Neuropsychological assessment

Question 1

What is clinical neuropsychology?

Answer 1

• Concerned with the study of the effect of brain dysfunction on a person’s behaviour
• An independent scientific discipline that evolved out of its parent disciplines neurology and psychology
• Neuropsychological, not neuropsychometric!
― evaluation and measurement of cognitive and behavioural function through review of medical, educational and occupational history, interview, observation and psychological testing to form an opinion about the presence and nature of brain dysfunction
• To be contrasted with psychological testing
― Where there is no consideration of the clinical context

Question 2

What are the 6 levels of cognition?

Answer 2

• Mental activity (consciousness, orientation, processing speed, attention)
• Intelligence and general abilities
• Language and ‘academic’ abilities
• Visuospatial and constructional skills
• Memory (encoding and storage of information)
• Executive functioning

Question 3

Why do we assess the different levels of cognition? (7)

Answer 3

• Localisation of brain injury
― not so much now
§ structural imaging (CT, MRI)
§ functional imaging (SPECT, PET, fMRI)
• Differential diagnosis
―is there a neurological issue, and if so, of what kind?
―are cognitive changes due to psychological factors?
• Documentation of functional strengths and weaknesses
― Plan rehabilitation strategies
― Arrange access to services, accommodation
― Provide medicolegal documentation
― Plan future activities and prepare person and care-givers

Question 4

How do we conduct the assessment?

Answer 4

― Fixed battery approach (e.g., Halstead-Reitan Battery in USA)
§ atheoretical, reduces interpreter bias
§ exhaustive testing is time-consuming and inefficient
― Flexible hypothesis-testing approach (most common in Australia)
§ Boston ‘process’ approach (e.g., Edith Kaplan, ~Walsh)
• emphasis paid on the approach taken to complete a test
§ efficient in narrowing focus of testing to relevant features
§ less reliant on psychometrics, requiring greater clinical skills

Question 5

How do we interpret the test results?

Answer 5

• Quantitative information
―Cutting scores
―Dissociations (specifically characterise a deficit)
―Pattern analysis (Looking not just at test results but if theres variability across performance of tests of same fction)
―Appropriate group norms
• Qualitative information
―Assessment is NOT purely a psychometric exercise, but an opportunity to use all available information to gain a thorough understanding of the client’s cognitive and behavioural functioning

Question 6

Which 6 factors constrain test selection?

Answer 6

• Reliability and validity
• Specificity and sensitivity
• Potential for repeated testing
• Availability of good normative data
• Ease of administration and scoring
• Time to complete

Question 7

What are 8 reasons for test failure?

Answer 7

Neuropsychological disorder
• Misunderstand test instructions
• Drug and alcohol effects
• Prior history of learning difficulties
• Low level of education
• CALD/ESL background
• Poor effort or malingering
• Other psychological conditions

Question 8

What is the role of general intellectual level?

Answer 8

• Level of intelligence is an anchor of the assessment
• It is the criterion against which many other functions are judged
• Most people are average
―most tests work best around average levels of performance

Question 9

How do we interpret tests? (3)

Answer 9

• Comparison with normative sample
―norms should be appropriate for the case
• Impaired vs normal performance
―intra-individual comparison
―between-domain comparisons
• Comparison with premorbid estimate

Question 10

Why do we assess premorbid intellectual status?

Answer 10

• What does premorbid mean?
―previous best level of cognition prior to injury/illness
• Why assess this?
―to establish a relevant reference point for interpretation of current performance
―is there a reduction in performance for that person?

Question 11

• How to assess premorbid functioning? (5)

Answer 11

―Previous neuropsychological assessment § (we wish!)
―Self and other report
§ not reliable
§ school reports can be helpful but are not always indicative of true intelligence: teachers like to be positive
―Demographic and other personal information
§ occupational and educational background (main influences)
§ Find out about other family members
§ judge accomplishments against opportunity, motivation, cultural expectations
§ ask about hobbies
• Assessing premorbid functioning through resistant cognitive skills. ―best scores on current testing (for whatever reason)
―these may correspond with well-learned skills and knowledge which are resistant to brain injury § vocabulary and general knowledge
• can be impaired by conditions like aphasia and dementia
• also affected by education and opportunity
• Assessing premorbid functioning through specific measures
• Words with irregular spelling-sound correspondences
• Word knowledge correlates highly with IQ
―if you don’t know the word you’ll say it wrong