Fibromuscular dysplasia with dissection of basilar artery presenting as "locked-in-syndrome".

We report on a young man with fibromuscular dysplasia involving the basilar artery detected at autopsy. He presented with sudden onset of stroke, and the lesion was complicated by thrombosis and dissection of the vessel wall. The organizing thrombotic lesion of the basilar artery was responsible for the ventral pontine infarct that resulted in "locked-in syndrome."