A transient ischemic attack (TIA), sometimes called a ministroke, is an episode of strokelike symptoms that usually lasts less than one hour. During a TIA, circulation to a part of the brain is interrupted briefly, then restored. This interruption can be caused by a narrowing of a brain artery because of atherosclerosis or a small floating blood clot that entered the bloodstream from somewhere else in the body, often the heart, and temporarily blocked a brain artery.

Symptoms of a TIA are the same as those of stroke. The old standard uses a 24-hour cut off — symptoms that completely resolve within 24 hours have been defined as a TIA, while symptoms that last longer are called a stroke. A more realistic and practical time frame for a TIA is less than one hour. Most TIAs actually last only 5 to 20 minutes.

These symptoms can include:

• Dizziness or confusion
• Weakness or paralysis on one side of the body
• Sudden, severe numbness in any part of the body
• Visual disturbance, including sudden loss of vision
• Difficulty walking, including staggering or veering
• Coordination problems in the arms and hands
• Slurred speech or inability to speak

Your doctor will ask about your current symptoms and your medical history, including conditions that increase your risk of stroke — high blood pressure, diabetes, high cholesterol, smoking and certain types of heart disease. He or she will examine you and will do a test called an electrocardiogram (EKG). While examining you, your doctor may pay special attention to the circulation in your neck, where major arteries supplying the brain are located. In examining your neck, he or she will listen with a stethoscope for turbulent sounds that indicate blood is flowing through narrowed arteries. Blood tests also will be done.

To help pinpoint the cause of a TIA, your doctor may order a computed tomography (CT) or magnetic resonance imaging (MRI) scan of your brain. To evaluate flow through blood vessels, your doctor may do other tests, including Doppler ultrasound, magnetic resonance angiography (MRA) or X-ray angiography. If your doctor suspects that floating blood clots are coming from your heart, special heart tests may be necessary.

The onset of any symptoms suggestive of a stroke or TIA requires immediate medical attention. You can expect a TIA to last less than one hour. If symptoms are not improving quickly after one hour, a stroke is likely to occur without emergent therapy.

You can help to prevent TIAs by controlling your risk factors for stroke, especially high blood pressure, smoking and diabetes. If you have high blood pressure, follow your doctor's recommendations for modifying your diet and taking your medication. If you smoke, quit. If you are diabetic, monitor your blood sugar level frequently, follow your diet, and take your insulin or oral medication as your doctor has prescribed. It is also wise to exercise regularly and to eat a healthy diet that is rich in fruits and vegetables but low in saturated fats and cholesterol.

In treating TIAs, the ultimate goal is to prevent a full-fledged stroke. Medications used for this purpose include anticoagulants (anticlotting medications) and antiplatelet medications such as aspirin and clopidogrel (Plavix).

If you have significant narrowing of part of the carotid artery in the neck, surgery called carotid endarterectomy or carotid artery stenting may be done to correct the problem and help prevent future TIAs and stroke.

Call your doctor immediately whenever anyone has symptoms of stroke, even if these symptoms last only a few minutes. TIAs can be a warning sign that a stroke is about to happen and they require prompt attention.

Without treatment, having a history of one or more TIAs significantly increases your risk of stroke compared with someone who has never had a TIA.

National Stroke Association
9707 E. Easter Lane
Englewood, CO 80112
Phone: 303-649-9299
Toll-Free: 800-787-6537
Fax: 303-649-1328
http://www.stroke.org/

National Institute of Neurological Disorders and Stroke
P.O. Box 5801
Bethesda, MD 20824
Phone: 301-496-5751
Toll-Free: 1-800-352-9424
TTY: 301-468-5981
http://www.ninds.nih.gov/