Spontaneous thrombosis of cerebral aneurysms presenting with ischemic stroke.

Complete spontaneous thrombosis of an unruptured cerebral aneurysm is a rare event that can be discovered incidentally on advanced neuroradiologic studies. Occasionally, this phenomenon may be symptomatic and can present as an ischemic stroke. The presumed mechanism is probably due to extension of the thrombi to the parent vessel, embolization of intra-aneurysmatic thrombi to distal arteries or arterial compression due to increased aneurysm mass effect. We present documented cases of this unusual entity and review the literature.