Psychiatric manifestations of right hemisphere infarctions.

Five right-handed patients (aged 45 to 78 years) developed acute psychotic disturbances in conjunction with infarcts in the right hemisphere. Their presentation was marked by agitation, inattention, suspiciousness, paranoid delusions, hallucinations, and lack of appropriate concern. Several of these patients initially received primary psychiatric diagnoses. Although neurological findings indicative of right hemisphere involvement could also be elicited, these were generally overshadowed by the more dramatic behavioral alterations. The electroencephalogram and computerized axial tomography were positive in most cases. These cases demonstrate that the possibility of a right hemisphere lesion needs to be entertained in patients who present with an atypical psychotic episode.