalities are common in migraine patients under 50. Transient global amnesia is associated with an increased rate of migraine but these disorders differ in age of onset, frequency of symptoms such as nausea and headache and occurrence of an aura. The migraine condition is characterized by several factors. In most cases, migraine is preceded by several other symptoms such as depression, euphoria, irritability, restlessness, fatigue etc. Homonymous visual auras are most common and include scintillating lights forming a zig-zag pattern, scotomas due to bright geometric lights or loss of vision. Objects may change in size or shape or zoom in and out. Usually the aura lasts for 1 hour, but it is possible to have the aura without the headache. The more common unilateral pain during the headache phase typically involves one periorbital region. Pain is associated with nausea. Migraineurs often feel tired, listless, and depressed during the succeeding hours to days though the converse sometimes occurs. Migraines occur most often in the morning. Findings from neuropsychological studies have been inconsistent about cognition in migraine patients. The performance of college students with classic and common migraines was similar to that of nonmigrainous students. These patients have normal EEG, normal CT scans and normal neurological examination, also no group differences are found on measures of learning, memory and motor tasks. Cognitive deficits appeared on some measures of attention, information processing speed, and recognition memory. For therapy, serotonin agonists seem to be effective. Such as antidepressants, magnesium replacement etc.
Degenerative disorders
Many disease processes involve progressive deterioration of brain tissue and of behavior. Nerve cell death is central to the manifest neurological and behavioral changes of degenerative neurological diseases. Degenerative disorders affect a large proportion of the elderly population. Neuropsychological differences between degenerative disorders typically show up in the early stages before the disease process has become so widespread as to nullify them. Patients share many behavioral symptoms when the disease has run its course. Symptoms are inattentiveness, inability to concentrate, track mentally, distractibility, apathy, impaired capacity to initiate, plan, memory disorders. Thus, the following descriptions of degenerative disorders pertain to relatively early symptoms presentations when distinguishing characteristics are still present. As their cognitive functions deteriorate, patients’sense of person, capacity for judgement, and ability to take care of themselves will deteriorate too. Total dependency is the end-point. All of the degenerative disorder can qualify as dementias. A narrower and commonly used definition of dementia as global cognitive decline includes several criteria: global implies impairment in more than one aspect of cognitive functioning. Dementia refers to processes that are progressive and irreversible.
Cortical dementias
Alzheimer
Alzheimer is t he best known dementia. It is characterized by inexorably progressive degenerative nerve cell changes within the cerebral hemispheres with concomitant progressive global deterioration of intellect and personality. In the brain it is an accumulation of amyloid plaques and neurofibrillary tangles. The disease process spreads out over the hippocampus, frontal and parietal areas and adjacent regions of temporal lobes. More than 66% of all cases of dementia are attributed to this condition. The diagnosis of alzheimer is mostly done on biopsy or autopsy. A diagnosis of dementia of the alzheimers type acknowledges both its necessarily questionable nature prior to direct examination of brain tissue. Risk factors of alzheimer are probably a genetic predisposition, although in most cases alzheimer is sporadic. Having a first degree relative or parent with alzheimer doubles the risk for alzheimer. Chromosome 14 seems to be important. Moreover, several predisposing genes have been identified. The gene has three variants. The association of the 4th allele with development of plagues and tangles may vary with both age and sex. Most gene studies have examined white populations. Alzheimer’s disease also have been linked with down syndrome, a condition in which mental retardation features are prominently, along with skeletal and other developmental abnormalities. Down syndrome occurs significantly more frequently in families with a history of alzheimer than in those without. Demographic factors: the major risk for alzheimer is age. Most cases occur after 60. Someone with no family history of alzheimer has 15% lifetime risk of getting it. Most studies report a higher prevalence in women. Genetically based, small differences have appeared among the races. However, racial differences have not always been found. Low educational and occupational levels have been associated with an increased risk for developing alzheimer. The role of TBI as a risk factor for developing alzheimer is still somewhat controversial. Many studies have reported a significantly high incidence of TBI history. Risk of developing alzheimer’s disease after a severe TBI is greatest for subjects lacking the ApoE4 allele. The cognitive and personality changes that are part of the punch drunk syndrome of boxers share many characteristics with the mental alterations of Alzheimer’s disease. Other risk factors are low levels of estrogen in postmenopausal woman, smoking, elevated systolic blood pressure and high serum cholesterol.
Neuroanatomy and pathophysiology
The neuropathological hallmark of alzheimer is the presence of neurofibrillary tangles and senile plagues. Neurofibrillary tangles develop when microtubules that transport substances from the nerve cell body to the end of the axon become twisted. The protein that helps maintain the structure of these tubules is tau. Several neurological systems are involved in the progress of the disease (zie pagina 209 voor de exacte hersendelen, vrij technisch verhaal). It is not clear yet if alzheimer evolves from neurofibrillary tangles and senile plagues or if this is just a by-product of the disease. Current research into treatments of alzheimer involves drugs that avert the formation of amyloid plaques or that may be protective against their formation (keep tau in its normal form). Neuronal loss is another common feature of Alzheimer’s disease. It involves larger neurons in the neocortex (especially temp. cortex, brainstem, basal nucleus and locus coeruleus). The pattern disconnects the temporal lobe structures from the rest of the cortex, and disconnects the prefrontal from parietal structures, thus creating a memory problem. Neural loss, especially in the three brainstem areas (nucleus basalis, raphe nucleus, locus coeruleus) appears to be related to reduced production of neurotransmitters by these centers in particular and by other brain structures. Along with cholinergic depletion, which occurs early in the course of the disease. Loss of neurons typically results in gross anatomic alterations of the brain which appear most obviously as enlarged ventricles and a thinning of the cortical mantle. Neuroimaging techniques show this prominent atrophy pattern, however there is a great variability within the nature and extend of atrophic changes of both Alzheimer patients and nondemented elderly persons, and other dementing conditions. Reduced metabolism in the frontal areas is closely related with dementia severity. Alzheimer patients show a reduced cerebral blood flow in the parietal lobe.
Process of the disease
If Alzheimer’s disease progresses slowly one or more stages will relatively prolonged, when progression is erratic, the duration of each stage may differ markedly. Many patients are unaware of the existence of Alzheimer’s disease because the disease progresses silently; behavioral decline is gradual and unsuspected. Early evidence of inattentiveness, mild cognitive dulling, social withdrawal, and emotional blunting or agitation are often confused with depression so that it is uncommon to find an Alzheimer patient who has recently been treated for depression. The sequence in which cognitive functions first show deterioration generally begins with memory but also with complex mental tracking and verbal fluency. Symbol substitution and construction tests usually decline steadily. As the disease progresses, cognitive impairment becomes broad and severe. The pattern of functional regression is the inverse of normal development stages. Clinical subtypes: Age based differences underlie the once generally accepted distinction between presenile (<65) and senile (>65) dementia. Greater involvement of one hemisphere than the other occurs in almost 40% of the patients. Lateralization of deficits tends to appear in typical patterns in which verbal oriented functions or visuospatial functions are coupled, remaining relatively intact or deterioration together. A posterior variant or visual variant has to be distinguished, early in the course of this subtype prominent visual disturbances occur such as visual agnosia, prosopagnosia, alexia, and Balint’s syndrome. In some cases patients show an occipitoparietal focus.
Diagnosis and prediction severity classification is done by several scales, one of them is the Clinical Dementia Rating, which is widely used in dementia research and rates severity on a 5 point scale. Ratings in this scale are based on memory and other cognitive abilities. Questionable dementia is defined either as mild consistent forgetfulness or slight problems with 2 or more cognitive areas. Mild Dementia is moderate difficulty with recent recall that interferes with daily activities. Moderate dementia is severe memory loss or moderate memory loss with severe impairment in three or more other cognitive areas. Severe dementia involves severe memory loss whit only memory fragments, orientation to person only. Inability to make judgments or solve problems.
Diagnostic issues; no single marker or set of markers for reliable positive identification of Alzheimer’s disease in living patients has yet been found. The clinical diagnosis of Alzheimer’s disease relies on information from a variety of sources, following diagnostic guidelines. Even mildly impaired early Alzheimer patients can be identified with a high degree of accuracy using informant reports and clinical judgment. Slow event related potientials can occur prior to the appearance of cognitive or behavioral symptoms. Characteristic cognitive impairment patterns have been identified for most dementing conditions but constructional deficits are also common. MRI evidence of the hippocampal atrophy can also contribute to a diagnosis of Alzheimer’s disease. The combination of memory loss and hippocampal atrophy is better than either one alone. No strong predictors of rate of cognitive decline have yet emerged. Many studies done have used the MMSE (mini-mental state exemination). Age is important as a predictor, sex differences are not. Extrapiramidal signs have been associated with a slightly faster course in some studies. Some cognitive variables have predictive value, patients with significant language dysfunction deteriorated more rapidly than those with relatively intact language skills.
Cognition
Alzheimer’s disease affects several areas of functioning, but memory and cognitive changes are the most obvious early symptoms. The overall course of the disease runs consistently downhill so that at the end all functions are lost and all patients reach a similar stage of behavioral dilapidation. The sensorimotor status varies among all patients. Patients may have defects in inferior visual fields, visuoperceptual deficits are common. Severty increases over time, but the pattern of dysfunction can vary greatly between patients as specific deficits tend to be independent of one another and do not necessarily worsen at similar rates. Object recognition tends to be more affected than visuospatial abilities. Auditory acuity appears to be no more of a problem in Alzheimer’s disease than in t he aging population generally. Olfactory acuity, measured by recognition, is typically impaired early in the disease course. Reductions in left hippocampal volume are also associated with impaired odor identification in Alzheimer patients.
Attentional deficits are part of the symptom picture of Alzheimer’s disease. Moreover it appears to remain unaffected, at lest for mildly to moderately demented patients. Impairments in nearly all aspects of attention have been reported, including defective focusing and shifting. Cognitive slowing results in longer reaction times for these patients. This ends up in social dependency and deterioration of personal habits; patients are unable to do more than one thing at a time. Orientation in space and knowledge of events are often compromised, but is unlikely to be the first symptom. Orientation may remain intact after deterioration of other functions has become evident.
Memory and learning problems show up on tests several years before the dementia diagnosis is warranted. The nature of the learning defect has been studies with a variety of techniques, mostly looking for verbal memory. Alzheimer patients show deficits in acquisition and retention of information and they perform poorly on learning tasks. The most sensitive measure of the memory deficit is delayed memory. Retrieval problems show up in several ways, in much lower recall than what is elicited by recognition, and priming techniques. Mildly impaired patients may perform normally on recognition tests but perform significantly below normal levels on visual as well as verbal tasks. Alzheimer patients do not appear to benefit from gist or other conceptual relationships. High imaginary does not improve word retention. Studies of testable patients have shown that many but not all have impaired memory. The addition of a distractor task to test working memory increases the deficit. Older memories tend to be more available than recent one. As the disease progresses, knowledge of current events and general information is compromised. Alzheimer patients are impaired on some implicit memory tests, depending on the type of tasks. They often show normal perceptual priming.
Verbal functions and academic skills deteriorate in the quality, quantity and meaningfulness. Semantic disruptions appear in many ways. Fluency tasks are especially difficult for Alzheimer patients because they make demands for both on directed generation of ideas and on semantic knowledge. Confrontation naming too elicits many fewer responses from Alzheimer patients than from intact persons along with many more errors. Perceptual errors may also occur on naming tests, but they are rare until the disease progresses do the moderate stage. Naming problems develop somewhat later than the generative problem. Speech content empties but the basic organizing principles of language remain relatively intact. An other problem is diminished comprehension of both written and spoken language. As language functions deteriorate almost all aspects of writing deteriorate as much or more. Spelling is also directly related to disease progression. An important aspect of verbal impairment that appears early in the course of the disease is loss of spontaneity so that conversations has to be initiated by someone(something) else. Arithmetic skills are often affected early in the disease. Performance of patients with mild Alzheimer’s disease on oral arithmetic correlated highly with sentence repetition.
Visuospatial functions, construction and praxis. The visuospatial competence of Alzheimer’s patients generally tend to be impaired; complex visuoperceptual discriminations become difficult. Unilateral visuospatial inattention is very common among Alzheimer patients; left or right sighted inattention. The constructional disabilities of these patients have been well documented. Simple tasks are defective and worsen the disease progression. On more difficult copy tasks most performance are defective. In handling construction material, Alzheimer patients may exhibit the closing-in-phenomenon. The presence of closing-in responses may aid in the differential diagnosis between Alzheimer’s dementia and dementing disorders due to vascular disease as the latter patients do not give this response. Apraxias in Alzheimer’s disease may shop up as impairment in pantomiming and in copying gestural patterns. Alzheimer patients have conceptual apraxia in which they make errors of tool-action or tool-object associations. Impairment in the ability to perform everyday activities was correlated with this disturbance of the conceptual system.
Thinking and reasoning. As may be expected, Alzheimer patients display reasoning (both visual and verbal material) impairments. Semantic knowledge becomes degraded such that concepts lose their distinctiveness and conceptual boundaries blur. Result of this progression of the disease can be the loss of participation in decision making. Executive functions are critical for social competence and effective behavior, and are compromised early in the course of Alzheimer. Self-awareness is typically impaired. The major part of the patients show diminished awareness of their cognitive deficits and inappropriate behaviors early in the course of the disease, with the severity of this problem roughly paralleling the deterioration of memory functions. Perseverations and intrusions in speech and actions represent another aspect of the impaired ability of the patient to execute behavior effectively. This latter kind of perseverative response (intrusion) has proven useful in differentiating Alzheimer’s disease from other dementing processes. There are 5 intrusions; test, conceptual, confabulatory, schift, & unrelated, intrusions. Intrusions show up on constructional tasks as well. Executive measures sensitive to mild stage Alzheimer’s disease include tests of working memory, set-shifting, and sequencing.
Personality and psychosocial behavior
Patients with Alzheimer’s disease are affected with behavioral disturbances, including personality changes and emotional disorders. Some different kinds of behavior problems are among the most common: apathy is the far most prevalent behavioral problem. Anxiety, depression, psychotic symptoms, sleep disorder and incontinence are also frequent behavior problems associated with alzheimer. Many patients have episodes of hallucinations and visual illusions. Other disturbances show up in increased activity as agitation and restlessness, with aimless wandering and burst of violence and destructiveness presenting serious problems for caregivers. Suspiciousness and paranoia affect the thinking of these patients. Negativism (stubbornness or refusal to cooperate) is frequently reported by caregivers. Whether more Alzheimer patients suffer from depression than organically intact persons of comparable ages remains unanswered. Other studies have not found an abnormal amount of depression among patients. Dementia patients with major depression may constitute a special subset with greater degeneration of subcortical structures than patients who have not been severely depressed. Yet psychiatric problems, particularly in the form of hallucinations and delusions, are common.
Treatment
Current pharmacological treatment of cognitive problems associated with Alzheimer’s disease involves use of several hormone inhibitors. Some patients benefit by becoming able to carry out functions that had been lost before treatment, and some show a slowing rate of cognitive decline over time. Disease modifying drugs are under investigation. Patients with psychosis and hallucinations or delusions may benefit from antipsychotic agents. Those with depression: antidepressants. However, attempts to increase memory skills are inadvisable because they can create false expectations and lead to unnecessary frustration.
Frontal Lobe Dementias
Frontotemporal dementias (FTD) are degenerative diseases of insidious onset and slow progression involving the frontal and temporal lobes with relative sparing of the posterior brain. Frontotemporal dementia and Alzheimer’s disease are easily confused because the conditions are similar and, in their later stages, may be indistinguishable. The most characteristic feature of frontotemporal dementia is the profound change in social behavior and personality that occurs, sometimes in advantage of diagnosis. Risk factors are seen in 40-50% of the cases where transmission took place by autosomal dominant inheritance. Most cases have tau pathology, and a small percentage have a mutated tau gene on chromosome 17. TBI may be a contributing factor, but prior TBI is relatively uncommon.
Neuroanatomy and pathophysiology
The parietal and occipital lobes remain unaffected in most cases, with atrophy concentrated in the temporal and frontal neocortex. Cortical atrophy can occur asymmetrically. In subcortical structures, the limbic system and the corpus striatum are affected but much less than t he neocortex. The extent of hippocampus and amygdale involvement varies from case to case. The two main cellular findings are prominent microvascular change and/or severity astrocytic gliosis with or without Pick bodies. In pure frontotemporal cases the tangles and plaques of Alzheimer’s disease are absent. Disease process in patients with FTD is stable and goes downhill in course. In the initial stages, silliness, socially disinhibited behavior, and poor judgement predominate. Progressive apathy, blunted affect, and cognitive dysfunction characterize the middle stages. In the late stages patients become mute and many display motor rigidity. The process ends in an vegetative state. Clinical subtypes. The clinical pattern is a reflection of the distribution of disease in the brain (geld voor alle degeneratieve ziekten). In the disinhibited type, a frontal atrophy is confined to orbitomedial zones with relative sparing of t he dorsolateral cortex. Patients with the apathetic type have disproportional atrophy of the dorsolateral cortex. With left temporal involvement, language impairment is predominant. Patients with right sided dominance, socially undesirable behavior is displayed. Motor neuron disease can develop from a rapidly progressing form of frontal lobe dementia. Pick’s disease, first described over a century ago, is one type of frontotemporal dementia that is frequently confused with Alzheimer’s disease. Dysnomia is a regular feature of Pick’s disease. Also characteristics of Pick’s disease is a Kluver Bucy like syndrome.
Diagnosis
The chief diagnostic problem is differentiating frontal lobe degenerating from Alzheimer’s disease as many of the verbal defects are similar. Alzheimer neuropathology may approach on the frontal lobes or frontal projection routes producing a mixed diagnostic picture. However, in the early stages, silliness and socially inappropriate and even boorish behaviors with relatively intact cognition can help distinguish these diseases from other disorders. Neuroimaging shows degeneration of the frontal and temporal lobes.
Cognition
Cognitive alterations typically follow personality and behavioral changes, although this is not always the case. Formal assessment is not always possible with these patients, even early in their course, as disinhibited or apathetic behavior may make it difficult to engage their cooperation. Frontotemporal patients perform even more poorly on verbal fluency tests than patients with Alzheimer’s disease. Speech may be characterized by pressure of speech, etc.
Executive functions
Among the characteristics of FTD are executive disorders and reasoning deficits. Executive impairments are greater than memory deficits. With lateralized disease patients exhibit the usual left-right differences with greater impairment on verbal or nonverbal executive tasks.
Personality and psychosocial behavior
Initial symptoms typically appear in frontal lobish kinds of personality changes (silliness, social disinhibition, poor judgement, impulsivity, apathy and impaired capacity for sustained motivation. Hyperorality may occur later in the course, with mouthing of inedible objects. Affectively these patients tend to be blandly inappropriate.
Dementia with Lewy Bodies (DLB)
Another less common form of primary degenerative dementia (Lewy Body Dementia) was unrecognized before the 1970s. It may account for as many as 20% of patients with dementia. DLB is typically associated with progressive dementia, extrapyramidal signs, visual hallucinations and delusion, and most noteworthy, severe fluctuations in cognitive functioning. Although others report less variability. It shares clinical features with both Alzheimer’s and Parkinson’s disease, and hence is not easily conceptualized as either a cortical or subcortical dementia. Risk factors are generally similar to Alzheimer’s disease. DLB patients have an elevated allele frequency and have a more rapid decline than those with Alzheimer’s disease.
Neuroanatomy and pathophysiology
Most DLB patients display neuropathological findings seen in both Parkinson’s and Alzheimer’s disease. The defining feature is the Lewy bodies (protein deposits found throughout the cortex and paralimbic areas and in the substantia nigra). In addition, senile plaques are common although neurofibrillary tangles are few. When Lewy bodies occur with neurofibrillary tangles and amyloid plaques, it is considered a Lewy body variant of Alzheimer’s disease. Functional imaging has shown decreased dopaminergic activity.
Diagnosis and prediction
The pattern of neuropsychological impairment aids in the differential diagnosis of DLB as on cognitive testing these patients usually have prominent visuospatial deficits but perform better on memory tests than Alzheimer patients and may have deficits associable to frontosubcortical dysfunction. The clinical diagnosis of possible DLB is based on the presence of two features: fluctuating levels of cognitive functioning and recurrent visual hallucinations.
Cognition
Sensorimotor findings in DLB patients are entirely consistent with the pathology. Extrapyramidal signs akin to Parkinson symptoms develop in 50%. Praxis is often impaired while sensory function is largely intact. Fluctuating attention is a core feature of the disease. Attention and lucidity may fluctuate for a few minutes or over weeks or months, and transient confusional states occur. Attentional impairment has also appeared on simple and choice reaction time and computerized vigilance test. Verbal functions follow the Alzheimer pattern of deterioration. Visuospatial impairment is an early and prominent feature of DLB. These patients have more difficulty coping designs with blocks than do Alzheimer patients.
Personality and psychosocial function
Depression may develop in as many as half of the DLB patients. Sleep disturbances are common. Hallucinations, usually visual, can appear early in the disease course. Many patients also have paranoid delusions. The high frequency of these symptoms often leads to an initial psychiatric referral. Accurate diagnosis is important as inappropriate treatment with neuroleptics can result in severe, nonreversible, motor dysfunction that will exacerbate parkinsonian symptoms. For the treatment; patients may show improvement in both cognitive and behavioral symptoms from cholinesterase inhibitors. Patients who respond to cholinesterase inhibitors are more likely to have DLB than Alzheimer.
More Cortical Atrophies
Neurodegenerative disorders sometimes take the form of focal cortical atropy. Two may be classified as variants of frontotemporal dementia; primary progressive aphasia and semantic dementia. The first one is a gradually progressive aphasia syndrome that occurs without memory impairment or dementia early in the disease, the disorder often starts with anomia and proceeds to impaired grammatical structure and language comprehension. Sementic dementia refers to a rare condition in which the meaning of words, objects, and concepts becomes impaired. Contrasting with other dementias, recent memories are better preserved than remote ones. Lateral temporal lobes are involved in the process. The amydala is affected and hippocampal atrophy may be present. Word finding difficulties occur but most striking is impaired knowledge of word meaning. Unlike anomic patients who know the meaning of a word but cannot retrieve it, these patients, when given a word to define, demonstrate that they do not know the meaning although the word may seem familiar.
8. Neurobehavioral Variables and Diagnostics
Behavioral changes because of brain injury are determined by multiple factors like size, location, kind and duration but also predisposing variables like the individual’s premorbid abilities and experiences, cultural and historical background of the individual.
CHARACTERISTICS of lesions
Diffuse and Focal Effects
Diffuse effects | Focal effects |
Do not affect all brain structures equally | Some diffuse repercussions do take place I other temporarily or ultimately. |
Results typically from widespread conditions; infection, hypertension, intoxication, metabolic and nutritional diseases. Occurrence in most closed –head injuries; car accidents. | Trauma, space-displacing lesions, localized infections and cerebrovascular accidents. |
Behavioral expression includes memory, attention and concentration disabilities. Also general response slowing, emotional flattening or lability. | Some systemic conditions may devastate brain structures and result in predominantly focal symptoms picture. Sometimes focal signs of brain damage accompany an acute exacerbation of systemic disorder confusing the diagnostic picture. |
Symptoms most severe shortly after accident or as conditions worsens. | Can often be distinguished by lateralized signs because most lesions involve only one hemisphere. When damage extends to both hemispheres its apt to be asymmetrical. |
| When one function or several related specific functions are significantly impaired while other functions remain intact and alertness, response rate, either vernal or nonverbal learning ability and orientation are relatively unaffected, the cerebral insult is focal. |
Site and Size of Focal Lesions
From a neuropathological perspective, the site of the lesion should determine many characteristics of the attendant behavioral alterations. but in reality so many factors contribute to the outcome that predicting much more than the broad outlines from of the behavioral symptoms from knowledge of the lesion’s location is impossible.
Certain brain areas may be critical for specific cognitive functions but brain regions are not isolated. They work as fully interconnected, distributed neural networks. Complex mental functions (i.e. memory) involve brain regions distributed over wide areas. The severity of deficit may be best estimated for a specific function by taking into account jointly both size and hemisphere side of lesion as the importance of lesion size differs between the hemispheres and the importance of hemispheric contributions differ with the task. In most cases, information about where in the brain a secrete lesion is located must be viewed as only a partial description that identifies the primary site of damage.
Depth of Lesion
Sub cortical damage associated with a cortical lesion compounds the symptom picture with the added effects of disrupted pathways or damaged lower integration centers. The depth and extent to which a cortical lesion involves sub cortical tissue will alter the behavioral correlates of similar cortical lesions. So has depth of lesion been clearly related to the severity of impairment of verbal skills. Another example is with anosognosia whereas similar cortical lesions but different amounts of subcortical involvement create different types of behavioral effects.
Effects of distance
Diaschisis
Refers to depression of activity that takes place in areas of the brain outside the immediate site of damage, usually in association with acute focal brain damage. This concept applies mostly to the depression of relatively discrete or circumscribed clusters of related functions than to global dampening of cerebral activity associated with radical physiological alterations that take place following an acute injury to the brain.
Depressed functioning in cerebral areas that have been structurally damaged can be seen most clearly in stroke patients who exhibit deficits associated with the non -infarcted hemisphere, like reduced blood flow and EEG abnormalities.
Disconnection Syndromes
Both diaschisis and disconnection syndromes involve disrupted neural transmission trough subcortical white matter. Cortical lesions that may or may not extend to white matter give rise to diaschisis though, while disconnection syndromes result from damage to white matter that cuts cortical pathways, disconnecting one or another cortical area from the communication network of the brain. Thus cortical involvement is not necessary for a cortical area to be rendered nonfunctional. The most dramatic disconnection syndromes are those that occur when interhemispheric connections are severed, whether by surgery or as a result of disease or developmental anomaly.
Disrupted systems
‘An intact hemisphere in a damaged brain cannot operate as it does in an intact brain’. Damage in a given area will have secondary adverse effects n the activity of distant but normally interacting area because of the complex system that is our brain.
Lesion-nature
Type of Damage
When the lesion involves tissue removal with little or no diseased tissue remaining, repercussions on other, anatomically unrelated functions tend to be minimal and the potential for rehabilitation runs high. Dead or diseased brain tissue, which alters the neurochemical and electrical status of the brain can produce more extensive and severe behavioral changes than a clean wound. Functional impairments tend to result in behavioral distortions involving other functions, to have high level cognitive repercussions and to affect personality. It can also affect circulation and metabolism of surrounding tissue both immediately and long after.
