Basilar artery occlusion caused by thrombosis of atherosclerotic fusiform aneurysm of the basilar artery.

BACKGROUND Basilar artery occlusion caused by thrombosis of atherosclerotic fusiform aneurysm of the basilar artery is rare. We present a case confirmed by 6 years of follow-up and autopsy. CASE DESCRIPTION A 63-year-old man suffered from brain stem infarction. Computed tomography and angiography showed a fusiform aneurysm on the proximal portion of the basilar artery. At the time of the third attack 5 years later, complete thrombosis of the aneurysm was found, and the proximal basilar artery was occluded. On autopsy, an atherosclerotic aneurysm 15 mm in diameter was found. CONCLUSIONS A large atherosclerotic fusiform aneurysm of the basilar artery often causes brain stem infarction and involves a risk of complete thrombosis of the aneurysm and subsequent parent artery occlusion.