A stroke, or "brain attack", occurs when blood flow to the brain is interrupted by a blood clot or when a blood vessel bursts. This typically occurs when a blood vessel in or around the brain gets blocked or ruptures.
The lack of oxygen kills brain cells in the immediate area, often causing symptoms such as weakness or numbness on one side of the body, trouble walking, vision or speech changes.
There are two major types of stroke: an ischemic stroke occurs when a blood vessel gets plugged; a hemorrhagic stroke occurs when a blood vessel ruptures. Ischemic strokes account for about 85% of all strokes, while hemorrhagic strokes account for about 15%. The more common type of stroke, the ischemic stroke, is associated with Carotid Artery disease. Carotid Duplex testing checks for Carotid Artery Stenosis (narrowing) by allowing doctors to test the blood flow and directly look at the carotid arteries. The tighter the narrowing, the higher the risk of stroke.
|Normal carotid artery
||50% narrowed carotid artery