Transient Ischemic Attack (TIA)

What is a transient ischemic attack (TIA)?

A transient ischemic attack (TIA) is a brief loss in brain function. It happens when the brain does not get enough blood because a blood vessel is blocked for a short time.

The symptoms of a TIA are similar to the symptoms of a stroke. A TIA is different from a stroke because it does not cause lasting damage to the brain. However, if you have had a TIA, you have a high risk of having a stroke. Getting a diagnosis and treatment for a TIA right away can help prevent the damage and disability a stroke could cause.

What is the cause?

TIAs may be caused by anything that blocks the blood supply to a part of the brain for a short time. 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 an artificial mechanical heart valve may form such clots.
• A spasm of blood vessels in the brain.

Conditions that put you at risk for having a TIA or stroke are:

• atrial fibrillation (irregular heartbeat)
• high blood pressure
• high cholesterol
• heart disease
• previous TIA
• diabetes
• smoking
• abuse of alcohol
• obstructive sleep apnea

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:

• sudden numbness or weakness of the face, arm, or leg, especially on one side of the body
• sudden confusion, trouble speaking, or trouble understanding others
• sudden trouble seeing in one or both eyes (visual disturbances)
• sudden trouble walking, dizziness, or loss of balance or coordination
• sudden severe headache with no known cause

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 healthcare provider will ask about your symptoms and medical history. He or she will ask when the symptoms 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 used to diagnose a TIA are:

• MRI (magnetic resonance imaging), which uses magnetism, radio waves, and a computer to make pictures that can show plugged blood vessels in the brain or neck
• CT scan, which uses computerized X-rays to make pictures that can show plugged blood vessels in the brain or neck
• ultrasound scans to show blood flow in blood vessels of the head and neck
• carotid angiogram, which uses X-rays and dye injected into an artery to look at the arteries traveling up each side of the neck, bringing blood to the brain
• cerebral angiogram, which uses X-rays and dye injected into an artery to look at the blood vessels in the brain
• electrocardiogram (ECG), which is a recording of the electrical activity of your heart
• echocardiogram, which is an ultrasound scan of the heart
• blood tests

If your healthcare 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?

You may need to stay in the hospital for complete diagnosis or if your provider determines that you have a high risk of stroke.

Your healthcare provider may prescribe some medicine--for example, a drug that helps prevent blood clots or a drug to lower your cholesterol. Aspirin is usually recommended after a TIA. If you are already taking aspirin, your provider may prescribe a higher dose or a different medicine to help prevent clots.

If the blood vessels in the neck leading to the brain are more than 70% narrowed, you may have an operation called carotid angioplasty or carotid endarterectomy.

• With angioplasty, a tiny tube (catheter) is threaded from the groin through blood vessels up into the narrow place in the artery. A balloon is inflated to widen the narrow spot, and a device called a stent is often inserted to keep the artery open.
• For carotid endarterectomy, a cut is made in the neck and carotid artery and the blockage is removed.

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?

Often the symptoms of a TIA go away within a few minutes. The effects are usually gone within 24 hours.

It is important to understand that although the symptoms last just a short time, a TIA occurs because of an underlying serious problem that must be treated. People who do not receive medical attention for TIAs have a high risk of a stroke. Treatment can greatly reduce your risk of having a stroke.

How can I take care of myself and help prevent a TIA?

Follow your healthcare provider's advice for preventing another TIA or a stroke. Take any medicines exactly as prescribed. Don’t take any other medicines, including nonprescription drugs, without letting your provider know.

Follow these general guidelines for good health:

• Keep your blood pressure under control.
• Keep your cholesterol levels within the limits recommended by your healthcare provider.
• If you smoke, quit, and avoid being around others who are smoking.
• Lose weight if you are overweight, and keep a healthy weight.
• Limit your use of alcohol.
• Stay fit with the right kind of exercise for you.
• Eat a healthy diet that is low in sodium and saturated and trans fat.
• Reduce the stress in your life with relaxation and psychological counseling if needed.
• If you have diabetes, make sure your blood sugar is well controlled.