lectures Flashcards
The purpose of neuropsychological assessment is:
- Diagnosis
- Distinguish between different neurological conditions
- Discriminating between psychiatric and neurological symptoms
- Identifying a possible neurological disorder - Patient care and planning
- Identifying cognitive strengths and weaknesses needed for optimal and
- Identifying behavioural alterations careful management of many
- Identifying personality characteristics. disorders - Treatment planning and remediation
- What is the most appropriate cognitive rehabilitation treatment? - Treatment evaluation
- Did the treatment have an effect? - Research
- Forensic neuropsychology
- In the context of claims of injury and loss of functionIn criminal cases (Is there reason to suspect brain dysfunction that contributes to misbehaviour)
Evidence based medicine relies on
(1) clinical judgement,
(2) relevant scientific evidence,
(3) patient values and preferences
Formulating hypothesis and going through the diagnostic cycle is important because it helps you avoid interpretation errors. There are multiple forms of interpretation errors.
- The tendency to rely strongly on some results and to disregard others
- Disregarding the base rate of disorders
= A neuropsychologist who works a lot with patients with Alzheimer’s disease will have the tendency to diagnose Alzheimer’s disease more often - Conformation bias
= Looking for results that support you hypothesis - Thinking that subjective complaints are objective disorders
There are Two classical test approaches in neuropsychological assessment:
- Psychometric approach (Reitan-Halstead testbattery)
o Standardized assessment and scoring
o Uses normative data and cut-off scores per test and for the total test performance
o Quantitative test approach
o Not based on theories about the brain
Each person will be tested and scored exactly the same way. Scoring can be done two ways. - Cut-off scores
You either have an impairment or you don’t. - Calculation impairment index
≤ 0.4 = No impairment, ≥ 0.5 = Impairment, 1 = Severe impairment
There is also criticism on the Reitan-Halstead testbattery.
- it is a-theoretical (not based on theories about the brain)
- the test battery is fixed
- it focuses only on abilities and not on dysfunctions (it gives no insight into the
nature of the problem or directions for rehabilitations) - Behavioural neurological approach (Luria’s behavioural-neurological method)
o No empirical testing of his theory
o No normative data qualification of the symptoms
o No standardization testing hypothesis
o Based on observation
o Flexible test battery which is adjusted to the individual patient
o Qualitative assessment approach
o Does give direction to rehabilitation
After the 2nd world war a large number of patients came home with brain injury. Test batteries were developed on the theory of the brain where attention is regulated by the brain stem, perception by the posterior part of the brain and organization and planning on the anterior part of the brain. It became also known that perception has multiple levels: primary (image), secondary (interpretation), and tertiary (cross modal integration).
Luria’s behavioural-neurological methods consisted of simple tasks to provoke symptoms.
There is criticism on Luria’s behavioural-neurological method as well.
- the theory is strongly focussed on the left hemisphere
- it gives no insight into the severity of disorders (you’re impaired or you’re not)
- no standardization, normative data or data about the reliability and validity of the
tests.
In evidence based medicine, now called Differential diagnostic thinking, you have to..
listen to complaints of patients in a unjudgmental manner
try to cluster down syndromes, symptoms and impairments
be aware of the halo-effect (Assuming that a patient has certain complaints or characteristics which in reality are
But before the assessment takes place you should make a couple of decisions..
- do I use a fixed or flexible test battery
- do I use a quantitative or qualitative approach
- which cognitive domains should be tested, and which tests do I choose for that.
There are some problems however (with tests)
- Neuropsychological tests rarely measure only the function they are supposed to measure. In complex figure of Rey examinees are asked to reproduce a complicated line drawing, first by copying it freehand (recognition), and then drawing from memory (recall). Many different cognitive abilities are needed for a correct performance, and the test therefore permits the evaluation of different functions, such as visuospatial abilities, memory, attention, planning, and working memory (executive functions).
- Tests require intact visual and auditory perception
- Tests always rely partly on attention, memory, executive functions, language and motor skills
- Motivation, mood, speed of information processing, fatigue, etc. can have a significant negative influence
So now you have done all your tests, how do you interpret your results?
An impaired performance can be due to either an impairment in the function the test is supposed to measure, or can be due to disturbing factors
a) Cognitive impairments in other domains than those that measure a test.
b) Emotional disturbances
c) Disturbed visual and/or auditory processing
d) Cultural backgroundThese are important to consider when formulating a hypothesis.