Severity
No single measure of severity applies to all the kinds of damage than can interfere with normal brain functioning. In many cases, to evaluate the severity of a brain disorder, one should rely on a number of different kinds of measures, including the behavioral measures obtained in neuropsychological assessment. The latter are often quite sensitive to subtle alterations in the brain’s activity or to changes in areas of the brain that do not involve consciousness, or motor or sensory behavior directly.
Momentum
As a general rule, regardless of the cause of damage, the more rapid the onset of the condition, the more severe and widespread will its effects be. TBI and stroke are rapid-onset conditions. The effect of the rapidity shows wit which the lesions evolves shows up when comparing behavioral deficits of tumors developing at different rates. A fast growing tumor is more likely to be accompanied by swelling of the surrounding tissue, resulting in greater amounts of behavioral dysfunction with more diffuse effects than a slow-growing tumor.
TIME
Brain disease is a dynamic phenomenon, even when the lesions are static and nonprogressive. Regular trends in patterns of improvement or deterioration depend on the nature of the cerebral insult, the age of the patient and the function under study.
Nonprogressive Brain Disorders
TBI, ruptured aneurysms, stroke, anoxia, toxic/metabolic conditions and nutritional deficiencies are examples of disorders that have time-limited direct action on the brain. In some patients though, cerebrovascular disease behaves like a progressive brain condition in which the ongoing detoriation is irregularly slowed by periods of partial improvement.
Psychological characteristics of brain conditions
Acute | Chronic |
With nonprogressive or single-event brain Disorders, the recency of the insult may be the most critical factor determining the patient’s cognitive status | Chronic functions, particularly involved in memory, attention and concentration and specific disabilities associated with the site of of the lesion continue to improve markedly during the first 6 months |
Apart from variations in specific functional defects arising from personal and lesion differences, the most common behavioral characteristics of an acute brain lesion in conscious patients are impaired retention, concentration and attention; emotional lability; and fatigability. Disruption of memory can be very severe. | Rate and nature of improvement is always u uneven and does not follow a smooth cours. Different functions improve at different rates. |
Much of the patient’s behavioral reintegration usually takes place the first month or two following brain injury. Test data extracted may a apply only for a short duration. | Old memories and well learned skills re generally turn most quickly ( Ribot’s Law). rerecent memory, abstract thinking, mental flexibility and adaptability return slower Though these general tendencies vary greatly depending upon the site and extent of the lesion and the patient’s premorbid ability. |
| Brain injured test scores fluctuate considerably over time and between functions during the first few years after injury. Prediction of future abilities is therefore very chancy. |
| Behavioral deterioration generally involves th the highest levels of cognitive activity having to to do with mental flexibility, efficiency of lelearning and recall and reasoning and jujudgment about abstract issues. |
| Behavior most common are temperoutburst fatigue and poor memory. Care must be taken though to distinguish true memory deficits from attention or concentration problems and expression of insureness about mental experiences. |
| Depression troubles most adults who were not rendered grossly defective by their injuries. Severity and duration vary greatly. Also heightened irritability is a common complaint for both patient and family. |
Predicting outcome
Self report and the presence and severity of sensory and motor symptoms are most often used in clinical practice, although this technique has setbacks with patients who have lower cognitive than physiological capacity. . The usual criterion of good outcome for younger adults, and therefore most TBI patients, is return to gainful employment.
Variables influencing outcome
The severity of the lesion is by far the most important variable in determining the patient’s ultimate level of improvement. Strokes due to infarction whether thrombonic or embolic, have longer survival times than hemorrhagic strokes. Age has only affect at the age extremes. Premorbis competence( cognitive and emotional/social) may be related to outcome and cognitive reserve. General physical status may also be associated with outcome for stroke patients, so can nutrition pre-and post morbid. Positive mood, high levels of consciousness and normal speech are predictors for good outcomes with stroke patients. So has early stroke rehabilitation and familiy support. Side of lesion can be relevant as r-hemisphere stroke has poorer outcomes.
Improvement Mechanisms
Compensatory techniques and alternative behavioral strategies enable patients to substitute different and newly organized behaviors to accomplish activities and skills that can no longer be performed as originally. The evolve quite unconsciously and become very useful. They are the major focus of rehabilitation. Increasing participation by homologous regions of the contra lateral hemisphere has received the most scientific support as explanation for the newly acquired skills.
Progressive Brain Diseases
Behavioral deterioration tends to follow an often bumpy but fairly predictable downhill course for particular sets of functions that may deteriorate at varying rates, depending on the disease. Conditions that are progressing rapidly are likely to continue to worsen at a rapid rate whereas slow progressions tend to remain slow. Longitudal study’s for patients by early onset assessment can give them a rough basis for forecasting the rate at which mental deterioration is likely to take place and aid future care planning.
Predicting the course of the behavioral affect due to a tumor is different from other progressively deteriorating diseases. The severity of the behavioral disorder bears some relationship to the type of tumor. The direction of the tumor growth is not very predictable though, so future behavioral changes can not be expected so straightforward.
SUBJECT VARIABLES
Age
A variety of factors have been identified that contribute to cognitive status with advanced age Higher education or higher intelligence show less age-related decline and less susceptibility to dementia. Active lifestyle, favorable environment, emotional status and the habits and interest all play there role. Genetics appear to play a substantial role in cognitive ability at old age. Aging effects can be different for men and women, depending on the variable.
Brain changment with age
The brain’s volume is at it’s peak at the early 20’s and then gradually declines over many decades. Some structures are affected more than others; widened sulci, narrowed gyri and thinning of the cortical mantle. Ventricular size dilates with increasing age. At least some shrinkage in brain tissue appears to be due to neuronal loss, which occurs unevenly in both cortical and sub cortical structures. Hippocampus and anterior dorsal frontal lobe are most susceptible to neuronal loss. Occipital lobes lose virtually none. Neuronal loss in the cortex is not significant. Among subcortical structures some such as the thalamus, basal ganglia, locus coeruleus and Purkinje cells in the cerebellum are particularly susceptible to neuronal loss. The role of white matter loss in cognitive deterioration is still not final, though it may play a role at tasks of processing speed, memory and executive funtions.
Recently identifies cellular mechanisms that could underlie the brain changes associated with aging include apoptosis( gene-directed cell death); cumulative biological errors in DNA replication, protein synthesis or protein structure and free radicals.
Cerebral blood flow also tend to show progressive decline which varies in intensity in different parts of the brain, most at prefrontal and temporal lobe. Patterns of blood flow become also more widespread in older persons, suggesting that the ability to focus neural activity may be more impaired.
Age does not appear to have a significant on cerebral acetylcholinesterase activity, indicator for the functioning central cholinergic system that is affected in Alzheimer.
Older persons show less A type brain waves .
Cognitive aging
Due to various methodological problems, unified agreement on normal cognitive aging is far from being reached. Cross-sectional design-potentially confound aging effect and cohort differences in culture, environment, medical status education and experience. Longitudinal Research -eliminates cohort, but retains bias associated with selective attrition( participants mostly higher educated and therefore not representative) and practice effects.
Another problem involves normality of some elderly volunteers who appear to be healthy and intact but have very subtle brain disease.
The pattern of cognitive aging
Aging patterns are very different for all individuals, especially on memory. So, researchers have relied on concepts of crystallized( over learned and well practiced, showing gains into the 60s) and fluid intelligence( reasoning, problem solving; showing slow decline through the middle years until the late 50s and then decline rapidly) to distinguish those abilities that hold up with advancing age from the ones that decline. Cognitive decline in elderly persons only affects some functions though. Verbal abilities are usually well retained although fluency may decline. The decline found in test performances do not translate into impairment in daily activities. Longitudinal studies generally show fewer age changes and most of the found changes are without practical significance.
Sensory and motor changes when aging
Sensory modalities decline in sensitivity and acuity, response times are increasingly slowed and fine motor movements seem clumsy. Visual acuity, binocular vision and oculomotor functions first show losses in the 40s-50s. Hearing decline parallels vision decline. Also odor sensitivity declines after it’s peak in the 20s-40s.
Older persons are characterized by all slowing in all aspects of behavior. At age 60 it is no more than 20 % of what it was in the 20s.
Attentional Functions when aging
The affect of age on attentional efficiency vary with the complexity of the task or situation. Thus simple span tends to remain essentially intact into the 80s. Gigher education/ higher occupation increases performance. Elderly persons tend to make mistakes or respond slowly when divided attention is called for, like choice reaction or dual task tests. Also they difficulty adjusting the size of attentional focus. Deficits in sustained and selective attention and in increased distractibility also accompany normal aging.
Memory functions when aging.
Different aspects of memory and learning differ in how the hold up with advancing age. Short term-or primary-memory as measured by brief retention of simple span shows only a slight age effect. It become vulnerable to aging when it requires mental manipulation/ organization or when the attention has to be divided.
Many clinical studies using standard neuropsychological tests have shown small declines in verbal memory with age, with larger changes in memory for visuospatial material or faces. The primary deficit is the efficiency of acquiring new information with retention over time relatively well retained, for example recognition memory. Implicit memory appears to be relatively preserved with aging, particularly for perceptual priming tasks. So are procedural memory and skill learning also relatively intact.
Memory complaints are unreliable predictors of significant cognitive deficits. The perception of memory problems can be affected by sex, education, depression and overall cognitive ability.
Verbal abilities in aging: Most verbal abilities resist the regressive effects of aging. Vocabulary and verbal reasoning scores remain relatively stable throughout the life span of the healthy individual.
Age effects on verbal fluency and confrontation naming have received much attention although research findings have been very confusing because of different research findings.
Visuospatial functions, praxis and construction when aging. Object and shape recognition stay relatively stable throughout the lifespan, visuoperceptual judgment ( spatial and nonspatial) decline steadily from at least age 65. Basic perceptual analysis appears intact, whereas perceptual integration and reasoning show age-related declines, especially when problem solving is involved. The effects of aging are most noticeable in tests involving time, although age differences do persist even in timeless tests. Copying complex, but not simple, designs is harder for the elderly, although there is good use of strategy.
Reasoning, concept formation and mental flexibility. Reasoning about familiar material and arithmetic problem solving hold up well with aging. When reasoning is brought to unfamiliar or structurally complex problems requiring distinguishment of relevance, elderly perform less accurate. So do concept formation and abstraction because of the concrete thinking found more often in older persons. Concept formation and mental flexibility ( i.e. Wisconson Card Sorting Test, WCST) also decline, yet this pronouncement may be stalled in healthy older individuals. In general age has been associated with slowness on the Stroop Test, which requires inhibition of a stronger response in favor of a weaker response.
Elderly people have been compared in the past with patients suffering from frontal lesions( less memory efficiency/strategy/ and learning). This comparison does not hold for the WCST.
Health and cognitive aging. Hypertension, diabetes cerebrovascular pathology are all examples of systemic diseases that bring with them cognitive effects ( chapter 7). In the elderly, nutritional habits and metabolism may change, although health problems alone are unlikely to account for most age-related declines in cognitive functioning. It is suggested that the increase in cerebral blood flow with exercise provides for better oxygenation of the brain resulting in better scores on cognitive tests.
Age of onset
When severity is not taken into account, agealone does not appear to make much difference in outcome for patients within the young to middle age adult range. Older adults though show less improvement one year after TBI, have a greater number of complications and are less likely to survive a severe injury. In progressive deteriorating conditions, the normal mental changes of advancing years can compound mental impairments due to the disease process.
Brain disease in aging
Cerebrovascular degenerative diseases of the brain increase sharply with advancing age, creating and ever growing social burden. Also they tend to suffer more from irreversible diseases( i.e. dementia, Alzheimer) then from curable conditions.
Sex Differences
Sex-Related patterns of brain structure and function
Keep in mind that this subject is still highly controversial and often sex differences have not been found in research studies. What has been foun though are the following:
• Asymmetry in cortical temporal en parietal areas > in right handed men
• Corpus collosum region that connect the functionally asymmetric temporoparietal regions is M<V.
• Men have larger left than right planum temporale( posterior superior temporal gyrus)
• Sex related asymetreis have been found in regions involved in sexual differentiation( i.e. hypothalamus.
• Male brains begin to grow faster until adult brain weight is achieved ( age 5-6). Body size is not the determining factor for brain size,
• Woman have consistenly smaller brains, primarily involved are the cerebral hemispheres and sometimes the cerebellum.
• Corpus callosum tends to be larger for woman, shrinks earlier in men.
• Men have greater neuronal density in language areas. Woman have greater interlacing of dendrites and axonal branches.
• Overall cerebral flow is higher in woman than in men, except for right frontal lobe areas. Alzheimer disease has probably a greater effect on the left hemispheres of men.
• Hormonal influences appear to be intimately involved with sexual differentiation during the course of development. Males given a one-time dosis of female hormones showed reduced practice effects on spatial orientation, but increase in verbal fluency. Injection of testosterone blocked practice effects of verbal ability in older males bit did not affect verbal/spatial memory.
• Menstrual cycles are involved in changes of verbal/music dichotic listening, language and olfactory acuity asymmetry, working memory, arithmetic, implicit memory and spatial abilities and fine motor skills.
• Woman have relatively a lesser degree of RH visuospatial superiority than in the LH. When RH functioning is, men lose more visuospatial competence. Woman have a RH superiority for facial expressive recognition, also their ability to discriminate melodic patterns or environmental sounds is superior to that of men.
• Improvement following a stroke may also vary with sex differences as woman tend to recuperate better than men in certain studies, while others give this credit to men.
Cognitive differences between the sexes.
The issue of sex differences is far from being simple and being settled. Males tend to have greater lateralization of functions. On all other aspects findings are controversial and differences tend to be declining over the years.
Perceptual speed and accuracy
Findings concerning these matters are contradictory and very confusing.
Verbal Functions
On many different kinds of verbal skill tests, no significant differences were found when data were combined from 165 studies. 6 % o these studies produced no sig. differences. The greatest advantage of woman appeared to be on general verbal ability and the quality of speech production. Culture/ethnicity may contribute to these differences.
Visuospatial functions
Males tend to fare better on many visuospatial tests, but considerable overlap in the score distributions of the two sexes will be found on any given task in which there is a male advantage. Men’s advantage in visuospatial processing may be more evident when tasks involve active processing rather than passive.
Mathematical abilities
Differences in these abilities almost always favor adolescent/ adult males over females. Performance differences begin to appear around age 7. A meta-analysis containing over 3 million subjects concludes that the size of sex differences has diminished over the years and is now quite small.
Sex and handedness interactions
Left handed males tend to perform more like right handed females in showing some superiority on tests of verbal skills and sequential processing, while left handed females and right handed males appear to have an advantage on visuospatial tasks and non verbal auditory stimuli. The relationship between hemispheric organization and handedness may differ between men and woman. Homosexual men and women have much higher rates of nonright-handedness than heterosexuals. Left handedness was associated with more female typical occupational preferences, self ascribed femininity and nonmasculinity in male homosexuals and a tendency for male-typical occupational pursuits along with nonfeminine and masculine preferences in female homosexuals.
Caveat
Important to keep in mind is that group differences rarely amount to as much as one-half of a standard deviation. Overlap in the distribution of scores for men and woman is much greater than the distance between them.
Lateral Asymmetry
Asymmetrical cerebral lateralization and unilateral hand preference are not exclusively human but characterize our ancestral line. There is evidence that we evolved as asymmetrical lateralized. Hand preference is mostly genetically determined although early trauma or even prenatal events may affect adult hand preference.
Hand preference and cerebral organization Right-handers
90-95 % of adults are right-handed but these figures tend to vary with age. Right handedness tends to be consistent-left hands are mostly used for simple motor actions. Left hemisphere in right handed people mostly contain the language representation also left cerebral language dominance.
Left-handers
Also called nondextrals. They can be grouped either as strong left -handers with no family history of left-handedness or as weak lefthanders with familial sinistrality( preference for the use of the left hand). The majority of nondextrals are left cerebral language dominant. Language lateralization is often simply characterized as typical or atypical, although most patients who are not left language dominant display bilateral rather then right language dominance. The incidence of right hemisphere language dominance increases linearly with the degree of left-handedness, therefore reflecting a natural relationship. Language laterality is not only related to the strength of hand preference but also to family history of left handedness, therefore suggesting a common genetic feature. So nondextrals are mostly left cerebral dominant for language although they are more likely to have atypical language representations, particularly in context of a left handed family history. Strongly biased familial lefthanders in the family are apt to resemble nonfamilial strongly left-handed people more than other familial left handers in having predominantly left hemisphere representation of language. It is suggested that right handers with left handers in the family have some bilateral representation for language functions.
Neuroanatomic correlates of handedness
The thickness of the mid and anterior regions of the corpus callosum and the size of the callosal area tend to vary with handedness. Subjects that have nonconsistent right hand preference have more collasal substance. However this relationship only holds for men, callosal size does not differ for woman, regardless of hand preference. Familial lefthanders have a decreased tendency to lateral asymmetry, nonfamilial showed asymmetry patterns like those of RH.
Handedness and cognitive functions
Right handers perform better than left handers on visuospatial tasks because lefthanders, like woman, have visuospatial skills that are mediated in a more diffuse manner by both hemispheres, instead of just the right like in right-handed males. A higher proportion of nondextrals than righthanders are represented at the extremes of cognitive compentency. Low skills are from people who have there left-handedness from brain injury.
Determining cerebral lateralization
The need to identify the language dominant hemisphere is most critical when neurosurgical intervention is planned. It can also be useful in developing individualized assessment protocols, in interpreting assessment findings and in making a rehabilitation plan.
Observational Methods
Easiest way for right handed identification is by letting people write and draw ( Wada testing) although this is only the case for detection of right-handedness and not left sided or ambidextral, because of training as a confounding factor. Handedness en footedness are highly correlated in right handed persons, only 60 of LH persons are LF. The side and strength of foot preferenece ( for hopping/standing, not kicking) may be an even more reliable predictor of the directing an extent of lateral asymmetry in cortical organization.
Laboratory Methods
The surest method of identifying the pattern of cerebral organization is the Wada test. Data from these studies have served as standards for measuring the effectiveness of noninvasive laboratory techniques such as dichotic listening tests or examination of visual half-field performance. Use of fMRI has produced good correlations with Wada language data although their concordance is not perfect. Functional transcranial Doppler and magnetic source imaging are other ways of noninvasive procedures for identifying language representations.
Behavioral techniques
In the clinic, congruent handedness and footedness probably gives the best indication of the pattern of cerebral lateralization, short of a laboratory study. A number of behavioral techniques have been devised to help ascertain both lateral preference and its strength( as measured by the consistency of side of choice). Informal set of tasks/questions that have to do with a variety of one-sided activities are mostly used. But not all one-handed tasks can be used to evaluate lateral preference, like tasks that require skill/ strength because strongly lateralized people with use both hands. Figure 8,1 and 8,2 on page 309 give examples of two tests that measure fine motor coordination for both the left and right hand.
Questionnaires and inventories
Formal questionnaires typically ask about choice of side in performing a variety of one-and two hand activities and other acts such as choice of foot for kicking or for dressing first. They may vary in length from as many ass 55 items or more to as few as 10 ( Table 8.1 page 310). Another important difference between preference inventories is whether items are dichotomized or offer a range of responses that better reflect the natural distribution of laterality preferences for any given activity. The items that most clearly discriminate right-and left handedness are those requiring into the hand for writing, drawing and throwing.
Although the incidence of right hemisphere or mixed cerebral lateralization is low in right-handed people, test behavior must be evaluated with these possibilities in mind. When deviations from the normal left-right organization of the brain appear, a very thorough study of all functional systems is necessary to delineate the nature of the patients cognitive disabilities fully for in these exceptional cases no systematic relationship between functions should be taken for granted.
PATIENT CHARACTERISTICS: RACE, CULTURE AND ETHNICITY
Race, culture and ethnicity tend to be used almost interchangeably as terms for categorizing individuals with respect to background, perhaps because they are somewhat interrelated and there is some conceptual confusion concerning their meaning.
Race suggests that distinctive biological groups have obvious physical characteristics that differentiate one group from another. But there is no such thing as a genetically isolated distinct group. Actually, within group variations in physical and behavioral characteristics are much more so than variations between groups. Race is not in itself an explanatory variable since it is often confounded with culture, language, educational attainment, environmental and socioeconomic factors. Factors like socioeconomic level, prenatal and perinatal complications, nutrition and health, family size, birth order and education have been shown to all correlate with cognitive performance.
Culture typically refers to learned experiences that form a way of life shared by a group of people. It is transmitted in social interactions that communicate social norms, roles, beliefs and values and by socially created aspects of the environment such as architecture, art and tools. When characteristics of cultural background or socioeconomic status are overlooked, test score interpretations are subject both to confusion of culturally determined ignorance or underdeveloped skills with brain dysfunctioning giving rise to false positive errors and to missing evidence of deficit on over learned or overpractised behaviors resulting in false negative errors.
Ethnicity refers to groups that have a common nationality, religion, language or culture and has been confounded with race. Like race and culture ethnicity is not an explanatory variable in itself.
The use of Race. Ethnicity/ Culture Designations
We do not know the genetic makeup of each individual, diagnosis is far from being perfect and treatment is often by trial and error. Within these present limitations, racial designation may have some usefulness. It can be argued that self designation of racial and/ or ethnic groups can be useful in identifying a genetic basis for disease risk and treatment response as well as the role of environmental and other variables.
The Assessment Language
Bilingualism
Individuals who speak two languages vary greatly in the relative knowledge of the languages they speak. When the examination is not conducted in the patient’s dominant language, inaccurate diagnostic decisions may be made in the basis of the apparent symptoms rather than actual cognitive impairments. It has been shown that just asking which language is preferred for testing or which is the primary language used is not an adequate way of deciding which language should be used.
Regional linguistic variations
Linguistic subgroups and regional differences in any language can create problems for test administration, scoring and interpretation.
Test translation and development
Tests developed in Western countries but used in other cultures can invite error of interpretation on the part of the clinician and researcher. Whether due to cultural insensitivity of naiveté, the consequences can be harmful. When tests are translate literally, many problems can occur. Item, construct of method bias can compromise test validity. Poor wording, inappropriate item content and inaccurate translation may introduce item bias. Method bias can enter a test protocol in many ways, by an unfamiliar stimulus and response format, in test instructions and administration, in the testing situation and its physical conditions, in patient variables such as motivation, in examiner’s characteristics and in the kind of communication taking place between examiner and patient. A multicultural, multilingual team is necessary for cross-cultural test development. Test may have to be adapted or made entirely new.
Ethical concerns in training and practice
Several principles and standards concerning ethics are about competence, integrity, professional and scientific responsibility and nondiscriminating respect for people’s rights and dignity for human differences. Language competence of the psychologist is included by implication.
PSYCHOSOCIAL VARIABLES
Demographic, experiential and some specific developmental and physical status variables can significantly affect response to a neuropsychological examination. No simple formula can be devised for teasing out their presence or he degree of their contribution to an individual patient’s behavior.
Premorbid mental Ability
Brain size contributes to premorbid ability level which, in turn, is closely tied to academic achievement and academic exposure. No single variable in this complex stands alone; when considered conceptually, each is a product of its interaction with all the many inherent characteristics and environmental experiences and exposures that go into human development.
The cognitive reserve hypothesis
On reviewing consistent finings of a sig. relationship between estimated or known premorbid ability and level of cognitive impairment with brain injury or disease a threshold theory was proposed. The threshold theory postulates that the amount of brain reserve capacity (BRC) represents structural or physiological brain advantages( such as size, redundancy of interconnections) or disadvantages. BRC advantages will show up in higher educational levels, higher scores on mental ability tests both pre and post morbidly, and better functioning after brain injury or disease onset. A greater learning capacity is one mechanism for greater cognitive enhancement in already bright people-the more you can learn the more you learn.
Education
The effects of education on neuropsychological functioning are potent and pervasive. Education effect show up on just about every kind of test involving cognitive abilities, including some that would seem to be relatively unaffected by schooling. Education can so greatly influence test performances that poorly educated but cognitively intact persons may get lower scores than mildly impaired but better educated patients. Illiteracy, the extreme condition of educational deprivation, demonstrates the importance of education to brain development and cognitive competence. However, brain injury can soothe education effects. When taking years of education into account, it may sometimes be necessary to pay attention to the quality of that education as well as the years as similar grade levels may have quite different knowledge and skill implications.
Illiteracy
Illiteracy can affect the development of cognitive abilities, processing strategies, processing pathways and functional brain organization. They tend to give poorer performances in many cognitive domains. Since the effects of education may be negatively accelerated( be greater as the educational level goes down), the impact on test performances is likely to be magnified at the lower end of the educational continuum. Functional measures should be included when giving a comprehensive neuropsychological examination for dementia to persons with little or no schooling to defend against overestimations of dementia on illiterate/low educated persons.
Premorbid Personality and Social Adjustment
The premorbid personal and social adjustment of brain impaired patients can have an effect, not only on the quality of their ultimate adjustment but also on the amount of gain they make when benefiting from good work habits and high levels of expectation for themselves. It can affect the kind of adjustment a patient makes following brain injury in a direct and indirect way. Direct effects-are fairly obvious since premorbid personality characteristics may not be so much changed as exaggerated by brain injury. Premorbidly good people can get impulsive, have anger outburst or have other forms of acting out because of frontal lobe damage. When these disrupting traits were already premorbidly present they can contribute to some of the sever behavioral disturbances found among this group of brain damaged persons. TBI severity though is the overriding outcome predictor for both poorly socialized and adequately socialized patients. Indirect effects-becomes apparent when the patient needs emotional support and acceptance in a protective but not institutional living situation. Those who were more sociable premorbidly tend to get better support through critical persona and social transitions.
Medication
The effects of medication on different aspects of behavior can significantly alter assessment findings and may even constitute the reason for the emotional and cognitive changes that have brought the patient to neuropsychological attention. Medications can complicate a patients neuropsychological status, especially combinations of medications. The effect of medications on cognitive functioning is a broad and complex issue involving many different classes of drugs and numerous medical and psychiatric disorders. The drugs with the highest incidence of cognitive side effects are anticholinergics, benzodiazepines, narcotics, neuroleptics, antiepileptic drugs and sedative-hypnotics.
