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Patient education: Transient ischemic attack (Beyond the Basics)

Patient education: Transient ischemic attack (Beyond the Basics)
Author:
Natalia S Rost, MD, MPH
Section Editor:
Scott E Kasner, MD
Deputy Editor:
John F Dashe, MD, PhD
Literature review current through: Nov 2022. | This topic last updated: Aug 23, 2021.

TRANSIENT ISCHEMIC ATTACK OVERVIEW — Transient ischemic attack (TIA) is the medical term for neurologic symptoms, such as weakness or numbness, which begin suddenly, resolve rapidly and completely, and are caused by a temporary lack of blood in an area of the brain. TIAs are common, affecting at least 240,000 people each year in the United States.

Some people call TIAs "warning spells" because anyone who has a TIA is at high risk for an impending stroke. As a result, it is important to be aware of the signs and symptoms of TIA and seek treatment as soon as possible.

This topic discusses the symptoms, diagnosis, and treatment of transient ischemic attacks. Topics that discuss stroke are available separately. (See "Patient education: Stroke symptoms and diagnosis (Beyond the Basics)" and "Patient education: Hemorrhagic stroke treatment (Beyond the Basics)" and "Patient education: Ischemic stroke treatment (Beyond the Basics)".)

WHAT IS A TRANSIENT ISCHEMIC ATTACK? — A TIA is an episode in which a person has signs or symptoms of a stroke (eg, numbness; inability to speak) that last for a short time. Symptoms of a TIA usually last between a few minutes and a few hours. A person may have one or many TIAs. People recover completely from the symptoms of a TIA.

A TIA is a warning sign that a person may be at high risk for a stroke, which could cause severe impairment. Immediate treatment can decrease or eliminate this risk. It is important to get medical help right away if you think you may be having a TIA or a stroke. (See 'When to call for emergency medical help' below.)

Most TIAs result from narrowing of the major arteries to the brain, such as the carotid arteries. These blood vessels provide oxygenated blood to brain cells. These arteries can become clogged with fatty deposits, called plaques. Plaques partially block the artery, and can lead to the formation of a blood clot. The blood clot can further narrow or completely block the artery. More frequently, a blood clot will detach from the wall of the artery, travel along the bloodstream to smaller branches, and block blood flow to the area of brain fed by that artery.

In some cases, TIAs can be caused by blood clots that form in the heart and travel to the brain. TIAs can also occur as a result of narrowing and closure of small blood vessels deep inside the brain. These vessels are frequently damaged by high blood pressure or diabetes if left untreated throughout a person's lifetime.

If an artery remains blocked for more than a few minutes, the brain can become damaged, as the tissue in that area can die. In a TIA, the temporary reduction in blood flow to the brain improves within minutes. In about one-third of people who have a TIA, however, the blocked artery does not open up fast enough, leading to a tiny region of damage in the brain. In such cases, uninjured parts of the brain rapidly take over the function of the damaged tissue, and the symptoms resolve quickly and completely.

Unlike a TIA, with a stroke, symptoms may not resolve completely.

Many people do not have a TIA before a stroke. However, a TIA is a warning sign that a person is at risk for a stroke. It is important to recognize and treat the symptoms of TIA to reduce the risk of having a stroke.

Transient ischemic attack symptoms — Symptoms of TIA are typically short-lived, lasting only a few minutes to hours. A TIA may occur only once, or may be recurrent (several times per day or per year).

The most common symptoms of TIA include the following:

Hand, face, arm, or leg weakness or numbness

Difficulty speaking (garbled speech), slurred speech, or inability to speak at all

Blurred, doubled, or decreased vision in one or both eyes

These symptoms are identical to those of a stroke. When the symptoms first develop, it is not easy to tell if a person is having a stroke or TIA.

