Neuropsychological assessment
College 1 Introduction
Neuropsychologist has several tasks, testing, supervising and advising
teams of health care professionals, report writing, conducting interviews
and multidisciplinary meetings.
Case report - Anamnesis is an interview with a patient, heteroanamnesis is
an interview with a close relative from the patient.
Neuropsychological assessment has multiple purposes
- The first aim of neuropsychological assessment is diagnosis:
distinguish between different neurological disorders, for example
different types of dementia. Discriminating between psychiatric and
neurological disorders, for example depression and psychiatric
disorders. And identifying a possible neurological disorder.
Neuropsychological assessment cannot localize the site of a lesion.
To localize you need neuroimaging techniques like PET or MRI. Or by
looking at a picture of the brain networks.
- A second purpose is patient care and planning: Identifying cognitive
strengths and weaknesses. Identifying behavioral alterations. And
identifying personality characteristics. Patient care and planning are
irrespective of a diagnosis and it is needed for optimal and careful
management of many disorders.
- The third goal is treatment planning and remediation: determine
what the most appropriate cognitive rehabilitation treatment is.
- The fourth purpose is treatment evaluation: did the treatment have
an effect?
- Another purpose is research, for example: neurological testing for
the master theses.
- Neuropsychological assessment can also be used for forensic
neuropsychology: In the context of claims of injury and loss of
function and in criminal cases. For example: is there reason to
suspect brain dysfunction that contributes to misbehavior or is the
defendant’s mental capacity sufficient to stand trial?
Diagnostic cycle
Neurological assessment starts with a referral
question, the next step is to collect data
about the patients’ medical history, (previous
diagnoses, medication use). Thereafter an
,interview with the patient (anamnesis and heteroanamnesis), can give
insight in the deficits from a patient. Followed by neuropsychological tests
and write a report.
Problem with this procedure: you have to rely on your clinical vision,
difficult if you have no or little experience in the field.
Scientific point of view: case study
Hypotheses also based on scientific literature. When there is a new
hypotheses then the process starts
again.
Evidence based medicine
- Clinical judgement
- Relevant scientific evidence
- Patients’ values and
preferences
Quality of evidence
Quality of evidence from
observational studies is the lowest,
because it is based on one person.
Give more weight to studies with
higher quality of evidence.
Why hypotheses? If you do not formulate hypotheses and go through the
diagnostic cycle you will easily make interpretation errors. Interpretation
errors can be:
- The tendency to rely strongly on some results and to disregard
others (pay much attention to impairments that fit your hypotheses).
And disregarding the base rate of disorders (for example a
neuropsychologist who works a lot with patients with Alzheimer’s
disease will have the tendency to diagnose Alzheimer’s disease
more often).
- Confirmation bias: looking for results that support the hypotheses.
- Thinking that subjective complaints are objective disorders. (Some
that experiences memory problems does not have necessarily have
memory impairment)
Retain – Halstead test battery’s psychometric approach
Standardized assessment and scoring. Uses normative data and cut-off
scores per test and for the total test performance. It is a quantitative test
approach. The test is not based on theories about the brain.
Category test: where does the picture remind of.
Tactual performance test: patient is blind-folded and has to place the
blocks in their appropriate space with the dominant hand.
Speech-sounds perception test: patient has to the underline the syllable
he hears.
Trail making test: in this test the patient has to connect numbers in a
certain order.
,Scoring for each subtest: does the patient score above the cut-off?
Calculate impairment index, above 0.5 means impairment.
For each subtest: does the patient score above the cut-off?
The percentage patients correctly identified as having no brain damage is
specificity.
The percentage patients correctly identified as having brain damage is
sensitivity.
Only indicating does a patient have brain damage or not, global
conclusion.
Criticism on the Reitan-Halstead testbattery:
- It is an a-theorethical approach, not based on knowledge about the
brain or related functions.
- It is a fixed test battery (every patient does the same test).
- And there is only focus on abilities and not on dysfunctions, this has
several problems: impaired performance can have several possible
causes. No insight into the nature of the problem. Gives no direction
for rehabilitation.
Luria’s behavioral neurological approach
After the second world war: a large number of patients with brain injury.
Luria Developed a test battery based on his view/theory of the brain. He
linked cognitive functions to different brain areas.
He concluded that attention is regulated by the brain stem. Perception is
related to the posterior part of the brain and organization and planning are
related to the anterior part of the brain.
He also distinguished different levels of processing. Perception primary
(image), secondary (interpretation), tertiary (cross-model integration).
Violin player: movement requires
involvement for the motor functions.
Listing is required which uses auditory
functioning. Feeling the strings uses
somatosensory functioning and visual
functioning is also involved.
The performance is playing the violin, but
a lot of functions are involved. And also,
different brain areas.
Luria used mostly simple tasks, with the aim to provoke symptoms. For
example, the patients’ needs to follow and replicate hand movements.
Another test measures higher order visual functions, visual images where
you have to mention what is represented (for example an old telephone).
Disadvantages: There is no empirical testing of his theory. No normative
date. No standardization. It is based on observations.
, Advantages: It is a flexible test battery, adjusted to the individual patient.
It is a qualitative assessment method and gives direction to rehabilitation.
Criticism on Luria’s method:
- Theory is strongly focused on the left hemisphere.
- No insight into the severity of disorders.
- No standardization, normative date or date about the reliability and
validity of the tests.
Differential diagnostic thinking
Listen to complaints of patients in an unjudgmental manner. Try to cluster
syndromes, symptoms and impairments. Be aware of halo-effect:
assuming that a patient has certain complaints or characteristics which in
reality are not present.
When a patient is coming with memory
complains, there might be memory
impairments. You have to consider which
diagnoses are accompanied by memory
impairment. For example, early dementia or
severe depression. How to distinguish? Both
are related to memory impairment. In early
dementia you expect severe memory
impairment whereas in severe depression there is only mild memory
impairment.
Another example, a child shows low
performance in school. The child could have a
behavior disorder: ADHD or a learning disorder.
How to distinguish these disorders? ADHD is
related to impairments in attention and
hyperactivity, whereas learning disorder is not.
A learning disorder is associated with
impairments in arithmetics and reading.
Neuropsychological assessment focused on different domains for example
intelligence, orientation, attention, speed of information processing,
executive functions (planning, cognitive flexibility, inhibition, working
memory), perception, motor skill (verbal and non-verbal) language, social
cognition, mood and personality. During the diagnostic cycle (medical
history, anamnesis, hetero anamnesis, observations and tests) domains
are repeatly coming back
In neuropsychological assessment you have to make decisions about a
fixed or flexible test battery. Use of quantitative or qualitative approach.
