A transient ischemic attack (TIA) is a short period of symptoms similar to those of a stroke. It's caused by a brief blockage of blood flow to the brain. A TIA usually lasts only a few minutes and doesn't cause long-term damage.
However, a TIA may be a warning. About 1 in 3 people who has a TIA will eventually have a stroke, with about half occurring within a year after the TIA.
Often called a ministroke, a TIA can serve as both a warning of a future stroke and a chance to prevent it.
Transient ischemic attacks usually last a few minutes. Most symptoms disappear within an hour. Rarely, symptoms may last up to 24 hours. The symptoms of a TIA are similar to those found early in a stroke. Symptoms happen suddenly and may include:
You may have more than one TIA. Their symptoms may be similar or different depending on which area of the brain is involved.
If you think you're having or have had a transient ischemic attack, get medical attention right away. TIAs most often occur hours or days before a stroke. Being evaluated quickly means healthcare professionals can pinpoint potential treatable conditions. Treating those conditions may help you prevent a stroke.
The cause of a transient ischemic attack is similar to the cause of an ischemic stroke, which is the most common type of stroke. In an ischemic stroke, a blood clot blocks the blood supply to part of the brain. In a TIA, unlike a stroke, the blockage is brief and there is no permanent damage.
The blockage that occurs during a TIA often results from a buildup of cholesterol-containing fatty deposits called plaques in an artery. This is known as atherosclerosis. The buildup also may occur in an artery's branches that supply oxygen and nutrients to the brain.
Plaques can decrease the blood flow through an artery or lead to the development of a clot. A blood clot that moves from another part of the body, such as the heart, to an artery that supplies the brain also may cause a TIA.
Some risk factors of a transient ischemic attack and stroke can't be changed. Others you can control.
You can't change these risk factors of a TIA and stroke. But knowing you have these risks can motivate you to change the risk factors you can control.
You can control or treat a number of risk factors of a TIA and a stroke, including certain health conditions and lifestyle choices. Having one or more of these risk factors doesn't mean you'll have a stroke, but your risk increases if you have two or more of them.
Knowing your risk factors and living healthfully are the best things you can do to prevent a transient ischemic attack. A healthy lifestyle includes getting regular medical checkups. Also:
A prompt evaluation of your symptoms is vital to diagnose the cause of a transient ischemic attack. It also helps your healthcare professional determine the best treatment. To pinpoint the cause of the TIA and to assess your risk of a stroke, your healthcare professional may rely on the following:
Physical exam and tests. Your healthcare professional performs a physical exam and a neurological exam. Tests of your vision, eye movements, speech and language, strength, reflexes, and sensory system are included.
Your healthcare professional may use a stethoscope to listen to the carotid artery in your neck. During this exam, a whooshing sound called a bruit may mean that you have atherosclerosis. Or your healthcare professional may use an ophthalmoscope. This instrument looks for cholesterol fragments or platelet fragments called emboli in the tiny blood vessels of the retina at the back of the eye.
You also may be checked for risk factors of a stroke. These include high blood pressure, high cholesterol levels, diabetes and sometimes high levels of the amino acid homocysteine.
Echocardiography. This test may be done to find out if a heart issue caused fragments in the blood that led to a blockage. A traditional echocardiography is called a transthoracic echocardiogram (TTE). A TTE involves moving an instrument called a transducer across the chest to look at the heart. The transducer emits sound waves that bounce off different parts of the heart, creating an ultrasound image.
Or you may need another type of echocardiography called a transesophageal echocardiogram (TEE). A flexible probe with a transducer is placed into the tube that connects the mouth to the stomach, known as the esophagus. Because the esophagus is directly behind the heart, a TEE can create clearer, detailed ultrasound images. This allows a better view of some things, such as blood clots, that might not be seen clearly in a traditional echocardiography exam.
Arteriography. This procedure is used in some people to get a view of arteries in the brain not usually seen in an X-ray. A radiologist inserts a thin, flexible tube called a catheter through a small incision, usually in the groin.
The catheter is guided through the major arteries and into the carotid or vertebral artery in the neck. Then a dye is injected through the catheter. The dye allows the arteries to be seen on X-ray images.
Once your healthcare professional learns the cause of the transient ischemic attack, the goal of treatment is to correct the issue and prevent a stroke. You may need medicines to prevent blood clots. Or you might need surgery.
Several medicines may lower the risk of stroke after a TIA. Your healthcare professional recommends a medicine based on what caused the TIA, where it was located, its type and how bad the blockage was. Your healthcare professional may prescribe:
Anti-platelet drugs. These medicines make a circulating blood cell called platelets less likely to stick together. Sticky platelets begin to form clots when blood vessels are injured. Clotting proteins in blood plasma also are involved in the process.
Aspirin is the most commonly used anti-platelet medicine. Aspirin is also the least expensive treatment with the fewest potential side effects. An alternative to aspirin is the anti-platelet drug clopidogrel (Plavix).
Aspirin and clopidogrel may be prescribed together for about a month after the TIA. Research shows that taking these two medicines together in certain situations reduces the risk of a future stroke more than taking aspirin alone.
Sometimes both medicines are taken together for a longer period. This may be recommended when the cause of the TIA is a narrowing of a blood vessel in the head.
When there's a serious block of a major artery, the medicine cilostazol may be prescribed with aspirin or clopidogrel.
Alternatively, your healthcare professional may prescribe ticagrelor (Brilinta) and aspirin for 30 days to decrease your risk of recurrent stroke.
Your healthcare professional also may consider prescribing a combination of low-dose aspirin and the anti-platelet drug dipyridamole to reduce blood clotting. The way dipyridamole works is slightly different from aspirin.
These medicines require careful monitoring. If you have atrial fibrillation, your healthcare professional may prescribe a direct oral anticoagulant such as apixaban (Eliquis), rivaroxaban (Xarelto), edoxaban (Savaysa) or dabigatran (Pradaxa), which may be safer than warfarin due to lower bleeding risk.
If the carotid artery in the neck is very narrowed, your healthcare professional may suggest a surgery called carotid endarterectomy (end-ahr-tur-EK-tuh-me). This preventive surgery clears carotid arteries of fatty deposits before another TIA or stroke can occur. An incision is made to open the artery, the plaques are removed, and the artery is closed.
Some people need a procedure called carotid angioplasty and stent placement. This procedure involves using a balloon-like device to open a clogged artery. Then a small wire tube called a stent is placed into the artery to keep it open.
A transient ischemic attack often is diagnosed in an emergency situation. But if you're concerned about your risk of having a stroke, you can plan to talk about it with your healthcare professional at your next appointment.
If you want to discuss your risk of a stroke with your healthcare professional, write down and be ready to discuss:
Your healthcare professional may recommend that you have several tests to check your risk factors. You're given instructions on how to prepare for the tests, such as fasting before having your blood drawn to check your cholesterol and blood sugar levels.