Which test do you choose? Check for:
- Reliability
a. Test/retest reliability, parallel versions, interrater reliability - Validity
a. Ecological validity, construct validity - sensitivity/specificity
- level of difficulty
a. 8 words test vs 15 word test (word test when memory is severely impaired) - quality of normative data (comparison group).
A test should preferably have a high test/retest reliability, high construct validity, good sensitivity, good specificity, detailed normative data, validated parallel versions, limited learning effects, no ceiling effects.
Objective vs subjective assessment.
Objective = performanceon tests
Subjective = Complaints of patient Observation from partner/children Observation of nursing staff Observation during neuropsy. assessment
Ethics
There are different, but overlapping, codes of conduct. The most important point mentioned are
- respect for a person’s rights and dignity
- competence (of the psychologist)
- responsibility
- integrity (being honest and transparent)
Always keep the interest of the patient in mind. The patients should decide themselves whether or not they want a neuropsychological assessment. Patients can terminated the ‘professional relationship’ at any time, without giving a reason. Patients are allowed to read the neuropsychological report. Patient data is confidential and can only be distributed if the patient grants his permission.
The empirical cycle, according to Adriaan de Groot.
- Observation: The collecting and organisation of empirical facts; Forming hypothesis.
- Induction: formulating hypothesis
- Deduction: deducting consequences of hypothesis as testable predictions (operationalisation)
- Testing: testing the new hypothesis with new empirical material
- Evaluation: evaluating the outcome of testing.
Phase 1: Observation. Collect facts and form hypothesis
Get as many facts as possible before the assessment.
- Autobiographical information
- Which problems is the patient experiencing?
- What is the referral question? patient-related information
- Medical History
- Neuroimaging data
- Previous assessments, etc.
- Get information from handbooks or articles about symptoms/syndromes Knowledge
related info
How does a clinician generate hypothesis from all these facts?
- pattern recognition based on knowledge (Example in lecture: chess players showed a phenomenal short term memory for chess positions as long as they fitted in with the known rules. When the pieces were randomly arranges their recall was not better than novice chess players. Relevant clinical experience is extremely important)
- Experienced clinicians are able to recognise a pattern (syndrome) based on minimal amount of facts.
- Clinical view is not just a mystic or irrational ‘gut feeling’; it is based on applicable and accessible knowledge. It is memory based.
- Requires specific and up-to-date knowledge of Clinical Neuropsychology, Neurology, Clinical Psychology, Cognitive Science, etc.
Phase 2. Induction: Formulating hypothesis
Why formulate hypotheses?
1. A hypothesis provides a clear statement of what needs to be investigated. It helps the
clinician to (1) identify the assessment objectives, and (2) identify the key abstract concepts
involves in the assessment.
2. Also, a referral question cannot be answered unless it is reduced to hypothesis form.
A good hypothesis …
Can be tested – verified, corroborated, or falsified
Is not too specific, nor to general
Is a prediction of consequences
Is considered valuable even if proven false
Has no moral or ethical judgement
It is always necessary to formulate multiple hypothesis.
o Null hypothesis: a theory that is being put forward because it is believed to be true or it is to be used as a basis for argument, but has not been proved.
In CN-PSY: the patients behaviour/cognitive functions are normal compared to the norm group.
A Null Hypothesis ‘forces’ a clinician to evaluate the possibility that cognitive functioning is not impaired or that the patients behaviour is normal
o Alternative Hypothesis: a statement of what your assessment is set up to establish.
• Is opposite to the null hypothesis
• Is only considered if the null hypothesis is rejected
• In many cases, the alternative hypothesis turns out to be the conclusion of the clinician.
• Always consider ‘personal’ and ‘environmental’ contributors (loss of partner), not just cognitive function.
In CN-PSY: patients behaviour/cognitive functions are abnormal.
Why is a null-hypothesis necessary?
1. Behaviour may be ‘normal’
2. All clinicians suffer from bias
3. A null-hypothesis ‘forces’ a clinician to evaluate the possibility that cognitive functioning is not impaired or that the patients behaviour is normal
Phase 3. Deduction: Deducting consequences of hypothesis as testable predictions
General considerations:
- neuropsychological assessment is an N=1 experiment
- you know the research question, you have formulated the hypothesis
- think of which results will tell you a hypothesis is true (confirmation)
- think of which results will tell you a hypothesis is false (contradiction)
So if we look at our example, what are the relevant facts to look for? Which facts would be exclusive.
look for test that are discriminating. Test that only score positive in case of dementia, and not for depression od MCI for example. It helps to use a matrix.
