Dissecting aneurysm of basilar artery presenting with recurrent subarachnoid hemorrhage.

Spontaneous basilar dissecting aneurysms secondary to subarachnoid hemorrhage are rare, usually presenting with ischemia rather than a subarachnoid hemorrhage (SAH). A 63-year-old man who had SAH repeatedly from a ruptured basilar dissecting aneurysm was treated with endovascular occlusion of the unilateral vertebral artery. Postoperative angiograms 1 month after the procedure showed complete obliteration of the aneurysm. The clinical follow-up at 20 months showed no evidence of recurrent hemorrhage.