Serial Neuropsychological Testing After Stroke: When Scores Disagree
Ms. R is a 58-year-old right-handed woman 4 months after a left middle cerebral artery infarct. She has mild nonfluent aphasia (Boston Naming Test 38/60, improved from 31/60 at 6 weeks) and right hemiparesis. She was a high school math teacher. She wants to return to work part-time. You are asked to do a repeat neuropsychological evaluation; the first was done at 6 weeks post-stroke. On this evaluation, her verbal IQ estimate is 88, but her performance on a timed visuospatial task is at the 60th percentile. Her employer wants a 'fitness for duty' statement. She reports fatigue that worsens by early afternoon and says she 'can't think straight' after 2 pm.
1. How do you interpret the discrepancy between the low verbal estimate and the high visuospatial score?
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Do not treat the verbal estimate as a clean measure of premorbid ability. At 4 months, a verbal IQ estimate is contaminated by aphasia - it under-represents her premorbid function, which was likely well above average given her occupation and education. The visuospatial score, by contrast, is relatively spared by a left-hemisphere lesion and may be closer to her true ability.
So the apparent 'discrepancy' is largely an artifact of the instrument's sensitivity to her language impairment. The correct interpretation: her verbal estimate is a floor, not a ceiling, and the visuospatial score suggests preserved right-hemisphere function. Use converging evidence (education, occupation, premorbid reading, informant report) rather than a single IQ estimate to anchor premorbid ability.
Flag that timed tasks and language-loaded tasks will underestimate her; choose measures with reduced language and timing demands where possible, and interpret any low verbal score in light of the aphasia profile.
2. Her employer wants a fitness-for-duty statement. What do you provide, and what do you refuse to provide?
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Provide a functional, conditional, and time-limited statement, not a global 'fit' or 'unfit.' Specifically:
- Describe what she can do (visuospatial reasoning, some verbal tasks with support) and what is impaired (naming, sustained verbal processing, fatigue-sensitive performance).
- Recommend accommodations: part-time schedule, morning-weighted cognitive demands, written rather than rapid verbal instructions, extra time, reduced language load, and a fatigue-management plan.
- State that the statement is based on current data and should be re-evaluated after a defined period (e.g., 8–12 weeks) or after a trial of modified duties.
Refuse to certify a fixed permanent capacity or to predict job performance beyond the data. Avoid answering 'is she fit?' as a binary; answer the functional question the employer actually needs. Clarify consent and release of information with Ms. R before communicating with the employer.
3. She says she 'can't think straight' after 2 pm. How does this change your testing and your recommendations?
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Treat this as a fatigue effect, which is common after stroke and is a real, measurable constraint, not malingering or lack of motivation. It means a single morning test session may overestimate her functional capacity across a workday, and an afternoon session may underestimate it.
Options: (a) test in the morning and note the time; (b) if feasible, do a brief afternoon probe to document the decrement; (c) explicitly measure and report within-day variability rather than a single score. In recommendations, build the fatigue pattern into the return-to-work plan: morning-heavy cognitive tasks, scheduled rest breaks, and a graduated schedule.
Document the pattern so the employer understands that a good morning score does not mean she can sustain 8 hours. This is a functional limitation, and it belongs in the fitness-for-duty statement as a constraint with accommodations.