Phase 4. Testing: testing the hypothesis
General considerations:
- During interview, observation and testing, new hypotheses may arise
- During interview, observation and testing, some hypothesis may be rejected almost immediately
- Keep your matrix and your predictions in mind! Think twice before changing plans!
- About neuropsychological testing: practice makes perfect.
Phase 5. Evaluation: evaluating the outcome of testing
Stepwise interpretation of the results (9 steps).
(re)integrate all available information and check for completeness.
Sources of information include:
- knowledge of function neuro-anatomy
- knowledge of brain diseases and their consequences for behaviour
- knowledge of psychology, clinical psychology, cognitive psy, and psychopathology
- referral question
- medical file, medical history, current status, neuro-imaging data
- psychosocial history of the patient
- interview with patient and peer
- observation data
- test results
Estimate the validity and reliability of the assessment .
Validity : measure that what you want to measure (you don’t measure your weight with a thermometer.
Reliability: a test should be consequent in the outcome when the input is the same.
A test is never 100% valid. A memory test never measure just memory.
Threats to validity include: sensory impairments, motor impairments, (mild) aphasia, perceptual problems, medication, motivation problems, concentration problems, fatigue, malingering, cultural background (all tests have a norm group of young Caucasian people).
Estimate premorbid functioning
There are ‘hold tests’ which measure crystalized intelligence and remain the same with aging. There are also ‘don’t hold’ tests which measure fluid intelligence and decrease with age.
Premorbid functioning can be estimated with information of previous work, education, and social activities.
Summarise observation and interview data
Calculate the standardized scores out of the raw scores.
It is preferable to recalculate all scores to on type of score (e.g. make it all z-scores or all t-scores). Then calculate your confidence interval and provide a clear legend.
When is a test score abnormal? This can be difficult, because a below average score does not necessarily mean an impairment.
- take the entire test profile into account
- more test will mean a greater difference between highest and lowest scores
- in most people a difference of 3 SDs between two tests is not uncommon.
- differences in aptitude are not always clinically meaningful
- consider premorbid functioning
- consider reliability of test and whether scores are corrected for age, education etc.
Rule of thumb 1 ½ Sd (6th percentile) – 2 Sd (1-2 percentile) below average is abnormal.
Calculate the Standard error of measurement (Sem)
Sem = Sd √(1-reliability)
Calculate confidence interval (test score =20, Sem = 2)
real score lies between (20-2xSem) 16 and (20+2xSem) 24.
Fill in matrix
Compare a priori test profile with real test profile
Make decisions about affirmation and rejection of hypotheses
Summarize results
Go back to the original question. Is there enough evidence to answer the question? Remember you are dealing in probability, not certainty.
Try to formulate the most important findings in 3-4 sentences.
The purpose of psychological reports are to
(1) increase others’ understanding of clients,
(2) communicate interventions in such a way that they are understood, appreciated, and implemented, and
(3) ultimately result in clients manifesting improved functioning.
The structure of a psychological report is as follows:
- Disclaimer
a. For who, for what purpose, for how long (expiry date) - Personal details
a. Name, date of birth, sex, education, handedness, marital status, social situation, test date, tested by.. - Referral question/ purpose of assessment
- Medical history and medication
a. Limit the information to relevant facts. - Interview
a. Keep in mind that you are not observing facts but opinions. Not: the patients memory problems started two years ago. But: according to the patient, his problems started two years ago.
b. Not just report the type of complaint but also the nature, duration, course, and intensity.
c. Differentiate to what the patient tells you and what others tell you. (neither are very reliable) - Observation
a. Only report an observation if it enhances insight into:
i. Premorbid functioning
ii. Current level of functioning
iii. Pattern of disfunction
iv. Inconsistencies
b. Be careful not to overinterpret - Test results
a. It is preferred to report by domain (intellectual functioning, attention/concentration, memory, etc.)
b. Avoid using words as ‘rather’, ‘fairly’, and avoid using jargon. - Summary and conclusions
a. Start with restating the purpose of the assessment
b. Summarize your main findins
i. Limit to what is important
ii. Do not name tests, only cognitive domains
iii. Do not limit this to positive findings (be aware of the conformation bias)
iv. Report serious threats to validity of your assessment (lack of motivation, extreme fatigue, visual impairments)
c. Evaluate your hypotheses, but better not name them explicitly. (e.g. the results do not fit with dementia, but are in line with a mood disorder)
d. If necessary advice further assessment
e. If required, give advice for rehabilitation, intervention or care. Stick to what you know (about behaviour, emotions, cognitive functions) and remember whom you are writing for.
