What Is Transient Ischemic Attack?
A transient ischemic attack (TIA)—also referred to as a mini-stroke—occurs when blood flow to part of the brain is interrupted by a temporary blockage in an artery supplying the brain. The pathological mechanism of a TIA is identical to that of certain kinds of stroke, except that normal circulation is restored within 24 hours and no permanent brain damage occurs.
Most TIAs are short-lived, resolving within a few minutes to an hour. Symptoms appear suddenly and vary considerably depending on the part of the brain affected. Although TIA symptoms disappear completely without treatment, they often recur. Prompt medical attention is important: TIAs are a warning sign of an impending stroke. Approximately 15 percent of all ischemic strokes are preceded by a TIA, and up to 17 percent of TIAs are followed by a full-blown ischemic stroke in the next three months.
Who Gets Transient Ischemic Attack?
About 240,000 Americans suffer a TIA each year.
- Sudden weakness, tingling, or numbness, usually affecting only one side of the body.
- Double vision or temporary blindness in
- Speech difficulty.
- Dizziness and loss of balance or coordination.
- Lightheadedness, confusion, or amnesia.
- Headache or eye pain.
- The majority of TIAs are associated with atherosclerosis, a buildup of plaques in the walls of the arteries. A TIA may develop when a plaque becomes substantial enough to reduce blood supply locally in an artery supplying the brain. More commonly, however, a TIA occurs when a small fragment of a plaque that has broken off from a blood vessel, or a blood clot (embolus), usually from the heart, travels to an artery supplying the brain and lodges in a site already narrowed by atherosclerosis.
- Major risk factors for TIAs include high blood pressure, heart disease, diabetes, smoking, aging, and a previous history of TIA.
- Patient history and physical examination are needed to rule out other disorders such as epileptic seizures and migraines.
- Blood tests are taken to rule out disorders like hypoglycemia.
- Imaging studies may be done, such as MRI (magnetic resonance imaging) of the brain or ultrasound scans of the carotid arteries.
- Cerebral arteriography (injection of a contrast material into the blood vessels supplying the brain to highlight them during an x-ray, CAT scan, or MRI) may be performed in some cases.
- Drugs that inhibit blood clot formation may be prescribed. Anti-platelet medications, which reduce clots by interfering with the aggregation (clumping together) of blood cells called platelets, are often prescribed to people who have had a TIA. Anti-platelet agents include aspirin, clopidogrel (Plavix), and aspirin plus dipyridamole (Aggrenox). More powerful anticoagulants such as warfarin and heparin may be warranted in some cases.
- Measures to control hypertension and blood cholesterol levels (including drug therapy) are undertaken if needed.
- Patients who have experienced one or more TIAs, who are healthy enough to have surgery, and who show evidence of substantial atherosclerotic narrowing in the carotid arteries (the two main blood vessels in the neck supplying the brain) may be good candidates for carotid endarterectomy—a surgical procedure to clear away plaque deposits in the arteries. This technique is not appropriate for all patients, but in those who do qualify, it has been shown to reduce the risk of having a stroke in the future.
- Seek treatment for any predisposing condition, such as hypertension, high cholesterol, diabetes, or heart disease.
- Don’t smoke.
- Lose weight if you are overweight.
When To Call Your Doctor
- If you experience the symptoms of a TIA, contact your doctor immediately. Do not ignore symptoms just because they go away by themselves.
Reviewed by Joseph V. Campellone, M.D., Division of Neurology, Cooper University Hospital, Camden, NJ. Review provided by VeriMed Healthcare Network.