lec 7/8 clincal neuropsychology assesment (PYSC ASSESMENT) Flashcards
case study of Mrs Y
-shows how important clincal neuropsyc is
- Goldstein & McNeill, Chapter 1, p10.
-gp refused referral to clinical neurpsychologist, but social worker insisted and it still went through
-CNP needs to understand the history
* Head injury 25 years previously
-her life changed after the head injury
-Distractible during testing
WAIS FSIQ = 98. Estimated premorbid IQ = 115.
* Memory OK but learning poor
* Performance on planning and sequencing poor
* Concluded historic head injury caused lasting executive dysfunction,highly likely this caused her difficulties to cope with life/have 3 children etc
-we know now to support people with head injuries, to help executive dysfunction issues
use of clinical neuropsychological assesment
-main aim
Main aim = understand
nature of problems (related to brain illness) and how
best to support functioning
in everyday life
-to test if someone has brain illness/injury
-Case formulation: understand nature of psychological problems
-to get to the bottom of the problems
-Patient care, prognosis, planning of
interventions
-Legal assessment
-involved in Research
procedure of assessment for clinical neuropsychology
- start by understanding Medical history , -medical assessment
- Including neuroimaging, history, medication
- Personal & family history, demographics (education etc)
- Structured clinical interview (try understand from patient perspective what their problems are)
: Assess symptoms and awareness, Assess mental state - Observations
- Tests
- Questionnaires/informant ratings etc asses mood/adaptive functioning
Test selection: issues to consider when choosing tests:
main aims of assessment
-Screening, (is there a memory problem?) diagnosis , case formulation, progress over time
* Assessment of care needs or functional potential
* Developing or measuring rehabilitation/treatment package
test selection: issues to consider when choosing tests
- Validity and reliability of tests
-predictive ability is often important : does the test predict whether the person will be able to function daily
- - Normative data
- Global or specific deficits?
- Patient characteristics
reporting scores of neuropsyc test
-raw scores rarely ever used
-can compare scores to normative data
- Standard scores: e.g. IQ (given to large sample and then normed)
- Percentiles: percentage
of the population who achieve less than a given score - IQ of 70 = 2nd percentile. (2 standard deviations below average score)
- How decide cut-off point for ‘impairment’?
How decide cut-off point for ‘impairment’?
what factors need to be considered when interpreting test scores
Consider test scores in context of:
* Medical history, behaviour, self-reports, and personal information
- Litigation and malingering (faking for some reason)
- Multiple testing sessions, over time
- Inconsistencies in performance?
- Trajectory of scores
Concentration, motivation and emotions
- Distractibility & fatigue
- Emotions: Flat affect, anxiety, depression and frustration
all these things can impact any assesment
sensitivity vs specificity
-does someone have a cognitive impairment
sensitivity :
-the percent of diseases patients a test can capture
-all genuinely have cognitive impairment
-also known as ‘true positive impairment
specificity:
-the percent of healthy patients a test can exclude
(misdiagnosis of healthy people)
-also known as ‘true negative rate’
part 2
Mood disorders following brain illness- Scholten et al., (2016) systematic review
- Anxiety and depression common following brain injury
- High long term prevalence of anxiety (36%) and depression (43%).
- Risk factors: gender (woman), unemployment, psychiatric history
Mood disorders following brain illness
-Other psychiatric factors (Brown, 2013)
Apathy, psychosis, functional neurological disorder
* May impact on all aspects of cognitive and social functioning
Methods of assessing mood in clinical neuropsychology
- structured interviews
-SCID = Structured Clinical Interview for DSM
-DSM = Diagnostic and Statistical Manual of Mental
Disorders
-brief psychiatric rating scale
-observations
-informant reports
-self reports
* E.g. Beck Depression Inventory,
* Hospital Anxiety and Depression Scales (HADS) - a brief 14 item scale designed to give a basic assessment of anxiety - ‘often feel butterflies etc;
* Importance of insight (do they know what they have)
Using the HADS to assess mood following brain injury
-Whelan-Goodinson et al. (2009)
100 participants with traumatic brain injury
* Completed SCID and HADS
* HADS high Cronbach’s alpha (>.85)good internal reliability
* SCID and HADS convergent validity
* But 31% of participants scored in clinical range for anxiety in HADS did not meet criteria for clinical anxiety in SCID (specificity vs sensitivity problem)
-suggests HADS is not being specific enough for diagnosing anxiety (too many false positives) - cant understand if its at a clinical level
HADS = Hospital Anxiety and Depression Scales
SCID = Structured Clinical Interview for DSM
part 3
-assesing change in cognitive function
-why a crucial aspect
Crucial question in clinical assessment:
has ability/behaviour changed since
illness/injury?
