Giant fusiform aneurysm presenting as fatal basilar artery occlusion.

Fusiform aneurysms are often asymptomatic, and therefore their actual incidence is unknown. Ischemic stroke has been linked to dislodgment of small thrombi formed inside the aneurysm but is uncommon. This article describes two patients with rapidly fatal infarction in the entire pons, both cerebellar hemispheres, thalamus, and occipital lobes, findings consistent with occlusion of the vertebrobasilar artery complex. In both patients, autopsies revealed a giant fusiform aneurysm of the basilar artery.