Summary Clinical Neuropsychology
Chapter 1: Clinical neuropsychology: a historical outline
Hippocrates (400 BC): all abnormal behaviours and emotions stem from the workings of the brain.
it is incorrect to attribute symptoms to extra-terrestrial forces such as the gods.
René Descartes (1596-1650): the soul is an undivided, independent, yet material entity.
Franz Joseph (1758-1828): there are many mental organs located in the grey matter or cortex of the
brain. development of phrenology.
Greeks distinguished between three different forms of soul: (1) for survival via food intake, (2) for the
activities of an organism in relation to the environment, (3) a higher-order soul that could distinguish
between good and bad.
The ventricles were called cells these cells were the site of the mind: the first cell was assumed to
receive the information from the various senses (sensus communis), the second cell was believed to
interpret the image.
Descartes: people are composed of two substances, namely the body (the res extensa) and the mind
(the res cogitans). Descartes regarded the res cogitans as a kind of manager. He was describing the
idea of the reflex.
Franz Joseph Gall drew up plans for a new psychology, which he preferred to call organology of
craniology (phrenology).
- First of all he assumed that all psychological functions were innate.
- Each of these functions was concerned with an independent organ.
- The functions are located on the outside of the brain, in the cortex.
Empiricism: when you don’t believe in innate characteristics and knowledge (John Locke).
Aleksandr Luria summarised the functional architecture of the brain using three broad classifications:
1. Three continually interacting functional units, related to the subcortical, posterior, and
anterior brain areas (activation, input, and output).
2. Three hierarchically organised levels of processing, related to primary, secondary, and
tertiary zones in the brain.
3. Behaviour that is or is not regulated by language processes, related to the left and right
hemisphere.
Neural networks are computer simulations – computer software that simulates a certain cognitive
function.
Chapter 2: Neuropsychology in practice
Neuropsychological assessment uses hypothesis testing. Neuropsychologists run through a diagnostic
cycle consists of four stages:
1. Complaints analysis
2. Problem analysis
3. Diagnosis
4. Indication for treatment
For each stage they formulate a hypothesis, which they test using data from the patient interview,
observations and neuropsychological tests and questionnaires.
Referral question and definition of the problem: a neuropsychological assessment always starts with a
well-defined referral question. During the examination, neuropsychologists formulate additional
questions if the current examination renders this necessary.
Interview with the patient: an interview with the patient is important for collecting information about
current complaints and symptoms and their progression. It also provides information about the
patient’s level of education, occupation, medication usage, and relevant medical history.
Interview with the informant: an interview with the informant can provide information when the
patient can’t report his/her problems. It provides subjective information and does not necessarily
provide a true representation of the actual functioning of the patient.
,Observation: observations are recorded during the interview with the patient, the tests, and even
outside the examination room. An essential function of observations is to look at how a test score
had been derived.
Tests and questionnaires: the specific tests and questionnaires that the neuropsychologist chooses
will depend on the referral question and the psychometric properties. Important factors: reliability,
validity, normative data, discriminate power (sensitivity and specificity), and the availability of
parallel versions.
Interpretation: this involves the integration of all the data discussed above – the interview with the
patient and informant, the observations, and the test results.
Reporting: this 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.
Reliability = the accuracy of an instrument. It reflects the extent to which the results of a test remain
the same when they are collected at a different time or by different researches.
- Test-retest reliability indicates the extent to which a test yields the same results when it is
taken at different times by the same patient.
Validity = the applicability of a test – whether the test measures what it is supposed to measure.
- The validity of a test consists of:
o Face validity = the extent to which a test initially seems to measure what it is
supposed to measure.
o Content validity = the extent to which a test is representative of the topic that is to
be measured.
o Construct validity = the extent to which the result of a test actually reflects the
cognitive functions that is being assessed.
o 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.
- Ecological validity is how accurately a test predicts daily functioning.
Confounding factor = an element that affects performance on a test but that does not fall within the
measurement objective of a test.
- An important confounding factor is underperformance during neuropsychological
assessment. Underperformance (or suboptimal performance) means that a patient’s
performance is impaired compared with what they would be able to achieve if they were to
make a normal effort.
Various health care institutions:
Hospitals: teaching or general hospital.
Rehabilitation centres: multidisciplinary work. The emphasis is usually more on treatment
than on diagnosis.
Mental health care
Residential homes, nursing homes, and supported housing: evaluates cognitive skills, and
helps to explore the cause of complaints, the expected course of the complaints, and the
starting points for treatment.
Forensic institutions: in context of a legal framework.
Chapter 3: Neuropsychology: the scientific approach
Dissociation demonstrates that sub-processes are independent of each other, as each of them can
be disrupted separately.
Distinction in scientific research of neuropsychology:
Fundamental neuropsychological research: focuses on achieving a better understanding of
underlying cognitive disorders and the related brain structures.
, Clinically oriented neuropsychological research: a greater focus on, for example, a more
detailed classification of symptoms, the usefulness of test instruments and procedures, and
the follow-up of the course of an illness.
Subtraction method = the procedure of subtracting the score obtained for a simpler condition from
the score for a more complex condition.
In neuropsychology, dissociation relates to a selective loss of function – in essence, cognitive
functioning is intact, but a specific part of the cognitive functioning has been lost.
In single dissociation the patient may be unable to perform task B (writing) but able to perform task A
(reading).
Double dissociation involves the demonstration of two more or less independent cognitive processes
that were originally thought to be a connected process. For example, patient 1 may have problems
with task A (reading) and not with task B (writing), whereas the opposite is true for patient 2.
