"Mini-stroke" is another name for a transient ischemic attack (TIA). A TIA is a sudden episode in which there is a brief interruption in blood flow to part of the brain. Most TIAs occur when an embolism or thrombosis blocks blood flow to the brain. They usually last less than 30 minutes and cause symptoms similar to those of a full stroke, such as loss of balance, trouble speaking or understanding speech, and confusion. If you or someone else experiences such symptoms, don't wait for them to go away -- call 911 right away.
The term "mini-stroke" refers to a transient ischemic attack (TIA for short). In a mini-stroke, there is a short-term interruption in blood flow to the brain. This causes temporary stroke symptoms (often just for a few minutes), such as weakness or tingling in an arm or leg. Mini-strokes do not cause brain damage, but they are important warning signs that a person is at risk of having a stroke.
If you have a mini-stroke, you should seek medical care right away to prevent a full stroke. Of the approximately 50,000 Americans who have a mini-stroke each year, about one-third will have an acute stroke sometime in the future.
What Causes a Mini-Stroke?
Mini-stroke causes are the same as those associated with ischemic strokes (see Stroke Causes). The only difference involves timing. By definition, a stroke produces symptoms that last for at least 24 hours. A mini-stroke causes symptoms that improve after a shorter period of time (usually within 30 minutes).
A mini-stroke occurs when there is a temporary lack of oxygen- or nutrient-rich blood to a part of the brain. This lack of blood supply is the result of a blood vessel that becomes severely narrowed or blocked.
There are several ways in which a blood vessel in the brain may become severely narrowed or blocked; however, most mini-strokes result from an embolism or thrombosis. In an embolism, a blood clot or other tissue from another part of the body (such as the heart) moves through the blood into the neck or brain.
Thrombosis occurs when a blood clot (known as a thrombus) forms within a blood vessel of the brain or neck. Unlike an embolism, with thrombosis the blood clot does not break free -- it remains attached to the artery wall.
Another way that a blood vessel can become narrowed or blocked involves stenosis. Stenosis, a severe narrowing of an artery, can affect arteries in or leading to the brain. In most cases, stenosis is the result of a plaque buildup on artery walls.
(Click Cause of Mini-Strokes for more information on these specific causes.)