Neuropsychological Assessment OL PDF

1 Psychology 4360 Section 9: Neuropsychological Assessment OL Psychology 4360 Psychological Assessment Section 9 - Neuropsychological Assessment OL (Ch. 10 in text) A...

1 Psychology 4360 Section 9: Neuropsychological Assessment OL Psychology 4360 Psychological Assessment Section 9 - Neuropsychological Assessment OL (Ch. 10 in text) A Introduction 1. What is neuropsychological assessment? Whereas neuropsychology is the sub-specialty of psychology which concerns itself with “brain- behaviour relationships”, neuropsychological assessment measures the brain’s “output” primarily in observable cognitive/intellectual function. This information is relevant to the question posed more so in the days prior to sophisticated neuroimaging: “Is there evidence of damage to the central nervous system?” Among my first referrals at Royal Columbian Hospital were those asking me to indicate if I thought a cognitive/ behavioural deficit or anomaly was “organic” or “functional” (i.e. psychiatric/psychological). The simple referral question put to me was: “Query organicity”. Also in those early days, information from neuropsychological assessment could be used to hypothesize where in the brain there was malfunction (called “localization”). There are now a number of sophisticated instruments that can measure brain structure or activity. For a brief overview, go to: https://www.khanacademy.org/test-prep/mcat/behavior/biological-basis-of-behavior-ner/v/ modern-ways-of-studying-the-brain A more common question addressed by neuropsychological assessment in these days of such sophisticated neuroimaging is “What are the functional effects of known CNS damage?” It is true, too, that some disordered brain processes may not be identified by neuroimaging devices where they may by neuropsychological assessment (e.g. dementia). 2. What conditions might lead to someone being referred for a neuropsychological assessment? a. Neurodevelopmental disorder (intellectual disability, ADHD) b. TBI (mild, moderate, severe; “closed” or “penetrating”) c. Cerebrovascular d/o (TIAs, strokes, - occlusive (block) or hemorrhagic (bleed)) d. Brain tumours e. Dementia (e.g. Alzheimer's or vascular types) f. Toxic effects (alcohol, pesticides, solvents, metals)  2 Psychology 4360 Section 9: Neuropsychological Assessment OL Read through the brief case studies #1 and #2 on p. 301 of the text. As we go through this section, think about how we could use neuropsych testing to clarify their situation. 3. What would be the value of such an assessment? To design or improve treatment, generate rehabilitation strategies and plans; estimate limitations, preserved functions, compensatory strengths, and infer implications for work, education, the capacity to live independently or manage one’s own affairs (“competency”). 4. Interaction of factors influencing functional outcome We now recognize the complex interactions of neurological, physical and psychological events and conditions. We recognize that lesions in similar locations may lead to different outcomes, that similar outcomes may result from lesions in different brain locations, that psychiatric and psychological conditions may display themselves in ways that look neurological and that psychological factors can influence cognitive/intellectual “output”. Here is a model of potential interacting factors leading to outcomes in someone’s functioning when they have suffered a Mild Traumatic Brain Injury. Think about this: How could these various factors influence the way a person functions after a mild traumatic brain injury? One idea - a very common symptom of having suffered a MTBI is fatigue (Physical factor). How might that influence objective (seen in testing) cognition? How might this then affect a person’s subjective evaluation of their cognition? How might this affect psychological factors (discouragement, anxiety, depression?) How might this affect how they are functioning? Trace it through the possible interactions. How about pain? How could this  3 Psychology 4360 Section 9: Neuropsychological Assessment OL influence the complex of interactions? B General Frameworks Relevant features of overall neuropsychological function would include testing of: R:L hemisphere- and Anterior (generative, expressive): Posterior (receptive) region-dominated functions; both general intellectual ability (g) and specific intellectual functions; acute: chronic cognitive conditions; weaknesses, strengths and “intact” areas of function; personality, affect and behaviour which might affect “output”. And – it should generate information useful to decision- makers, treatment-providers. We could organize much of this in one of the following frameworks: (Fig. 10.6 from Gregory, 2011; Fig. 11.1 from Mapou and Spector, 1995.) C The Assessment Process 1. The referral question guides neuropsychological assessment. It delimits what aspects of these general models must be assessed in order to generate relevant and useful conclusions and recommendations.  