Stroke: anatomy of a catastrophic event.

Subarachnoid hemorrhage (SAH) resulting from the rupture of a cerebral aneurysm represents one major cause of stroke. SAH may be followed by a spontaneous severe contraction of major cerebral arteries, a condition referred to as cerebral vasospasm. Vasospasm may result in brain ischemia or actual tissue death. This constrictive vascular state is devastating, remains largely untreatable, and is a major cause of morbidity and mortality in SAH patients. Approximately 30,000 Americans are affected by this condition each year. The overall death rates are 25%, and significant neurological complications occur in 50% of individuals who survive the initial bleed. This report highlights some of the important aspects of this vascular disease.