Multiple giant fusiform aneurysms with hydrocephalus.

Multiple giant fusiform aneurysms are uncommon. We report such a case of multiple giant fusiform aneurysms involving both internal carotid arteries and the basilar artery associated with hydrocephalus. The neurological deficits presented in this case were due to pontine infarction, which was suspected to be produced by thrombosis from the aneurysm, and a hydrocephalus might have been caused by a "water-hammering" effect of the elongated basilar artery.