David is a right-handed, 59-year-old male who has recently suffered an ischemic stroke of his posterior cerebral artery. An occipital lesion was apparent on his CT scan, and his neurological exam showed a right homonymous hemianopia. A general neuropsychological assessment yielded the following findings:
| Test | Administration | David’s Performance |
|---|---|---|
| Wechsler Adult Intelligence Scale-Revised (WAIS-R) | The WAIS is a series of subtests intended to assess verbal abilities (such as Information, Comprehension, Arithmetic, etc.) and non-verbal abilities (such as Picture Completion, Picture Arrangement). | Above average verbal score. |
| Pyramid and Palm Trees | A test in which a patient is asked to pick out which of two pictures is connected with a target picture (for example, when shown a pyramid, asked to choose between a palm tree and a oak tree). | Impaired. |
| Real object naming, both visual and tactile tests | Patient was shown 30 real objects, and asked to identify them by sight and then by touch. | David was only able to name 17 of the objects by sight, but all 30 by touch. |
David was also given a series of line drawings and color photos of common objects to identify. He was only able to identify two out of 13 line drawings and only two out of 10 color photos. Interestingly enough, when presented with the picture of a famous politician (whom he should have recognized) and told to identify it, he asked “Is it an apple?”
David was then given a series of drawing and other exercises, including one requiring him to copy and then identify line drawings of objects. He was able to copy these drawings with no trouble, although when asked to identify them, he often made errors. For example, while copying the drawing of the glass, he said that it was “a sitting animal, sheep or dog; there is the neck, a paw, a hoof, and here the shadow or the soil.”
Questions
- What condition or conditions (there may be more than one possibility) are being described in this case?
- What brain area or area(s) may be involved? Be sure to consider which visual stream is involved. Is there a specific hemisphere that is affected? How do you know?
- How should these brain areas function normally? What could be causing this dysfunction?
- What do the assessments and their results tell you about this person’s abilities and condition?
Remember to document your sources!
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