TIA (Transient Ischemic Attack)

When to see a doctor

Seek immediate medical attention if you suspect you've had a transient ischemic attack. Prompt evaluation and identification of potentially treatable conditions may help you prevent a stroke.

Causes

A transient ischemic attack has the same origins as that of an ischemic stroke, the most common type of stroke. In an ischemic stroke, a clot blocks the blood supply to part of your brain. In a transient ischemic attack, unlike a stroke, the blockage is brief, and there is no permanent damage.

The underlying cause of a TIA often is a buildup of cholesterol-containing fatty deposits called plaques (atherosclerosis) in an artery or one of its branches that supplies oxygen and nutrients to your brain. Plaques can decrease the blood flow through an artery or lead to the development of a clot. Other causes include a blood clot moving to your brain from another part of your body, most commonly from your heart.

Risk factors

Some risk factors for transient ischemic attack and stroke can't be changed. Others, you can control.

Risk factors you can't change

You can't change the following risk factors for transient ischemic attack and stroke. But knowing you're at risk can motivate you to change your lifestyle to reduce other risks.

• Family history. Your risk may be greater if one of your family members has had a TIA or a stroke.
• Age. Your risk increases as you get older, especially after age 55.
• Gender. Men have a slightly higher likelihood of TIA and stroke, but more than half of deaths from stroke occur in women.
• Sickle cell disease. Also called sickle cell anemia, stroke is a frequent complication of this inherited disorder. Sickle-shaped blood cells carry less oxygen and also tend to get stuck in artery walls, hampering blood flow to the brain.
• Race. Blacks are at greater risk of dying of a stroke, partly because of the higher prevalence of high blood pressure and diabetes among blacks.

Risk factors you can take steps to control

 

You can control or treat a number of risk factors, including:

• High blood pressure. Risk of stroke begins to increase at blood pressure readings higher than 115/75 millimeters of mercury (mm Hg). Your doctor will help you decide on a target blood pressure based on your age, whether you have diabetes and other factors.
• Cardiovascular disease. This includes heart failure, a heart defect, a heart infection or an abnormal heart rhythm.
• Carotid artery disease. The blood vessels in your neck that lead to your brain become clogged.
• Peripheral artery disease (PAD). The blood vessels that carry blood to your arms and legs become clogged.
• Cigarette smoking. Smoking increases your risk of blood clots, raises your blood pressure and contributes to the development of cholesterol-containing fatty deposits in your arteries (atherosclerosis).
• Physical inactivity. Engaging in 30 minutes of moderate intensity exercise most days helps reduce risk.
• Diabetes. Diabetes increases the severity of atherosclerosis — narrowing of the arteries due to accumulation of fatty deposits — and the speed with which it develops.
• Poor nutrition. Eating too much fat and salt, in particular, increases your risk of TIA and stroke.
• High cholesterol. Eating less cholesterol and fat, especially saturated fat and trans fats, may reduce the plaques in your arteries. If you can't control your cholesterol through dietary changes alone, your doctor may prescribe a statin or another type of cholesterol-lowering medication.
• High levels of homocysteine. Elevated levels of this amino acid in your blood can cause your arteries to thicken and scar, which makes them more susceptible to clots.
• Excess weight. A body mass index of 25 or higher and a waist circumference greater than 35 inches in women or 40 inches in men increase risk.
• Heavy drinking. If you drink alcohol, limit yourself to no more than two drinks daily if you're a man and one drink daily if you're a woman.
• Use of illicit drugs. Avoid cocaine and other drugs.
• Use of birth control pills. If you use any hormone therapy, talk to your doctor about how the hormones may affect your risk of TIA and stroke.

Exams and Tests

Almost always, the symptoms and signs of a TIA will have gone away by the time you get to the hospital. A TIA diagnosis may be made based on your medical history alone.

The health care provider will do a complete physical exam to check for heart and blood vessel problems, as well as for problems with nerves and muscles.

Your blood pressure may be high. The doctor will use a stethoscope to listen to your heart and arteries. An abnormal sound called a bruit may be heard when listening to the carotid artery in the neck or other artery. A bruit is caused by irregular blood flow.

Tests will be done to rule out a stroke or other disorders that may cause the symptoms.

• You will almost always have a head CT scan or brain MRI. A stroke will show changes on these tests, but TIAs will not.
• You will have an angiogram, CT angiogram, or MR angiogram to see which blood vessel is blocked or bleeding.
• You may have an echocardiogram if your doctor thinks you may have a blood clot from the heart.
• Carotid duplex (ultrasound) can show if the carotid arteries in your neck have narrowed.
• You may have an EKG and heart rhythm monitoring tests to check for an irregular heartbeat.

Your doctor may do other tests to check high blood pressure, heart disease, diabetes, high cholesterol, and other causes of, and risk factors for TIAs or stroke.

Treatment

The goal is to prevent a stroke.

If you have had a TIA within the last 48 hours, you will likely be admitted to the hospital so that doctors can search for the cause and observe you.

High blood pressure, heart disease, diabetes, and blood disorders should be treated as needed.

You may receive blood thinners, such as aspirin, to reduce blood clotting. Other options include dipyridamole, clopidogrel, Aggrenox or heparin, Coumadin, or similar medicines. You may be treated for a long period of time.

Some people who have clogged neck arteries may need surgery (carotid endarterectomy). If you have irregular heartbeats (atrial fibrillation), you will be treated to avoid future complications.

Outlook (Prognosis)

TIAs do not cause lasting damage to the brain.

However, TIAs are a warning sign that you may have a true stroke in the coming days or months. More than 10% of people who have a TIA will have a stroke within 3 months. Half of these strokes happen during the 48 hours after a TIA. The stroke may occur that same day or at a later time. Some people have only a single episode, and some have more than one episode.

You can reduce your chances of a future stroke by following-up with your health care provider to manage your risk factors.