Visual neglect in Parkinson's disease.

Recent studies have documented the presence of neglect in patients with subcortical lesions. In this study, we gave 31 patients with Parkinson's disease (14 bilateral, seven right sided and ten left sided) a visual cancellation test. Visual neglect was found only in the bilateral and left-sided parkinsonian patients. These data support the hypothesis that subcortical structures are involved in attentional mechanisms and indicate the dominance of the right hemisphere for these mechanisms.