4 Psychology 4360 Section 9: Neuropsychological Assessment OL 2. In history-taking, the neuropsychologist may need to elaborate on chart information or, in a non-hospital context, elicit relevant historical data (medical, educational, career, personal functioning, social “developmental milestones”) from relevant sources. Question: What would be important to know? (text pp 298 - 300) Neuropsychologist Robert L. Mapou (1995) identifies the essential components of a neuropsychological history as including: 1. the Current problem - the reason for referral for an assessment and how the patient and significant others are seeing it. 2. the person’s Medical history - current and past medical and neurological information. 3. Educational history, length, any learning disabilities, test results. 4. Occupational history - current and past. 5. Social history - relationship status, family structure, social support, recreational activities. 6. Family history of parents, siblings - ages, education, occupation, neurological and medical issues. 7. Substance use. 8. Current medications - what, how much, for what, how long? Question: Why would I want to know about medications/changes to medications? (cognitive and behavioural side-effects which could complicate the assessment) 3. Interviews are often structured to ensure that all relevant data is gathered. Here is a short sample of questions from the Neuropsychological Symptom Checklist interview format one might use to identify current symptoms: 1. Do you... ___ get lost often ___forget where you are _____ forget time and day 2. Does is seem that you... ___can’t think as quickly as before ____find it hard to think clearly 3. Have you had trouble... ___telling right from left ____remembering the right word when talking 4. Physical and Sensory-perceptual examinations may be conducted for reflexes, muscle tone and strength and coordination; auditory or visual sensation and perception. 5. Neuropsychological test selection: The Mini Mental State Exam may be used as a screen to determine if a patient should have a more extensive formal evaluation.  5 Psychology 4360 Section 9: Neuropsychological Assessment OL Neuropsychological tests are selected guided by the referral question and therefore the assessment goals. Other considerations would be? (characteristics of the test-taker, such as age, which could affect how long they can or will exert maximum effort, language competence. Will repeated testing be required, when? Only some tests are suitable for retesting and even then, only after a certain time has elapsed.) A number of tests may be combined into what are called “batteries”, which may be “fixed” or “flexible”. (text pp. 284 - 288) 1. Fixed Batteries: The grandparent of fixed batteries is the Halstead-Reitan Neuropsychological Battery first outlined in 1969. (text pp. 285, 286) It includes a small number of tests selected because they were found through the research to differentiate the brain-injured from the non-brain-injured, using a contrasting-groups method. These include the Seashore Rhythm Test, the Speech Sounds Perception test, the Tactual Performance Test, the Finger Tapping test and the Category Test. Scores from these are combined in an Impairment Index, used to answer the Query Organicity question (that is: brain damage or not?). Text Table 10-3 p. 286 describes Component tests of the Halstead-Reitan Battery. Other tests are included in this table as they were frequently used with the core battery.  6 Psychology 4360 Section 9: Neuropsychological Assessment OL Here is an image of the Tactual (Sometimes called Tactile) Performance Test (measures kinesthetic and sensorimotor function): The Finger Tapping test is shown in Figure 10.4 of the text on page 286. (measures motor speed) Here is an image of the Category Test (measures abstract reasoning, concept formation, and mental flexibility). (This is from the olden days which Dr. Meen remembers so well... could that be him at the terminal?) The stimuli are now presented either in booklet page form, or on computer.  7 Psychology 4360 Section 9: Neuropsychological Assessment OL To provide more detailed formulations, a number of other tests were typically administered, including the Aphasia Screening test, the Trail Making Test, measures of dominance (like hand dominance) and bilateral grip strength, sensory-perceptual examination for tactile, auditory, visual sensation-perception. In addition to these smaller tests, the Halstead-Reitan typically involves the administration of the entire WAIS (in its most current version) and MMPI. Think about it: Why the MMPI? (In order to identify complicating psychiatric/psychological factors.) Another prominent early battery was the Luria-Nebraska Neuropsychological Battery (text pp. 284, 285) designed to diagnose general impairment but also “lateralization” (R or L hemisphere-related) and localization (Where is the injury?). This