It often takes patients several weeks to adjust to a new drug and they experience changes in mental efficiency in the short term. Elderly people are often on multiple medications which by itself is a significant risk factor and most patients are bad historians concerning there medication use in the past.
Brain injury makes drug effects less predictable than for neurologically intact persons. The use of medications must be weighted against cognitive compromises.
Epilepsy
Etiology and diagnostic classifications
Epilepsy is not a single disease or condition but reflects an episodic disturbance of behavior or perception arising from hyperexcitability and hypersynchronous discharge of nerve cells in the brain that can be associated with a variety of etiologies. Te underlying causes are many and relate to scarring or brain injury from birth trauma, TBI, tumor, the consequences of infection or illness, metabolic disorder, CVA, progressive brain disease, or a host of other conditions, including genetic factors. It is among the most prevalent of chronic neurological disorders( 1% of the pop.,;30 % <18 yrs.)
Seizures can arise from any condition that heightens the excitability of brain tissue and may be associated with high fever, drug use, drug withdrawal and metabolic disorders. Epilepsy requires the presence of at least two unprovoked seizures( i.e. occurring in the absence of acute systemic illness or brain insult).
They are generally classified along two dimensions, focal or generalized, and whether their etiology is known, suspected or unknown. Seizures that have a localized area of onset are called partial/ focal and seizures that appear to involve large regions of both hemispheres simultaneously are referred to as generalized.
Etiology is characterized as idiopathic, cryptogenic or symptomatic. Idiopathic and cryptogenic epilepsies have no known etiology. Seizures from a know etiology are called symptomatic. In clinical practice however, a syndrome diagnosis is often given.
Partial seizures arise from a specific focal area of the brain, may be simple without any alteration of consciousness and may involve only one mode or expression. Complex partial seizures involve altered consciousness. A partial may be preceded by an aura and then develop in a complex partial. This may subsequently progress to involve the entire brain, a process called secondary generalization. Partials mostly originate from the frontal or temporal lobe.
Primary generalized seizures involve all or large portions of both hemispheres from seizure onset. They may be nonconvulsive , appearing as absence spells( petit mal attacks) of convulsive( grand mal seizures). The term absence is reserved for nonconvulsive primary generalized seizures and is not used when loss of awareness occurs with complex partial seizures. The distinction between focal and generalized seizures has practical implications since different seizure types often respond to different anticonvulsant medications. Specific EEG patterns are associated with many epilepsy syndromes and assist in formal
diagnosis.
Risk factors and vulnerabilities Genetic Predisposition.
Epilepsy may run in families and different seizures types can occur in family members who have epilepsy. Genetic factors appear to be more important in the generalized epilepsies but also play a role in some partial epilepsies. The mode of inheritance is complex and varies with seizure types and epilepsy syndromes.
Posttraumatic Epilepsy
The risk of developing epilepsy following penetrating head wounds is high. In general, the presence of any focal lesion, such as intracerebral hemorrhage and hematomes, increase the likelihood of posttraumatic epilepsy. Severe TBI is associated with a high posttraumatic seizure risk that is much more withstanding than mild TBI; the first unprovoked seizure may occur more than 10 years after injury. 25 % of TBI patients who have a seizure in the first week will have seizures later. The cognitive impairment seen in posttraumatic seizure patients probably reflects the effect of the brain injuries that give rise to seizures, rather than effect of the seizures.
Other epilepsies
Any other kind of insult to the brain also increases susceptibility to seizures. Seizures occur 3 times more often following hemorrharigic stroke than ischemic stroke and are usually associated with cortical involvement, but few stroke patients develop epilepsy.
Precipitating associations
Although most seizures happen with apparent provocation, some conditions and stimuli are associated with increasing seizure likelihood. Alcohol’s disinhibiting effect, alcohol withdrawal during ‘hangover period’ and a combination of alcohol and medication can all provoke seizures. Physical debilitation, no matter what the cause, can all increase the likelihood of seizures. In woman with epilepsy, the menstrual cycle can sometimes have effect on seizures which appears to be related to the ratio of estrogen to progesterone. Emotional stress and voluntary or spontaneous changes in behavior and thinking have all been implicated as seizure prone factors.
Reflex epilepsy refers to epilepsies characterized by a specific mode of seizure precipitation, like hearing a certain voice, photosensitivity, eating, playing videogames or watching tv.
Cognitive functioning
Behavior and cognition in epilepsy patients can be affected by multiple factors, including seizure etiology, type, frequency, duration and severity,; cerebral lesions acquired prior to seizure onset and age at seizure onset. Patients with epilepsy tend to have impaired cognition compared to matched control subjects. Seizure etiology is a principal factor affecting cognitive abilities; patients with seizures due to progressive cerebral degeneration typically have generalized cognitive impairment, patients with mental retardation have an increased incidence of epilepsy and patients with seizures due to a focal brain lesion may exhibit a specific neuropsychological pattern of deficits. But patients with idiopathic epilepsy have normal mental abilities. Earlier seizure onset age is associated with greater cognitive impairment.
Focal Seizures and cognitive dysfunction
Focal seizures originate from one side of the brain although seizure activity may spread to other brain areas. Sometimes, patients with focal seizure onset display a pattern of test performance like that of patients with nonepileptogenic lesions in similar locations.
-LH seizure onset-impaired verbal functioning, verbal memory deficits, compromise in abstract reasoning.
-RH seizure onset -display of visuoperceptual, visual memory and constructional disabilities. Magnitude of deficits often less then with comparable nonepileptic lesions.
Memory
Memory and learning disorders are common among epilepsy patients and become more pronounced with temporal lobe epilepsy ( TLE)Material specific memory deficits occur primarily for verbal memory in association with left TLE.
Personality and emotional behavior
Although the psychosocial behavior and emotional status of many persons with seizure disorders do not differ from normal, behavior and personality disorders are much more common among seizure patients with estimates of psychiatric comorbidity raging from 29-50%. All behavior disorders seem to appear with greater frequency among seizure patients than in the general population, i.e. depression, suicide attempts, psychosis and psychiatric hospitalization. This increases with indices of severity and a pattern of seizures of multiple types.
Persons with epilepsy also have lower levels of education and SES, poorer work histories and fewer socials supports due to the constricting nature of the disease. Persons with temporal lobe epilepsy have the greatest number of social and psychosocial disorders.
Temporal Lobe epilepsy
Depression is reported more frequently in patients with TLE and when it occurs it may involve more negative than positive depression symptoms but it is treatable with antidepressants. A relationship between TLE and personality changes have been found in certain studies but still remains a controversial subject.
Aggression in epilepsy
Epilepsy patients display episodes of aggressiveness that are no more common than in other populations with comparable neurologic disease.
Antiepileptic drug effects
AEDs are designed to reduce neuronal irritability. In addition to their effects on abnormal brain activity, however, AEDs decrease normal neuronal excitability, which may affect cognitive functioning. The risk of significant cognitive side effects increases however, with increasing drug dosages and when multiple AEDs are necessary to obtain seizure relief. The neuropsychological functions most likely to be adversely affected by AEDs are psychomotor speed, vigilance, memory and mood. Newer AEDs have less cognitive impairments than older AEDs.
Prognosis Is epilepsy progressive?
A continuing controversy in epilepsy is whether poorly controlled seizures contribute to progressive cognitive decline. Some studies have found declines in memory( especially visual memory) in patients with epilepsy and also hippocampical volume changes have been reported.
Some authors believe that, even in the absence of overall deterioration, epilepsy ‘refractoriness’ is related to cumulative effects resulting from the many negative neural events associated with a seizure and hence aggressive intervention to interrupt this process is warranted.
Effects of surgical treatment
Surgery is often an effective treatment option for selected patients whose seizures cannot be satisfactorily controlled with medication. Selection factors include early age at seizure onset, evidence of hippocampical atrophy on MRI and patterns of neuropsychological and Wada test findings that are compatible with the seizure onset laterality.
The side of the lesion affects cognitive outcome: Right temporal lobectomy -visual memory impairments ( though rare) Left temporal lobectomy -declines in verbal memory and confrontation naming. He largest postoperative declines in verbal memory tended to appear in patients who, preoperatively, have more normal verbal memory test performances. The best predictors of postoperative psychosocial outcome following anterior temporal lobectomy are the patient’s preoperative psychosocial adjustment and whether they become seizure free.
Nonepileptic spells/pseudo seizures
Nonepileptic spells are paroxysmal spells that may superficially resemble seizures. The diagnosis implies a psychological origin; most often they occur with anxiety disorder, depression, schizophrenia, conversion disorder, factitious disorder and malingering. They exist in only small percentages of cases/ No single cognitive or personality pattern characterizes persons who have nonepileptic spells as they are a very heterogenic group. Nonepileptic spells mimic just about every type of genuine seizure pattern and can display almost every associated symptom or problem. However they can have a longer duration than most true seizures, the ability of patients to recall their spell (seizures are rarely being recalled) and clear consciousness during the event. Also these spells can be accompanied by bizarre or purposeful movements such as kicking or slapping. Patients with nonepileptic spells perform almost at normal levels on neuropsychological testing in comparison to epilepsy people.
DIFFERENTIAL DIAGNOSIS: Problems
Questions wherein differential diagnosis is the central issue have to do with the possibility that brain disease may underlie an emotional or personality disturbance or that behavioral dilapidation or cognitive complaints may have a psychological rather than a neurological basis. In perplexing case o differential diagnosis a precise determination may not be possible unless an ongoing disease process eventually submerges the functional aspects of the patients confusing behavior or unless ‘hard’ neurological signs are evident.
Type I errors(false positive) involve the diagnosis of a physical disease when a patient’s condition represents a functional solution to psychosocial stress.
Type II errors ( false negatives) are diagnoses of functional disorders when a patients complaints have a neurological basis.
Subtle behavioral expression of many brain disease and the not uncommon sameness or overlap of symptoms of organic of organic brain diseases and functional disturbances make both kinds of errors common.
Emotionally Disturbances and Personality Disorders
Many serious and sometimes treatable neurological diseases first present with vague often transient symptoms that can worsen with stress and temporarily diminish or even disappear together with symptomatic or psychological treatment. Diagnostically confusing complaints can herald a tumor or postconcussion. TBI survivors for instant tend to show elevated profiles of emotional disturbance on certain tests involving anxiety, depression, health concerns and attentional problems. They risk diagnosis of emotional disturbance although they are just simple reporting common postconcussion symptoms.
Early diagnosis of neurological disease can be complicated by the fact that these are the same complaints expressed by many persons for whom functional disorders serve as a life-style or a neurotic reaction to stress.
Neuropsychological decisions about the etiology of these symptom pictures rely on criteria for both functional and neurologic disorders. An inappropriate-usually bland or indifferent-reaction to the complaints, symbolic meaningfulness of the symptoms, secondary gains, perpetuation of a dependent or irresponsible life-style, a close association between a stressful event and the appearance of the patient’s problem, and an unlikely or inconsistently manifested pattern of cognitive impairment suggest psychogenic contributions t the patient’s problems, regardless of the patient’s neurological status.
Evidence of lateralized impairment lends to strong support to the possibility of neurological involvement. As a rule only the most simplistic or severly impaired persons will present clear-cut symptoms of brain damage without soms emotional disturbance.
Conversion disorders ( conversion hysteria)
Conversion disorders can be spotted by several signs: 1) An unconcerned attitude of ‘la belle indifference’ 2) anomalous sensory complaints 3) changing patterns of sensory loss 4) sensory and motor findings changing with suggestions 5) hemianaesthesia that splits the midline exactly 6) unilateral loss of vibratory sense with sequential bilateral stimulation of forehead or sternum 7) ‘lapses’ into normal exertion on motor testing of a supposedly weakened limb ( the ‘giveaway’ sign).
Men and woman can both have a conversion hysteria. But far from being pathogenic for hysteria, at least on and, in one case, all seven of the classical signs of hysteria appeared in a series of patients with acute structural CNS damage ( mostly from stroke)
Psychogenic Memory Disorders
Nonpathological functional amnesias contain losses of memory experienced by everyone. Pathological psychogenic amnesias can take a number of forms, some of which mimic neuropathologically based memory disorders.
Dissociative amnesia is an inability to recall important personal information.
Dissociative fugue is a loss of self-knowledge, including identity and history, without an awareness of this loss.
Psychotic Disturbances
A neurological disorder can also complicate or imitate severe functional behavior disturbances. The neuropsychological identification of a neurologic component in a severe behavior disturbance relies on the same criteria used to determine whether neurotic complaints have a neurological etiology. Here, too, a pattern cognitive dysfunction selectively involving predominantly lateralized abilities and skills makes a strong case for a brain disorder, as does a pattern of memory impairments in which recent memory is more severely affected than remote memory, or a pattern of lowered scores on tests involving attention functioning and new learning relative to scores on tests of knowledge and skill. The inconsistent or erratic expression of cognitive defects suggest a psychiatric disturbance.
Identifying those psychotic conditions that have a neuropathologic component is often more difficult than distinguishing emotional disturbances or character disorders from symptoms of brain damage because some psychiatric disorders are as likely to disrupt attention, mental tracking and memory as are some neurological conditions.
Before concluding that a psychotically disturbed patient is neurologically impaired, the examiner will require a clear-cut pattern of lateralized dysfunction or neurological memory impairment, a number of signs, or a cluster of considerably lowered test scores that make neurological or neuropsychological sense.
Neuropsychological differentiation of organic and functional disorders tends to be easier when the condition is acute and to become increasingly difficult with chronicity. Neurological conditions are more apt to develop during of following physical stress such as an illness, intoxication, TBI, or some forms of severe malnutrition. Emotional or situational stress more often precedes functionally disturbed behavior disorders.
Schizophrenia
The high incidence of premorbid neurological disorders( head injury, perinatal complications, childhood illnesses) suggests that in many cases the schizophrenic disorder may not be so much a disease entity but a mode of response to earlier cerebral insults. Schizophrenia may be hereditary and has several subtypes.
As a group, schizophrenics perform below expectation on a wide range of cognitive tests, particularly those associated with frontal lobe regulation: attention, strategy use and problem solving. Also memory impairments have been reported. Individuals response levels can differ due to poor motivation of inefficient use of strategies.
Neurological Disorders with psychotic features
Unlike many postcentral lesions that announce themselves with distinctive lateralized behavioral changes or highly specific and identifiable cognitive defects, the behavioral effect of frontal lobe tumors may be practically indistinguishable from those of progressive character disorders or behavioral disturbances. Degenerative brain diseases can produce psychiatric symptoms including psychosis.
Dementia -delusional
Alzheimer/ Parkinson -visual hallucinations.
Frontotemporal dementia( including Pick’s disease)-marked personality change with loss of social graces. Absence of an earlier psychiatric history, the insidious onset of symptoms, and an accompanying memory impairment usually distinguish these dementia patients from psychiatric patients.
Basal ganglia -depression
Temporal lobe lesions -erratically and irrationally disruptive; marked personality changes and wide mood swings. Schizofrenic type symptoms may occur. Swithings between rational and controlled behavior to temper/ destructive outbursts or hallucinations and bizarre ideation.
RH disease -paranoidal ideation, hallucinations and agitation. ( parietal lobe damage results in visuospatial deficits)
Psychiatric symptoms can also accompany a variety of non-neurological illnesses.
Depression
Depression can complicate the clinical presentation of a brain disorder or the effects of aging. Even in neurologically young persons, it may interfere with the normal expression of cognitive abilities like slowed mental processing and mild attentional deficits. Also memory impairments for both verbal and visuospatial material has been demonstrated, also for recognition memory. These deficits are not due to effort demands or poor motivation.
Inconsistent findings in research my be due to differences in severity between patient groups, length of depressive illness and medications.
Poor cognitive performance by patients with bipolar disorder, during periods of well-being, was associated with hippocampical asymmetry ( R>L) suggesting that variations in limbic structure or function may be an important variable.
Some studies proclaim that negative or neutral stimuli are better remembered by depressed persons then positive stimuli.
Depression in old age
The most common problem complicating differential diagnosis of behavioral disturbance in older persons id depression, which can mimic or exacerbate symptoms of progressive dementing conditions. Depression is often preceded by very stressful events and it takes on more of the character of a reactive depression rather than a MDD. Chronicle physical illness can increase the likelihood op depression because of the medication prescribed.
Studies of memory functions in elderly depressives are similar to those of younger depressed persons in producing contradictory findings. One distinctive feature of older depressants is that they complain a lot about poor memory even when tests say it’s in normal range. Deficits in language has also been shown among long depressed elderly.
Differentiation: dementia and depression
Depresive reactions may be the first overt sign of something wrong in a person who is experiencing the very earliest subjective symptoms of a dementing process. Those aspects of the clinical presentation of both an early dementing process and depression that are most likely to contribute to misdiagnosis are depressed mood or agitation, a history of psychiatric disturbances; psychomotor retardation, impaired immediate memory and learning abilities, defective attention, concentration, and tracking; impaired orientation; an overall shoddy quality to cognitive products; and listleness with loss of interest in one’s surroundings and, often, in self care.
Nontheless, functionally depressed patients and those with neurological disease may differ in a number of ways;
• depressed patients somatize their distress, demented patients are less likely to experience vegative features of depression
• structure and content of speech remains essentially intact in depression but deteriorates in dementia of Alzheimer.
• Severity of memory is much greater in Alzheimer (!)
• Intact incidental learning in depressed patients will be reflected in fairly appropriate temporal orientation; demented people are less like to know day/date/time.
• Presence of aphasias, apraxias or agnosias clearly distinguish an organic dementia from the pseudodementia of depression.
• Severe impairment in copy/recall of drawing/constructional by dementia due to perseverations although they try; depressed patients just don’t care. If they do care they make an accurate response.
• Depressed patients have better scores on neuropsychological tests. Also they are more likely to be keenly aware of their impaired cognition, complaining more than what tests reveal. Dementia patients are less aware.
Historical data can greatly help to differentiate dementia patients who are depressed from depressed patients who appear to be demented. The cognitive deterioration of a dementing process is slower than in depression. The context in which the dysfunctional symptoms appear can be extremely important in the differential diagnosis, as depressive reactions are more likely to be associated with an identifiable precipitating event or a series of precipitating events, usually losses. Most often, the disturbed behavior of elderly psychiatric patients has a mixed etiology in which emotional reactions to significant losses interact with the behavioral effects of physiological and anatomical brain changes to produce a complex picture of behavioral decay.
Effects of electroconvulsive therapy (ECT) for depression
Complaints of poor memory are common with this treatment. Problems include impaired learning ability and defective retrieval as well as apparent loss of memories, those preceding the treatment are most likely permanently lost and recent personal memories are more vulnerable than older ones. Bilateral treatments have more memory complications than unilateral. In the long run though, ECT side effects are benign.
Transcranial magnetic stimulation is a noninvasive tool for treating medication resistant major depression and it appears to pose no cognitive danger.
Depression with brain disease
Depression may be a prominent feature of a number of neurological disorders, like Parkinson, Huntington, AIDS dementia, and stroke. Depression tends to add to cognitive compromise, particularly affecting memory functions. Discriminating between depressed and nondepressed dementia patients can be nearly impossible. It can be also important to identify treatable depression in patients with brain disease whose poor insight or impaired capacity to communicate stop them from seeking help, A number of clues for the presence of depression are un unexpectedly low rate of improvement from the neurological insult or unexpected deterioration in a condition that had been stable or improving, uncooperativeness in rehabilitation.
Malingering
This is a special problem in neuropsychological assessment because so many neurological conditions present few ‘hard’ findings and so often defy documentation by clinical laboratory techniques. A critical determinant in differentiating malingering from other pseudoneurologic disorders is the extent to which the patient is aware of the nature of the dysfunctional behavior. But sometimes an effort to identify malingering will involve determining whether and to what extent the patient’s problems are symptomatic of a psychogenic disturbance rather than deliberate pretence. History of the patient and its current psychosocial circumstances are the most useful for information. Malingering in itself may be symptomatic of a psychological disorder which ads further problems to the differentiating process.
Inconsistency in performance levels or between a patient’s report of disability and performance levels, unrelated to any fluctuating physiological conditions is perhaps the most usual indicator of malingering or at least a pseudoneurologic condition.
Examination of memory has received special attention as a tool of discriminating malingering from true cognitive impairments ad inconsistency between memory scores and scores on other tests should raise the suspicion of the examiner.
Even when the patient’s behavior or the history strongly suggest some deliberate stimulation, brain damage may also be contributing to the symptom picture, like in Munchhausen syndrome.
Generally, but not always, a thorough neuropsychological examination performed in conjunction with careful neurological studies will bring out performance discrepancies that are inconsistent with normal neuropsychological expectations.
9. Awareness
Orientation: the awareness of self in relation to one’s surroundings, requires consistent and reliable integration of attention, perception, and memory.
Orientations defects → most frequent symptoms of brain diseases → of these, impaired awareness of time and place is most common. Involved are: cortical fields, lesions in the limbic system, or damage to the reticular activating system of the brainstem.
In a patient population, orientation status was related to memory impairment and age but was independent of education and simple attention as measured by digit span.
Awareness interview: structured interview, consist of questions to patient orientation for person, place and time, plus items dealing with patients’ appreciation of deficits in motor functioning, thinking, memory, speech and language, and visuoperceptual function. High awareness scores correlate with patient abilities to successfully function in daily activities.
Temporal orientation test: a scoring technique In which negative numerical values are assigned to errors in any one of the five basic time orientation elements; day, month, year, day of the week, and present clock time. →→ For example, errors in naming months are given 5 points for each month of difference between the present and the named month.
Another simple time estimation task required the patient to guess the length of time by a just-completed test session. Woman are less accurate than men at estimating short intervals. The basal ganglia is critical for accurate time estimation.
Place: assessment of orientation for place generally begins with questions about the name or location of the place in which the examination is being held. Orientation for place also includes an appreciation of direction and distance. For example: in what direction the patient must travel to get home.
Autosopagnosia, disorientation of personal space, tends to be associated with problems of localization in space → involves both sides of the body (although associated with left side damage). Disturbances of body schema occurring with frontal lesions appear to be associated with defects in scanning, perceptual shifting, and postural mechanisms. Personal orientation test: a sixth task tests for astereognosis by asking for the names of seen and felt objects. Those whose symptoms were predominantly left-sided or bilateral made many more errors that patients with predominantly right-sided symptoms.
Finger agnosia, a specific manifestation of autotopagnosia, and be most evident on examination of the middle three fingers. It can occur with lesions on either side of the brain, but most lesions associated with finger agnosia involve the left angular gyrus. A technique for examining finger agnosia is → finger localization. It has three part:
• Part A: requires subject to identify their fingers when touched one at a time at the tip.
• Part B: differs from part A only in shielding the hand from the subject’s sight.
• Part C: two fingers are touched at a time. Tactile finger recognition, the examiner assigns a number to each finger (eyes are closed), then the subject reports the finger they think was touched. Patients with right sided lesions made more both contralateral and ipsilateral errors than patients with left hemisphere damage.
Right left orientation test (RLOT), 20 item test, challenges the subject to deal with combinations of right and left side with body parts and with the subject’s own or the examiner’s. Standard road-map test of direction sense, paper and pencil assessment of right left orientation. The examiner traces a dotted pathway with a pencil, asking the subject to tell the direction at each turn, right or left.
Neurological finding → the left frontal group made twice as many errors than as the right parietal group → the authors suggested that the failures of the left frontal patients reflect the test’s conceptual demands for making mental spatial rotation.
Spatial disorientation: refers to a variety of defects that in some way interfere with the ability to relate to the position, direction or movement of objects or points in space → different areas in the brain are associated with different kinds of spatial disorientation. Spatial orientation is one of the components of visual perception. Spatial disorientation en visual scanning defects can both contribute in impaired distance judgment.
Mental rotation deficits → parietal lobe lesion.
Mental re-orientation → spatial orientation test. Also been called the left-right re-orientation test. The subject’s task is to state whether the black disc (see page 345) is on the figure’s right or left side. Puppet test → a variation of the Mental Reorientation task, examines spatial reorientation on visuoperceptual and visuomotor tasks.
Space thinking: 21 item multiple choice test of spatial orientation. The subject’s task is to indicate whether the flag shows the same or the opposite side of the flag as the target (see page 346).
Spatial dyscalculias: difficulty in calculating arithmetic problems in which the relative position of the numbers is a critical element of the problem → posterior lesions → right hemisphere.
Topographical orientation: defective memory for familiar routes or for the location of objects and places in space involves an impaired ability for revisualization → the retrieval of established visouspatial knowledge. Topographical memory can be tested by questing the patient to locate prominent cities on a map of the country. Fargo map test: this test of geographic knowledge takes into account not only familiarity with the major features of the United States bus also the regions with which the subject, by history, should have familiarity.
Route Finding: the inability to find one’s way around familiar places or to learn new routes is not uncommon in brain impaired patients. Rivermead Behavioral Memory Test → includes a test of learning and recalling a route.
Reaction time: as slowed processing speeds often underlies attentional deficits, reaction time tests can serve as relatively direct means of measuring processing speed and understanding the nature of the associated attentional deficit.
Vigilance tests examine the ability to sustain and focus attention in itself. These tests typically involve the sequential presentation of stimuli (such as strings of letters or numbers) over a period of time with instructions for the patient to indicate in some way (tap raise hand) when a given number of letter (the target stimulus) is perceived.
Continuous Performance test (CPT) (1) → computerized vigilance test → for example react only when you see a X on the screen. CPT is intended to measure sustained attention. (CPT) (2) → the subjects indicates every time a letter other than X appears on the screen.
Continuous performance test of attention (CPTA) → subjects are asked to tap their finger each time they hear a target letter.
Short-term storage capacity
Basic dimensions of attention: how fast the attentional system operates and how much it can process at once. These two dimensions can, and should, be examined separately insofar as possible.
Digit span → for immediate verbal recall → most used the digit span test in the Wechsler batteries → two different tests → digit forward and digit backward. Both involve → auditory attention. And both depend on → short-term retention capacity. Point digit span: the as the digit span test, except that the respond modality do not require speech, so that the verbal span of patients who are speech impaired can be tested. Letter span: lower average scores on a simple letter span task, than on the digit version of the task.
