Aneurysmal subarachnoid hemorrhage is a serious condition with a high morbidity and mortality. There are approximately 11 cases per 100,000 population per year, and approximately 40% of these cases are fatal. (Ingall) Among the fortunate subjects who survive the initial bleed, vasospasm and subsequent stroke are a major cause of morbidity. Vasospasm is defined as a prolonged severe, although reversible cause of arterial narrowing that occurs after bleeding into the subarachnoid space, most commonly after aneurismal rupture. (Youman) The reduced arterial diameter inhibits blood flow and deprives the brain of oxygen, which often results in a stroke.