Posterior cerebral artery territory infarct presenting as acute psychosis.

An 82-year-old man with a past medical history of hypertension was admitted to a psychiatric hospital for sudden onset of acute psychosis. He was then transferred to an acute geriatric unit for further evaluation. During the admission the patient was noted to be very restless, agitated and noisy and was shouting and screaming incessantly. This was interspersed with occasional short periods of calm and quiet. Clinically, no obvious focal neurological deficits were detected. A CT scan of the brain was performed and it revealed an acute infarct involving the area supplied by the left posterior cerebral artery. This was a rather atypical presentation for an infarct involving this area.