top of the basilar syndrome

Emboli to the rostral portion of the basilar artery can produce this syndrome, with a wide variety of possible symptoms. Caplan (1980, Stroke) described 61 patients in a series, including 47 with an acute confusional state. 92 % had neuro-opthalmological abnormalities, especially affecting vertical eye movements. These include selective upgaze or downgaze syndrome or both, one and a half syndrome, Parinaud syndrome, skew deviation, and third and fourth nerve palsies. Nystagmus and light-near dissociation, homonymous field defects, internuclear opthalmoplegia, poorly reactive pupils, visual agnosias, memory deficits, hypersomnolence, all occur.