battery also involved “qualitative” evaluation of errors in order to tease out just what was amiss that led to them. 2. Flexible Batteries: (text pp. 287 - 296) This is more commonly the practice among neuropsychologists now. Since there has been a movement away from the “Query Organicity” referral question toward questions about specific neuropsychological functions across the full range of them,  8 Psychology 4360 Section 9: Neuropsychological Assessment OL neuropsychologists will select tests allowing them to address these specifics and build a battery aimed at the referral question. See Table 10.4 in the text (text p. 287) Examples of Tests Used to Assess Various Cognitive Domains It’s also true that a test battery would be added to on the basis of what is observed about the test-taker’s performance on the initial battery. Some questions will emerge and require more investigation. D One Framework for creating a Flexible Battery Following the model shown in Figure 11-1: a. You’ll see that at the base of this triangle are measures of global functioning, including general intelligence, and academic achievement. What have we reviewed as far as Achievement tests go? Look at Table 10.4 again. You are aware from our work in the cognitive ability section that intelligence tests give us a global indication of intelligence and more specific information about composite sub-abilities. On this diagram, we see that information from intelligence tests would be relevant to foundation skills, modality-specific skills, and even integrated skills levels. Which Wechsler test factor scores (VCI, PRI, PSI, WMI) would speak to levels 2, 3 and 4 (from the top, down) of this model?  9 Psychology 4360 Section 9: Neuropsychological Assessment OL b. Let’s look further at the foundation skills level. i. Arousal/attention Attention, including attention span, “working memory” (holding information in immediate memory while using it to solve a problem), concentration and ability to sustain attention (“vigilance”), is obviously a key feature of any complex cognitive activity. We are especially concerned to evaluate attentional function when? (diagnosing effects of an acquired brain injury or where we suspect ADD/ ADHD, neurocognitive disorders like dementia) The WMI of the Wechsler Intelligence scales gives us information concerning simple attention span (Digits Forward), repeating digit strings backward from the way they are presented (Digits Backward) and re- arranging letter-number sequences (working memory), while the Wechsler Memory Scale gives us also visual attention span. The PSI gives us information about the speed of mental processing. Specialized tests include the (Connors) Continuous Performance Test, the Paced Serial Addition Test (PASAT) and the Stroop Color-Word Test. ii. Sensory and motor functions These are tests examining sensation/perception in any modality and the integration of sensory and motor activity. The Seashore Rhythm test requires you to listen to two rhythms and decide if they are the same or different, and the Speech Sounds Perception test which presents a nonsense word in auditory mode and then you choose the correct printed representation of that word-like sound sequence. A widely-used complex copy task, the Bender Visual-Motor Gestalt Test, requires adequate visual processing of information and its motoric reproduction (drawing!). Here are some figures like those on the Bender (from Gregory, 2011)  10 Psychology 4360 Section 9: Neuropsychological Assessment OL Note that visual-motor proficiency increases to young adulthood and shows a normal, age-related decline thereafter. Question: What would this require, therefore? (suitable age norms in order to detect genuinely abnormal function) iii. Executive, problem-solving, and reasoning ability. (Anterior regions) Executive function is that combination of skills that allows for the correct and efficient execution of a complex task, therefore involving organizing, planning, having cognitive flexibility, being able to stay on task, and to evaluate progress toward a goal. We recognize these functions as subserved by the frontal and prefrontal areas of the brain. One classic test of executive function is the Porteus Maze where you are to draw a pathway through a maze, from beginning to end. The Behavioural Assessment of Dysexecutive Syndrome test has a number of planning and tasks (like planning a search in a field, a trip through a map) that then require executing follow-through on the task. Cognitive flexibility can be tested by the Wisconsin Card Sort Test, in which the test-taker places cards from the deck into a correct category by matching “key” cards. The category is changed without notice but feedback (the test giver will reply “incorrect” when the test-taker makes an error in matching the new category) cues the test-taker to changes in the principle used to categorize or match. Someone with cognitive flexibility will respond to the cue by testing out another matching principle. A deficit in cognitive flexibility results in what we call “perseveration”. This is repeating an incorrect match based on a principle no longer in force and despite being given feedback that the match is incorrect.  