CHAPTER 2
2.1 introduction
Neuropsychologists are scientist-practitioners.
They have knowledge of neuropsychological symptoms and test methods;
They use this knowledge to make diagnosis and treatments for patients with brain disorder;
They know a lot of neurological and psychiatric syndromes that cause disorders in cognitive
functions, emotions, and behaviour;
They conduct scientific research to increase our knowledge;
They are not a brain researcher.
Before neuroimaging: neuropsychologist looked at bumps in the head to make diagnosis.
After neuroimaging: what is left of the brain, what can the patient still do?
Shepherd Ivory Franz was one of the first psychologists to focus on patients with brain disorders. He
was very interested in plasticity – adaptations from the brain. Franz discovered that other parts of
the brain can takeover certain functions. This is called substitution.
2.2 neuropsychological tests
2.2.1 diagnostic cycle
Neuropsychologist run through a diagnostic cycle that consists of four stages: complaints analysis,
problem analysis, diagnosis and, indication for treatment.
1. Complaints analysis: it includes an interview with the patient and an interview with the
informant
2. Problem analysis: tests
3. Diagnosis: data from the analysis are integrated to draw a conclusion.
4. Indication for treatment: the need for further diagnostics or options for treatment is
examined.
Testing the hypothesis:
1. Multi-informed
Patient, significant other
2. Multi-method
Tests, questionnaires, clinical interview, observation
3. Multi-conceptual
Neuropsychological, personality, contextual environment
2.2.2 referral question and definition of the problem
The assessment always start with a well-defined referral question. Neuropsychologists formulate
additional questions if the current examination renders this necessary.
2.2.3 interview with the patient
Interviewing the patient is important for collecting information about the current complaints and
symptoms and their progression. It also provides an important initial impression of the patient’s
cognitive abilities and their behaviour, which is helpful for the selection of test and questionnaires,
and may contribute to the diagnosis.
,2.2.4 interview with the informant
Not every patient is able to provide reliable information about their complaints. Information can be
obtained from the patient’s partner, children, parents… The informant can also tell about the
limitations in daily functioning, or to assess the workload of the care system.
Interviewing the informant does not necessarily provide a true representation of the actual
functioning of the patient. Emotional overload or underlying relationship problems can result in an
over-reporting of complaints and changes. Acceptance can lead to minimising the complaints.
2.2.5 observation
Observations are crucial for neuropsychological examinations, especially for cognitive functioning.
Observations are recorded because they are as free from interpretation as possible (e.g. people can
see crying as sad but it can also mean frustration, powerlessness, or joy).
2.2.6 tests and questionnaires
Fixed test battery: a predetermined set of tests that is the same for every patient, regardless of their
complaint or the reason for their referral.
Flexible test battery: allows a larger degree of ‘customisation’, with the choice of test being
prompted for each patient by the specific referral question, complaints, and disease, and with the
neuropsychologist having the freedom to adapt the battery on the basis of previous findings.
Computer tests have a high level of standardisation, accurate recording of responses, and time
saving. The disadvantage is that these test lack qualitative observations and flexibility when taking
the test and not everyone is able to use a computer.
Neuropsychologist also use questionnaires about personality traits, styles of coping, and mental
complaints to see if they affect performances on tests or if they determine neuropsychological
problems in daily functioning.
2.2.7 interpretation
Interpretation involves the integration of all the data.
There are a few considerations:
1. Are the test results reliable, valid, and do they truly reflect the level of cognitive or emotional
functioning of the patient who has been examined.
2. Which age groups are represented and have corrections been made for gender and
educational level.
Differential diagnosis: a check to ascertain whether the complaints and problems might not also have
another explanation.
2.2.8 reporting
Reporting can be done verbally and in writing. Written reports are initially drawn up for the referrer.
Verbal reports take place with the patient as well as in multidisciplinary team meetings or in an
meeting with the referrer.
2.3 reliability and validity
Reliability: the accuracy of an instrument. Do the results of the test stay the same when they are
collected at a different time or by different researcher?
Validity: whether the test measures what it is supposed to measure.
, 2.3.1 reliability
Test-retest reliability: the extend to which a test yields the same results when it is taken at different
times by the same patient.
Inter-rater reliability: the degree of correspondence between the results of different researchers
(cohens kappa).
2.3.2 validity
Ecological validity: how accurately a test predicts daily functioning
Face validity: the extent to which a test initially seems to measure what it is supposed to measure.
Content validity: the extent to which a test is representative of the topic that is to be measured.
Construct validity: the extent to which the result of a test actually reflects the cognitive function that
is being assessed.
Criterion validity: the extent to which a test can predict the performance of a patient with regard to
an external criterion – something that needs to be measured but that cannot be directly ascertained.
Predictive validity: how accurately a test predicts actual behaviour.
Concurrent validity: the difference between a neuropsychological test and another tool that
aims to measure the same criterion.
2.3.3 confounding
Confounding factor: an element that affects performance on a test but that does not fall within the
measurement objective of a test.
It is crucial that neuropsychologists include confounding factors in the interpretation of test results.
2.3.4 underperformance
Underperformance (suboptimal performance): a patient’s performance is impaired compared with
what they would be able to achieve if they were to make a normal effort.
A patient that is very tired or nervous will probably underperform what can lead to a false diagnosis.
Various test (Test of Memory Malingering, TOMM) have been develop to identify underperformance.
These tests are based on several principles: A test seems to be difficult and appears to measure a
cognitive function, whereas in fact it is very easy and calls on mental processes that are intact in
virtually all patients with brain damage.
2.4 neuropsychological treatment
Neuropsychological treatment focuses on cognitive disorder, emotional disorders and behavioural
disorders resulting from brain injury.
Neuropsychologist have to have a good knowledge of psychotropic drugs.
2.5 the professional team
2.5.1 the hospital
Neuropsychologist working in a hospital usually collaborate closely with a number of specialities
(neurology, geriatrics, rehabilitation,…).
