What Is the Cause of Mini-Strokes?
A
transient ischemic attack (also known as a
TIA or "
mini-stroke") is caused by a temporary lack of oxygen- or nutrient-rich blood to a part of the brain. This lack of blood flow occurs because a blood vessel becomes severely narrowed or blocked.
The cause of mini-strokes is the same as that of an
ischemic stroke (
see Stroke Causes). The difference between a
stroke and a mini-stroke involves duration. By definition,
stroke symptoms last for at least 24 hours, while a mini-stroke often lasts less than 30 minutes.
A blood vessel in the brain may become severely narrowed or blocked in several different ways. The two most common are an embolism and thrombosis. An embolism develops when 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.
A blood vessel in or near the brain can become narrowed or blocked through stenosis, which is severe narrowing of an artery. Stenosis is most often caused by a
plaque buildup.