What Is It?
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
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 1 hour. Most TIAs actually last only 5 to 20 minutes.
These symptoms can include:
Diagnosis
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.
Expected Duration
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 within one hour from onset, a stroke is likely to occur without emergent therapy.
Prevention
You can help to prevent TIAs by not smoking, keeping blood pressure within the normal range and lowering your LDL cholesterol level. Exercise regularly and eat a healthy diet that is rich in fruits and vegetables but low in saturated fats and cholesterol. If you need medications to bring down your blood pressure, take them daily as directed by your doctor. For high levels of LDL cholesterol that don't respond to diet, statin drugs offer the most protection against TIA and stroke.
Treatment
In treating TIAs, the ultimate goal is to prevent a full-fledged stroke. Most TIAs are treated with antiplatelet medications. The choices include:
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.
Some TIAs are related to small free floating blood clots in the heart that can occur in people with atrial fibrillation or advanced heart failure. In this situation, your doctor may choose anticoagulation (anticlotting medications) such as heparin and warfarin.
When To Call a Professional
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.
Prognosis
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.
Additional Info
National Stroke Association
9707 E Easter Lane
Building B
Centennial, CO 80112
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/
