What is a transient ischemic attack?

A transient ischemic attack (TIA) is a temporary loss of some function of the brain. The attack begins without warning and usually disappears within 24 hours.

How does it occur?

A TIA occurs when the blood supply to a portion of normal brain tissue is decreased temporarily.

One underlying cause of a TIA is the narrowing of the blood vessels in the brain, usually from arteriosclerosis. This is a condition in which fatty deposits begin to fill and plug the blood vessels. This makes the blood vessels narrower and blocks the flow of blood.

Blood flow can also be blocked when an artery in the brain contracts during a spasm. A TIA is also caused when small pieces of one of the fatty deposits break off from the wall of the blood vessel and completely block a smaller blood vessel downstream.

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 is deprived of its blood supply. These are common symptoms of a TIA:

• visual problems; including double vision or temporary loss of vision

• slurring of speech or inability to speak clearly

• loss of movement in the arms, face, or legs

• weakness in the legs

• dizziness.

How is it diagnosed?

Your doctor will ask you about your health history. He or she will ask about your cholesterol level and past problems with high blood pressure or diabetes, and your smoking habits.

A chest x-ray, an electrocardiogram (ECG), and a Doppler ultrasound will probably be done. A Doppler ultrasound shows blood flow in the major veins and arteries of the head. Blood tests that help in evaluating a TIA usually include a complete blood count, a blood sugar test, cholesterol level, and a measure of how quickly your blood clots. If heart disease is suspected, you may also wear a continuous heart monitor to see how your heart functions during an entire day or an echocardiogram may be done to ensure that the clot did not originate in the heart. You may also have scans of your brain to help pinpoint where the problem is and to eliminate other reasons for your symptoms.

A special test known as a cerebral angiogram may also be done. In this procedure, dye is injected with a small needle into a blood vessel in your arm or groin. The dye flows into your brain and x-rays of your brain are taken to pinpoint where the problem areas are.

How is it treated?

Treatment may include aspirin or other drugs that thin the blood and help prevent future clots from forming.

If the blood vessels in the neck leading up to the brain contain deposits of material, an operation known as a carotid endarterectomy may be done to remove the material within the artery.

Treatment also includes changing your lifestyle to try to control the advance of arteriosclerosis. Changes you can make include:

• stopping smoking

• eating foods low in fat and cholesterol

• managing your stress well and participating in regular exercise

• controlling your diabetes.

Your doctor can help you with all of these changes or refer you to other health professionals who can.

How long will the effects last?

The effects of a TIA are usually completely gone within 24 hours. Often the symptoms will 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.

How can I take care of myself?

If you have had a TIA, it is extremely important for you to see the doctor immediately after the TIA and then regularly thereafter. The problems causing a TIA are generally not reversible and long-term medical management is essential.

If you are taking an anti-clotting drug, it is critical to check with your doctor often to make sure that the dose you are currently taking is effective and will pose the least risk.

The most important things you can do to help your recovery are:

• Follow the diet your doctor gives you.

• Do not overexert yourself during activities.

• Stop smoking cigarettes.

• Follow the instructions on the medication your doctor gives you.

• Do not take any other medication, including over-the- counter drugs, without letting your doctor know.

• Reduce the amount of stress in your life by exercise, relaxation, and psychological counseling if needed.

What can be done to prevent a transient ischemic attack?

Prevention of TIAs occurs early in life with lifestyle choices. Based on your family history, you may be more prone to have arteriosclerosis than others.

If you have a family history of heart disease or stroke:

• Stop smoking.

• Maintain a normal weight.

• Avoid a diet high in fat or cholesterol.

• Exercise regularly.