Ask the Doctor Definition of Stroke Stroke, or cerebral vascular accident, is a medical term referring to an injury to the brain which has been produced by the blood flow that supplies the brain.
Blood flows through the arteries in the body, supplying nutrition to all the body's cells.
The arteries that penetrate through the skull, and feed the surface and underlying portions of the brain, can close up, producing what is called an ischemic infarct . Another form of stroke occurs when the arteries in the brain form a balloon, or aneurysm, that can explode. This type of blood flow injury is called a hemorrhagic stroke , i.e. blood is freely present in the brain substance, not contained within the arteries. Either of these two types of brain injuries can produce similar symptoms in a stroke victim. In these cases the arteries that become veins are formed abnormally and are at risk to give away and rupture.