Elsevier

World Neurosurgery

Volume 91, July 2016, Pages 669.e1-669.e5
World Neurosurgery

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

Presented as a poster at the American Association of Neurological Surgeons 2015 Annual Meeting in Washington, DC, May 2015.
https://doi.org/10.1016/j.wneu.2016.03.037Get rights and content

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.

Introduction

Nearly 15% of all cases of spontaneous subarachnoid hemorrhage (SAH) are nonaneurysmal, and in one third of those cases, another vascular, tumoral, or systemic cause is ultimately identified.1 More recently, ischemic stroke has been recognized as a possible cause of spontaneous isolated convexity SAH.2, 3, 4, 5, 6, 7 However, it remains a much less established cause of cisternal SAH and is seldom considered in the differential diagnosis of intracranial aneurysm rupture. Only 3 previous case reports of concomitant cisternal SAH and perforator infarcts exist in the literature, which have been postulated to result from rupture of small perforating arteries.8, 9 In contrast, embolic stroke is not a recognized cause of aneurysmal-like SAH. We report 2 unique cases of embolic cerebral infarction mimicking intracranial aneurysm rupture.

Section snippets

Patient 1

A 64-year-old woman, who was hypertensive and a heavy smoker, presented with sudden onset of the worst headache of her life but no other accompanying neurologic symptoms. The neurologic examination was unremarkable. Head computed tomography (CT) revealed diffuse and symmetric cisternal SAH (Figure 1A). She was classified as World Federation of Neurosurgical Societies grade 1 and Fisher grade 3. CT angiography of the head was unremarkable. CT angiography of the neck demonstrated high-grade

Discussion

In 85% of cases, spontaneous SAH results from rupture of an intracranial aneurysm. Another 5% are caused by less common entities, including cerebrovascular malformations, intracranial dissections, cerebral venous thrombosis, moyamoya disease, cerebral vasculitides, amyloid angiopathy, tumors, vascular lesions in the spinal cord, coagulopathy, and central nervous system stimulant (e.g., cocaine, amphetamines) abuse. Finally, despite a complete work-up, the cause of approximately 10% of SAH cases

Conclusions

Embolic stroke is a rare cause of cisternal SAH and should be included in the differential diagnosis of angiogram-negative SAH, particularly in older patients, patients with multiple cardiovascular risk factors, and patients with known atherosclerotic disease. In this setting, brain MRI and vascular imaging of the neck can provide invaluable information and should thus be incorporated in the routine work-up of patients with angiogram-negative SAH. Specifically, our findings suggest that the

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Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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