11 Psychology 4360 Section 9: Neuropsychological Assessment OL Non-verbal reasoning can be tested with picture absurdities and abstract visuo-spatial reasoning tasks like Matrix Reasoning as found in Wechsler scales. One uses one’s observations of the way test-takers handle organizational tasks on the WAIS, especially in (visual) perceptual reasoning, to evaluate how orderly or systematic the person’s approach to a task is. Tests of verbal reasoning include the Similarities and Comprehension subtests from the Wechsler tests, and various proverbs. Here’s a proverb for you: what does this mean? “A stitch in time saves nine.” c. At the modality-specific skills level of our triangle, we would consider language and visuo-spatial functions (also lateralization L:R) i. If we have completed a Wechsler scale, we already know what about language? (Verbal comprehension - the VCI) Where we are testing someone with known spoken (“expressive”) language limitations, we might have to use a test such as the Peabody Picture Vocabulary test. See text pp 227, 228 regarding the Peabody We can test verbal fluency with the Controlled Oral Word Association Test. It requires you say as many words as you can, in a fixed time period, that begin with a particular letter. Of course, we are noting all relevant observations about the test-taker’s expressive and receptive language over the course of the assessment. We could use the WRAT to assess basic written language features like spelling  12 Psychology 4360 Section 9: Neuropsychological Assessment OL and word reading. We’ve looked at the Aphasia Screening Test from the extended Halstead-Reitan battery. ii. Visuo-spatial function -- once again, if we’ve started with a WAIS, we have some relevant data from what factor score? (visual Perceptual Reasoning (PRI)). Visuo-spatial constructional tasks can include drawing tasks like the Rey Complex Figure Test or “building” tasks like the Wechsler scales’ Block Design or Object Assembly. If motor skill is insufficient, the Hooper Visual Organization Test may be used.. d. Integrated skills At the top of our pyramid are learning and memory. To remind you of what you’ve studied in previous courses, here is a model of the learning and memory process:  13 Psychology 4360 Section 9: Neuropsychological Assessment OL External or internal sensory input through all sensory modalities is registered, consciously or not, then perhaps encoded into short-term/working memory, and again perhaps into long-term memory. Recall that LTM can be procedural or declarative. Declarative memory can be semantic or episodic. The assessment of memory function may require testing at all of these stages of the process, to diagnose and recommend treatment, or accommodation. Testing for memory function can be modality-specific. Question: What modalities you see in the above diagram are more or less important, do you think? The Wechsler Memory Scale: See the text pp. 231 - 235 for the WMS IV. The Wechsler Memory Scale tests and reports indexes for verbal and visual memory, of short-term and “delayed” (still considered “long-term” in some  14 Psychology 4360 Section 9: Neuropsychological Assessment OL models, “short-term” in others) duration, and Visual Working Memory. See the text for some similar items. You can distinguish delayed from long-term memory by the time elapsed between testing. On the WMS IV “delayed” memory is for up to 30 minutes, so this is a brief “long-term” memory. You’ll see that the authors on the text chapter regard delayed recall as still Short-Term memory. Even longer term memory is sometimes called “remote” memory. The WMS evaluation shows internal consistency and test-retest reliability acceptable for the indexes with some variation when the subtests are considered. Validity is shown to be satisfactory largely as a measure of short term memory. Contrasted groups show the predicted differences in memory scores. Interestingly, the newest version of the WMS has separate batteries for Adult and Older Adult people. Why do you think that would be useful or important? Other Memory Tests Suitable for the Elderly, especially when the referral question concerns dementia or cognitive competency: With elderly, possibly dementing patients: the Buschke Cued Recall Test, or the memory portion of the Canadian Cognitive Competency Test can be used. The Canadian Cognitive Competency Test has a brief memory test for practical information like the details of a doctor’s appointment, immediately after hearing the information and after a delay of some minutes. It also asks for remote memory of the person’s address and telephone number. It draws out a simple route from one map location to another and then asks the person