What was PREMORBID ABILITY? - before ilness
Demographic methods to estimate premorbid ability (what function was like before ilness
-Use age, sex, gender, ethnic and cultural background, education and
occupation to predict premorbid IQ
* Regression methods
E.g. Crawford & Allan (1997)
* Demographic variables predict about 50% of variance in FSIQ
* Better at predicting verbal than non-verbal ability
* Poor at estimating IQs < 69, and > 120
* Occupation best predictor
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specific tests pf premorbid ability
-tests that guess
-Hold’ tests: insensitive to brain injury
* Vocabulary tests, especially multiple choice
* Word reading tests:
* Asked to pronounce irregular words
* E.g. ACHE, IDYLL
* E.g. National Adult Reading Test (NART)
* Wechsler Test of Adult Reading (WTAR)
- Support for construct validity:
- Word reading fairly insensitive to
illness/injury, and highly correlated to IQ in
healthy sample
Comparison of different methods of predicting IQ
Bright and van der Linde (2020)
Compared NART, WTAR, demographics + other methods in predicting WAIS IQ
* NART strongly predicted WAIS IQ in healthy sample (r = .69)
* WTAR similar but more limited range
* Demographic variables poorer prediction IQ
* Demographics add some incremental validity to NART prediction of IQ (add validity to nart when measuring IQ)
- Problems with NART:
- Regression estimates for FSIQ in manual obsolete
- Lack of large scale norming and item analysis
caution in interpreting reading tests as measures of premorbid ability
- Evidence of validity of NART/WTAR to assess
premorbid ability: - Good measure of vocabulary size
- In healthy sample correlate highly with IQ
But reading tests are sensitive to some brain disorders:
* Moderate dementia and aphasia
-nart may not be giving an accurate measure as dementia impairs ability (memory) , same for aphasia (language problems)
May be invalid where:
* Dyslexia or pre-existing language problems
* English not 1st language
* Poor access to education
An example of use
of the NART in a
real life situation
“Laced with poison:
On July 6, 1988, 20 tons of
aluminium sulphate was
accidentally dumped directly
into the household water
supply of Camelford,
Cornwall.”
-residents experienced weird taste in water, and months/years later people experienced memory and attention issues
-they were told it was just anxiety
* Mail Online 19th April 2014
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An example of use
of the NART in a
real life situation
-Use of the NART in Camelford poisoning case
Altmann et al (1999) BMJ
* Compared memory and attention of
* Camelford sample (n = 55) alleged to be poisoned
* Control group of relatives (who didnt live there or drink the poisoned water )
-
* Also gave NART to assess premorbid functioning (so any difference after the nart could be actually due to the poising)
- Results indicated poisoning impaired cognition
- Camelford group poorer memory and attention than relatives
- No group difference in NART (so they must have had similar levels of cognitive functioning before the poisining)
- This and subsequent studies led to a Government enquiry and apology in 2013
camelford water poisoning
carole cross case
Carole Cross continued to drink the water after the water authority assured people that it was fit to drink. She had been a skilled craftswoman but became less able and started to have difficulty performing simple tasks such as
shopping.
- She died in hospital in Somerset in 2004, aged 59, and was found to have a severe form of the brain disease cerebral amyloid angiopathy, (CAA) usually associated with Alzheimer’s disease. There was a “very elevated level” of
aluminium in the brain
