
Acute ischemic stroke affects about 800,000 patients a year in the U.S.; 600,000 of these cases are a first stroke. Stroke is a leading cause of permanent cognitive and function-limiting disability, and it ranks fifth among all causes of death. Prompt recognition of an acute ischemic stroke is crucial, as studies show that the volume of irreversibly damaged brain tissue expands rapidly until reperfusion occurs. The American Heart Association guidelines call for rapidly recognizing a neurological deficit, ruling out the mimics of a stroke, and making the early diagnosis of stroke.