Transient Ischemic Attack

Transient ischemic attacks (TIAs) are “mini-strokes” in which stroke symptoms such as weakness, numbness, blindness, or confusion occur for a limited amount of time and then resolve. These incidents are significant because they may herald an impending stroke. Although there is no treatment for a TIA, there is benefit to a medical workup looking for modifiable risk factors for stroke, such as high blood pressure and smoking, which can be treated and reduce the risk of future stroke.

TIAs are incidents where a blood vessel supplying the brain is temporarily occluded, leading to dysfunction of the brain cells which are deprived of the blood's oxygen. These cells are damaged, leading to symptoms, but can recover and lead to resolution of the symptoms. This most often occurs when a clot or other occlusion occurs inside one of the blood vessels. Several medical conditions can cause these clots; for instance, certain heart problems (such as atrial fibrillation, heart valve problems, or even heart attacks) may cause tiny blood clots to be made in the heart and travel to the brain, or cholesterol deposits in blood vessels within the brain may occlude the vessel. Diseases in which the blood is more prone to clot, such as certain cancers or hereditary blood clotting disorders, may also cause TIAs.

TIAs can lead to symptoms such as weakness, numbness or tingling, blindness, confusion, or dizziness. The symptoms are usually on only one side of the body. These symptoms may last only seconds or hours, but all TIA symptoms will resolve soon after they begin. To be considered a TIA, the symptoms must resolve within 24 hours of onset; if they persist and become permanent, a stroke has occurred.

People who are experiencing stroke or TIA symptoms should go to the emergency room, and will likely be treated as stroke patients if their symptoms are still present, because there is no way to determine whether the symptoms will go away on their own. They receive the same testing as stroke patients, which includes a computed tomography (CT) scan of the brain.

Because TIAs always resolve on their own, no treatment is needed. However, it is important that people who experience a TIA see a doctor and receive testing which may give clues as to why the TIA occurred, because there is a strong chance that a stroke will occur in the future. This testing may include studies of the heart, blood clotting, blood vessels, and brain. Education on ways to prevent strokes is also important, and includes smoking cessation and control of blood pressure, high cholesterol, and diabetes. Some patients may be put on aspirin to reduce the chance of having a stroke. People who have experienced a TIA should [Page 1677]not be reassured that the symptoms have resolved, because this “mini-stroke” may be a sign that a larger, permanent stroke is about to take place.