to trace it out.  15 Psychology 4360 Section 9: Neuropsychological Assessment OL The Buschke has the test-giver lay out a dozen cards with simple drawings of common objects. After the array is removed, the test-taker is asked to name the objects pictured. When they are unable to recall an object freely, they are given a category word as a cue and another chance to name the object. There are three learning trials and two delayed trials. Memory tests which also provide information about Learning: Tests which also uses lists of words are the Rey and the California Auditory Verbal Learning Tests. The particular advantage of list-type repetition tests is that they reveal the test-taker’s learning slope over the repeated trials. Does the person benefit from repetition of the information to be learned? You’ll note also a distraction list which shows the effect on memory of competing information. Visual memory: This can be tested separately with the recall trials of the Rey Complex Figure Test or the Bender Visual-Motor Gestalt test that we’ve already considered. See Table 10.5 on page 288 of the text for the Top Ten Tests Used by Neuropsychologists E Test conditions Needless to say, conditions of testing must be optimal if the person’s best performance is to be assessed. This would concern? The setting; the person’s mental or physical state, glasses or hearing aids present, medication effects, energy level. The effort invested by the test-taker should be considered. There are any number of possible contributors to weak effort – like? It would be important to distinguish between malingering and amotivational syndrome – when might we be dealing with the latter? As I’ve already emphasized, it is critical that the administration of an assessment evaluate and report evidence of reliability and validity of the assessment itself. Sometimes, “image management” or outright malingering may occur, involving deliberate dissimulation. In neuropsychological assessment this may be tested by an instrument like the Symptom Validity Tests, designed to look difficult and presented as such, but really so easy most people can do them. Are the responses extremely poor, beyond a reasonable failure rate. Another test of malingering is a forced choice testing which items would be 50:50 correct: incorrect. Scores obviously below chance levels are considered evidence for deliberate dissimulation.  16 Psychology 4360 Section 9: Neuropsychological Assessment OL The Rey 15 item “memory” test - how hard should this be? F Evaluation of Score Differences: Normative vs. “Within the Individual” 1. Normative comparisons: When using standardized tests we compare an individual’s level of ability against normative samples to estimate their ability as Above Average (strong, to varying degrees), Below Average (weak to varying degrees) or Average (“intact”) relative to this group. Of course, the norm group against which we are to compare the person should be relevant to what is being asked for in the referral question (e.g. can this 50 yr. old person perform adequately at work which is being done satisfactorily by 30 year olds?). 2. “Within the Individual” comparisons: There are times when we want to know about what might have changed in the person’s cognitive function, or what areas are stronger and which are weaker among her cognitive or intellectual functions. a. What is the person’s level of some cognitive/intellectual function currently, relative to what it was previously (that is: is there a meaningful change between Time 1 and Time 2 within this individual?). E.g., why might a clinical or rehabilitation psychologist want to test and then re-test someone on their cognitive function (maybe including memory)? (evidence of normal aging effects, or the effects of intervening events such a brain injury or disease, psychiatric disorder (“pre-morbid”), or recovery from any of these.) b. Of psychoeducational diagnostic interest is often the pattern of abilities within the individual currently of relative strengths and weaknesses in their cognitive/intellectual functions. (Pattern Analysis) E.g., why might a School Psychologist want to investigate any young person’s pattern of personal cognitive strengths and weaknesses? (to recommend educational interventions which draw on her strengths to help where she is weak, in general to focus remediation efforts by her teachers.)  