Embolic Stroke: A Rare but Probably Real Cause of Aneurysmal-Like Subarachnoid Hemorrhage.

BACKGROUND Ischemic stroke is being increasingly recognized as a possible cause of spontaneous isolated convexity subarachnoid hemorrhage (SAH). However, it is a much less established cause of cisternal, aneurysmal-like SAH. Only 3 case reports of concomitant cisternal SAH and perforator infarcts exist in the literature, raising the possibility of perforating artery rupture as a potential mechanism. In contrast, embolic stroke is not recognized as a cause of aneurysmal-like SAH. CASE DESCRIPTION In 2 patients with embolic cerebral infarctions mimicking intracranial aneurysm rupture, diagnosis was confirmed by magnetic resonance imaging with diffusion-weighted imaging after cerebral angiography failed to reveal an underlying vascular lesion. Extracranial atherosclerosis was identified as the source of emboli in each case. One patient was started on antiplatelet therapy, and the other underwent surgical revascularization. Both patients had a favorable hospital course, with no recurrent hemorrhage or ischemia. CONCLUSIONS Based on these observations, embolic stroke should be included in the differential diagnosis of angiogram-negative SAH. Therefore, brain magnetic resonance imaging and vascular imaging of the neck should be part of the routine work-up of this relatively common entity.