TRANSIENT ISCHEMIC ATTACK RISK FACTORS — A number of factors can increase a person's risk of TIA, including the following:

Age greater than 40 years

Heart and blood vessel disease (eg, atrial fibrillation, carotid stenosis)

High blood pressure

Smoking

Diabetes

High blood cholesterol levels

Illegal drug use or heavy alcohol use

Recent childbirth

Previous history of transient ischemic attack or stroke

Sedentary lifestyle and lack of exercise

Obesity

Current or past history of blood clots

Risk of stroke after TIA — The risk of stroke after a TIA is highest in the first few hours to days after the TIA. For example, the risk of having a stroke in the first two days after TIA has been estimated to be 4 to 10 percent. People with certain characteristics are thought to have a higher risk (ie, closer to 10 percent) of stroke compared with people without these characteristics:

Diabetes

Older than 60 years of age

High blood pressure (more than 140/90), measured after the TIA

Weakness on one side of the body (eg, face, arm, leg) during the TIA

Speech problems during the TIA

TIA symptoms for 60 minutes or longer

Severely clogged or narrowed arteries

The existence of brain damage caused by the TIA that is visible on CT or MRI brain scans

TRANSIENT ISCHEMIC ATTACK DIAGNOSIS — Despite the fact that the symptoms of TIA usually resolve quickly, TIA is a medical emergency that should be evaluated as soon as possible because there is a high risk of a stroke after TIA.

When to call for emergency medical help — If you think you or someone else might be having a TIA, call for emergency medical attention immediately. Emergency medical services are available in most areas of the United States by calling 9-1-1.

Emergency medical services (EMS) personnel will respond as quickly as possible, and will take the person to a hospital equipped to care for people during and after a TIA. Most clinics and medical offices do not have the ability to diagnose and treat people with a TIA. For these people, every minute is important.

A person who may be having a TIA should not drive to the hospital and should not ask someone else to drive, but should call 9-1-1. In addition, it is not necessary to call a doctor or nurse to ask for advice because precious time will be lost waiting for a return call. Getting to the Emergency Department quickly is the best option. Calling 9-1-1 is safer than driving for two reasons:

From the moment EMS personnel arrive, they can begin evaluating and treating the person. If the person drives to the hospital, treatment cannot begin until after arriving in the emergency department.

If a dangerous complication of a TIA occurs on the way to the hospital, EMS personnel may be able to treat the problem immediately.

Brain imaging — Depending upon the results of the history and physical examination, the clinician will usually order blood tests and a brain imaging test (eg, CT scan or MRI). The imaging test allows the clinician to see the area of the brain affected by the TIA.

Blood vessel imaging — The larger blood vessels that supply the brain can also be imaged using CT or MRI; these scans are referred to as CTA (computed tomography arteriogram) and MRA (magnetic resonance arteriogram). Ultrasound can be used to determine if there are blockages in blood vessels.

Occasionally, a catheter must be inserted through a blood vessel in the groin and threaded up to the blood vessels of the neck, where dye is injected to highlight any areas of blockage. This is called conventional arteriography.

Heart testing — An electrocardiogram (ECG) is usually performed to help the clinician diagnose and treat heart problems and identify abnormal heart rhythms that cause stroke as quickly as possible.

In some people with TIA, the heart or the aorta (the large vessel that comes out of the heart) can be the source of a TIA-causing blood clot. Blood vessels that supply blood to the brain originate in the aorta. Other heart testing, such as an echocardiogram, may also be needed. This test uses sound waves to examine the heart and the aorta.

Heart monitors (also called Holter or loop monitors, or mobile cardiac telemetry) may be used for an extended period of time. The monitors can detect intermittent atrial fibrillation, which is a temporary abnormal heart rhythm. (See "Patient education: Atrial fibrillation (Beyond the Basics)".)

TRANSIENT ISCHEMIC ATTACK TREATMENT — The optimal treatment of a TIA depends upon the presumed cause of the TIA, how much time has passed since the first TIA symptoms occurred, and the person's underlying medical problems.

The goal of treatment is to reduce the risk of having a stroke. There are several types of treatment:

Treating risk factors, such as high blood pressure

Antiplatelet therapy

Statin therapy to lower LDL cholesterol levels

Anticoagulant therapy

Revascularization (a procedure to restore blood flow by opening up a partial blockage in an artery)

These are discussed in more detail below.

