Van Zandvoort (2019). Neuropsychological questions and methods

Basic knowledge of neuropsychological is required for the diagnostician because proper referral is necessary. Clinical neuropsychology refers to the scientific area that involves the study of the relationship between the brain and behaviour in patient-oriented research. In clinical neuropsychology, the focus on organic holism tends to change with lateralization and localization and vice versa.

The idea currently is that brain dysfunctions may have consequences that stem from both selective, localization-related disorders as well as more general consequences.

There are several misconceptions about neuropsychology:

1. Neuropsychological diagnostics only involves the examination of functional cognitive disorders and intellectual deterioration
   Neuropsychology also focuses on emotional factors (1), personality factors (2), coping skills (3), the client’s experiences (4), limitations in everyday life (5) and consequences for social roles and relationships (6). Establishing which of the patient’s functions are intact is important in establishing the patient’s independence and his compensation options.
2. The explanation question should require an answer in terms of a medical diagnosis and/or the localization of the lesion.
   The conclusions should be drawn on the basis of cognitive functional domains and their influence on behaviour. This does not necessarily lead to a medical diagnosis. Behavioural information can sometimes offer information for the localization of brain lesions and can be conclusive for medical diagnoses.
3. The psychologist should limit himself to the question originally formulated by the initiator
   The original question is usually vague and is rarely based on knowledge of the capabilities and limitations of clinical neuropsychology. Therefore, other questions should also be addressed.

There are three type of neuropsychological questions:

1. What is the cognitive profile of the patient
   This involves identifying the behavioural, cognitive and emotional disorders. There is no link yet between strengths and weaknesses with certain brain diseases or lesions.
2. Which behavioural consequences can be identified as a result of brain injury
3. What is the cause of the behavioural changes?
   It is important to establish what practical significance this question has for the patient.

Test-retest reliability is important in neuropsychological tests because sometimes tests need to be made in a short span of each other to indicate improvement after treatment or surgery. There are four groups of neuropsychological tests:

1. Level tests and screening tests
   Level tests can be used to indicate general level of cognitive functioning (e.g. intelligence test) Screening tests are presumed to give an indication of a potential deficit. The screener tests should have a low cut-off score (i.e. very sensitive). Examples of screener tests are the NLV and the IQCODE-N (i.e. asking a friend of the client about the client’s cognitive functioning).
2. Cognitive tests
   In order to examine the cognitive functions of a person, cognitive tests can be administered. Attention (1), information processing speed (2), perception (3), memory and learning (4), language (5), spatial functions and executive functions (6), social cognition (7) and targeted action (i.e. praxis) (8) should be assessed. It is not possible to assess everything in its totality so testing should be in accordance with the hypotheses.
3. Emotional functioning, personality and attitude tests
   There are limited tests for this part and mostly observation and interviews are used. The neurological patient’s actual and somatic problems can alter the meaning of depression and personality items. The hospital anxiety and depression scale (HADS) does not contain any items that rely on somatic aspects to reduce that bias. The psychological components attributing to potential issues should be addressed.
4. Clinimetric methods
   These methods focus on instruments that measure the effects of illness and abnormalities (e.g. functional health and quality of life).

There are several commonly used cognitive tests:

1. Attention
   The Stroop test is used to assess selective attention, distractibility and the ability to inhibit responses (e.g. read the colour instead of the colour word). The Bourdon test assesses sustained focused attention (e.g. cross off specific lines). The behavioural inattention test can be used to assess neglect. The test of everyday attention is a screening test for attention. Subtests from intelligence tests are also used to assess attention.
2. Information processing speed
   There is a distinction between psychomotor speed, simple information processing and complex information processing. An interpretation problem is that both the specific cognitive nature of the task and the generally slow pace may result in poor scores. A good reaction time test instrument with the corresponding norms is not available.
3. Perception and visuospatial functions
   There should not be any doubt about the functioning of the sensory organs before testing perception and visuospatial functions. The Cortical Vision Screening Test (CORVIST) is a short screening instrument for the functioning of the sensory organs (e.g. vision). This test, in combination with Visual Object and Space Perception Battery (VOSP) can be used to examine underlying disorders. The Benton facial recognition test can be used to evaluate facial recognition abilities. The Benton Line Orientation Test and the maze tests can be used to measure visuospatial orientation. The Seashore test can be used to examine auditory recognition.
4. Memory and learning
   There are various tests for declarative memory. Working memory can be assessed using registration tasks (e.g. Corsi Block-Tapping Task). There are verbal and non-verbal tests for long-term retention and learning. Semantic memory can be assessed using semantic fluency tests (e.g. recall as many examples of a category as possible).
5. Language
   All aphasia batteries make a distinction between utterances and language comprehension and between disorders at word or sentence level.
6. Executive functions
   The Wisconsin Card Sorting Test, the Tower of London test, the Trail Making Test (TMT) and the Stroop test are used to assess executive functions. Problems with executive tests are that the tasks are quite structured. The executive function route-finding task is a systemized observation method in which participants must independently find their way through a building complex. Observation scales and questionnaires can also be used.
7. Praxis
   The Luria tasks are tasks where a distinction is made between different subclassifications. The Goldberg task is focused on ideomotor apraxia. There are no adequate norms for these tasks.

The main objective of a neuropsychological examination is to be able to establish a cognitive profile in which statements can be made about the cognitive functions that have been affected amidst the cognitive functions that have been relatively spared. The behaviour and behavioural limitations in daily life can be explained on the basis of this functions profile.

It is important to assess information processing speed because it may have an impact on additional test profile without it saying anything about the underlying specific functional domains. Intelligence tests should not be used as a screener for possible disorders in cognitive functioning.

There are several problems in interpretation of neuropsychological data:

1. Test conditions
   It is the question whether a person with brain injury can fully partake in the batteries of tests that are required to assess brain damage. The testability of the patient may skew interpretation.
2. Premorbid functioning
   The premorbid functioning of a patient needs to be assessed when trying to draw conclusions about acquired brain damage. This can be done by forming a purely qualitative idea (i.e. usually stereotyped views) (1), assume that the client has functioned normally before (2) and use the Nederlandse Leestest voor Volwassenen to screen intelligence (3).
3. Multiconditionality
   The neuropsychological test scores are influenced by brain damage as well as other conditions (e.g. age, level of education). Not all of these factors can be taken into account. The interpretation may be skewed because a range of other functions may play a role in determining the neuropsychological test score rather than the issue at hand.
4. Sensitivity and specificity
   This is related to the distinctiveness of a test score with respect to an external criterion (e.g. clinical diagnosis). Sensitivity refers to how often a poor test score is obtained by people with the relevant diagnosis. Specificity refers to how often a good test score is obtained by people without that diagnosis. The sensitivity and the specificity can skew the interpretation of the results (i.e. false positives and false negatives).