Vanishing cerebral aneurysm in serial angiography.

The angiographically documented spontaneous thrombosis of an internal carotid-posterior communicating aneurysm in a 63-year-old woman is reported. Serial angiography performed 10, 17, and 29 days after the initial attack of subarachnoid hemorrhage demonstrated progressive thrombosis of the aneurysm. Clinical analysis of this case and a review of the literature suggest that vasospasm and the relative narrowness of the aneurysmal neck played crucial roles in the spontaneous thrombosis of the aneurysm, although neither is definitely responsible.