Slow progressive bilateral posterior artery infarction presenting as agitated delirium, complicated with Anton's syndrome.

Three patients presented with an acute agitated delirium as the earliest sign of bilateral posterior cerebral artery infarction. All patients showed a unique slow progressive deterioration with a remarkably long interval between the first neuropsychological and subsequent visual and neurological symptoms, ranging from 3 to 30 days. Repeated CT scans demonstrated hypodensities in the posterior artery territory only after a long interval of 9-12 days, in case 3, and between 33 and 48 days in case 2. In the latter case MRI was still negative 33 days after onset. In 2 patients the cortical blindness was complicated with anosognosia for blindness. Clinical condition worsened progressively in all patients, leading to death, probably due to brainstem infarction. In all 3, the combination of clinical and radiological findings indicated a 'top of the basilar' distribution, which could be confirmed in two by autopsy.