A patient’s performance on several neuropsychological tests can be compared with the
performances of a normative group (standardised scores), and analysed to ascertain whether there is
a loss of function on specific tests. This approach is not useful if there are few or no good tests
available.
Another option is to conduct intra-individual research. It is possible to give a patient all kinds of
specific tasks, and to compare conditions with each other. This method can be used to introduce a
large number of variations in conditions in order to study the nature of the cognitive problem as
accurately as possible.
Longitudinal research is a research design that charts the course of the disease over time. This
involves monitoring a patient or a group of patients over time, which makes it possible to monitor
performance over time at an individual or group level. This design constantly has to deal with test-
retest effects, which can be regarded as a confounding factor.
Cross-sectional design involves obtaining measurements for different patients at different times in
the disease process within a population with a particular medical condition. Prognoses can then be
formulated at group level with regard to how a disease affects cognitive functioning over time.
However, this design can make prognoses only about the average course of the disease; the actual
course of the disease will vary from patient to patient.
In order to determine whether a treatment is effective, it is important to be able to exclude the
possibility that any progress is the result of spontaneous recovery. On solution for spontaneous
recovery is the multiple baseline design.
In order to ascertain whether a treatment has a specific effect, a control task can be used.
Randomised controlled trail (RCT): not the time of the treatment is randomised. Instead it is the
patients who are assigned at random to either the experimental treatment group, the control group,
or the care-as-usual group.
Chapter 19: Alzheimer’s disease
Dementia is the name for a syndrome that is characterised by increasing cognitive impairment. This
term describes the syndrome, or complex of syndromes, but says nothing about the cause.
Alzheimer’s disease is the most common type of dementia. Memory impairment is the most
distinctive symptom of Alzheimer’s disease. The memory impairment gradually increases as the
illness slowly creeps in. The diagnosis of dementia due to Alzheimer’s disease is made if two or more
cognitive domains are affected.
Globally, over 46 million people are estimated to have Alzheimer’s or a related dementia. will
increase because of two factors that have given rise to the phenomenon double ageing:
1. The demographic structure of western society is changing, as a result of which the number of
elderly people in the population will increase.
2. The average life expectancy has increased and is continuing to do so.
Risks: age is the main risk factor for Alzheimer’s disease. A second risk factor is female gender –
women have a higher risk of developing the disease than men. Genetic predisposition is a third risk
, factor for development of Alzheimer. Familial types are caused by mutations in three genes, namely
the amyloid precursor protein (APP), presenilin-1 (PS-1), and presenilin-2 (PS-2). Another group of risk
factors are vascular risk factors, such as hypertension, diabetes mellitus, and smoking.
A diagnosis is usually made in two steps:
1. The severity of the symptoms is determined (syndrome diagnosis), that is, whether dementia
is present or not.
2. What type of dementia (etiological diagnosis)?
Mild cognitive impairment (MCI) criteria:
Memory complaints
Objective loss of memory established during a neuropsychological assessment
Relatively normal performances in other domains
Relatively intact functioning without dementia
The neuropathological characteristics of Alzheimer are senile plaques and neurofibrillary tangles.
- Senile plaques are accumulations of amyloid beta-protein between the brain cells.
- Neurofibrillary tangles are tangles in the brain cells consisting of the phosphorylated form of
the tau protein.
The presence of plaques and tangles causes brain cell death and atrophy (shrinkage) of the brain.
Amyloid cascade hypothesis:
- Best known hypothesis for the pathogenesis of Alzheimer’s disease.
- Amyloid precursor protein (APP) and amyloid beta protein are central.
- The first step in the development of Alzheimer is the abnormal cleavage of the APP. This
creates an imbalance between the production and breakdown of amyloid beta protein, as a
result of which this protein starts to aggregate and form plaques. At a later stage, the tangles
of the tau protein are added.
The vascular hypothesis argues that cerebrovascular damage plays an important role in the
development of Alzheimer. This is an alternative – or rather an addition- to the AC hypothesis. This
hypothesis argues that vascular risk factors and vascular brain damage result in an reduction in blood
circulation and consequently a deficiency of oxygen (ischaemia) in the brain. causes the hardening
and decreased flexibility of both the larger and smaller blood vessels in the brain, as a result of which
these vessels become fragile and susceptible to damage.
Diagnosis: the diagnostic assessment in the case of dementia starts with a clinical interview, and in
particular with someone who knows the person with suspected dementia well.
The neuropsychological assessment is essential to the diagnosis of Alzheimer, in particular because
cognitive deterioration is the classic symptom.
Distinction in older literature:
- Cortical dementia: characterised by amnesia, aphasia, apraxia or agnosia.
- Subcortical dementia: slowness, impaired information processing or motor problems are
prominent.
Posterior cortical atrophy (PCA): if cortical visual dysfunction is prominent, with relatively intact
memory in the initial stage of the disease. PCA is also referred to as the visual variant of Alzheimer.
Dementia often involves changes in behaviour and psychological functioning, also referred to as
neuropsychiatric symptoms.
Neuroimaging, using either CT or MRI is often part of the diagnostic work-up.
Treatment: currently Alzheimer cannot be cured, but there are some drugs that inhibit the symptoms
to a certain extent.
- Cholinesterase inhibitors have a positive effect on cognitive functioning and daily functioning
in patients with mild to moderate Alzheimer.
- N-methyl-D-aspartate (NMDA)-receptor antagonist is for patients with moderate to severe
Alzheimer. This drug has a modest positive effect on the daily functioning of these patients.