Knox cube test (KCT): the four blocks are affixed in a row. The examiner taps the cubes in prearranged sequences of increasing length and complexity, and the subject must try to imitate the tapping pattern exactly. Measures → immediate visuospatial attention span. Corsi block tapping test: testing memory impairment of patients who had undergone temporal lobe resection. Consist of nine black cubes in a random order to a black board. Each time the examiner taps the blocks in a prearranged sequence, the patient must attempt to copy this tapping pattern.
→ almost the same WAIS-RNI and WMS-III spatial span. WMS-R Visual memory span → cards with eight squires. Examiner point the dots, patient repeat the examiner’s movement. Dot locations task → the examiner point to two or more dots (up to nine), the subject must drawn the dots on a blank sheet of paper in the correct order and general location.
Sentence repetition: assessing auditory span. Persons with strong dialects should not be given this tests. Failure on these test → associated with lesions of the left hemisphere. Failure may occur at the level of 1) auditory comprehension, 2) articulation of words of 3) because of a dissociation between auditory input and speech output. Silly sentences (1) → recall silly sentences Silly sentences (2) → the subject reads 100 short sentences, and indicates whether each is sensible or silly.
Mental tracking: tests of working memory
Working memory tests require people to hold information in mind while performing a mental operation. The simplest test of mental tracking is digit span reversed (Digit backwards). Patients that have shorter reversed span → left hemisphere damage, visual field defects, temporal lobectomy, frontal lesions.
Wechsler memory scale and its revision (WMS-R): Three item test of mental tracking → 1) count backwards from 20 in 30 sec. 2) repeat the alphabet in 30 sec and 3) count from 1 to 40 by 3’s in 45 sec.
Serial subtractions → subtracting serial sevens (SS7) → take seven from 100 → you get 93, take seven from 93 etc. until you can’t go any further.
Alpha Span: Subject listen to increasingly longer lists of common, unrelated words and recall them in alphabetical order. Alphanumeric sequencing: the patient alternates between counting and reciting the alphabet aloud beginning with “1-A-2-B…” continuing through L. Letter-number sequencing: in this test subjects hear list of randomized numbers and letter in increasing lengths (from 2 to 8 units). Subjects are asked to repeat numbers and letters from the lowest in each series, and numbers always first, for example, “6-F-2-B” the subject should respond “2-6-B-F”
→ Alzheimer patients have difficulty on this test.
N-back task: this task asks the subject to report when a stimulus item presented serially is the same as an item “n” steps back from the item at hand. For example, for the 2-back condition, if the sequences where 8-7-1-8-6-3-6, the subject would say ‘yes’ following the second 6.
• prefrontal cortex involved.
Paced auditory serial addition test (PASAT): for example, if the examiner reads the numbers → 2-8-6-1-9, the subject’s correct responses are 10-14-7-10 (8+2=10, 6+8=14, 1+6=7 and 9+1=10). Performance on this test decline with age. Most people experience this sensitive test as very stressful.
Stroop test: this tests are based on findings that it takes longer to call out the color names of colored patches than to read words and even longer to name the color of the ink in which a color name is printed when the print ink is a color different that the color name.
• this test is unpleasant to take, particularly for patient with concentration problems.
• visual competence is important. Color blindness may preclude use of this test,
Complex attention tests
Visuographic task: disadvantage → persons unused to handling pencils and doing fine handwork under time pressure are at a disadvantage on these tests.
Digit symbol (Wechsler): it consist of rows containing small blank squares, each paired with a randomly assigned number from one to nine. Above the rows is a printer key that pairs each number with a different nonsense symbol. The subject must fill in the blank spaces with the symbol that is paired to the number above the blank space (see page 368).
→ sensitive to brain damage, extreme sensitive to dementia, Huntington patient perform poorly on this test.
Symbol digit Modalities test (SDMT): this test preserves the substitution format of Wechsler’s Digit Symbol test, but reverses the presentation of the material so that the symbols are printed for the numbers to be written in (see page 370).
• enable the patient to respond with the more familiar act of number writing
• allows a spoken response trial Pfeffer and colleagues found the SDMT to be the ‘best discriminator’ of dementia and depression out of a set of 8 tests.
Trial making test (TMT)
Test of scanning and visuomotor tracking, divided attention and cognitive flexibility. The subject must first draw lines to connect consecutively numbered circles on one work sheet (part A0 and then connect the same number of consecutively numbered and lettered circles on another worksheet by alternating between the two sequences (part B) → see page 371.
• education plays a significant role
• sensitive to the progressive cognitive decline in dementia
• patient with mild TBI (traumatic brain injury) are slower that those of control subjects, and slowing increases with severity of damage.
Color trials: nonalphabetical parallel form of the “TMT” test for use in cross-cultural studies. In color trial-1 subjects are given a page with scattered circle numbered from one to 25 with even-numbered circles yellow and odd-numbered ones colored pink. Color trial-2 also present the subject with a page containing 25 circles, but on this sheet each color set is numbered: to 13 for the yellow odd numbers, to 12 for the pink even ones. The task is to fellow the number series with a pencil but to alternate between the two colors as well, for example → 1Y – 1P – 2Y etc.
Test of everyday memory (TEA): attention is assessed with activities that are meaningful to patients. The eight tasks measure selective attention, sustained attention, attentional switching and divided attention.
10. Perceptual tests
Perceptual tests usually require little or no physical manipulation of the test material. Most tests also measure attention, spatial orientation or memory.
Visual Perception
Brain impairment involving one visual function will most likely affect a cluster of functions. There are only rare occasion where a visuoperceptual disorder will be confined to a single or small-set dysfunction.
Visual perceptions can be divided into two broad categories:
1 Verbal/symbolic stimuli – shapes of words or number, usually processed by the left hemisphere
2 Configural stimuli – pictures, usually processed by the right hemisphere
NB: The right hemisphere is also involved in verbal/symbolic stimuli as these also have spatial dimensions which are processed as configurations.
There is a theoretical separation between attentional en perceptual functions, yet this is only a theoretical reflection of how we conceptualize complex mental phenomena rather than a representation of how these functions work.
Visual inattention Visual inattention (visual neglect, visual extinction) usually involves absence of awareness of visual stimuli in the left field of vision, reflecting it’s common association with right hemisphere lesions, usually in posterior lesions (occasionally anterior).
Visual inattention is more likely to be apparent during the acute stages of a sudden-onset condition such as stroke or trauma. After the acute stages of the condition and the obvious signs of inattention have passed, sometimes subtle inattention to visual stimuli remains.
It can be detected by close observation of the patient when walking, talking or handling an array of objects. It can also be detected by tests designed for other purposes.
Tests of unilateral inattention Different tests for inattention appear to have different levels of sensitivity to inattention in general and to the nature of the inattention phenomenon.
Long series of inattention tasks, meaninglessness and discontinuity of stimuli, and distracting stimuli on the side of space ipsilateral to the lesions may all increase a task’s sensitivity to inattention.
The examiner must always be alert to visuospatial inattention when handling visual test materials. Some tests have the option where the material can be realigned.
Line Bisection Tasks
The examiner draws a line for the patient or asks the patient to copy an already drawn horizontal line. The patient is then instructed to divide the line by placing an “X” at the centre point. The score is the length by which the patient’s estimated centre deviates from the actual centre. When the patient has to copy the examiner’s line first, a second score can be obtained for the deviation in length from the original line.
Line Bisection Characteristics
-Left-handed subjects show the left-sided deviation more than right-handed ones
-Short lines are less likely to elicit a deviation from the centre than long ones
-The longer the line, the greater the deviation
-Patients with right-sided lesions give greater deviations to the right and patients with left-sided lesions move the bisection further left with increases in line length.
- Patients with visual defects tend to underestimate the side of the line opposite to the defective visual field
-More than one trial is necessary to demonstrate a visuoperceptual defect.
Line Bisection Test (LB) The subject is shown a set of 20 lines of different sizes arranged so that six are centred to the left of the midline, six to the right of the midline and six in the centre of a piece of paper. They are asked to mark the middle of each line with a mark. All capable patients take one trial with each hand, with randomized orientation of the page (it can be rotated by 180 degrees). Percent deviation scores are obtained, with positive scores for marks placed right from the centre and negative scores for marks placed left of the centre.
Cancellation Tasks for testing visual inattention
Format: rows of stimuli with targets randomly interspersed among a larger number of foils. Stimuli may be short lines, letters, numbers, other symbols or even little pictures. The patient is instructed to cross out all designated targets. Performance is usually scored for omissions and errors and sometimes also for time.
Cancellation tasks are dual purpose tests: when given to elicit unilateral inattention they may be untimed or response speed may be secondary as the examiner looks for the location and number of omissions and errors.
Capacity for sustained attention, accuracy of visual scanning and activation and inhibition of responses are assessed. When timed, lowered scores can also reflect the general response slowing and inattentiveness of diffuse damage or acute brain conditions.
Test of Visual Neglect, also called Line Crossing
Patients are asked to cross out lines scattered in a seemingly random manner over a sheet of paper. This tests shows that only a few patients with left-sided lesions display unilateral inattention on this test, but those patients with right-sided lesions leave many more lines uncrossed. Patients with inattentional problems are also likely to omit responses in a quadrant, which reflects a vertical dimension to the phenomenon of inattention.
Bells Test In this test 315 little silhouetted objects are distributed in a pseudo-random manner on a page with 35 bells scattered among them. The objects are arranged in seven columns with five bells to a column, although the objects appear to be randomly arranged. The subject must circle the bells without losing any time. The examiner notes by number on a diagrammed page the order in which the subject finds the bells. This enables to examiner to document the subject’s scanning strategy or lack of it.
The Balloons Test This test consists of two pages with each 202 circles of the same size scattered in a random appearing fashion. On the first page (A) 22 circles have a short line extending downwards like a balloon. On the second page (B) all but 22 circles have the balloon-like line. For each page the patient has to cross out as many balloons as possible in a three minute time limit. When the performance on A is better than on B, it demonstrates that visual fields are intact and that errors on B can be attributed to inattention.
Letter cancellation tests and variants
The nine cancellation tests by Diller, Yishay and colleagues consist of: -two forms for digit stimuli -two forms for letter stimuli -two forms for easy three-letter words -two forms for geometric figures -one form using pictures.
The basic format consists of six 52-character rows in which the target character is randomly interspersed approximately 18 times in each row. The point is to cross-out (or cancel) the target character. Performance deficits appear to be associated with “spatial neglect” problems with right-sided strokes and slowed information processing problems with left-sided strokes.
The Behavioural Inattention Task A shorter letter cancellation task in which upper case letters are printed in five lines of 34 items each of which 40% are targets. The targets are distributed equally on either side of the array.
Cancel H This cancellation task consists of three letter cancellation forms used to document normal response patterns over the life span. This test has shown that the youngest group worked the fastest and the oldest group worked the slowest. The difference between age groups for the number of omissions was negligible.
Star Cancellation This untimed test was designed to increase cancellation task sensitivity to inattention by increasing its difficulty. Within a jumble of words, letters and stars are 56 small stars 3hich comprise the target stimuli.
Two and Seven Test This test was developed to assess the differences between automatic (obvious distracters) and controlled (less obvious distracters) visual search. Automatic condition – consists of lines of randomly mixed capital letters with the digits 2 and 7 randomly intermixed. Controlled condition – the digits 2 and 7 are randomly mixed into lines of also randomly mixed digits. The time allowed for each condition is 5 minutes. Scores are obtained for correct cancellations and for omitted items up to the last item completed within the time limit.
Visual Search and Attention Test A cancellation test consisting of four 60 second lasting trials. The first trial is a straightforward letter cancellation format The second trial displays typewriter symbols (e.g. [,], <, >, %) The third trial is composed of letters with colour serving as an additional distracter, as the letters are printed in red, green or blue. The fourth trial is composed of typewriter symbols with colour serving as an additional distracter as the symbols are printed in red, green or blue. Performance is evaluated for left and right sides separately to facilitate evaluation of hemi-inattention. There is also a total score.
This test is very sensitive to brain damage and so should not be used for screening purposes.
Picture description tasks for testing visual inattention Symmetrically organized pictures can elicit “one-sided” response biases indicative of unilateral visual inattention. Patients are shown two or more pictures and are asked to describe what they see or count specific objects or people.
Picture Scanning (part of the Behavioural Inattention Test) Three large colour photographs of common views:
1. A plate with food on it
2. A bathroom sink with toiletries set around it
3. A window wall flanked by a steel locker and wheelchair on the left, a walker and privacy
Screen on the right. The subject is asked to look at the picture carefully and point out major items in the picture. The test is scored for omissions
Reading tasks for testing visual inattention.
Both aphasic and non-aphasic patients with visual field defects tend to ignore the part of a printed line or even a long printed word that falls outside the range of their vision when the eye is fixated for reading. Patients with left-hemisphere damage may ignore the right side of the line or page and patients with right hemisphere lesions will ignore what is on the left.
Battersby and colleagues developed a set of ten cards on which were printed ten familiar four-word phrases. Omission or distortions of words on only one side was considered evidence of a unilateral defect.
Menu Reading (part of the Behavioural Inattention Test) A large card containing two columns of five food items each, printed in large letters o either side of a centrefold. A number of the items contain two words.
Article Reading (part of the Behavioural Inattention Test) Three columns in print a little larger than newspaper copy, the articles are about political economy.
Menu Reading proves to be more sensitive to errors of inattention than Article Reading.
Indented Paragraph Reading Test (IPRT) This test is effective in eliciting inattention errors as well as tendencies to misread. The subject must read the text out loud and the examiner records the first word read on each line and omissions, as well as the time taken to complete reading the whole text.
If the subject has completed half the text without errors, the test can be discontinued for clinical purposes. Is many errors are made on the first 14 or 15 lines, the test can also be discontinued as it can be a painful situation for both the patient and the examiner.
Writing techniques for examining inattention Left unilateral visual inattention for words, a defect that interferes with the reading accuracy and pleasure of many patients with right brain damage, may be clearly shown by having the patient copy sentences or phrases.
The Address/Sentence test (part of the Behavioural Inattention Test) Task 1 – a four-line address to be copied Task 2 – a three-line sentence, such as might be in a newspaper article.
Drawing and copying test for inattention Both free drawing and drawing to copy can elicit the inattention phenomenon.
Patients are asked to copy five items (a diamond, a cross, a cube, a three-dimensional pipe, and a triangle within a triangle) and to draw free hand a clock with numbers and hands (time not specified), a daisy in a flower pot and a house in perspective showing two sides and a roof, by Strub and Black.
The Behavioural Inattention Test contains: Representational drawing – a clock face with numbers, a man or woman and a butterfly Figure and Shape Copying – a star, a cube and a daisy.
A characteristic that is common to most of the stimuli asked to draw or copy is that they are either bilaterally symmetrical or where left-and right-sided details are equally important.
Drawing tends to be somewhat less sensitive in eliciting inattention than cancellation tasks are. Figure and Shape copying tend to be much more sensitive to inattention than the free drawing of specified objects.
Inattention in spatial representation Unilateral visuospatial inattention is a spatial as well as a visual phenomenon. Left-sided spatial inattention can be elicited by requesting the subject to describe a familiar locale (so without a visual stimulus).
Left-sided inattention then appears as the absence or scant mention of features on the left of the familiar locale, in contrast to very detailed descriptions of structures to the right of each given perspective.
Behavioural Inattention Test (BIT) A test battery developed to provide a more naturalistic examination of tendencies to hemi-inattention, whether left or right. There are two sections:
1 The conventional subtests: line crossing, star cancellation, figure and shape copying, line bisection, representational drawing, and letter cancellation.
2 The behavioural subtests: picture scanning, menu reading, article reading and address and sentence copying, telephone dialling, telling and setting the time, coin sorting, map navigation.
Telephone dialling – the patient must dial three numbers presented in large print on separate cards on a disconnected telephone. Telling and setting the time – the patient must read numbers pictured on a digital clock; read a large clock face and set the time with movable hands on a clock face. Coin sorting – the patient must identify six denominations of coins laid out in three rows in front of the subject Map navigation – the patient must trace different pathways that the examiner calls out with his or her finger on a grid of paths with a different letter at each choice point.
Visual Scanning Many brain lesions come with visual scanning defects. These defects can seriously compromise activities such as reading, writing, performing paper-and-pencil calculations and telling the time. Visual scanning defects are also associated with accident-prone behaviour.
Counting dots The patient is asked to count aloud the number of dots – 20 or more – widely scattered over a piece of paper, but with an equal number in each quadrant. Errors that occur can be due to visual inattention to one side, difficulty in maintaining an orderly approach to the task or problems in tracking numbers and dots consecutively. This test can reveal poor scanning strategies.
Visual Scanning Test Thirty-two letters and number appear scattered on an A4 size paper, but are actually arranged in eight rows and four lines providing 32 cells for tracking subject responses. The examiner tracks the path of target selection on a separate graphed page.
Inattention patients show direction shifts (controls don’t show these) and more strategy shifts than controls.
Visual Search There are four versions of a 9 x 9 checkerboard pattern stimulus figure. The patient must indicate in which of the outlying grids is the position of the two little black squares like that of eight centre test grids. (See fig. 10.10 in book)
Colour Perception In neuropsychological assessment tests of colour perception can identify:
1 People with congenitally defective colour vision
2 People with colour blindness – performance on tasks requiring colour recognition might otherwise be misinterpreted
Defective colour vision will affect the evaluation of responses to coloured materials such as the Rorschach technique or Stroop Tests. Many aphasic patients have pronounced colour recognition deficits (colour agnosia)
The Dvorine and the Ishihara are screening tests for the two most common types of colour blindness. The H-R-R Pseudoisochromatic Plates screen for two rare forms of colour blindness, as well as for the two common types of colour blindness.
The stimulus materials for all these three tests are cards printed with different coloured dots, which form recognizable figures against a ground of contrasting dots.
Farnsworth’s Dichotomous Test for Colour Blindness (D-15), Lanthony Desaturated 15 Hue Test (D15-d) Consist of 16 colour caps, all of similar brightness but a little different in hue, together representing a continuous colour range. The Lanthony set are desaturated and sensitive to even mild forms of defective colour vision.
15 colour caps are spread out in front of the patient and the patient is then asked to find the colour cap with the hue closest to that of a cap fixed to one end of a horizontal tray. The, one by one, the patient must try to line up the 15 movable caps in a consistent colour continuum, always seeking the hue closest to the one just matched.
Neitz Test of Colour Vision A paper-and-pencil colour perception test suited for individual and group testing of both blue-yellow and red-green discrimination deficiencies. The patient sees a sheet with nine greyish circles, each filled with rows and columns of small, mostly greyish dots, but some dots are in muted colours forming a geometric figure within the circle that can only be detected by colour competent viewers. The types of errors made help to discriminate between the two most common colour vision defects.
Colour-to-Figure Matching Test This test consists of nine black on white line drawings of common objects which are not linked with a unique prototypical colour along with 30 coloured pencils, including many shades of some colours (e.g. five shades of red, four shades of green, but just one for black and white). The patients are scored on correctness of colour choices. This test was originally designed to see whether Alzheimer patients had impaired colour vision (dyschromatopsia).
Discriminating between colour agnosia and colour anomia Colour agnosia – colours are seen but have lost their object context. Colour anomia – colours cannot be named
Colouring of Pictures – required the subject to choose a crayon from a multicoloured set and fill in simple line drawings of familiar objects that have strong colour associations (e.g. banana, frog) Wrongly Coloured Pictures – the examiner shows the patient a line drawing that has been inappropriately coloured (egg a green dog) and asks what the picture represents.
To further investigate the correctness of colour associations Varney developed a set of 24 line drawings of familiar objects. Each drawing is accompanied by samples of four different colours, of which only once is appropriate for the item. This format only requires a pointing response.
Colour name sorting test – the examiner names a colour and the subject must identify the general colour category to which it belongs (scarlet – red, violet – purple). A verbal task – A colour name is asked for a purely verbal concept. “What colour name would you give for being jealous… for royal blood?”
Visuo-verbal tests – ask for colour naming on visual confrontation. “Show me the colour of a banana” or “Give the colour name of an object”
In the Boston Diagnostic Aphasia Examination there are also some colour items. Word discrimination: the patient must point to six colours named by the examiner Visual
Confrontation Naming – the subject must name these six colours. Written Confrontation Naming – two colours are shown for their names to be written Performance on these three tasks may help sort out the presence and nature of a problem with colours or at least alert the examiner that a problem with colours need further investigation.
Although these tests can distinguish between agnostic and anomic conditions, examiners must be alert to the possibility that the agnosia or anomia involves much more than colours.
Visual Recognition
Angulation The perception of angular relationships tends to be a predominantly right hemisphere function except when the angles readily lend themselves to verbal description (e.g. horizontal, vertical, diagonal) so that they can be mediated by the left hemisphere as well as the right.
Judgement of Line Orientation (JLO) Examines the ability to estimate angular relationships between line segments by visually matching angled line pairs to 11 numbered radii forming a semicircle. There are also short forms which can be used for visuospatial screening; the original JLO should be used when visuospatial impairment is an issue.
Unusual views of pictured objects Examines the relative accuracy with which patients with right or left hemisphere lesions could identify familiar objects under distorting conditions. First condition: 20 enlarged drawings of small objects to be recognized in their usual size. Second condition – showing 20 familiar objects in their conventional view and an unconventional view. The temporal lobes are necessary for object recognition and the parietal lobes provide the spatial conceptualization necessary to identify objects from strange views.
Perceptual Speed (Identical Forms) A timed paper-and-pencil picture matching task in which both visuospatial accuracy and speed in making perceptual judgements contribute to the performance. Each of 140 items displays a target figure (an abstract design of an object such as a clock or bird) with five similar designs of which one is identical to the target. A five minute limit insures that virtually no one can complete the test. Most of the items are not tricky or difficult.
Face Recognition There is no regular relationship between inability to recognize familiar faces (prosopagnosia) and impaired recognition of unfamiliar faces, so there is a separation of facial recognition tests into those that involve a memory component and those that do not. Tests of familiar faces call on stored information and ease of retrieval. Left-hemisphere damaged patients identify but have difficulty naming familiar people’s faces. Right-hemisphere damaged patients show defective recognition. Patients with frontal lesion show a lack in search strategy. Facial recognition difficulties tend to occur with spatial agnosias and dyslexias and with dysgraphias that involve spatial disturbance.
Recognition tests of unfamiliar faces involving memory have appeared in several formats:
-Photos can be presented for matching either one at a time or in sets of two or more. When the initial presentation consists of more than one picture, this adds a memory span component. |
-By having to match unfamiliar faces following a delay, patients with brain damage involving the right temporal lobe demonstrated significant performance decrements, linking memory for configural material to the right temporal lobe. |
Test of Facial Recognition. This test was developed to examine the ability to recognize faces without involving a memory component. The patient matches identical front views, front with side views and front views taken under different lighting conditions. It may take 10 to 20 minutes to administer depending on the patients response rate and cautiousness in making choices. There is therefore also a shorter version.
Patients with right parietal lesions perform more poorly than those with right temporal lesions on the facial recognition reflecting this task’s substantial visuospatial processing component. The task may also have a linguistic component because aphasic patients with defective language comprehension fail on this test at rates a little lower than those with right parietal damage.
Recognition of the facial expression of emotion Assessment procedures – a variety of photograph sets for examining facial expressions are available to examine various aspects of emotion perception. A different format includes four conditions that pair:
1. Same person, same expression
2. Same person, different expression
3. Different person, same expression
4. Different person, different expression This permits the examiners to distinguish between affect discrimination and facial discrimination
Patients with right-sides lesions are much more likely to perform poorly when tested for identifying facial affect than patients with left-sided lesions.
Patients with right sided lesions recognize happy emotional expressions to about the same degree as patients with right sided lesions, but are significantly impaired in recognition of negative or neutral expressions. Patients with right posterior lesions are relatively more impaired than patients with right anterior lesions or left hemisphere damaged patients.
Patients with ventral lesions of the frontal lobe also do poorly in identifying facial expressions.
The New York Emotion Battery (NYEB) Presents photos of facial expressions on slides using a timed slide projector with exposure times ranging from 5 seconds (a matching task) to 20 seconds (an identification task).
Figure and design recognition Accuracy of recognition of meaningless designs is usually tested by having the patient draw them from models or from memory.
A few responses from the WIS-A Picture Completion Test will show whether a patient can recognize meaningful pictures.
Visual Form Discrimination A multiple-choice test of visual recognition. Each of the 16 items consists of a target set of stimuli and four stimulus sets below the target, one of which is the correct match. The other three sets contain small variations of displacement, rotation or distortion.
Left anterior, right parietal and bilateral diffuse lesions were associated with the highest percentages of impaired performances.
The multiple choice format easily converts to a memory test, which can be a disadvantage.
Visual Organization Tests requiring the subject to make sense out of ambiguous, incomplete, fragmented or otherwise distorted visual stimuli call for perceptual organizing activity beyond that of simple perceptual recognition.
There are three broad categories of visual organization:
1. Those requiring the subject to fill in missing elements
2. Tests presenting problems in reorganizing jumbled elements of a percept
3. Test stimuli lacking inherent organization onto which the subject must impose structure
Tests involving incomplete visual stimuli These test are the least vulnerable to brain damage, probably because their content is usually so well structured and readily identifiable. They are not especially sensitive to problems of perceptual organization except when the perceptual disorder is relatively severe.
Gestalt Completion Tests Several sets of incomplete pictures are used to examine the perceptual closure capacity.
Poor performance on gestalt completion tests has generally been associated with right brain damage.
Differences in test scores can also be due to stimulus characteristics such as whether lines are straight or curved, perspective or content information cues, verbalized features or subjective contour illusions.
Closure Speed (Gestalt Completion) This ‘figural’ test presents 24 degraded pictures of objects or animals to be identified within three minutes. Space is provided for subjects to write in each item name. The ease of administration and accessibility of materials recommends this test for both clinical and research work.
Gollin Figures Test that uses incomplete drawings to assess perceptual functions. It consists of 20 picture series of five line drawings of familiar objects ranging in completeness from a barely suggestive sketch (set I) to a complete drawing of the figure (set V). The score is the sum of all the set numbers at which each picture is correctly identified.
This test does not discriminate between right and left hemisphere lesioned groups. Patients with right parietal lesions only show a small trend towards poor performance.
