Cause of Mini-Strokes

The cause of mini-strokes involves a lack of blood flow to the brain that occurs because a blood vessel becomes narrowed or blocked. Most mini-strokes occur when an embolism or thrombosis leads to a blood clot blocking a blood vessel in or near the brain. Stenosis (a severe narrowing of an artery) can also be a cause of mini-strokes.

Mini-Strokes

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.

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