Identification of visual scanning deficits in adults after cerebrovascular accident.

Visual scanning deficits can result in the inefficient acquisition of information about one's environment. For adults who have had cerebrovascular accidents (CVAs), such deficits can interfere with the independent performance of many daily activities. The present study examined five tests designed to measure visual scanning deficits in post-CVA adults. Subjects with right and left hemisphere lesions were matched with control subjects by age and sex, and their performances on the tests were compared. The difference between the matched groups was statistically significant for all tests, with the hemiplegic subjects achieving lower scores than their normal counterparts. Deficits in visual scanning speed, identification of visual stimuli in the hemifield on the involved side, use of a systematic scanning pattern, and the ability to reproduce accurate visual designs were identified in the hemiplegic group. Statistically significant correlations were obtained on test-retest and interrater data, which indicates that the tests are reliable measures. The results of this study show that visual scanning deficits are present in post-CVA patients and can be measured with simple clinical evaluations. The presence of scanning deficits may significantly interfere with performance on tests measuring higher level visual-perceptual skills such as visual closure, figure-ground perception, and visual memory. An accurate assessment of visual-perceptual skills cannot be made without prior evaluation of such basic oculomotor functions as scanning. This approach is consistent with the developmental framework applied to most areas of treatment with brain-injured adults but is one that traditionally has not been applied in the evaluation of visual-perceptual skills.