Visual Object and Space Perception Battery Experimental techniques for exploring visual perception have been incorporated into this nine-test battery. The tests can be used individually or as a whole.
1 Shape Detection Screening – checks whether the patient’s vision is sufficiently intact to permit further examination.
2 Incomplete Letters – shows 20 large alphabet letters, one to a card, which have been randomly degraded so that only 30% of the original shape remains.
3 Silhouettes – blackened shapes of 15 objects and 15 animals as they appear at the angular rotations affording a range of difficulty beginning with an item identified correctly by only 36% of the controls and ending with highly recognizable stimuli.
4 Object Decision – presents the subject with 20 cards each printed with four black shapes of which one is a silhouette of a real object, thus giving only minimal clues to the object’s identity.
5 Progressive silhouettes – presents only two items – both elongated object – to be identified, first at a virtually unrecognizable 90 degree rotation from the familiar view, then sequential rotation of the other nine silhouettes gradually approaches the familiar lateral view. The score is the number of silhouettes seen before correct identification of the object.
6 Dot counting – presents ten arrays of five to nine dots each, randomly arranged on separate cards.
7 Position Discrimination – each of the 20 items presents a card with two identical horizontally positioned squares, one containing a black dot in the centre, the other with a black dot slightly off-centred. The subject must decide which square contains the centred dot.
8 Number Location – presents two squares each on ten stimulus cards, this time one square is above the other with the numbers from 1 to 9 randomly spaced within the top square. The bottom square contains a dot in the location of one of the numbers which the subject must identify.
9 Cube Analysis – a ten-item block counting task.
Patients with right hemisphere damage failed more on these tests than patients with left hemisphere damage.
Tests involving fragmented visual stimuli Perceptual puzzles requiring conceptual reorganization of disarranged pieces test the same perceptual functions as does Object Assembly.
Hooper Visual Organization Test (HVOT) Test consists of 30 pictures of more or less readily recognizable, cut-up objects. The patient’s task is to tell each object’s name if the test is individually administered, or write the object’s name in spaces provided in the test booklet. On the individual administration discontinuation is allowed when performance is poor.
Patients with right sided lesions will more likely give fragmented or part responses. Patients with left sided lesions will more likely make naming errors.
A multiple-choice HVOT This test reduces the problem of object naming for anomic patients. This test permits a better understanding of anomic patients’ visual integration capacities.
Tests involving ambiguous visual stimuli Some of these tests were developed as personality tests and not as tests of cognitive functioning. Examiners became familiar with the kinds of responses made by different patient groups so started to use them in neuropsychology.
Rorschach Technique The examiner looks at many different aspects of test performance, such as productivity, response style and the affective quality of the subject’s associations. The evaluation of the perceptual component can focus on four aspects of perceptual activity:
1 The accuracy of the percept – certain areas of the blots tend to form natural gestalts and to elicit similar associations from normal, intact adults. The poor form responses reflect the kind of perceptual problems that accompany brain injury, such difficulties in synthesizing discrete elements into a coherent whole, in breaking down a perceptual whole into its component parts, in clarifying figure-ground relationships and in identifying relevant and irrelevant detail.
2 The ability to process and integrate multiple stimuli – some brain disorders reduce the capacity for handling a large perceptual input at once. Patients can also have difficulty in integrating discrete parts of the blot into a larger, organized percept or in separating associations to discrete blot elements that happen to be continuous. Brain damaged patients also do not often mention colour changes, texture and shading or introduce movement into the percept.
3 Reliability – many brain impaired patients feel that they cannot trust their perceptions. Uncertainty about one’s interpretations of the inkblots is relatively common among brain damaged patients.
4 Slower reaction times among brain damaged patients.
Visual interference Visual recognition tests complicated by distracting embellishments. Visual interference tests require the patient to analyse the figure-ground relationship in order to distinguish the figure from the interfering elements.
Figure-ground Tests
Hidden Figures, Closure Flexibility (Concealed Figures) The Hidden Figures Task requires the subject to identify the hidden figure by marking the outline of the simple figure embedded in the more complex one.
Closure Flexibility is a 49-item multiple choice version of the embedded figures test where there are two correct solutions for each item. Successful performance on this task is strongly associated with “the ability to form a perceptual closure against some distraction and the ability to hold a closure against distraction.
Overlapping Figures Test The outlines of many figures overlap each other and the subject has to name as many figures as he or she can. Ghent’s Test of overlapping figures shows the overlapping objects in specific categories such as fruit or animals. The total time to completion is recorded and subjects indicate their responses on a multiple choice form.
The 15-objects test contains two figures, each an overlapping drawing of 15 different items. The test is scored for both response time and erroneous identifications.
Some examiners ask the subject to also name the general category of the overlapping figures, unless there isn’t one.
A patient can fail this test in two ways:
1. Posterior lesions – the inability to perceive more than one object at a time or to shift gaze
2. Anterior lesions – passivity or inertia of gaze, perseverated responses or confused responses
Picture Search Hidden Pictures of the Snijders-Oomen Nonverbal Intelligence Test (SON-R) involves visual search and recognition of parts of objects or of objects at unusual angles.
Auditory Perception The verbal and nonverbal components of auditory perception appear to be functionally distinct. There are many techniques for examining verbal auditory functions; however psychologists have paid less systematic attention to nonverbal auditory functions. The most common sources of defective auditory comprehension are deficiencies in auditory acuity resulting from conduction and/or sensorineural hearing losses and deficits in auditory processing associated with cortical damage.
Auditory Acuity Most patients with hearing problems are aware of their problem; however when hearing loss is mild or involves very specific defects of sound discrimination without affecting loudness, the patient may not appreciate the problem. Patients who do not report their hearing problem betray it in their behaviour. Persons whose hearing is better on one side tend to favour that side by turning the head or placing themselves so that the better ear is closer to the examiner.
The examiner who suspects that the patient has a hearing problem can test for it crudely by speaking softly and noting whether the patient’s level of comprehension drops. The examiner should insist that the patient see an audiologist for a thorough audiological examination. It is important to be aware of hearing problems because they can be an early sign of brain tumour, but also patients can learn to compensate for them and, when indicated, get the benefits of a hearing aid or, for some conditions, surgical remediation.
Auditory Discrimination Some patients have difficulty discriminating sounds even when thresholds for sound perception remain within the normal hearing range and no aphasic disability is present.
Auditory discrimination can be tested by having the patient repeat words and phrases spoken by the examiner, or by asking the patient to tell whether two spoken words are the same or different, using pairs of different words, such as “cap” and “cat” or “vie” and “thy”, interspersed with identical word pairs.
Phoneme Discrimination This 30-item tape-recorded task uses half identical, half similar pairs of nonsense words.
Wepman’s Auditory Discrimination Test This test uses single syllable word pairs, some identical, some differing only by a phoneme coming from the same phoneme category. Thirteen word pairs differ in their initial consonant, thirteen in their final consonant and four differ in the middle vowel sound.
Sound Blending and Incomplete Words (W-J III) The Woodcock-Johnson III Tests of Cognitive Abilities contain two tests of auditory-verbal perception, both administered by audio recording.
Sound Blending examines the ability to synthesize language sounds by presenting familiar words slowly with syllables separated in time. Sound Blending is associated with “general intellectual ability” and “phonemic awareness”. Incomplete Words is also described as a test of “auditory processing”, in which the subject hears words lacking one or more phonemes; again the task is to identify the word. Incomplete Words is associated with “phonemic awareness”.
Speech Sounds Perception Test (SSPT) This test is in the Halstead-Reitan Battery. It consists of sixty sets of nonsense syllables each beginning and ending with different consonants but based on the vowel sound “ee” comprise the items, which are administered by tape recording. Subjects note what they think they heard on a four-choice form laid out in six 10-item sections (called “series”) labelled from A to F.
Patients with hearing impairments, particularly those with high-frequency loss are likely to perform poorly on this test.
This test is sensitive to brain damage in general and to left hemisphere damage in particular. Patients with left-sided lesions make more suffix errors and patients with right sided or bilateral lesions made more prefix errors. The SSPT is also sensitive to attentional deficits.
SSPT-30 is a short form with 30 sets instead of 60 but has a lower reliability.
Aphasia It is always important to look for evidence of aphasia in patients displaying right-sided weakness or complaining of sensory changes on the right half of the body. Aphasia must also be considered whenever the patient’s difficulty in speaking or comprehending speech appears to be clearly unrelated to hearing loss, attention or concentration defects, a foreign language background, or a thought disorder associated with a psychiatric condition.
Auditory Inattention Some patients with lesions involving the temporal lobe or central auditory pathways tent to ignore auditory signals entering the ear opposite the side of the lesions, much as other brain damaged patients exhibit unilateral inattention on the side contralateral to the lesion.
Auditory inattention can be tested by the examiner making soft sounds at each ear separately and simultaneously, randomly varying single and simultaneous presentations of the stimuli. With practice the examiner can produce sounds of equal intensity with both hands. The sound is usually a soft rustling sound by rubbing the thumb and first two fingers together.
Auditory-Verbal Perception When presenting problems of judgment and reasoning, learning and memory orally, the examiner has an opportunity to make an informal estimate of the patient’s auditory capacity. Subtle problems of auditory processing include difficulty in processing or retaining lengthy messages although responses to single words or short phrases may be accurate, inability to handle spoken numbers without a concomitant, impairment in handling other forms of speech, or inability to process massages at high levels in the auditory system when the ability to repeat them accurately is intact.
Impairments in the recognition or processing of speech usually indicate a lesion involving the left or speech-dominant hemisphere.
The examiner can couple an auditorily presented test with a similar task presented visually. Test pairs can be readily found or developed for most verbal tests at most levels of difficulty.
Testing for Auditory Comprehension
Complex Ideation Material, of the Boston Diagnostic Aphasia Examination Begins with eight paired questions requiring “yes” or “no” answers. These are followed by four stories of increasing complexity, each accompanied by four questions, again calling for a “yes’ or “no” response.
Putney Auditory Comprehension Screening Test (PACST) A 60-item set of a mix of half true, half false statements testing auditory comprehension. The vocabulary consists of words and names in common usage, which can be answered with “yes” or “no”. Responses can be given verbally or through buzzers.
Nonverbal Auditory Reception The recognition, discrimination and comprehension of nonsymbolic sound patterns, such as music, tapping patterns, and the meaningful noises of sirens, dog barks and thunderclaps are subject to impairment much as is the perception of language sounds. Defects of nonverbal auditory comprehension tend to be associated with both aphasia and bilateral temporal lobe lesions.
Seashore Rhythm Test A subtest of Seashore’s Test of Musical Talent. Requires the subject to discriminate between like and unlike pairs of musical beats. Musical education can make a significant difference as many cognitively impaired patients with musical backgrounds achieve scores in the normal range. This test is also very sensitive to fatigue and/or reduced concentration.
Testing for amusia Defective perception of music or of its components is usually associated with temporal lobe disease, and is more likely to occur with right-sided involvement than with left. The examiner can whistle or hum several simple and generally familiar melodies. Pitch discrimination can be tested with a pitch pipe. Recognition for rhythm patterns can be tested by requiring the patient either to discriminate similar and different sets of rhythmic taps or to mimic patterns tapped out by the examiner with a pencil on the table top.
Recognition of emotional tone in speech The flat or misplaced intonations of patients with right hemisphere damage can debase the quality of these patients’ social adjustment and can lead to an underestimation of their affective capacity when their problem is one of perceptual discrimination rather than emotional dulling.
The Emotional Perception Test (EPT) Consists of recordings of three sentences each read in five different emotional tones: happy, angry, frightened, sad and neutral.
The Prosodic Perception Task (in the New York Emotion Battery) Consists of four neutral sentences, each spoken in one of eight emotional tones. There is a discrimination part and an identification part to this test. Patients with right-sided lesions made more errors
Tactile Perception Tactile Sensation The integrity of the somatosensory system I the area of neuropsychological interest should be evaluated before testing tactile-perceptual functions. The patient’s eyes should be closed of the hand being tested kept out of sight when sensory functions are tested.
Tactile Inattention Occurs with right hemisphere damage and frequently accompanies visual or auditory inattention. It is usually tested by points on some part of the body being touched on each side, first singly and then simultaneously (double simultaneous stimulation).
Face-Hand Test (FHT) An examination for tactile inattention that involves two bilateral stimulation points on each trial, administered with the subject’s eyes closed. This test is sensitive to dementia progression.
Quality Extinction Test (QET) After becoming familiarized by sight and touch with an assortment of different surface textures, blindfolded subjects are required to identify these materials when they are brushed against their hands.
Tactile Recognition and Discrimination Tests Stereognosis (recognition of objects by touch) Object recognition (testing for astereognosis). Patients are asked to close their eyes and to recognize by touch such common objects as a coin, a paper clip, a pencil or a key. Each hand is examined separately. Size and texture discrimination are also tested.
Skin Writing The technique of tracing letters or numbers on the palms of the subject’s hands. This test is useful for lateralizing the site of damage and indicating the severity of a tactile perceptual defect.
Fingertip Number-Writing Perception The examiner writes with a pencil each of the numbers 3,4,5,6, in a prescribed order on each of the fingertips of each hand, making a total of 20 trials for each hand.
Olfaction Diminished olfactory sensitivity has proven useful in discriminating neurodegenerative disorders from depression in elderly persons, or in predicting cognitive decline or possible advent of Parkinson’s disease. Informal olfaction testing is frequently performed by neurologists using a few common odours. The University of Pennsylvania Smell Identification Test (UPSIT) is used for a more precise odour detection.
11. Testing memory
Memory = the capacity to retain information and utilise it for adaptive purposes. (memory complaints may be the most frequent reason for neuropsychological referral. Dysnomia = word finding difficulty, can occur along with effective retrieval of episodic memory (and the other way around) Deficits in processes other then memory can still affect memory performance = attention, concentration, strategy etc.)
Examining memory
A comprehensive memory evaluation should include:(by adults first examination of attention) 1) orientation to time and place. 2) prose recall to examine learning and retention of meaningful information. 3) rote learning ability, tested with free and recognition trials. 4) visuospatial memory. 5) remote memory. 6) autobiographical memory. The examiner should also consider the aspects of cognition that don’t depend on memory.
Necessary testing procedures for understanding strengths and weaknesses of patients: 1) delay trials, for rebound effects. 2) interference during the delay period. 3) means of assessing learning that bypass simple recall, usually learning by recognition. Be mindful of other impairments that may influence the task: vision and hearing problems.
Verbal memory
Verbal automatism’s
Materials learned by rote in early childhood and frequently used throughout life. More than one error on a task usually means brain dysfunction. Asks for alphabet, days of the week, numbers 1-20.
Letters and digits
Brown-Peterson technique, also called Auditory Consonant Trigrams. After hearing or seeing three consonant the subject has to count backwards for several seconds and then report or identify the stimulus. Assessing short term memory, without manipulation of the information held in memory.
Increasing the tested span, supraspan
Patients with brain disorder have an immediate memory span as long as that of normal adults, so longer and more complex span formats are necessary (8 or more numbers) to get the needed results. This is sensitive to age, education level, brain impairment. In normal subjects recall is at or little below normal span. For brain disorders it is 2 or more shorter. Telephone Test. 7 or 10 digit strings. The longer the string the shorter the amount of recall. Serial Digit Learning (Digit Sequence Learning). 8 or 9 digits to be repeated until recalled correctly two times, or all twelve trials.
Words
Words can be categorised in all sorts of dimensions: familiar, concrete, emotional, structural. The examiner must be alert to the potential effects that these dimensions (categorise and subsequent recall) can have on the comparability of items, or interpreting differences between groups.
Brief word learning tests 3 or 4 words to repeat and remember after 5 minutes of normal interview. Examples are the Mini Mental State Examination and the Four Unrelated Words. Most people under 60 have no difficulty is these tasks. Benson Bedside Memory Test. 8 words are read to the patient after each of 4 trials. Free recall is after 5 to 10 minutes. Followed by category-cued recall for misers + multiple choice prompting for words that are still not recalled.
Word span and supraspan Everybody can remember 5 words, but older people start having difficulty at 9 words. Some tests use shopping list words to appear more practically relevant.
On supraspan learning tasks it appears that both short-term retention and learning capacities are engaged. Brain damaged people do as well as normal people on initial trials, but not on subsequent trials. The have a recency effect, but not the primacy effect normal people also have. By using lists several times learning strategies can be discovered (making associations) -Intrusion of words not in test shows interference from internal association. -Repetition = saying the same word several times during recall trial, attention problems.
Auditory Verbal Learning Test. A five trial presentation of a 15 word list. Single presentation of an interference list. Two post-interference recall trials and recognition of the target words presented with distracters. Obtained measures = immediate word span under overload conditions, final acquisition level, total acquisition, amount learned in 5 trials, proactive interference, retroactive interference, delayed recall, recognition, number of repetitions, number and types of intrusions. Examiner writes the remembered words down, to see what strategy was used. -in the recognition task, two colours are used for the cards, only remembering words of one colour. Large jumps in test scores are usually due to slowness in shifting from one task to another. Most patients with brain disorders show a learning curve. When this is still present for the recall trials these patients may be capable of benefiting form psychotherapy, counselling and rehabilitation training.
California Verbal Learning Test. Designed to assess the use of semantic associations as a strategy for learning words. 16 words per list in 4 category’s. Category items are presented randomised. Disadvantage = confounding effect of concept apprehension and conceptual organisation. -procedure is similar to AVLT, after free recall follows recall in categories. This should be beneficial for people who didn’t make any associations. 20. min later another recall trial, and a recognition trial. On the second version different categories are used, with a higher familiarity. There is also a forced choice trial to measure motivational lapses. The frontal lobe plays a role in strategic memory processes and source memory, so people with lesions here have difficulty doing this test. Left temporal lobe lesions also cause trouble.
CERAD word list memory. Sensitive to memory loss of early stage dementia, and useful for the very elderly. List of 10 unrelated words. Patients read the words from cards that are presented in a different order on each of the three learning trials. Recall follows after each trial + after 5 min, and a recognition task with unrelated distracter words.
Hopkins verbal Learning Test. 12 words in 3 semantic category’s learned in three trials. Followed by a 24 word recognition list with the targets, 6 unrelated and 6 semantically related words. And a delayed recall trial. Alzheimer patients are more likely tot say yes to semantically related words then Huntington, but both occasionally say yes to unrelated words, while controls do not.
Interference Learning Test. 4 trials, 20 target words + 24 distracters. Only remember the words on the white cards, not on the blue ones. The second list has 16 targets and no distracters. Trials are = recall of list 1 after two learning trials of list 2, followed by short and long delayed trials, category cued recall and yes/no recognition trials. Recall of the to be ignored words is also tested with a recognition trial.
Selective Reminding Procedure 12 words are learned for immediate recall. On the next trials only words are repeated that were not mentioned by the patient before. This continues till all words are recalled or 12 trials. After recalling all words 3 times a delayed recall follows (free, cued or 4 choice recognition) Recall of 4 or less is brain damage. Consistent long term retrieval = words recalled from trial to trial. Measured is long and short term recall, storage and retrieval. Retrieval failure or just weak encoding/ difficulties in acquisition can also be the cause of low scores. Differences in learning efficiency show up between patients whose head injuries differ in their severity. Only people with very severe brain damage don’t continue to show improvement on 12 learning trials. Other methods.
Word List. 12 unrelated words in the same order for 4 trials. Recall in any order. One trial with interference list followed by recall of the first list. A long delayed free recall and a recognition trial. The long delay recall was not very reliable.
-Free an Cued Selective Reminding. 16 items to be learned, selected form cards with drawings. |
-Double Memory Test = more items per category and a total of 64 items, to prevent ceiling effects. |
Paired associate word learning test Associate learning, Verbal Paired Associates. 6 easy word pairs + 4 hard to associate (in second test only hard trials, which is demotivating for the patient) Three randomised trials with recall after each reading. It is possible to ad a delayed recall trial, or completing word pairs. People who have ‘recovered’ from mind head injuries are still visible on these tests. The tests are also useful for documenting deterioration.
Story Recall
These test provide (closest to real life) a measure of both the amount of information that is retained under overload and the contribution of meaning tot retention and recall. Influences of prior experiences are important. It is necessary to ask for ‘out of order’ information as well. Not all patients do so spontaneously. There a problems with scoring because info is seldomly repeated literally. (synonyms, additions, omissions, shifts is sequence) Rapaport: “Correct if the change does not alter the general meaning of the story or it’s details”
Logical Memory. Two stories, immediate free recall after each + a 30 min. delayed recall trial. Speed of presentation can vary although this is an important factor for older people. Perhaps repeating a story for anxious patients, to discover whether they can not get a higher score. Detailed scoring systems are necessary. Learning slope = improvement after second presentation of the story. Immediate recall shows decline after age 55. Delayed recall after age 45.
Babcock Story Recall Format. Two stories = read one, free recall, reread the story, delayed recall. Followed by same procedure for second study. The immediate recall provides on opportunity for documenting problems from defective hearing by rereading the stories. Delayed recall gives a clearer pictures of learning capacities.
Story Memory Test. 29 item story presented up to 5 times until at least 15 items are remembered. Partial correct info receives partial scores. Learning score = number of points recalled on last trial divided by number of trials necessary. Memory score = percentage of the difference recalled on the last trial and on 4-hour delayed recall.
Visual Memory
The examiner should make an estimate of the relative contribution of perception, constructional or visuomotor skills and memory (visual or spatial). These factors can all influence test results. Best is to use abstract designs and nonsense figures to minimise verbal mediation.
Visual Recognition Memory.
Evaluating visual memory when free recall is impaired, or for patients who can not adequately draw. Recurring Figures Test. 160 cars with geometric irregular nonsense figures. In 8 trial blocks, but a continuous presentation. 8 of the first 20 cards come back in every block. The patient has to indicate whether the designs are new or not.
Continuous Recognition Memory Test. 20 line drawings of plants and animals organised in 6 blocks. First set = 8 targets + 12 foils. Next set = 8 targets + 8 similar pictures + 4 different categories. Are the drawings old or new. When using sets of cards this test can also be turned into a recognition trial.
Continuous Visual Memory Test Like CRMT but now with abstract item designs. 112 items. Only 7 target pictures in 7 blocks. There are not only trials for perceptual accuracy but also a 30 min. delayed recognition trial.
WMS-3 Faces. Memory of faces is good for assessing memory functions associated with the non-dominant hemisphere. 24 target faces. Recognition of these 24 among 24 foils. + a delayed recognition trial with 24 new foils.
Family Pictures. Designed to measure = complex, meaningful, visually presented information. A picture of a family portrait of 6 people and their dog. Individual pictures of several people in different situations. Remember as much about each scene as possible for immediate recall + 30 min. delayed recall trial.
Visual Recall: Design Reproduction.
5 to 10 seconds exposure followed by drawing trial to depict what they remember, most of these tests have been used to assess right hemisphere damage.
Visual Reproduction. 3 cards with printed designs. The 3rd card has a double design. Recall after each exposure by drawing. + 30 min. delayed recall. No other drawing tasks given in this time to limit the interference. Possible modifications to the test: an extra design with circles and a simple design to lower the flour of the test.
Complex Figure Test – Recall Administration. Rey-Osterrichts figure is most commonly used. Recall typically follows the copy trial immediately, on delay, of both. With two recall trials the second assesses retention. Occasionally switching pencil colour will make the strategy being used visible. (may also help improve patients memory) Less organisational strategy = less recall of the details
-recognition format = recognition + matching trial following delayed free recall. Copies and
foils of internal details (small and big) The patient has to mark the correct ones.
-Extended complex figure test = 30 items, each 5 vertically positioned stimuli. 1 target + 4 foils.
Benton Visual Retention Test. 3 figure design format that is sensitive to unilateral spatial neglect. Two big stimuli and one small on each card. There are several ways for administration. 5 or 15 seconds exposure followed by immediate recall by drawing. A copying test. Or waiting 15 seconds before responding.
Visual Learning
Buber Figure Learning Test. Ten test items, each composed of two geometric figures and 30 distracters. (3 for each target figure). After exposure the patient has to draw from memory on 5 learning and recall trials. + 1 immediate recognition trial + 20 min delayed recall and recognition trial (also possible to add: immediate reproduction of each design and a copy trial)
Visual Spatial Learning Test. Suitable for patients with movement disorders. 6x4 grid and 7 different nonsense designs that are very difficult to verbalise. Properly place the 7 out 15 designs on an empty grid, where they were placed before. 5 learning trials + 30 min. delayed recall.
Diagnosticum fur Zerehalschade – Revision. Learn nine simple geometric designs. (connecting 5 separate lines) – recall by using 5 wooden sticks. Maximum of 6 trials, no feedback. + 30 min. delayed recognition trial of targets and 12 foils.
Heaton Figure Memory Test. Learn a pathway or trail through circles spread over a piece of paper. Circles are interconnected by lines. 15 step path that is not the shortest route. Patients are not told how to choose from the different alternatives. Learn by trial and error. When the path is incorrect, patient are told to go back to the last correct circle. This is done until the path has been completed 2 times, or through al 15 trials.
Shum Visual Learning Test. Chinese characters = 5 learning trials, second set for interference, recognition of first. 10 targets. The foils are slightly modified targets.
Hidden objects
Testing immediate memory and learning for spatial orientation and span of immediate memory by asking for recall of where and what objects have been hidden. (in Stanford-Binet tests) patient seen and names the objects being hidden and had to find or pinpoint them after 10 minutes of interpolated activity.
Tactile Memory
Tactual Performance Test. 3 trials (left hand, right, both) blindfolded solving a puzzle with geometric figures. The score is the time to completion. + drawing the figure form board from memory as a recall trial.
Tactile Pattern Recognition. Subjects don’t see the items. 4 pieces of wire, twisted into distinctly different nonsense shapes. Matching the figures with time delay.
Incidental Learning.
Look at learning as it occurs naturally in the course of events. Examples of test where this is possible are: WAIS-R Digit Symbol – recall used symbols from memory, write out as many as the patient can remember. WS-A Similarities – free recall and cued recall after completing this test. Boston Naming Test
Prospective Memory
Remembering to execute an action planned for the future requires a mechanism for signalling when the appropriate time has arrived and recall of the nature of the intents (time or event based) Biggest age differences are for time-based tasks. ‘frontal’ regions are important for good performance on target recognition tests, more important than the hippocampus in prospective memory. TBI patient (severely injured) often have impaired prospective memory. Event based trials were easier then time-based both for patients en controls.
