According to the “Brain Attack” website, studies with animals have shown that brain injury occurs within minutes of a brain attack and can become irreversible within as little as an hour. In humans, brain damage begins from the moment the stroke starts and often continues for days afterward. Scientists now know that there is a very short window of opportunity for treatment of the most common form of brain attack or stroke. Because of these and other advances in the field of cerebrovascular disease stroke patients now have a chance for survival and recovery.  A stroke can be devastating to individuals and their families, robbing them of their independence. It is the most common cause of adult disability. Each year more than 500,000 Americans have a stroke, with about 145,000 dying from stroke-related causes.

There are two broad categories of stroke: those caused by a blockage of blood flow and those caused by bleeding. While not usually fatal, a blockage of a blood vessel in the brain or neck, called an ischemic stroke, is the most frequent cause of stroke and is responsible for about 80 percent of strokes. These blockages stem from three conditions: the formation of a clot within a blood vessel of the brain or neck, called thrombosis; the movement of a clot from another part of the body such as the heart to the neck or brain, called embolism; or a severe narrowing of an artery in or leading to the brain, called stenosis. Bleeding into the brain or the spaces surrounding the brain causes the second type of stroke, called hemorrhagic stroke.