17 Psychology 4360 Section 9: Neuropsychological Assessment OL c. Finally, there are times when we want to compare an individual’s scores obtained on different tests. Here is where the co-normed psychoeducational batteries like the Woodcock-Johnson or the Wechsler scales we’ve mentioned along the way are particularly helpful since they have the same means and standard deviations by design. E.g., why might the Neuropsychologist want to compare someone’s Wechsler Adult Intelligence Scale performance against their Wechsler Memory Scale performance? (evidence of Alzheimer’s Neurodegenerative disease - requires deterioration in memory function. Check for intact non-memory related intellectual abilities.) Why might an Educational Psychologist want to compare a person’s Wechsler intelligence scale against their Wechsler Individual Achievement Test performance? (evidence of Learning Disability - what does the diagnosis require?) Why might a clinical or rehabilitation psychologist want to test and then re-test someone on their cognitive function (maybe including memory)? (evidence of normal aging effects, or the effects of intervening events such a brain injury or disease, psychiatric disorder (“pre-morbid”), or recovery from any of these.) Why might a School Psychologist want to investigate any young person’s pattern of personal cognitive strengths and weaknesses? (to recommend educational interventions which draw on her strengths to help where she is weak, in general to focus remediation efforts by her teachers.) 3. Interpreting score differences using the Standard Error of Difference: How big a difference is big enough to be “real”? (and not just due to test unreliability) Here’s our last use of the Standard Error idea. The key question is how big a difference has to exist between two of an individual’s test scores before we’re reasonably confident that a true difference exists, that the difference isn’t just due to test unreliability! To do such an evaluation the Standard Error of Difference is calculated as follows: ________________  18 Psychology 4360 Section 9: Neuropsychological Assessment OL SEdiff = √ SEmeas12 + SEmeas22 SEmeas1 and SEmeas2 are how we designate the two tests’ Standard Errors of Measurement. (Note that the tests have to have the same mean and standard deviation to use this method.) SEmeas1 and SEmeas2 are the same number when we are comparing premorbid with current scores on the same test or index (2X SEmeas1). Note that the reliability of a difference score is always less than that of either test in the comparison, therefore, standard errors of difference will always be larger than either of the standard errors of measure for the two tests on which scores are being compared. Once we have our standard error of difference, we can determine how many standard errors separate the two scores in question and decide, therefore, how likely it is (or how confident we are) that the two scores are truly different. A common convention is that a difference between two scores should give us a confidence level of 95% that a true difference exists, so - how many SEdiff should separate the two scores? (1.96) Where does this number come from? The normal distribution, because the Standard Errors are distributed normally, again! Fortunately, the test developers calculate the standard error of the difference for us and put the 95% confidence gap between the two scores in tables! (I know, I know - you are really disappointed...) We’ll take a look at the WAIS as our example: Here is the Analysis sheet of the WAIS report form, and the first part of that - the Discrepancy Comparison. Remember the WAIS factor scores (Indexes).  19 Psychology 4360 Section 9: Neuropsychological Assessment OL Now - here’s a quick example of how big a difference between two index scores would have to be before we could say we are 85% (level of significance.15) or 95% (level of significance.05) confident there is a TRUE DIFFERENCE between them - and therefore evidence of relative strength or weakness between the two. Find the difference required for someone who is 21 years old, between his Verbal Comprehension Index and his Processing Speed Index. So, if I test Ahmad and his VCI is 98 and his PSI is 110, can I say that there is likely a true difference and that his Processing Speed is indeed very likely to be strong as compared to his Verbal Comprehension as tested on the WAIS? The numbers in this table are calculated using the SEdiff. This test also allows you to evaluate any subtest score against the mean subtest score on the whole test. You can now evaluate, using the tables, whether any particular subtest score represent an area of relative strength or weakness when compared to the overall mean subtest score for the test. The same procedure applies when comparing Woodcock-Johnson Ability vs. Achievement, the WAIS vs. the WIAT. G Note that differences between scores can be statistically meaningful, but not clinically meaningful. One way to address this latter issue is to consider just how common a difference was found to be in the standardization study (called the Base Rate, which is usually reported in test manual tables, too.).  20 Psychology 4360 Section 9: Neuropsychological Assessment OL Now - weave together what you have learned in this section. Go to p. 301 and read through Case #1. Think it through - what kinds of tests would be useful, how would you combine information from different tests to generate your diagnostic impressions? And, now Case #2 on p. 302 - walk yourself through the same process.