Assessment can be done 4 different ways
- Psychometric neuropsychological tests
- Clinical interviews (unstructured, semi structured, structured)
- Questionnaires (self-report, other reports)
- Observations (during clinical assessment)
Different types of assessment provide different types of information. Therefore all assessments are necessary for an complete picture.
Before the interview it is important to look at the patients record. Here you can find:
1) information of the injury and post-injury records (head injuries, tumours, epilepsy, alcohol abuse),
2) neuroimaging data,
3) psychiatric history (developmental-, psychotic-, affective-, anxiety-, personality disorders)
4) previous assessments
5) previous treatments
6) school records
7) vocational records
8) physical problems
If you are well prepared before the interview, you are able to answer the following questions:
what is the purpose of assessment?
What is the aim, which question will be addressed?
Are you confident your assessment will help to answer this question?
Are you confident your level of expertise is sufficient to answer this question?
you confident your equipment is sophisticated enough to answer this question?
Performing the interview (de stappen)
I. inform the patient about the purpose and content
a. The patient’s reports and behaviour can only be interpreted in a valid fashion if the patient has been informed about purpose, content, and duration of the interview
II. collect biographical information
a. family situation, school situation, vocational situation, socio-economic status, private situation, living situation interests/hobbies, stressors (partner crisis, money)
III. measure the premorbid level of functioning Can only be done in acquired brain
a. look at previous assessments (if there are any) damage
b. school education
c. vocational situation
d. income
e. hobbies and interests
f. family background
g. involve a spouse or parent: These are not necessarily more valid or reliable. But the discrepancy between self- and informant reports are important. This helps yo to evaluate the insight of the patient.
IV. ask for the type and nature of the complaints
a. start with spontaneous self-reported complaints. Continue with more specific questions (how did it start, when, at which intensity). Eventually determine complaints on cognitive/modular level (attention, memory, planning, impulse control etc.)
V. what are the course of the problems (sudden onset, slow progressive onset)
a. are the complaints getting worse, since when, how, etc.
VI. ask for the consequences of the complaints.
a. Do complaints affects daily life functioning
Observations
You can observe the patient in multiple situations. Like in the waiting room, on the way to the testing room, during the interview, during testing. Thera are a lot of things we can learn from observing…
Furthermore, you can observe someone’s appearance (overweight, personal care) and the behaviour (motor skills, facial expression, attitudes)
Motor skills observation:
Overall e.g. speed of movements, hyperactivity, restlessness, fidgeting, clumsiness, sudden or careless movements, neglecting one side of body, (partial) paresis, involuntary muscle spasms, tremor, difficulty controlling movements.
Walking e.g. speed, flexibility, rigidity, tripping, bumping into things (on the left or right), requiring assistance, losing balance, struggling with climbing stairs, etc.
Facial expression observation:
General impression: e.g. vivid, expressive, cheerful, dramatic, rigid, motionless. Reaction to emotional content of conversation. Eye contact.
Overall attitude observation:
E.g. confident and cheeky vs. shy, hesitant, and quiet
Active and alert vs. passive and not accessible.
Positive and optimistic vs. tensed and not at ease.
Attitudes towards (test) supervisor and (test) instructions:
- Friendly, sincere, and aiming to meet other’s expectations
- Over-polite, business-like, aiming to impress
- Clingy, dependent, insecure
- Sloppy, superficial, careless
- Suspicious, criticising, shows aggression or annoyance
- Disinhibited, comments on all actions, responds to contact straightforwardly
Behavioural observation at specific actions:
- Writing/reading
- Planning meetings and making agreements (e.g. questionnaires, medication)
- instruction phase and practice trials of neuropsychological tests
- Reactions to feedback in neuropsychological tests
- Describing complex drawing
- Drawing complex figures (copying, or clock drawing)
- Strategy of planning tasks
when is a observation valid and when is it reliable?
When is an observation valid: when the conclusions are accurate
When is an observation reliable: when there is consistency between clinicians
Validity and reliability higher when:
Specific questions are asked that relate directly to behaviour
Structured or at least semi structured interviews are used
- To decide whether a person is impaired or not, introduction
we use normative data (a large group of healthy individuals).
But is this data valid?
The assessment of symptom validity is an essential part of a neuropsychological evaluation. The clinician should be prepared to justify a decision NOT to assess symptom validity as part of a neuropsychological evaluation.