Remote Memory
Testing very long term memory is important for retrograde amnesia – thus usually concerning persons with: Korsakoff’s, temporal or frontal lobe pathology, or electroconvulsive therapy. Mostly tested by recall and recognition of common information, so constant update of test items is needed. Problems: 1) measured info could have been relearned at a later stage. 2) The patient may not have found the events interesting enough to remember. 3) Cultural homogeneity is no longer that big so developing a good test is difficult.
Recall of public events and famous persons
News events tests Warrington and Sulbestein. 3 tests in a 6 month period. Age and the passage of a year’s time affect recall and recognition of once known information, but recall the most. Other tests = Events Questionnaire, Famous Events Test, Public Events Test.
Famous People Tests Presidents Test. 6 items of the last presidents. 1) verbal naming. 2) verbal sequencing. 3) photo naming. 4) photo sequencing. Other tests = Famous Faces Test, Old-Young Test.
Autobiographical Memory
Personal memory, seldomly affected by retrograde amnesia. Difficult to verify that what is told is correct. The Crovitz Test. Examine the efficiency of autobiographical recall form specific time periods. Describe experiences of a unique episode associated with each of ten nouns. Healthy subjects produce memories from all ages, most from the previous decade. Autobiographical Memory Interview. Autobiographical incidents + personal semantic memory. Three questions from each three time block for the incidents: childhood, adult life, recent events. For semantic memory questions are asked about: background information, childhood, early adult life, recent events.
Forgetting
Memory decay over time = inability to retrieve information by free recall or recognition. -savings method = learning material on more occasions. Less trials needed on the next occasions to learn something means that information (verbal and non-verbal material) is remembered. Delayed recall : by immediate recall x 100 Older subjects have a higher forgetting rate then younger subjects. Scores should be interpreted with looking at the initial learning levels.
12. Batteries, Paired Memory Tests and Questionnaires of memory
MEMORY BATTERIES
The older batteries have haphazard norms, and each has limitations in its scope and emphases such that none provides a suitably well-rounded and generally applicable means of examining memory functions. The ideal memory battery would be more extensive than intensive. A general overview of memory functions is often not needed. Many interesting memory assessment techniques examine different aspects of memory problems with varying degrees of suitability for different patients. Because of increased statistical refinements (for example: standard deviations), newer tests provide a reasonable comparability across test scores from different tests. Thus, many neuropsychologists pick and choose memory tests based upon the appropriateness for the individual patient and the limitations of the particular examination situations. The primary advantage of most batteries is that they include a variety of memory tasks, with the most recently developed ones likely to have good age-graded norms. The chief drawbacks are: 1) Battery instructions for the examiner typically assume that the entire battery will be given at one time, so that one memory test immediately follows another. Patients with impaired memory thus have to give one deficient performance after another. Instructions usually fail to remind the examiner that the individual test can be reorganized or resequenced, so that the patients can experience some successes along with their failures. It makes testing less depressing for them. 2) Having completely given one of the larger batteries, some examiners may imagine that they have given an adequately comprehensive examination without realizing that not all important aspects of the patient’s memory problems have necessarily been addressed. 3) Additionally, not all tests in a battery will be relevant for a particular patient or issue.
Wechsler Memory Scale (WMS-O, WMS-R, WMS-III)
The Wechsler Memory Scale (WMS), and its revisions, is likely the most widely used and most recognizable memory battery. First published in 1945, the most recent edition in 1997. The original 1945 version (WMS-O) is rarely used now. The Wechsler Memory Scale-Revised (WMS-R) and Wechsler Memory Scale-III (WMS-III) are both popular choices for memory assessment. They have important differences.
Wechsler Memory Scale-Revised (WMS-R)
The WMS-R represents a major effort to correct most of the most glaring defects of the WMS-O: 1) the unitary Memory Quotient (MQ) score; 2) the scanty assessment of visual/ nonverbal memory; 3) the absence of delayed recall measures; 4) the inadequate norming procedures and normative sample. In each of these respects, the WMS-R is an improvement, but in each it falls short. The WMS-R has only one form. This is a serious limitation since retesting is often required and memory and learning tests are susceptible to practice effects. The WMS-R contains 9 tests (with 6 in the original WMS): Information and Orientation questions ask for age, date of birth, identification of current and recent public officials and orientation to time and place; Mental Control assesses automatic speech and simple conceptual tracking; Figural Memory is an immediate recognition test of abstract designs; Logical Memory I and II test immediate and 30 min. delayed recall of short verbal stories; Visual Paired Associates pairs abstract line drawings with colors with a color pointing response required (immediate and delayed conditions are tested); Verbal Paired Associates tests verbal associative ability for words and contains both immediate and delayed conditions; Visual Reproduction I and II assesses immediate and delayed recall for a visual drawing task; Digit Span measures forward span, beginning with 3 and up to 8 digits and backward span from 2 up to 7 digits; Visual Memory Span is a nonverbal analog of Digit Span which measures the ability to reproduce the spatial pattern of tapping sequences on an array of blocks beginning with 2 and going up to 8 blocks plus the ability to reverse the tapping sequence from 2 up to 7 blocks.
Battery characteristics
1) Trading in the MQ for indices The MQ is replaced by 5 indices: Verbal Memory, Visual Memory, General Memory, Attention and Concentration, and Delayed Memory. The scores on the different indices are composed from the scores on the 9 tests.
2) Disconnections between Index names and contributing factors. The Attention / Concentration Index appears to be appropriately named since it separates out much of the attentional tests in this battery. Although each of the other indices appears from the titles of the component tests to bear a meaningful relationship to its given name, neither the indices nor the contributing tests are always discriminated by factor analyses. Intercorrelations between the tests tend to be low, mostly below .31, indicating that they are mostly measuring different functions; but the pattern of intercorrelations varies considerably with different age groups, raising questions as to just what is being measured.
3) Lengthened administration time The additional tests needed to calculate factor scores significantly lengthened the administration time for the entire battery. The WMS-R manual states that a short form can be given by eliminating the delayed recall components. An alternative (and better) method for reducing administration time uses immediate and delayed recall of the 3 tests that appeared in the original scale (Logical Memory, Verbal PA and Visual Reproduction) to predict the General and Delayed Memory summary scores.
4) Enhanced nonverbal representation? The tried to remedy the verbal bias by adding Figural Memory and Visual PA, but unfortunately it didn’t work.
5) Addition of delayed recall measures. While the WMS-R has remedied the lack of delayed recall trials in the original WMS, by encouraging the confusion of visual and verbal measures in the Delayed Recall Index (DRI), much of the potential gain has been vitiated for those who attempt to interpret WMS-R performances based solely on index performances. Moreover, appropriate recognition testing was not included so that the relationship between storage and retrieval must remain obscure for all persons whose delayed recall performances are appreciably lower than their immediate recall.
6) Samples and norms. The manual gives normative data for 9 age groups from 16-17 to 70-74. However, for age groups 18-19, 25-34, and 45-54 the data are extrapolated as only 6 age groups were actually tested. Although the extrapolations are based on assumptions of linear decline for all Index Scores, Attention/Concentration Index in particular may show a different decline pattern which can produce erroneously large discrepancies between this and other Indexes for persons in the 45-54 age range. Also, the sample sizes for each of the 6 examined age groups are somewhat small. All 5 indices showed education effects leading the manual to recommend that education be taken into account when interpreting these scores.
Neuropsychological findings. The indexes do reflect some disease-associated patterns of
memory impairment. There is a report that patients in early stages of Huntington disease differ from the early Alzheimer pattern in having better DRI scores. In another report however, the WMS-R failed to report this difference. The restriction of index scales to a low end standard score of 50 appears to create a ‘floor’ effect which does not allow for discrimination of memory deficits in patients with more advanced disease, or in patients with severe memory disorders generally (for example: patients with Korsakoff, TBI or multiple sclerosis).
Wechsler Memory Scale-III
The WMS-III contains an even larger number of tests than the WMS-R, further lengthening the battery, but classifies many of them as ‘optional’. The core battery consists of 6 tests, 3 of them (with slight alterations: Logical Memory, Verbal Paired Associates, and Spatial Span) appeared in the WMS-R. As with the WMS-R, parallel forms are lacking although a table can provide some guidance in interpreting change scores from follow-up testing. The new WMS-III core battery tests are Letter-Number Sequencing, Faces, and Family Pictures. Visual Paired Associates and Figural Memory (in WMS-R) have been dropped. Information and Orientation, Mental Control, Digit Span, and Visual Reproduction are now classified as optional tests along with a newly developed verbal task that is appropriately named Word Lists. Most tests contain separate immediate and delayed recall components. The battery no longer characterizes performance on Logical Memory and Verbal Paired Associates as ‘verbal’, instead using the label ‘auditory’. It does change the focus from material-specific memory, to modality-specific memory. The normative age range has been considerably extended, with the highest age bracket now 85-89 years. This is a significant improvement. Similarly improved is the size of the normative sample (1250 vs. 300 in WMS-R).
Battery characteristics
The core WMS-III tests generate 8 primary ‘memory indices’ (Auditory Immediate, Visual Immediate, Immediate Memory, Auditory Delayed, Visual Delayed, Auditory Recognition Delayed, General Memory, and Working Memory). Most of the indices are now, in comparison with the WMS-R, computed differently so the 2 measures are not comparable. Working Memory Index is the new name for what was Attention / Concentration in the WMS-R. It is the popular term for active processing of information in the short term. Working Memory is equally weighted for auditory (task: Letter-Number Sequencing) and visual (task: Spatial Span) stimuli. Verbal Memory tests and the Auditory Indexes have changed in several ways from previous formats. There is a slight change in administration of the story (it’s also tested after a delay). Verbal Paired Associates contains only words that are not readily associated, so no longer ‘easy’ items included. The downside is that a subject’s failure to make easy associations can no longer be used to alert the clinician to possible poor task motivation by the patient. Word Lists contains 12 words that have no semantic association presented over 4 trials, followed by a single trial of a second, interference list. Then, recall of the first list is requested. Two delayed trials follow: free recall, and yes/no recognition in which the examiner reads the 12 words interspersed among 12 foils. In addition to the indices, the WMS-III provides for the computation of 4 ‘Auditory Process Composites’ derived from immediate and delayed performances on Logical Memory and Verbal Paired Associates: Single-Trial Learning, Learning Slope, Retention, Retrieval. Less verbalizible memory tests and the Visual Memory Indexes now include 2 completely new tests: Faces and Family Pictures. Faces (immediate and delayed recall components, with yes/no format) is a recognition task in which 24 faces are first shown one at a time for ± 2 seconds each. Family Pictures (immediate and delayed recall) is designed to measure ‘complex, meaningful, visually presented information’. 4 pictures are shown for 10 seconds and the subject has to recall 4 out of 7 members of the family, what they are doing and their location in the picture. Digit Span now contains harder and easier sequences. Reliance solely on the information presented in the WMS-III Manual can lead to erroneous conclusions since the manual does not provide tables stratified for general level of intellectual function.
Neuropsychological findings.
Despite the many improvements over its predecessors, a variety of criterion validity studies have offered only limited support. There are found some relations with seizure onset laterality, and the WMS-III is more sensitive to effects of mild TBI at some summary measures.
The Camden Memory Tests
Five tests of different aspects of memory and learning are included in this battery. All are first shown at a one per 3 sec rate with the recognition trial following immediately. The tests had the expected age gradients. The tests can be purchased individually or as a battery.
1) The Pictorial Memory Test (CPRMT) consists of 30 color photos of a wide variety of distinctive subjects. The recognition trial presents 30 pages each containing 3 photos, 1 target, and 2 foils. This test was made very easy to identify both patients too impaired to proceed (for example: patients with left-and right-lateralized lesions) to the other tests and subjects performing below their capacity.
2) The Topographic Recognition Memory Test (CTRMT) substitutes for Face Recognition by presenting 30 more colored photos, detailed pictures of a variety of places. Unlike in the CPRMT, the 2 foils that go with each picture on the recognition trial are quite similar to the target. Because these pictures are more verbalizible, you see a bigger difference in significant deficit scores between left and right lesioned patients.
3) The Paired Associate Learning Test (CPALT) The word pairs are supposed to be moderately related, but some may be too easy for some subjects. The subject has to read the pairs out loud. In the initial format immediate recall after each pair is requested, and later recall after all the pairs are read. Trial 2 clearly distinguishes the laterally lesioned groups.
4) & 5) Included in this battery are 2 briefer forms of the Warrington Recognition Memory Test (WRMT): Short Recognition Memory Test for Words (CSRMT-W) and Short Recognition Memory Test for Faces (CSRMT-F).These tests have 25 items each and the same administration format as the longer form. For patients with diffuse brain damage, a greater proportion of mildly impaired patients were recognized as having a deficit on Faces, the more severely impaired scored more impaired on Words.
Randt Memory Test
This set of tests was specifically designed for longitudinal studies of patients with mild to moderate impairment of storage and retrieval functions. They thought it was useful in investigating drug effects, particularly memory-enhancing drugs, it has also been successfully used to examine cognitive side effects of different anxiolytics, as well as to characterize the memory effects of ECT.
The test contains 7 subtests and is quite brief (20 min). it has a set order of presentation in which acquisition and retrieval from storage are differentiated by separating immediate recall and recall following fixed tasks. They also use telephone interviews to obtain 24-hour recall data. This memory test has 5 different forms for repeated examinations. The first and last modules (General Information and Incidental Learning) are identical in all forms. The middle 5 modules test recall of 5 words using the selective reminding technique, of digits forward and backward, of word pairs, and of a paragraph, and also include a module testing recognition and name recall of 7 out of 15 line drawings of common objects. Scores between subtests are not comparable.
Battery characteristics.
Excepting General Information, at least 1 trial of each subtest has demonstrated sensitivity to the effects of aging or to the memory impairments of a group of patients with memory complaints of one or more years’ duration. However, this highly verbal test cannot qualify for general use in neuropsychological assessment since it necessarily penalizes patients with language disorders and would probably be relatively insensitive to memory impairments involving nonverbal material. Some of the subtests are so easy that ceiling effects can be expected, particularly with younger subjects who may have memory problems.
Memory Assessment Scales (MAS)
This set of memory tests was developed to be a comprehensive, well-designed, standardized memory assessment battery. It was originally called the Vermont Memory Scale (VMS). It addresses 3 kinds of memory functions: attentional functions and short-term memory; learning and immediate memory; and memory following a delay. These functions are examined in both verbal ad nonverbal modalities (and one integration of these 2). 2 tests contribute to Short-Term Memory, the summary score for attentional functions. Verbal Span is composed of Numbers Forward, which is the longest span in a 2 to 9 digit series with 2 trials for each length; and Numbers Backward, which presents span lengths from 2 to 9 and scores in like manner. In Visual Span the subject sees a card on which is printed a randomized array of stars. The examiner touches the stars following a predetermined pattern and the subject has to copy that. It begins with 2 stars and continues until both trials of the same length are failed or the subject recalls the longest sequence of 9. Verbal learning is examined by 2 tests that have immediate and delayed recall trials. List Learning consists of 12 words, which are read to the subject in 6 learning trials or until 12 words are recalled in a single trial. This test generates 6 learning or recall scores: List Acquisition, List Recall (following interference), Cued List Recall, Delayed List Recall, List Recognition. The Visual Memory summary score is based on 2 tests (only immediate trials contributing): Immediate Visual Recognition presents more or less simple geometric designs for 5 sec followed by a 15 sec visual distraction task, after which the subject must identify a newly presented design as same/different, or pick which of the 5 is seen in learning trial. In Delayed Visual Recognition, he has to identify the original 10 target figures from an array of 20. Visual Reproduction has 2 trials in each of which the subject sees a design for 10 sec that must be drawn after a 15 sec interference by a visual distraction task. In Names and Faces the subjects sees a set of 10 named faces for 2 learning trials, each followed by a recall trial (delayed recall after 15 min).
Neuropsychological findings.
Patients with lateralized lesions differed in the expected directions on the Verbal Memory and Visual Memory summary scores. TBI’s had their least difficulty on the Short-Term Memory component. Dementia patients scored below all other groups on all subtests except for Visual Memory. However, all patient groups scored below normal expectations. The test loses something in not scoring story recall per se, nor delayed design recall. Another problem is that the designs appear to be verbalizable despite the manual’s references to them as nonverbal tests.
Denman Neuropsychology Memory Scale
The goal of developing this test battery has been to create a useful set of measures of selected memory functions for clinical settings. The battery includes 8 tests, of which 4 are classified as ‘Verbal’ and 4 as ‘Non-Verbal’. The battery has only 1 form. In the Verbal section, Story Recall is based on a single 42-item story, of which the keynote is similar to the WMS Anna Thompson stories, with several identical words and phrases. It was made almost twice as long as most other stories in general use to avoid a ceiling effect. Paired Associate Learning contains 14 word pairs, of which 5 are conceptually related (easy) and the rest are unrelated (hard). This list of pairs is also longer than usual to avoid a ceiling effect. Remote Verbal Information contains 30 questions popular culture, newsworthy events and persons, and general knowledge. The Memory for Digits is identical to that of the WAIS-R. Both Story Recall and Paired Associate Learning have delayed recall trials. The Non-Verbal section: in Figure Recall, the Rey-Osterrieth complex figure is administered in the usual manner with a copy trial and 2 recall trials, immediate and delayed. Musical Tones and Melodies is a tonal matching task with a format like that of the Seashore Rhythm Test. Memory for Human Faces contains 1 card with 16 facial photos printed in a 4 x 4 array, which is shown for 45 sec. Following a 90 sec distractor task, another card is presented with 48 photos (large number, but again chosen to avoid a ceiling effect) on it, including the original 16 to be identified. The 4th test poses 30 questions about visual details of familiar objects, signs, symbols, and sights.
Battery characteristics.
For subjects aged 39 and younger, Memory for Digits and Immediate Story Recall loaded together on a second factor, which suggests that they share immediate memory span and attention/concentration components.
Rivermead Behavioural Memory Test (RBMT, RBMT-II)
This test was developed to provide measures that could be directly related to the practical effects of impaired memory and for monitoring change with treatment for memory disorders. It was also designed to have face validity so that nonpsychologists could readily understand its findings. The test has 4 forms that differ for every subtest except Orientation and Date. The test includes practically relevant tasks such as: Remembering a name associated with a photograph; Remembering a hidden belonging, in which the examiner hides from sight some object belonging to the patient, than instructing the patient to remember where it is hidden and than later ask for it. Remembering an appointment, Remembering a newspaper article: the subject has to recall it later. Face Recognition in which 5 photos seen a few minutes earlier must be identified out of a group of 10. Remembering a new route (immediate and delayed [10 min] recall). Delivering a message, Orientation and Date are also tasks of the RBMT. Picture Recognition, in which 10 pictures are shown the subject who, a little later, is asked to identify them when they are mixed with 10 foils. The revision (RBMT-II) has the same format as its predecessor. 2 sets of adult norms are available, for ages 16-64 and 65-96, and it can also be used with children in the 11-15 age range. The tests themselves differ from the original in that the 5 faces for ‘Face Recognition’ include persons from other than European stock, and instructions for ‘Remembering a new route’ have been clarified to facilitate scoring. Picture stimuli are now presented in booklets rather than on separate cards.
Neuropsychological findings.
The memory problems of moderately to severely injured TBI patients are brought out by this test. Geffen, Encel and Forrester found that length of coma was significantly associated with lower RBMT scores. When compared with stroke patients, TBI patients tend to do more poorly on remembering names, the appointment, orientation, pictures and the story on both immediate and delayed trials. When comparing stroke patients with lateralized brain injury, only the relatively lower scores on name recall and delayed story recall distinguished those whose damage was on the left. ‘Remembering a hidden belonging’, in itself, is useful in identifying patients with impaired prospective memory; invariably, persons who fail this test have sustained frontal lobe damage. The test does have practical value, but it lacks sensitivity at both the high and the low ends of memory functioning. The test is useless for identifying subtle or small memory deficits. The RBMT has been a useful instrument in the characterization of memory impairment in disorders ranging from basal forebrain amnesia, Parkinson’s disease, cardiac failure, TBI, MS, normal aging, liver failure, MDMA (XTC), stroke, Alzheimer’s disease and dementia, to limbic encephalitis.
The Rivermead Behavioural Memory Test (RBMT-E)
The test has been modified for patients with more subtle memory problems. The RBMT-E increases the level of difficulty by doubling the amount of material to be remembered and by combining material from forms A and B, and C and D of the original test to produce 2 parallel versions of the new extended test which avoids the ceiling and floor effects associated with the original scale.
Learning and Memory Battery (LAMB)
The battery has only 1 form, and includes 7 tests: Paragraph lists 31 items about a person, which is read twice with free and cued recall trials following each reading (delayed [free and cued] recall after 20 min, multiple-choice recognition). Word List contains 15 words, each from a different category. Free and cued recall trials for 5 trials or until the subject recalls all words in 2 trials. Word Pairs consists of 3 easy and 11 difficult word pairs using the selective reminding procedure. Digit Span records the longest number of digits recorded in forward and backward series. Supraspan is a 12-trial testing learning of a span 2 digits longer than Digit Span forward. Simple Figures presents 4 simple geometric figures for 15 sec in 3 acquisition trials with a 20 min delayed recall trial, which is followed by a copy trial. This quite easy task was included to assess persons unable to learn the Complex Figure (the Taylor Figure). In 4 acquisition trials the figure is exposed 30 sec each time, than delayed recall and copy trial. Each subtest yields 3 scores: initial trial score, total trial score, and retention.
Battery characteristics.
The most interesting and clinically valuable contribution of this battery may be the acquisition format developed for the 2 visual learning tests. Because norms are available for every trial for every test, all of the battery’s tests can be used apart from the battery. The relatively long lists of items in the 3 list-learning tasks may well provide for finer gradations of deficits, and the thoughtfully selected foils is a useful addition. A downside of the test is that all the word-based tests succeed one another, as are the 2 number-based tests, as are the 2 drawing tests. When given as a whole, may of the battery’s findings will be very likely be redundant: Paragraph, Word List and Word Pair are all a form of cued list learning. There is no doubt that the tests in this battery will examine memory efficiently and will distinguish memory problems as well as other batteries. However, many clinically relevant questions about memory and learning can probably be answered with fewer tests more appropriately administered.
PAIRED MEMORY TESTS
Each test set in this category consists of 2 tests, 1 verbal and 1 presumably nonverbalizable, with the stated or implied purpose of examining material-specific memory disorders.
Russell’s Version of the Wechsler Memory Scale (RWMS)
The measures of immediate recall Logical Memory (LM) and Visual Reproduction (VR) (both from WMS) together provide a balanced assessment of verbal (semantic) and configural (figural) memory. First administration of the test directed by Wechsler, than second recall trial 30 min later. For each test there are 2 sets of 3 scores: short-term memory score, long-term memory score, and Percent Retained. Formula Percent Retained:
( delayed recall / immediate recall) x 100 On the delayed trials, when the subject denies any recall, the examiner can suggests questions.
Test set characteristics.
As is typical for memory tests, significant practice effects appeared over the course of 4 administrations of the 2 tests in this set when given at 1 week to 3 month intervals.
Neuropsychological findings.
Comparisons between semantic/verbal and figural scores distinguished between left and right lateralized lesions. Percent Retained also proved effective in discriminating between a group of dementia patients and normal aging. But Percent Retained alone can’t tell much about the subject’s performance.
Recognition Memory Test (RMT)
This is a set of 2 tests, parallel in form but providing verbal (words) and nonverbalizable (faces) stimuli for assessing material-specific memory deficits for adults in the 18-70 age range. Both tests contain 50 target memory items followed by a recognition trial pairing the targets with 50 distractors. All items in the Recognition Memory for Words (RMW) test are 1 syllable high frequency words. For the recognition trial, subjects see a large card with each target word listed and paired to the left or right of a foil. In the Recognition Memory for Faces (RMF) test all faces are male (clothing below the neck included). The recognition trial pairs each target face with a photo of a man of similar age and with similar hairline, again with randomized right-left positions.
Retention is assessed immediately after the learning trial by asking the subject which item of each word or face pair had been seen earlier.
Neuropsychological findings.
In a study of the effects of lesion lateralization, patients with right-sided lesions performed in the impaired range only on RMF, but patients with left-sided brain injury performed poorly on both tests, although better on RMF than those with right-sided damage. Some patients with lateralized memory impairment may use the clothing on the pictures to help remember particular faces. Some data suggest that RMT floor effects limit discriminations at low levels of functioning. RMW and RMF are quite effective at differentiating dementia patients from normal subjects. The RMT is suitable for measuring mild memory disorders and is certainly appropriate for patients with motor disorders.
Memory Test for Older Adults (MTOA)
The MTOA consists of paired memory tests (Word List, Geometric Figure) explicitly designed for persons 55 years and older, and has 2 forms with multiple learning trials. The longer one (MTOA:L) is intended for diagnostic use when the question is whether memory is impaired. The shorter form (MTOA:S) contains less difficult stimuli to be used when memory impairment is no longer in doubt. The short and long form have the same overall format. The MTOA:L Word List presents 15 words over 5 trials, with category cueing for each word not recalled. ± 10 min after the final trial, both free and cued recall is tested again. Recognition memory testing has the patient circle the 15 correct words interspersed among 30 foils. MTOA:S uses a 10-word list, 3 trials and 20 foils. The Geometric Figures test consists of either a 13-component design (MTOA:L), or 9 component design (MTOA:S). In each of the 3 learning trials, the figure is shown for 30 sec (MTOA:L) or 15 sec (MTOA:S). The subject draws the figure following each presentation. ± 10 min after the final trial, delayed recall is tested, followed by a copy trial.
MEMORY QUESTIONNAIRES
Questionnaires that document patients’ self-perceptions can be used to characterize the nature of a patient’s memory problems as measures of the accuracy of the patient’s self-perceptions. Questionnaires may also be used when counseling the families of patients whose lack of appreciation of their memory deficits can create very practical problems for both themselves and their families. Memory questionnaires differ on a number of dimensions: length, responses (for example: Likert-scale or yes/no), more or less ease of administration, scoring, interpretation, reliability. The usefulness of memory questionnaires to predict memory impairment has been called into question.
