Visuospatial ability in cortical dementia.

The level and pattern of visuospatial ability were comparatively examined in patients with putative cortical dementia (CD) and acute right hemisphere (RH) injury. Visuospatial ability was evaluated using measures of block construction, spatial reasoning, hemispatial search, and visuoconstructive copy. The incidence of neglect was also determined using special index measures derived from the spatial tasks. There was no difference between the CD and RH groups on measures of block construction, visuoconstructive copy, and spatial reasoning. While the overall incidence and severity of neglect was generally equivalent between the two clinical groups, 50% of the CD patients exhibited a pattern of right spatial neglect. In addition, a strong relationship was not evident between neglect laterality in CD and corresponding asymmetric cognitive and sensory-perceptual compromise, suggesting that neglect in CD may be due to different mechanisms than those causing neglect following right hemisphere injury. The findings indicate that while patients with putative CD perform like individuals with recent right hemisphere injury with respect to mean level of visuospatial ability, many exhibit a differential pattern of compromise related to the laterality of visuospatial neglect. The relevance of these results for the clinical diagnosis of CD is discussed.