Transient Ischemic Attack (TIA)

What is a transient ischemic attack (TIA)?

A transient ischemic attack (TIA) is a temporary loss in brain function when the brain does not get enough blood for a short time. It is a minor stroke that does not cause permanent damage.

Without treatment, about 1 in 3 people who have a TIA will have a stroke within 5 years. It is important to diagnose a TIA in order to prevent the damage and disability a stroke could cause.

How does it occur?

TIAs may be caused by anything that briefly blocks the blood supply to a part of the brain. The blood supply may be blocked by:

• Narrowing of the blood vessels in the brain, usually from atherosclerosis. Atherosclerosis is a condition in which fatty deposits build up in the blood vessels, creating thickened areas called plaque. The plaque and the narrowing of the blood vessels can block the flow of blood.
• A small piece of plaque breaking off from the wall of a blood vessel and completely blocking a smaller blood vessel downstream
• Small blood clots moving to the brain from other parts of the body. For example, people with an abnormal heart rhythm or those with artificial mechanical heart valves may form such clots.
• Blood vessels in the brain may go into spasm.

What are the symptoms?

Each part of the brain performs a specific function. The symptoms of a TIA depend on which part of the brain loses its blood supply. Common symptoms of a TIA are:

• loss of movement in the arms, face, or legs
• weakness in the legs
• slurring of speech or inability to speak clearly
• seeing double or being partially blind
• numbness or tingling of the skin
• dizziness.

The attack begins without warning and usually lasts 2 to 30 minutes. Rarely does an attack last longer than 1 to 2 hours. You may have several TIAs over a period of days or weeks.

How is it diagnosed?

Your health care provider will ask about your symptoms and medical history. He or she will ask when the TIA spells occurred, how long they lasted, and what parts of your body were affected. A physical exam may show a heart problem that can produce blood clots or narrowed arteries leading to the brain.

Tests you may have are:

• chest x-ray
• electrocardiogram (ECG), which is a recording of the electrical activity of your heart
• Doppler ultrasound, which uses sound waves to show blood flow in the major veins and arteries of the head
• blood tests
• echocardiogram, which is an ultrasound scan of the heart
• CT scan (computerized x-rays), to look for bleeding into the brain
• MRI (magnetic resonance imaging), which uses magnetism, radio waves, and a computer to make pictures that can show plugged blood vessels
• cerebral angiogram, which uses x-ray pictures of dye injected into an artery to look for blockage or narrowing of blood vessels in your brain.

If your health care provider thinks you may have a heart problem, you may also wear a continuous heart monitor to see how your heart functions during an entire day.

How is it treated?

If you have TIAs often, you will probably have to stay in the hospital because your risk of stroke is high. If you haven't had many TIAs, you may not have to stay in the hospital, depending on how bad the spells have been.

Your health care provider may prescribe a drug that thins the blood and helps prevent clots.

If the blood vessels in the neck leading to the brain are more than 70% narrowed, you may have an operation called a carotid endarterectomy or a carotid angioplasty. These procedures remove deposits in the carotid arteries in your neck.

Treatment also includes changing your lifestyle to try to control atherosclerosis (see the guidelines for good health that follow).

How long will the effects last?

The effects of a TIA are usually completely gone within 24 hours. Often the symptoms go away within a few minutes. It is important to understand that although the symptoms disappear quickly, a TIA occurs because of an underlying serious problem, which must be treated. People who do not receive medical attention for TIAs will probably have a major stroke. Treatment with aspirin or carotid endarterectomy can greatly reduce your risk of having a stroke.

How can I take care of myself?

Follow your health care provider's advice for preventing another TIA or a stroke. Take any medicines exactly as prescribed. Do not take any other medicines including nonprescription drugs, without letting your health care provider know. For example, ask your provider if you should take aspirin. Low-dose aspirin therapy reduces the risk of stroke for women. For men, aspirin has been found to lower the risk of a first-time heart attack but has little effect on the risk of stroke.

Follow these general guidelines for good health:

• If you smoke, quit. Ask your health care provider for help if you need to.
• If you are overweight, ask your provider for help with weight control.
• Eat a low-fat, low-cholesterol diet.
• Exercise regularly for at least 30 minutes, 3 or 4 times a week.
• Reduce the amount of stress in your life with exercise, relaxation, and psychological counseling if needed.