Memory Functioning Questionnaire (MFQ)
This questionnaire was devised for examining memory complaints of older people. Its 64 items come in 7 sections, each to be rated on a 7-point scale. It begins with a general rating about the presence of memory problems. Frequency of forgetting (1stsection, 18 items) asks how often common memory problems occur; in dementia studies 2 items are omitted. The 2and 3sections (5 items each) have to do with the frequency of poor reading recall. Section 4 (4 items) asks about quality of recall of “things that occurred” anywhere from last month to between 6 and 10 years ago. The 5section repeats the 1section, asking for rating of seriousness of the memory problem. The 6thsection (Retrospective Function) asks for comparisons of current memory with 5 time frames. The last section, Mnemonics Usage, gives a list of 8 compensatory techniques to be graded for frequency of usage. This format effectively distinguished depressed middle-aged persons from a nondepressed group. The complexity of the test makes it unreliable for assessment of more than quite mildly impaired persons.
Inventory of Memory Experiences (IME)
Recall of both remote and recent personal experiences is examined by this inventory. 48 questions (Part F, frequency) have to do with how often one forgets personal day-to-day events and details. Part R (remote) consists of 24 questions of remote memory. All questions are accompanied by a follow-up question, and all are rated on a 7-point scale. 8 factors emerged when analyzing part F: rote memory; absent-mindedness; names; people; conversations; errands; retrieval; and places. Women recalled memories from early childhood a little better than men.
Subjective Memory Questionnaire (SMQ)
This shortened and somewhat simplified variation on the IME consists of only 43 questions with a 5point rating scale. Most questions call for an evaluation of how good is memory or learning for specific material, and 7 require judgment of the frequency of a problem. This questionnaire differentiated moderate from severe TBI patients. Comparisons of self-ratings by TBI patients living at home with those of their relatives found that the patient indicated better memory than their relatives did. Temporal lobe patients reported significantly more memory problems. Their overall levels of memory problems brought to light some unexpected interactions between age at time of surgery, time since surgery, sex, and side of excision.
Memory Assessment Clinics Self-rating Scale (MAC-S)
This 49-item questionnaire addresses the Ability to remember and the Frequency of Occurrence of memory problems in 2 separate scales containing 21 and 24 items, plus 4 Global Rating items involving comparisons with others, to previous best memory, speed of recall, and degree of concern about memory. Each item is rated on a 5-point scale. There are 5 Ability factors: Remote Personal Memory, Numeric Recall, Everyday Task-Oriented Memory, Word Recall/Semantic Memory, and Spatial Topographic Memory. There are also 5 Frequency of Occurrence factors: Word and Fact Recall/Semantic Memory, Attention/Concentration, Everyday Task-Oriented Memory, General Forgetfulness, and Facial Recognition.
Memory Questionnaire
It is a 30-item scale in which each item is associated with one of 4 “factor-driven memory” classes/scales: Attention/prospective memory (15 items), Retrograde memory (7 items) Anterograde memory (3 items), Biographic/overload memory (3 items), plus 2 items of currently relevant memory. Each item is rated on a 5-point scale. TBI patients in rehabilitation reported more memory problems in all 4 memory categories than did control subjects.
Everyday Memory Questionnaire (EMQ)
This questionnaire has 27 items that must be rated on a 9-point scale, ranging from “Not in the last 3 months” to “More than once a day”. Items are divided in 3 classes: 6 ‘floor’ items concern memory problems that typically trouble only very impaired persons; 6 additional items were added when reported by 2 or more of the original study patients or their relatives; and discriminator items. On a somewhat simplified version of this test stroke patients 1 month post-onset reported significantly more memory problems than control subjects, and their relatives reported even more than the patients.
Memory Symptom Test
This memory quiz asks patients to compare their current memory in 10 areas of common memory complaints (for example: knowing the month, remembering names enz.) with what it was before it was impaired (rated on a 3-point scale: unimpaired, slightly impaired, very much impaired)
13. Verbal and language skills
Aphasia Occurs as part of the behavioral picture in many brain disorders -Question is not whether the patient has aphasia, but rather how the aphasia contributes to the patient’s behavioral deficits. Questions concerning the presence of aphasia can be answered by a systematic review of the capacity to perceive, comprehend, remember and respond. Such a review includes examining the following aspects: 1) spontaneous speech; 2) repetition of words, phrases and sentences; 3) speech comprehension -give simple commands, yes-no-questions, pointing to specific objects; 4) naming -for example; asking for names, colors, letters of objects; 5) reading (aloud); 6)writing.
Fluency -ease and quantity of production Prosody -articulatory error, speech rhythms and intonation Paraphasias -presence of misspoken words
An examiner should be aware that familiar and personally relevant stimuli will elicit the patient’s best responses (Patient communicate better at home with family than on standardized test).Formal aphasia testing may be done for the following purposes: 1) diagnosis of presence and type of aphasic syndrome, 2) measurement of the level of performance over a wide range, 3) comprehensive assessment of the assets and liabilities of the patient in all language areas.
Aphasia Tests and Batteries Test batteries -most widely used aphasia tests. Product is score of index for diagnostic purposes or an orderly description of communication disabilities. They include a wide range of tasks. Items represent very simple and concrete tasks most children can pass (questions about naming objects, recognizing spoken words, acting on serial commands, repeating words and phrases, recognizing simple printed letters, giving verbal and gestural answers, printing or writing letters, words, etc.) Some tests discussed:
Y BDAE-2/BDAE-3 (Boston Diagnostic Aphasia Examination)
BDAE-2 provides for a systematic assessment of communication and communicated-relation functions in 12 areas, with 34 subtests. A complete examination takes 1-4 hours. BDAE-3 has a short version that only takes an hour. The extended version of 3 contains instructions for examining the praxis problems. Evaluation is based on thee kinds of observation. Score for the Aphasia Severity Rating Scale has a 6point range for BDAE-2 and a 5-point range for the BDAE-3. Subtests are scored for number correct and converted into percentiles. These scores are registered on the subtest summary profile, so the examiner can see at a glance the patient’s deficit pattern. For some of the scales relatively low interrater reliability coefficients have been reported. Supplementing de BDAE is a Spatial Quantitive Battery. Patients with both frontal and parietal damage are most likely to be impaired on this test. The range and sensitivity of the BDAE makes it an excellent tool for the description of aphasia and treatment planning. Further has it evident face validity.
Y CADL-2 ( Communication Abilities in Daily Living)
The original CADL examined how people might handle daily life activities by engaging them in role playing. CADL-2 eliminated the role-playing part and retained the focus on naturalistic everyday communication. There are 7 communication categories: 1) reading, writing and using numbers, 2) communication sequences, 3) social interactions, 4) response to misinformation or proverbs, 5) nonverbal communication, 6) contextual communication, 7) recognition of humor, metaphor. CADL is sensitive to aphasia, age, institutionalization, but not for sex or social background. The categories also identified subtypes of aphasia. CADL-2 has test-retest reliability and interrater reliability. It tends to be more sensitive to the communication strength of many speech-impaired patients than are traditional testing instruments.
Y FCP (Functional Communication Profile)
45 items, takes 20-40 minutes. Evaluation proceeds in five different areas: movement, speaking, understanding, reading, other. Test has no sex bias. Scoring is on a 9-point scale and are recorded on a histogram. Test is of practical value in predicting functional communication and for documenting poststroke improvement.
MAE ( Multilingual Aphasia Examination)
A seven-part battery to provide for a systematic, graded examination of receptive, expressive and immediate memory components of speech and language functions. Most of the tests have two of three forms -reducing practice effects. Each test -age and education sensitive, effects have been reported for many of them. Each test can be used separately.
NCCEA (Neurosensory Center Comprehensive Examination for Aphasia)
24 short subtests, 20 different aspects of language performance and four control tests of visual and tactile functions. These last are only given when a patient performs poorly on visual and tactile stimuli. A variety of materials are used and they can all be easily purchased. This test has proven sensitivity, particularly for moderately and severely aphasic patients and also for distinguishing kinds and degrees of speech and language impairments.
PICA ( Porch Index of Communicative Ability)
Highly standardized, statistically reliable instrument for measuring a limited sample of language functions. Contains 18 ten-items subtests, four of them verbal, eight gestural and six graphic. Each response is scored according to a 16-point scale. Each point describes performance. Testers undergo a 40-hour training which lead to higher interrater reliability. PICA provides sensitive measure of small changes in patient performance. The data it generates are too limited for making diagnostic classifications or inferences about underlying structural damage.
WAB (Western Aphasia Battery)
Many of the items were taken from BDAE. WAB consists of four oral language subtests, spontaneous speech, auditory comprehension, repetition and naming. Each score can be charted on a 10-point scale, the scores together give a profile of performace. The Aphasia Quotient can be calculated by multiplying each of the scores by 2 and summing them. 100 is normal performance. Tells nothing of the nature of the problem. WAB had been used to evaluate the language abilities of patients with a variety of neurological diseases. Patients with strokes on the left were significantly impaired on all five scales. Lower fluency, repetition and naming scores distinguished left hemisphere stroke patients from patients with mild Alzheimer disease, for example.
Aphasia Screening Are best used as supplements to a neuropsychological test battery. They do not enable the examiner to make either a reliable diagnosis or the fine discriminations required for understanding the manifestations of an aphasic disorder.
Aphasia Screening Test Created by Wepman. Most widely used of all aphasia tests. Has 51 items, which cover all the elements of disabilities and takes rarely longer than 30 minutes to complete. There are no rigid scoring standards. There are no provisions made to grade test performance on the basis of severity, nor information provided for classifying patients, nor are guidelines given for clinical application. Wepman rejected the test, because it contributed more confusion than clarity to diagnosis and description. A second revision appeared -Aphasia Test, contains 37 items. Has a simple error-couting scoring system which converts to a 6-point rating scale. Snow did item-by-item comparisons and found that only one item, copying the drawing of a key, discriminated significantly the two groups -right hemisphere disease made more errors on this item. Significantly correlations between this test and both mental ability and education have been recorded. If one goes by score alone, this test cannot qualify for aphasia screening.
Token Test
Created by De Renzi and Vignolo. Simple to administer, score and sensitive to the disrupted linguistic processes. Can identify those brain damaged patients whose other disabilities may be masking a aphasic disorder. Consists of 20 ‘tokens’-made from construction paper, thin sheet, plastic or wood and in two shapes ( circles and squares), two sizes (big and little) and five colors. They are laid horizontally in four parallel rows (big circle, little circle, and big square, little square). The only thing a patient has to do is to follow up the instructions, for example: touch the red circle, touch the small blue circle, etc. Each correct response earns 1 point on the 62-point scale.
Instructions are separated in 5 parts, part 1 to 4 contain 10 items, part 5 contain 22. 1 -only about large circles and squares, 2-about large and small circles and squares, 3-same as part 1, but instruction is combination (touch red square and white square), 4 -same as part 2, but instruction is a combination, 5 -large squares and circles, involving relational concepts. Part 5 alone could be used without the other 40 questions to identify those patients with left hemisphere lesions misclassified as nonaphasiac.
Age effects have been documented, men and woman perform similarly, test-retest reliability was high (between .92 and .96) on aphasic patients and .50 by intact elderly. Practice effects were nil. These tasks give the examiner insight into nature of comprehension or performance deficits. Patients whose failures are mostly due to auditory comprehension tend to confuse colors or shapes and to carry out fewer than the required instructions. A study found the Token Test to be sensitive to dementia severity.
Spreen and Benton developed 39-item modification of Token Test, from which Spellacy and Spreen constructed a 16-item short form that used the same 20 tokens and includes many items from part 5. This last test identified 85% of the aphasiac and 76% of the nonaphasiac brain damaged patients. There is a short version of the token test, which consist of 36 items and takes half the time of the original. It contains a sixth part, the new part 1, which contains 7 items requiring comprehension of only one element in combination with ‘touch’.
Verbal expression
Naming
Confrontation naming -ability to pull out the correct word at will, when impaired -dysnomia. Left temporal lobe is essential for this task in right-handers. Lesions of posterior superior temporal and inferior parietal regions -semantic paraphasic errors. Lesions of insula and patamen -phonologic paraphasic errors. Confrontation naming is conducted with body parts and objects, going from the most frequently used name to names often called upon. Pictures are the most usual stimulus. Kremin recommended asking for verbs and prepositions. Pictures sets with only very common objects are unlikely to prove discriminating when examining suspected of early dementia patients.
Boston Naming Test (BNT) -consists of 60 large ink drawings ranging from very familiar to very common pictures. Adults begin with picture 30, moving forward unless they make a mistake in the first eight items. When patients are unable to name a drawing, the examiner gives a semantic cue (it’s a bird), if still unable to give a correct name -phonetic cue (“pe..”) There is also a 15-item short version and a multiple-choice format for recognition testing. 30-year-olds and 50-year-olds do not differ in scores or qualitative responses on the BNT. This test effectively elicits naming impairments in aphasic patients. Kaplan recommends using it with patients with right hemisphere damage too. It is also widely used in dementia assessment as a sensitive indicator of both presence and degree of deterioration. BNT is also effective in identifying word-findings problems in MS patients and following mild head trauma.
Visual Naming Test -30-items, is in Multilingual Aphasia Examination. In a sample of 100 men, education accounted for 13% of the variance.
Graded Naming Test -30 items, early items would be correctly named by most adults and final ones would be so difficult that many normal people would fail them.
Other naming tests -A few studies have compared the retrieval of proper names with object names. Elderly had no more difficulty with both than younger people, mild Alzheimer patients had more difficulty naming famous people based on information than on pictures. The Category Specific Names Test had 4 categories (animals, fruit/vegetables, man-made objects requiring an action and man-made object not associated with a specific action). The Action Naming Test was designed to study verb naming.55 line drawings of actions ranging from common to less common.
Vocabulary Dual function: vocabulary level is excellent guide to general mental ability of intact, well-socializes persons ánd have proven equally valuable in demonstrating the effects of dominant hemisphere disease. Most common used is the individually administered Vocabulary. Words are listed in order of difficulty. Test continues until the subject fail five or six words or until the list is exhausted. The scores reflects both the extent of recall vocabulary and the effectiveness of speaking vocabulary. Takes 15-20 minutes to administer and 5 minutes to score, so it is the most time-consuming verbal test. Education affects vocabulary scores to a much greater extent than age. Sex differences are negligible. Early socialized experiences tend to influence vocabulary development even more than schooling. Practice effects are minimal. Vocabulary has high test-retest reliability (.78 to .84). This test also holds up relatively well in early dementia, but will eventually decline. This test is relatively sensitive to lesions in the left hemisphere.
WAIS-R NI -35 vocabulary words with fives alternatives ( one 2-point, one 1-point and three 0-point). Particularly helpful with patients who can recognize but not bring up spontaneously the correct definition. Mill Hill Vocabulary Scale -mc-test, sensitive to left hemisphere disease and dementia. Little time to administer and easy to score. Gates –Macginitie Reading Tests -vocabulary and reading comprehension test. Four-choice format. There are also nonverbal response vocabulary tests. They permit evaluation of the recognition vocabulary of many verbally handicapped patients. Further you have the PPVT-III and the Quick Test:
-The PPVT consists of 204 picture plates, each with 4 pictures. Patient points to or gives the number of the picture most like the stimulus word. The items span both very low levels of mental ability and levels above average adult ability. The essentially verbal nature of this test has been proven.
-Quick Test -50 items, originally for measuring IQ, but this test primarily examines vocabulary used in situational contexts. Subject is shown a card with 4 pictures and examiner reads words from a list. Patient has to point to the appropriate picture. Test may underestimate mental ability of brightest subjects, but is quite accurate for persons in the average ability ranges.
Discourse Pictures are good stimuli for eliciting usual speech patterns. Open-ended questions about patients activities or skills also elicit samples of their normal speech. To compare people, questions like “how do you shave” (men) and “how do you cook spaghetti” (women) are asked.
Verbal fluency
Impaired verbal fluency is associated with frontal lobe damage. Patients with left dorsolateral lesions were the most significantly impaired on letter fluency task. Patients with superior medial frontal lesions of left or right hemisphere had moderate impairment. With aging writing fluency tends to slow down much earlier than speech fluency, which healthy persons maintain well into the 70s.
Fluency of speech -measured by the quantity of words produced, within a restricted category or in response to a stimulus and usually within a time limit. Has been measured by rate of speech production as well as word counts. Estes points out that successful performance on these tests depends on the ability to organize output in terms of clusters of meaningfully related words. Laine defined two clusters appearing as two or more words with similar features: 1) phonological clusters -share same initial sound (salute, salvage), 2) semantic clusters -meanings are associated (soldier, salute).
Age, sex and education influence performance on these tests. Women do better after age 55 than men. The COWA (Controlled Oral Word Association) consists of three word-naming trials. There are sets of three letters. Words beginning with the first letter have a relatively high frequency, words beginning with the second letter a somewhat lower frequency and words beginning with the third have the lowest frequency. The examiner asks the patients to name as many words as they know that begin with the given letter. The score is the sum of all acceptable words within 3 minutes. Norms are available for education and sex, age/education and ethnicity and for age and ethnicity. The means differ not significant for the different ages and performances for men and women are the same. Researchers concluded that initial responses depended on rapid acces of words from semantic memory with very little effort, while late productions depended on strategies for effortful searching of semantic memory COWA is sensitive indicator of brain dysfunction. Frontal lesions -depress fluency scores, left = lower word production than right. Left temporal lobe epilepsy, MS, mild TBI are often associated with deficits in letter fluency tests.
Category fluency- less difficult than letter fluency. People produce more animals than words. It declines with age. Ethnic differences have been found (Hispanic and African American named fewest animals, Chinese and Vietnamese the most). Alzheimer patients have more difficulty with category fluency than letter fluency, usually attributed to a breakdown in semantic knowledge about categories. This also counts for Parkinson patients. Depressed patients are better in animal naming than dementia patients and they could also name more sad than happy events.
Action fluency: Parkinson patients were compared with elderly subjects on three fluency tasks: animal naming, FAS (letter naming) and verb generation. Results are not the same for different researchers.
Writing fluency -TWFT: write as many words beginning with the letter S as they can in five minutes and then write as many four-letter words beginning with the letter C as they can in 4 minutes. Milner observed that this task was more discriminating than object naming because the writing task is harder. There was a pattern of relative impairments: frontal output < nonfrontal, left < right hemisphere, left frontal < right frontal.
Clinical observations led to speculations that patients with right hemisphere damage may use more words when writing than do other persons. On a number of items of the TAT showed that those patients gave very wordy responses indeed.
Quality of writing is tested by asking patients to write down “Help keep America clean” on an unlined sheet of paper. You can observe spelling, organization, use of capitalization. By comparing oral and written descriptions of Alzheimer patients, the oral ones were longer than the written ones and oral ones were more sensitive to word-finding difficulty.
Writing speed is measured in two ways: speed of copying a 12-word sentence printed in one-inch type and speed of writing dictated sentences. There were no significant differences, but they did show up when the 12-word sentence changed in a 97-word story. When writing speed had been slowed by a brain disorder, the slowing may become more evident as the length of the task increases. The Sentence Writing Time also measures speed of writing.
Verbal academic skills
Reading
Reasons to examining reading: 1) to obtain general appraisal of reading ability in patients without a distinctive impairment of reading skills; 2) to evaluate comprehension of verbal material; 3) for diagnostic purposes; 4) for fine-grained descriptions of very specific deficits for research or treatment purposes. Some tests to measure reading ability are: -GMRT -paper and pencil mc tests. Three of them are appropriate for most adults. It measures two
aspects of reading -simple word recognition and the ability to understand written passages. They both have generous time limits.
-SRA Reading Index -mc test, brief assessment of readings skills: 1) Picture-Word association; 2) Word Decoding; 3) Phrase Comprehension; 4) Sentence comprehension; 5) Paragraph comprehension. Untimes test, which usually takes 25 minutes.
-Understanding communication -40 statements consisting of one to three sentences with the final wording incomplete. People can choose from four one-word or short phrase choices to complete each sentence.
-NART -50 phonetically irregular words. Correct pronunciation of these words implies prior knowledge of them. There do not appear to be sex effects, interrater reliability and test-retest reliability are high. NART scores do show a decrement with dementia severity, this decline is mild compared to measures of cognitive function showing marked declines.
-NAART -61-word version of NART. Modified for appropriateness for North American subjects.
Education was more strongly related to performance than was age. -American NART -27 words from British version and 23 new words. -WRAT-R en WRAT-3 -R = 75 words, age 45 and over and 3 = 84 words, ages 5 to 75. Time
limit for each response is 10 seconds. No sex effects, word pronunciation format is identical to that of the NART. Assumption is that familiar words are pronounced correctly and that familiarity reflects vocabulary. This test gives only a rough measure of academic achievement.
-K-FAST -34 item, reading as it relates to daily activities. No sex effects.
Writing
Patients with right hemisphere lesions tend to repeat elements of letters and words. Patients with left hemisphere lesions are more likely to have a wide right-sided margin and they tend to leave separations between letters or syllables that disrupt the continuity of the writing line. Writing test allow the examiner to evaluate other dysfunctions associated with brain damage. With brain disorder, alterations in writing size or writing output may also occur. There is a three part writing test which shares some items with the BDAE: 1) writing to command, sentence about the weather and sentence about the job; 2) writing to dictation of words; 3) copying a printed sentence in script writing. Patients writing were characterized by dysgraphia in the form of motor impairment, spatial disorders, agrammatism and spelling.
Spelling Can represent the residuals of slowed language development or childhood dyslexia. The subjects background should be taken into account along with the nature of errors.
-WRAT-R en WRAT-3 -15 seconds allowed for each word. Ten failures is the criterion for discontinuing.
-John Hopkins University Dysgraphia Battery -1) primary tasks, A. writing to dictation and B. Oral spelling; 2) Associated Tasks, C. writes the words depicted in a picture, D. gives a written description of a picture, E. and F. copied printed material either directly or as soon as it is withdrawn from sight. 3) Error Coding.
Knowledge Acquisition and Retention
-Information -has been incorporated into neuropsychological assessment batteries and research programs almost universally. The items test general knowledge. Items are arranged in order of difficulty.
-Administration suggestions -you can prepare people for the difficult items to protect them from feeling of failure etc. When more answers are given, the examiner must insist on getting one answer. He may use some discretion in following the rule of discontinuation after 5 failures. On the one hand some patients are unable to recall information on demand and therefore fail several simple items in succession. Little is lost by discontinuing early. On the other hand acquired expertise in their own field will not become evident. You can begin at different difficulty levels for different subjects. It is very important to differentiate between failures due to ignorance, loss of once-stored information and inability to retrieve old learning or say it on commend. Sometimes people cannot answer a question, but they know they once knew the answer. Then you can write down four options and mostly they choose the correct answer. They have problems with retrieval. This kind of additional information (the mc question you give the patient) raises scoring problems. Can be solved with double scoring: scoring under both standard and adapted conditions. This enables the examiner to discover the full extent of the capacity.
-Test Characteristics -information scores hold up well with aging when education effects are controlled. After controlling for age, sex and education there was significant difference in ethnicities. Test-retest reliability is high. Information and Vocabulary are the best measures to general ability.
-Neuropsychological findings -Glucose metabolism increases in the left temporal lobe and surrounding areas during the test, with much smaller increases also noted in the right temporal lobe. Information performance can be a good predictor of the hemisphere side of a suspected focal brain
lesion.
14. Constructional functions
The concept of constructional functions embraces two large classes of activities – drawing and building, or assembling.
Constructional activity combines perception with motor response and inevitably has a spatial component. The integral role of visuoperception in constructional activity becomes evident when persons with more than very mild perceptual deficits encounter difficulty on constructional tasks. Commonly used constructional tests vary considerably in their level of difficulty and in the demands that they place on other cognitive functions. Because of the complexity of functions that influence performance on a constructional test, numerical scores convey only a limited amount of information about an individual’s performance. Careful observation of how patients go about doing constructional tasks and the types of errors they make is necessary to distinguish the possible contribution of perceptual deficits, spatial confusion, attentional impairments, organizational limitations, motor planning difficulties and motivational problems.
Awareness that the two cerebral hemispheres differ in their information processing capacities has brought increasing attention to the differences in how patients with unilateral lesions perform constructional tasks. Patients with right hemisphere dysfunction tend to make a piecemeal, fragmented approach, losing the overall “gestalt” of the constructional task. In contrast, patients with left-sided lesions may get the overall idea and proportions of the construction correct and their drawings may be symmetric, but they tend to omit details and generally turn out a shabby production.
Drawing.
The major subdivisions within this class are copying and free drawing. The overlap between them is considerable, yet many persons whose drawing skills are impaired can copy with reasonable accuracy. Reverse instances are relatively rare. This differential becomes pronounced with advancing age, as copying is relatively unaffected, but free drawing shows a disproportionately greater loss of details and organizational quality of aging.
Drawing tasks have achieved a central position in neuropsychological testing by virtue of their sensitivity to many different kinds of deficits. Although they are a rich sources of data, drawing tests have limits to the amount of information that they can provide. The examiner who uses them needs to remember that every kind of drawing task has been performed successfully by cognitively impaired patients, including some patients with lesions that should have kept them from drawing well. Furthermore, no matter how sensitive these tests might be to perceptual, practice and certain types of cognitive and motor organization impairment, they still leave many cognitive functions unexamined. In drawing, the phenomenon of spatial hemi-inattention tends to be reflected in the omission of details on the side of the drawing opposite the lesion. Patients with unilateral lesions tend to position their drawings on the same side of the page as their lesions, thus under utilizing the side of space that is most susceptible to inattention.
Copying.
Bender-Gestalt Test. The Bender-Gestalt was one of the first and most widely studied tests of drawing. This test serves not only a visuoconstructional task for neuropsychological assessment, but also as a neuropsychological screening measure and as a projective technique for studying personality. The Bender material is a set of nine designs originally used to demonstrate the tendency of the perceptual system to organise visual stimuli into Gestalten. Like other visuographic deficits, difficulties with the Bender are more likely to appear with parietal lobe lesions, especially right parietal lobe lesions are associated with poor performance. A normal appearing Bender clearly does not rule out CNS pathology, but it does reduce the likelihood of parietal involvement. Patients with right hemisphere damage are most susceptible than those with left-sided lesions to errors of rotation and fragmentation. Bender error scores distinguish Alzheimer patients from healthy control subjects.