Treating risk factors — Anyone who has had a TIA has an increased risk of having another TIA or a stroke in the future, especially within the first 48 hours after the TIA. Treatment can significantly reduce risk in the long term. In addition, lifestyle changes and careful management of underlying medical problems can help to reduce the risk of future strokes. Depending on the person's situation, these may include the following:

Treatment of high blood pressure (see "Patient education: High blood pressure treatment in adults (Beyond the Basics)")

Controlling diabetes (see "Patient education: Type 1 diabetes: Overview (Beyond the Basics)" and "Patient education: Type 2 diabetes: Overview (Beyond the Basics)")

Stopping smoking (see "Patient education: Quitting smoking (Beyond the Basics)")

Treating high cholesterol and lipids (see "Patient education: High cholesterol and lipids (Beyond the Basics)")

Antiplatelet therapy — Platelets are a type of cell that circulate in the blood and normally help the blood to clot. In TIA, platelets clump together and form clots inside narrowed arteries; this can temporarily block blood flow in the brain. Antiplatelet therapy means medications that can help prevent new clots from developing.

Expert guidelines recommend that most patients with a TIA and no contraindication start taking an antiplatelet medication to reduce the risk of subsequent stroke. Options include aspirin, clopidogrel, and the combination of aspirin plus extended-release dipyridamole (brand name: Aggrenox) are all acceptable options for treatment. In some cases, two antiplatelet medicines are used together for a short time after a TIA, as discussed below. (See 'Short-term dual antiplatelet therapy' below.)

An exception is that people who have a TIA related to an irregular heart rhythm (atrial fibrillation) should be treated with anticoagulation. (See 'Anticoagulant therapy' below.)

Aspirin — Daily aspirin can help to reduce the risk of a future stroke. Aspirin typically costs far less than other antiplatelet medications and is well tolerated.

Clopidogrel — Clopidogrel (brand name: Plavix) is an antiplatelet medication that is also used in patients after TIA to reduce the risk of stroke.

Compared with aspirin, clopidogrel causes a slightly higher frequency of rash and diarrhea, but a slightly lower frequency of stomach upset or gastrointestinal bleeding.

Cilostazol — Cilostazol is another antiplatelet medication that reduces the risk of ischemic stroke after TIA. It has been tested mainly in China and Japan for stroke prevention, and it is most often used for this indication in Asian countries. Side effects may include headache, diarrhea, dizziness, heart palpitations, and an increase in heart rate. People with heart failure should not take cilostazol.

Ticagrelor — Ticagrelor is an antiplatelet medication that is sometimes used alone or in combination with aspirin after a TIA to reduce the risk of a stroke.

Dipyridamole and aspirin — Dipyridamole is a medication that may be given after a TIA to reduce the risk of stroke. It is often given as an extended-release form, combined with aspirin (aspirin-extended-release dipyridamole, brand name: Aggrenox). It is taken two times per day. Side effects of dipyridamole include headache, upset stomach, and/or diarrhea. Headaches usually improve over the first week.

Short-term dual antiplatelet therapy — In some cases, "dual antiplatelet therapy" with two medications (eg, aspirin and clopidogrel, or aspirin and ticagrelor) is started immediately after a TIA and continued for 21 days or more, depending on the type of TIA. After this, antiplatelet therapy is continued with one of the medications listed above (aspirin, aspirin-extended-release dipyridamole, clopidogrel, or cilostazol).

Anticoagulant therapy — Anticoagulants are often referred to as "blood thinners." They work by decreasing the formation of blood clots. Anticoagulant therapy is usually recommended for selected people with an irregular heart rhythm (atrial fibrillation) who have had a TIA or are at risk for a TIA or stroke. Oral anticoagulant medications include:

Apixaban (brand name: Eliquis)

Dabigatran (brand name: Pradaxa)

Edoxaban (brand names: Savaysa, Lixiana)

Rivaroxaban (brand name: Xarelto)

Warfarin (brand name: Jantoven)

Your health care provider can talk to you about your options and the differences between the available medications. People who take warfarin need to get regular blood tests to monitor how well their blood is clotting. They also need to be careful to eat about the same amount of vitamin K in their diet each day, as vitamin K affects how well warfarin works. (See "Patient education: Warfarin (Beyond the Basics)".)

