Abducens paresis. A rare presenting sign of posterior-inferior cerebellar artery aneurysm.

Posterior fossa aneurysms comprise a minority of intracranial aneurysms, but produce a wide array of signs and symptoms. We report a patient with slowly progressive unilateral sixth nerve paresis secondary to a saccular aneurysm of the posterior-inferior cerebellar artery. Neuroradiologic investigation of subarachnoid hemorrhage is discussed, and the literature concerning posterior circulation aneurysms is reviewed.