- Benton Visual Retention Test (BVRT). The three alternate forms of this test permit the use of one of them for a copy trial. The copy trial usually precedes the memory trial, thus allowing the subject to become familiar with the test before undertaking the more difficult memory trials. The performance of patients with frontal lobe lesions differed with the side of injury: those with bilateral damage average 4.6 errors, with right-sided damage 3.5 errors and with left-sided damage the average 1.0 error is comparable to that of a normative group. BRVT copy is one of the predictors of cognitive decline in Alzheimer’s disease, with poorer copy associated with faster rate of dementia progression. Using Binder’s basic approach, Parkinson patients tended to copy the main structural units of the figure poorly, in contrast to healthy elderly subjects who rarely omitted main section elements. Parkinson patients also tended to draw the main elements towards the end of the trial, and this is an interrupted fashion as if main elements were incidental detail rather than critical parts of the figure’s structure.
• Complex Figure Test (CFT). A “complex figure” was derived by André Rey to investigate both perceptual organization and visual memory in brain impaired subjects. Results derived from this test showed that more than twice as many patients with right temporal epileptic foci made two or more errors than did patients whose seizure focus involved the left temporal lobe. Furthermore, researchers found that older and younger subjects did not differ in their organizational approach. Eventually, men tend to get higher scores than women and left-handedness of the subject, plus a mathematics or science academic major, distinguished women whose copies were most accurate from women who performed less well. The overall conclusion is that patients with right hemisphere damage produce much less accurate copies than patients with left CVA’s who, although on the whole less accurate than the normal control group, still showed some overlap in accuracy scores with the control group. Of patients with progressive dementia, Alzheimer patients generally do produce very defective copies, even when many abilities test scores are still within the average range. Huntington’s disease also greatly affects ability to copy the figures but not to the same degree as Alzheimer’s disease.
Free drawining.
The absence of a model changes the perceptual component of drawing from the immediate act of visual perception involved in copying a geometric design or object to the use of mental imagery to create a perceptual construct, a “picture in the mind”, in response to an introduction to draw a particular shape or object. Drawings of left hemisphere patients are more likely to have fewer details, giving the drawings an “empty” or poorly defined appearance. The presence of these lateralizing characteristics may enable the examiner to identify some cognitively impaired patients on the basis of their free drawings.
-Human figure Test. Human Figure Tests have been particularly prized for measuring the cognitive potential of or specific performance patterns of developmentally disabled or neurological impaired children. Human figure drawing tests have also been used as brief cognitive screening procedure with young children. Descriptions of human figures drawn by cognitive impaired patients with either specific visuographic disturbances or conditions of more generalized cognitive debilitation usually include such words as childlike, simplistic, etc. Several features of human figure drawings have been associated with brain impairments: lack of detail, disproportionate size and shape.
-Bicycle Drawing Task. Comparing the accuracy of drawings of a cube, a house and a bicycle, researchers found that 56% of patients with frontal damage failed to draw an adequate bicycle, either due to a generally impoverished rendition or to poor organization, although spatial relationships overall were not likely to be distorted. Failures due to poor organization distinguished patients with frontal lesions (82%) from a group with nonfrontal lesions (28%). Frontal patients tended to draw without an apparent plan and without focusing first on the bicycle’s structure before drawing details. The bicycle drawing task may also bring out the drawing distortions characteristic of lateralized involvement. Patients with right hemisphere lesions tend to reproduce many of the component parts, but misplace them in relation to one another; whereas left hemisphere patients are more likely to preserve the overall proportions but simplify the elements of the bicycle. Severely impaired patents perform this task with great difficulty, producing incomplete and simplistic drawings. -Clock Face Task. Quantitative scores from the varied clock drawing systems are often less helpful in identifying lesion location in patients with focal lesions than are qualitative analyses of their error patterns. Patients with right parietal lesions may be more prone to distort or neglect the lower left quadrant of the clock face, whereas those whose lesions are predominantly right temporal are more likely to have difficulty with the upper left quadrant. Patients with left-sided lesions may be inattentive to the right side of the clock face. Patients with Alzheimer’s disease consistently do much worse than healthy controls on clock drawing tests. Clock drawing performance may be able to differentiate patients with Alzheimer’s disease from those with other forms of dementia. Other researchers made a similar observation regarding the tendency for the clock drawing performance of Alzheimer patients to improve during the copy conditions, whereas that of Huntington patients did not. Although both patient groups made visuospatial errors, graphomotor planning problems were exhibited almost exclusively by patients with Huntington’s disease, whereas conceptual errors were observed primarily in the drawings of patients with Alzheimer’s disease.
Assembling and building.
More than any kind of test, assembling and building tasks involve the spatial component in perception, at the conceptual level, and in motor execution. With Block Design and Object Assembly, the Wechsler tests contribute two of the basic kinds of construction tasks on the neuropsychological examination.
•Block Design. On this construction test, the subject is presented with red and white blocks. The subject’s task is to use one of the blocks to construct replicas of the easy block constructions made by the examiner. Concrete-minded persons and patients – particularly those with right hemisphere damage – with visuospatial deficits have particular difficulty constructing these diagonal patterns. Impaired persons sometimes do not comprehend the Block Design task when given the standard instructions alone. Men generally tend to score higher than women on Block Design, at least at younger age. This may be explained by the Testosterone supplementation. Block Design is generally recognised as the best measure of visuospatial organization in the Wechsler scales. Block Design scores tend to be lower in the presence of any kind of brain impairment, suggesting that test performance is affected by multiple factors. In normal subjects, Block Design performance has been associated with increased glucose metabolism in the “posteroparietal region”, particularly the right side. In patients with lateralized lesions, Block Design performance is most often deficient when lesions are on the right side and involve posterior areas, particularly the parietal region, and is impaired les often when the lesion is confined to the left hemisphere, except when the left parietal lobe is involved. In Alzheimer patients, Block Design performance is strongly associated with atrophy in the right parietal region. Patients with left – particularly left parietal – lesions often show confusion, simplification and concrete handling of the design. In contrast, patients with right-sided lesions may have difficulties with design orientation and may distort major elements of the design. Patients with severe damage to the frontal lobes may display a kind of “stickiness” on this test. In contrast, the Block Design scores of Alzheimer patients are typically among the lowest in the Wechsler battery. Patients with neurodegenerative diseases that typically involve subcortical structures – such as Huntington’s disease, Parkinson’s disease and multiple sclerosis – often do poorly on Block Design, although less so than patients with Alzheimer’s disease.
• Object Assembly. This test contains cut-up cardboard figures of familiar objects. Responses are scored for both accuracy and speed. The speed component of Object Assembly renders it relatively vulnerable to brain impairment in general. As a test of constructional ability, Object Assembly tends to be sensitive to posterior lesions, more so to those on the right than the left. Thus many patients, particularly those with right posterior lesions, who do poorly on Block Design are also likely to do poorly on Object Assembly. The patterns of variations of Block Design and Object Assembly scores relative to one another to other tests allow the examiner to infer the different functions that contribute to success on these tasks:
-Impaired ability for visuospatial manipulation; |
-Impaired ability for visuospatial conceptualization; |
-Ability for visuospatial conceptualization dependent on visuomotor activity; |
-Impaired ability to appreciate details; |
-Structure dependency. |
-Concrete-mindedness. |
15. Performance in executive functioning and motor skills
Motor performance
I Executive functions (EF)
Intrinsic to the ability to respond in an adaptive manner to novel situations.
Basis of many cognitive, emotional and social skills.
• 4 components:
1. volition
2.planning
3.purposive action
4.effective performance
-Each involve a distinctive set of activity-related behaviour.
-All are necessary for appropriate, socially responsible and effectively self-serving adult conduct.
-Defective executive behaviour typically involves a cluster of deficiencies, of which one or two may be prominent.
Which parts of the brain:
• Frontal lobe damage is implicated concerning EF, particularly when orbital or medial structures are involved there are behavioural and personality changes (Phineas Gage).
Subcortical and cortical damage may also be involved. When:
Anoxic conditions that involve limbic structures.
Can be the result of alcohol abuse.
Inhalation of organic insolvents
• For example patients with:
Korsakoff,
some Parkinson patients,
Right Hemisphere Damage.
1. Volition
(Wilsbesluit = het bewust en vrijwillig selecteren van bepaalde handelingen of het maken van keuze uit vele mogelijke handelingen of keuzemogelijkheden. (Reben, woordenboek van de psychologie))
• Precondition for volitional behaviour:
o Motivation
o Awareness of oneself
1.1 Motivation
• Examining motivational capacity:
o Likes- dislikes: many volitionally impaired patients are apathetic with diminished/absent capacity for emotional response.
o Volitionally competent persons make spontaneous (appropriate) conversation or ask questions.
o Volunteer nothing or little.
o Examiner needs to find out and verify credibility of activity plans;
e.g. when they last dated, planning and cooking of meals etc.
1.2 Awareness of oneself,
• Assessment of the capacity for self-awareness depends on observation and interview:
o Defective self-awareness occurs in varying degrees and is multifaceted.
o Self-awareness includes:
1.2.1 Awareness of one’s physical status:
Mature awareness requires an integrated appreciation of one’s physical status and ongoing psychical relationship with the immediate external environment.
Test: awareness of physical self
– Request to draw a human figure.
– Impaired appreciation of one’s physical strengths and limitations.
– Reduced or absent appreciation of physical states and bodily functions.
– Loss of appetite
– Loss of satiation cues
– Sexual disinterest
– Sleep disturbance
1.2.2 Awareness of the environment: An appreciation of being a distinctive person in a world which mainly exists outside of one’s immediate awareness and is inhabited by many other distinctive individuals.
Test: Awareness off the environment and situational context is reflected in patients use of environmental cues
– Asking time of day, season and temporal events or situations (e.g. Christmas) are questions that can easily be deduced of verified by alert patients who are attentive to their surroundings.
– Story and Picture material from standard tests -> Testing the patients ability to infer a story from a picture;
– The problem of facts items -Termen and Merill Standford-Binetscale.
– The Cookie Theft picture -Boston Diagnostic Aphasia Examination.
– Picture Arrangement items – WIS -A.
1.2.3.Social awareness: Appreciation of oneself as an interactive part of the network of a social relationships.
Test: Social awareness tests depend upon interviews and observations;
– Interviews: Information regarding their appreciation of social roles and acceptance of codes of social behaviour.
– Observations: Poor grooming (slechte uiterlijke verzorging) and childish or crude behaviour in contrast with premorbid history of social competence.
Each facet can be disturbed by brain damage and each can be examined in its own right.
2. Planning
The identification and organization of the steps and elements (e.g. skills, material, other persons) needed to carry out an intention or achieve a goal, constitute planning and involve a number of capacities:
– Conceptualize changes from present circumstances -> look ahead.
– Deal objectively with oneself in relation to the environment and view the environment objectively -> take the abstract attitude (see p. 84 chapter 3).
– Be able to conceive of alternatives, weight and make choices.
– Entertain both sequential and hierarchical ideas necessary for development of a conceptual framework or structure that will give direction to the carrying out of a plan.
– Good impulse control.
– Reasonably intact memory functions. All these require: Capacity for sustained attention.
Use of standard examination procedures: Test:
– TAT -> reflect the patients handling of sequential verbal ideas.
– Picture Arrangement and Block design provide information about whether patients order and plan ahead naturally and effectively, laboriously, inconsistently, or not at all.
– Sentence arrangement of the WAIS RNI: can patients organize their thoughts into a sensible and linguistically acceptable construct.
– The complex Figure Test -> elicits planning behaviour: how systematic is the patients response to this task.
– Questioning can bring out defective planning: executing daily procedures such as
– Food purchasing and preparation
– Personal care and grooming.
2.1. Working memory tasks:
Effective planning entails decision making and developing strategies for setting priorities. The working memory depends on an attentional controller, which Baddeley and Hitch (1974) called the supervisory attention system: which selects and operates strategies for maintaining and switching attention as needs arise. Failure of this system produces the Dysexecutive syndrome
Tests:
– Self ordered pointing test:
– Assesses strategy use and self-monitoring.
– Subject points to a stimulus not seen on previous trials, in an array of stimuli on each trial. The position of the stimuli shifts from trial to trial so that the subject must try to monitor previous choices from memory.
– Patients with FL, HD and PD fail
– Maze tracing (doolhof)
– Involvies planning and fore-sight (highest levels of mental functioning).
– Porteus Maze Test:
– Various difficulty levels; scores reported in terms of test age.
– Goal: trace the maze without entering any blind alleys, test is no timed. Test is quite sensitive to brain disorders.
Patients with Frontal Leucotomy.
– Pre-and postoperatively measure showed that psychosurgery resulted in slowing (+ more errors post-operatively).
– Mazes in the Wechsler Intelligence scale for Children (WIS-R WISC III)
– These test batteries contain a shorter maze test with time-limits and an error scoring system.
– Easy to give due to format and time limit and therefore, for clinical purpose, a practical and satisfactory substitute for the lengthier Porteus test.
Tower Test: get to the heart of planning disorders.
Tower of London
– Subject must determine the order of moves necessary to rearrange three colored rings/balls from their initial position on two of three upright sticks to a new set of predetermined positions on one or more of the sticks.
– Goal: measure ability to plan ahead, also working memory, response inhibition and visuospatial memory.
Patients: Focal lesions -> made more moves and used a trial-and-error strategy and slower.
– Frontal lobe dementia -> made more moves, committed more rule violation, made more incorrect solutions and were slower in executing moves.
Tower of Hanoi
– More complex: rings are of varying sizes
– Restriction: a larger ring may not be placed on a smaller ring
– Does not asses planning as much as it assesses inhibiting a prepotent response.
– Goal: constitutes a sub goal conflict: it involves a move that is essential for the solution of the puzzle, but that does not place a ring immediately into its goal position.
Tower of Toronto
– Adds one more layer of complexity: a fourth ring (same sized rings, 4 different colours)
– Restriction: lighter colored rings on top of darker ones as they move.
– The set of four rings has to move from the left of three pegs to the peg on the right.
– Goal: examine planning -> development of strategies, learning, memory of previously developed strategies by second trial after 1 ••• hours.
Battery of Cognitive Processing Tasks
o Visual Search: score is time to find target figure among many figures.
o Trails: alternative version of the Trail making test
o Matching numbers: finding pairs of identical numbers. Factor Analyses: these 3 make clusters
• Every Day Tasks
o The abstract nature of many standard tests is different from planning requirements of ordinary daily activities.
o Several methods have been developed to asses the every day planning skills of patients.
• Script generation
o Technique original developed to study memory functions, but it also investigates the ability to plan sequence of routine actions.
o Involves activities undertaken by almost everyone (e.g. visit to the movies, restaurant, doctor).
o More recently investigators asked subjects to plan actions to be carried out in a virtual apartment presented onan interactive computer screen.
o Two aspects of what seemed to be the same task involved different subsets of the executive functions.
o The authors conclude that the cognitive and behavioural responses generated in laboratory studies differ from those elicited by real life.
3. Purposive action
The translation of an intention or plan into productive, self serving activities requires the actor to initiate, maintain, switch and stop sequences of complex behaviour in an orderly and integrated manner. Disturbances in the programming of activity can thwart the carrying out of reasonable plans regardless of motivation, knowledge, or capacity to perform the activity.
Familiar, routine tasks and automatic behaviours can be expected to be much less vulnerable to impaired brain functions than are not routine or novel activities (particular when impairment involves the frontal lobes).
Tests:
Tinker toy Test (TTT) (Lezak, 1982)
o Opportunity to initiate, plan and structure a potentially complex activity and to carry it out independently.
o The TTT gives the patients an opportunity to make a ‘free’ construction without the constraints of a model to copy or a predetermined solution.
Patients:
– Sensitive to disorders of executive functions in TBI patients.
– The TTT may be useful for differentiating between dementia types.
3.1 Self-regulation
3.1.1. productivity
Reduced or erratic productivity can be due to dissociation between intention and action as well as to weak or absent development of intentions or to a planning defect. In short, a defect of translation from thought to action.
Tests:
Slowed responding is probably the most common cause of low productivity in people with brain disorders. Slowing can and should be documented as it may provide cues to the nature of a disorder which are not apparent in the patients responses in themselves.
– The Cookie Theft Picture
– Patients: timing words per minute show a significant difference between patients with
– Multi-infarct dementia,
– Alzheimer’s disease, and
– Elderly controls.
– Picture completion, Picture Aaangement, Block Design
3.1.2: Flexibility and the capacity to shift
The ability to regulate one’s own behaviour can be demonstrated on tests of flexibility that require the subject to shift a course of thought or action according to the demands of the situations. The capacity for flexibility in behaviour extends through perceptual, cognitive and response dimensions. Defects in mental flexibility show up perceptually in defective scanning and inability to change perceptual sets easily. Conceptual inflexibility appears in concrete or rigid approaches to understanding and problem solving, and also as stimulus-bound behaviour in which these patients cannot dissociate their responses or pull their attention away from whatever is in their perceptual field or current thoughts. Inflexibility of response results in perseverative, stereotyped, nonadaptive behaviour and difficulties in regulating and modulating motor acts. Typically associated with lesions in the frontal lobes.
Distinguish:
perseveration: is due to a breakdown in automatic regulatory mechanism and results from an inability to terminate an activity or switch into another activity (stickiness). repetition: is due to attentional deficits made by patient whose abilities for mental and motor flexibility are intact, but who have difficulty keeping track of immediately previous or ongoing actions.
Tests:
Perseveration or inability to shift smoothly through a movement, drawing or speaking sequence is always evidence of the patient’s difficulty with self-regulations!
• Use of Objects and Alternate Uses Test (AUT)
o Assess inflexibility in thinking and identifies creativity in bright children.
o Task: write as many uses as possible for five common objects (pencil, paperclip etc.)
o Convergent thinking = search for the ‘right’ or logical solution.
o Divergent thinking= many different and often unique and daring ideas are generated without evident concern for satisfying preconceived notions of what is correct or logical.
o Divergent thinking -> sign of cognitive flexibility.
• Homophone meaning Generation Test
o Tests flexibility in thinking.
o Task: generate at least 3 different meanings for 8 common words. Each of the words (form, slip, tick, tip, bear, cent, right, and bored) has at least 3 distinct meanings.
o Requires switching among dissimilar verbal concepts.
o Patient:
• Frontal lesions have deficits in generation of concepts and in cognitive flexibility
• Item Generation
o Effective means of exploring EF.
• Cognitive Bias Task (CBT)
o Subject has to indicate a preference, there is no right or wrong.
• Design Fluency
o This test was developed as a nonverbal counterpart of Thurnstone’s Word Fluency test. In the first – free condition-trial, the subject is asked to ‘invent drawings’ (many different) that represent neither actual objects nor nameable abstract forms and that are not merely scribbles. Second condition is fixed (4 lines). Examiner closely monitors and interacts.
• Five Point Test
o Material: page with 40 adjacent squares in a 5 x 8 array, each square contains five symmetrically and identically arranged dots.
o Task: make as many different figures as possible by connecting the dots with straight lines without repeating any figure.
• Ruff Figural Test
o Variation on the Five Point Test with interference patterns and asymmetrically placed dots.
Design Fluency Test
o 3 Conditions with filled and/or unfilled dots, between which lines have to be drawn. Test is time limited.
3.1.2.1. Assessment of perseveration
Perseveration is one of the hallmarks of impaired capacity to shift responses easily and appropriately. Goldberg and Bilder describe 4 types of perseveration: 1.hyperkinetic-like motor perseveration: the inability to terminate an elementary movement that continues in multiple overdrawings of single elements of continuation until stopped by the edge of the paper (= true motor perseveration). 2.perseveration of elements: elements of previous drawings are introduced in new ones. 3.perseveration of features: features (e.g. openness) of previously drawn figures are introduced in new ones. 4.perseveration of activities.
Tests: Copying and drawing tasks containing repeated elements tend to bring out preservative tendencies
-E.g. to copy and maintain alternating letters or patterns or repetitive sequential patterns of hand movements with separate trials for each hand ( to determine whether there are laterality differences in hand control).
-Copying and drawing: perseveration patients often have difficulty in just writing the alphabet, number series or their address.
-Perseveration is least likely to show up in signatures (over practiced).
3.1.2.3.Examining motor regulation
– Luria techniques: many examination techniques used today were described by Luria (1966) and incorporated into test protocols. Important when testing motor regulation is that the task is continued long enough for defective responses to show up. If patient’s responses deteriorate, the examiner should ask the patient to recall the instructions as patients with frontal lobe damage may be able to repeat the instructions accurately while continuing to respond incorrectly, thus demonstrating dissociation between comprehension and action.
– Impaired regulation of motor responses can be elicited by test in which the patient must make converse responses to the examiner’s alternating signals.
– Withholding responses (the go/no-go paradigm) also examines motor regulation. In these formats the subject must respond to only one of two signals.
Tests
– Behavioural Dyscontrol Scale
– Executive Control Battery: the four tests in this battery derive from the work of Luria
– The Graphical Sequences Test involves drawing sequences of simple figures following verbal commands. Scored for the presence of the four types of perseveration (see above).
o Manuel Postures Test assesses ability to imitate hand postures.
o Motor Sequence Test requires quickly changing movements of one or both hands.
o Competing Programs Test examines ability to respond to commands under conflict conditions.
• Frontal Assessment Battery (FAB) has items examining:
conceptualization (similarities on three items)
item generation (letter fluency)
motor sequencing (Luria’s “fist-edge-palm”)
sensitivity to interference (conflict task)
inhibition control (go/no-go task)
environmental autonomy (testing for imitation or utilization behaviour).
• Perseverance
o Problems with perseverance may also compromise any kind of mental or motor activity. Inability to persevere can result from distractibility or it may reflect impaired self-control.
4. Effective Performance
A performance is as effective as the performer’s ability to monitor, self-correct and regulate the intensity, tempo and other qualitative aspects of delivery. Some patients cannot correct their mistakes because they do not perceive them.
Testing performance effectiveness: All test performances provide information about how the subject responds. The nature of the patient’s errors, attitudes (including awareness and judgement of errors) idiosyncratic distortions, and compensatory efforts will often give more practical information about the patient than test scores that can mask either defects or compensatory strengths.
Tests:
• Random Generation Task
o The subject is asked to generate a sequence of 100 letters of the alphabet in random order.
o Output is measured in three ways: -the frequency of each letter, -the frequency of letter pairs, and -the frequency of letter pairs in alphabetic sequence
o As in fluency tests which forbid repetition, self-monitoring is necessary for success on this task; when self monitoring fails, this task will be failed.
• Mental Dice Task:
o Subjects are asked to call out digits in a sequence as random as possible.
• Patients:
Patients with frontal lobe dysfunction are impaired on these tasks as they demonstrate a strong sequential response bias.
Patients with anterior communicating artery aneurysms.
Korsakoff’s syndrome.
Parkinson’s disease.
Alzheimer’s disease.
II: Executive functions: wide range assesment
Some techniques for examining EF involve so many aspects, that they defy classification. Naturalistic observation being the most important but time consuming, the tests below are useful substitutes.
Tests:
• Behavioural Assessment of the Dysexecutive Syndrome
o Set of tests developed to examine performance on a wide range of real-world tasks:
Rule Shift Card Test (assesses flexibility).
Action Program Test (figure out a way to get a cork out of a tube).
Key Search Test (finding a lost key in a square-shaped area).
Temporal Judgement Test (ask question about how long activities take)
Zoo map Test (planning an effective route through a zoo).
Modified Six Elements Test (planning and priority).
• Delis-Kaplan Executive Function System
o Set of nine tests, each intended to stand alone (no composite score).
o Authors state that tests were selected to be sensitive to many of the types of executive impairment seen in patients with brain disorders.
Trail Making Test
Verbal Fluency
Design Fluency
Colour-word Interference Test (Stoop conflict task)
Twenty Questions Test
Tower Test
Proverb Test
• Executive Function Route-Finding Task
o To accomplish this task subjects must find their way from a starting point to a predetermined destination within the building complex in which the examination is given (with a minimum of five choice points and one change in floor level away from starting point).
o Performances are rated on a 4-point scale to measure the degree to which the patient was dependent on the examiner for:
understanding the task;
seeking information;
remembering instructions;
detecting errors;
correcting errors;
ability to stick with the task (on-task behaviour).
• Behavioural Assessment for Vocational Skills: Wheelbarrow Test
o This ingenious and quite naturalistic examination technique requires the subject to assemble the parts of a mail-order wheelbarrow within a 45 minute period.
o Performances are rated on a 5-point scale for 16 vocationally relevant aspects such as
following directions, problem solving, emotional control, judgment and dependability.
III Motor performance
Whether a disturbance of motor function is the result of executive dysfunction or specific disorders of motor functions is a difficult distinction to make. As such, many motor disorders that accompany cerebral brain damage cannot, by themselves, necessarily be linked with particular anatomic areas.
Examining for Apraxia
Apraxia = disturbance of purposeful expressive functions, literally “no work” (= onvermogen om doelbewust handelingen uit te voeren). It typically involves impairment of learned voluntary acts, despite adequate motor innervation of capable muscles. Examination by reviewing a variety of learned movements of the face, the limbs, and the body. The integrity of learned movements (particular of the hands) is examined under two conditions:
1) Imitation of the examiner of a) symbolic or communicative movements, such as familiar gestures; b) using actual objects; or c) pantomiming their use without objects.
2) To command for each of these three kinds of activity.
Patients: focal lesions or degenerative diseases such as Huntington’s disease, Alzheimer’s disease, Parkinson’s disease and corticobasal degeneration may produce apraxia. Apraxia may occur in only one or two modalities, usually with visual (imitation) or verbal (command) presentation. Failure is more likely in command than in imitation.
Neuropsychological Assessment of motor functions: The motor dysfunctions within the reach of neuropsychology are those that can occur despite intact capacity for normal movement.
Tests:
– Purdue Pegboard Test To assess manual dexterity (handigheid) for employment selection . It has been applied to question of lateralization of lesions and motor dexterity among brain-damaged patients.
– Standard instructions: the patient places the pegs first with the
preferred hand, then the other hand and then both hands simultaneously. Each condition lasts for 30 seconds.
– The score is the number of pegs placed correctly.
– Test characteristics: women do better on this test, scores dropping with advancing age.
The disparity between hands tends to increase with age; the non dominant hand shows greater slowing over time.
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