Aneurysmal subarachnoid hemorrhage: an overview for the practicing neurologist

Subarachnoid hemorrhage (SAH) accounts for ~5% of strokes, but causes high rates of morbidity and mortality and occurs at a relatively young age. The rupture of an intracranial aneurysm is the leading cause of nontraumatic SAH and will be the subject of this review. Rebleeding remains the most imminent danger until the aneurysm is secured (i.e., excluded from the cerebral circulation). Therefore, prompt aneurysm treatment is crucial to minimize this risk. Endovascular occlusion of the aneurysm with coils has been shown to be associated with better short- and long-term outcomes than surgical clipping in select patients. Yet, angiographic surveillance is necessary after endovascular treatment and retreatment with additional coiling may be required. Delayed cerebral vasospasm is the leading cause of brain damage once the aneurysm has been treated. Hemodynamic augmentation therapy remains the mainstay of medical treatment, but various agents are being tested as means to prevent or ameliorate vasospasm, including magnesium sulfate, statins, and an endothelin antagonist. Medically refractory vasospasm demands angioplasty of the affected vessel or intraarterial infusion of vasodilators. In this review, the authors provide an overview of the diagnosis and management of aneurysmal SAH with an emphasis on these main topics.