The assessment for the validity of self-report and performance should be included in ALL evaluations. The committee recommends the use of psychometric instruments that include proven validity measures.
Performance and symptom validity
So in all evaluations you should assess the validity:
Performance validity: test performance in cognitive test
Symptom validity: evaluating what the patient tells you
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Reports of Performance • social desirability (faking good) • Faking (bad) • Random responding (carelessness) • Acquiescence (yes-saying) • Opposition (no-saying) • Positional (e.g. extremity, midpoints)
- Assessment of symptom validity (SVT): Self-reports
check for inconsistency
Invalid response style if different responses are given to items of similar content.
E.g.
over-reporting
Use of standard symptom scales. Invalid response indicated if score much higher than control and clinical groups.
construction of validity scales (SIRS-2)
o rare symptoms: Infrequently or rarely endorsed
‘Do you believe automobiles have their own religion?’
o Symptom combinations: seldom observed together
‘At the times when you feel hopeless, do you also feel lightheaded?’
o Symptom severity: Symptoms often not unbearable
‘Do you have problems with feelings of self-doubt, and if yes, is this unbearable to you? ’ (while problems can be hard, they are almost never unbearable)
o Overly specific symptoms
‘Do you feel hopeless particularly in the middle of the week?’
scaling of items.
o Reverse items to avoid tendency to score ‘always right’ or ‘always left
o Use even number of response alternatives to avoid endorsement of middle
o Change scaling across items in long (batteries of) questionnaires
- Assessment of performance validity (PVT)
There is a difference between embedded/derived PVT’s and standard-alone PVT’s.
Embedded and Derived PVT is based on a pre-existing standard measure of cognition.
Standard-alone PVT is developed specifically to assess noncredible performance.
These standard-alone PVT’s may appear difficult to perform, but are simple to accomplish by most individuals, also those with severe impairments! (e.g. Test of Memory Malingering (TOMM), Groningen Effort Test (GET), Amsterdam Short Term Memory Test (ASTM), Dot Counting Test (DCT)).
- What do the tests tell us? How to make a decision
Common misconceptions:
- SVTs/PVTs do NOT contribute to diagnostic process of disorder at question
- SVTs/PVTs do NOT tell whether somebody is feigning
- Do NOT accuse an individual of feigning based on SVT/PVT failing
- Do NOT make decisions based on one measure
Interpretation of SVT/PVT test results
SVTs/PVTs indicate whether performance is credible or noncredible
SVTs/PVTs indicate whether routine clinical measures are valid
There are many reasons to fail SVT/PVT, feigning is only one of them
How to integrate all results to make a decision? Use all information:
1. Symptoms and performance validity assessment (SVT/PVT)
2. Check the consistency of: self-reports, reports of others, clinical observations, clinical history, routine neuropsychological test performance.
3. Check for evidence for external incentive?
- When failing SVT or PVT: the feedback session
Phase 1:
1) Establish effective working relationship with client
2) Establish and clarify expectations
3) Obtain informed consent, incl. consequences of poor effort
4) Ask about prior exposure to neuropsychological tests
5) Decide whether to use SVTs/PVTs to which the examinee was previously exposed
Phase 2:
1) Complete or quit testing when evidence of invalid performance is encountered?
2) Explore patient willingness to acknowledge poor or inconsistent effort
Mind terms such as “faking”, “lying”, “putting on a show” Use “not fully invested”,
“disengaged”, “did not stay motivated” or “mobilize effort”
3) Note if there is a lack of acknowledgment of poor effort
4) Schedule feedback session separate from that of the test administration
Phase 3:
1) Inquire about the patient’s own perception of performance on the tests
2) Remind the patient that strengths and weaknesses are common and expected
3) Report the ‘‘good news’’ and ‘‘bad news’’ Bad news: Large number of low test scores Good news: Patient could likely do better when putting forth better effort
4) Describe objective basis of conclusions (objectivity of test results)
5) Seek patient agreement that results should be better than those of persons with well-established and severe psychiatric or neurological conditions (possibly visually supported by graphs).
6) Describe test results as a comparison between the patient’s scores and those of various clinical groups (psychiatric or neurological)
7) Explain that there is a significant non-neurological or non-psychiatric component
8) Good news: Poor test scores can substantially improve if the non-neurological factors are addressed
9) Debrief the patient regarding the feedback content and process, including answering questions and addressing concerns
10) Document results of feedback session
