Transient ischemic attack (TIA, Mini-Stroke): A neurological event with the signs and symptoms of a stroke, but which go away within a short period of time. Also called a mini-stroke, a TIA is due to a temporary lack of adequate blood and oxygen (ischemia) to the brain. This is often caused by the narrowing (or, less often, ulceration) of the carotid arteries (the major arteries in the neck that supply blood to the brain).
TIAs typically last 2 to 30 minutes and can produce problems with vision, dizziness, weakness or trouble speaking.
If not treated, there is a high risk of having a major stroke in the near future. People who have a TIA have a 25% greater risk of having a stroke or other serious complication within 90 days.
In one study of people followed for 3 months after a TIA, about 10% had strokes, half of them in the 2 days after their TIA. This was more than 50 times the stroke rate expected in people of their age. One fifth of the strokes were fatal and nearly two-thirds were disabling.
A TIA is a sign of an impending stroke particularly if
- The TIA occurs in someone over 60 years of age,
- The TIA is in someone who has diabetes,
- The TIA lasts more than 10 minutes,
- There is weakness with the TIA, or
- The TIA causes difficulty with speech.
If you suspect a TIA, you should seek medical attention right away. An operation to clean out the carotid artery and restore normal blood flow through the artery (a carotid endarterectomy) markedly reduces the incidence of a subsequent stroke. In other cases, when a person has a narrowed carotid artery, but no symptoms, the risk of having a stroke can be reduced with medications such as aspirin and other blood thinners, which act by partially blocking the function of the blood elements, called platelets, that assist in blood clotting.