Revascularization — Revascularization is the medical term for reestablishing blood flow to an area. In people who have had a TIA, revascularization usually refers to an invasive procedure that opens a partially blocked artery in the neck (the carotid artery), which reduces the risk of stroke. This procedure is called "carotid endarterectomy." The amount of blockage in the carotid artery can be measured with a non-invasive test, such as ultrasound, CT, or MRI scan. (See 'Blood vessel imaging' above.)

Carotid endarterectomy is most successful when it is performed by a vascular surgeon who has specialized training and experience with the procedure. However, even in experienced hands, the procedure has risks, including bleeding, brain injury, stroke, and even death.

Some people are likely to benefit from carotid endarterectomy. For others, the risks of the procedure are greater than the potential benefits. Placement of a stent in the carotid artery (a small tube to hold the blood vessel open) is an alternative if carotid endarterectomy is not an option or if the person prefers not to have surgery.

WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem.

This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.

Patient level information — UpToDate offers two types of patient education materials.

The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.

Patient education: Stroke (The Basics)
Patient education: Transient ischemic attack (The Basics)
Patient education: Mitral valve prolapse (The Basics)

Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.

Patient education: Stroke symptoms and diagnosis (Beyond the Basics)
Patient education: Hemorrhagic stroke treatment (Beyond the Basics)
Patient education: Ischemic stroke treatment (Beyond the Basics)
Patient education: Atrial fibrillation (Beyond the Basics)
Patient education: High blood pressure treatment in adults (Beyond the Basics)
Patient education: Type 1 diabetes: Overview (Beyond the Basics)
Patient education: Type 2 diabetes: Overview (Beyond the Basics)
Patient education: Quitting smoking (Beyond the Basics)
Patient education: High cholesterol and lipids (Beyond the Basics)
Patient education: Warfarin (Beyond the Basics)

Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.

Antihypertensive therapy for secondary stroke prevention
Long-term antithrombotic therapy for the secondary prevention of ischemic stroke
Early antithrombotic treatment of acute ischemic stroke and transient ischemic attack
Definition, etiology, and clinical manifestations of transient ischemic attack
Differential diagnosis of transient ischemic attack and acute stroke
Initial evaluation and management of transient ischemic attack and minor ischemic stroke
Management of asymptomatic extracranial carotid atherosclerotic disease
Management of symptomatic carotid atherosclerotic disease
Overview of secondary prevention of ischemic stroke
Overview of the evaluation of stroke
Secondary prevention for specific causes of ischemic stroke and transient ischemic attack

The following organizations also provide reliable health information.

National Institute of Neurological Disorders and Stroke, Transient Ischemic Attack Information Page

American Heart Association, TIA (Transient Ischemic Attack)

MedlinePlus, Transient ischemic attack

MedlinePlus, Accidente isquémico transitorio (in Spanish)

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ACKNOWLEDGMENT — The editorial staff at UpToDate would like to acknowledge J Philip Kistler, MD, Hakan Ay, MD, and Karen L Furie, MD, MPH, who contributed to an earlier version of this topic review.

This generalized information is a limited summary of diagnosis, treatment, and/or medication information. It is not meant to be comprehensive and should be used as a tool to help the user understand and/or assess potential diagnostic and treatment options. It does NOT include all information about conditions, treatments, medications, side effects, or risks that may apply to a specific patient. It is not intended to be medical advice or a substitute for the medical advice, diagnosis, or treatment of a health care provider based on the health care provider's examination and assessment of a patient's specific and unique circumstances. Patients must speak with a health care provider for complete information about their health, medical questions, and treatment options, including any risks or benefits regarding use of medications. This information does not endorse any treatments or medications as safe, effective, or approved for treating a specific patient. UpToDate, Inc. and its affiliates disclaim any warranty or liability relating to this information or the use thereof. The use of this information is governed by the Terms of Use, available at https://www.wolterskluwer.com/en/know/clinical-effectiveness-terms ©2023 UpToDate, Inc. and its affiliates and/or licensors. All rights reserved.
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