Transient ischemic attack (patient information)

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Overview
A transient ischemic attack (TIA) is when a person has stroke-like symptoms for up to 1 - 2 hours.

A TIA is often considered a warning sign that a true stroke may happen in the future if something is not done to prevent it.

What are the symptoms of Transient ischemic attack?
Symptoms begin suddenly, last only a short time (from a few minutes to 1 - 2 hours), then disappear completely. They may occur again at a later time. Symptoms usually occur on the same side of the body if more than one body part is involved.

A TIA is different from a stroke. However, the symptoms of TIA are the same as the symptoms of a stroke and include the sudden development of:


 * Muscle weakness of the face, arm, or leg (usually only on one side of the body)
 * Numbness or tingling on one side of the body
 * Trouble speaking or understanding others who are speaking
 * Problems with eyesight (double vision, loss of all or part of vision)
 * Changes in sensation, involving touch, pain, temperature, pressure, hearing, and taste
 * Change in alertness (sleepiness, less responsive, unconscious, or coma)
 * Personality, mood, or emotional changes
 * Confusion or loss of memory
 * Difficulty swallowing
 * Difficulty writing or reading
 * Lack of coordination and balance, clumsiness, or trouble walking
 * Abnormal sensation of movement (vertigo) or dizziness
 * Lack of control over the bladder or bowels
 * Inability to recognize or identify sensory stimuli (agnosia)

What causes Transient ischemic attack?
A transient ischemic attack (TIA) is caused by temporary disturbance of blood supply to an area of the brain. This results in a sudden, brief decrease in brain function. (A decrease in brain function is called a neurologic deficit.)

A TIA is different from a stroke. Unlike a stroke, a TIA does not cause brain tissue to die. The symptoms of TIAs do not last as long the symptoms of a stroke. TIAs also do not show changes to the brain on CT or MRI scans. (Strokes usually show changes on such tests.)

The temporary loss of blood flow to the brain can be caused by:


 * A blood clot within an artery of the brain
 * A blood clot that travels to the brain from somewhere else in the body (for example, the heart)
 * An injury to blood vessels
 * Narrowing of a blood vessel in the brain or leading to the brain

For instance, the temporary disruption in blood flow could be due to a blood clot that occurs and then dissolves. The blockage breaks up quickly and dissolves.

Less common causes of TIA include:


 * An irregular heart rhythm called atrial fibrillation
 * Certain blood disorders, including polycythemia, sickle cell anemia, and syndromes where the blood is very thick
 * Conditions that cause blood vessels problems such as fibromuscular dysplasia, systemic lupus erythematosus, and syphilis
 * Inflammation of the arteries such as arteritis, polyarteritis, and granulomatous angiitis
 * Spasm of the small arteries in the brain

Atherosclerosis ("hardening of the arteries") is a condition where fatty deposits occur on the inner lining of the arteries. This condition dramatically increases the risk for both TIAs and stroke. About 80 - 90% of people who have a stroke due to atherosclerosis had a TIA episode before.

Who is at highest risk?
Risks for TIA include:
 * High blood pressure
 * Heart disease
 * Migraine headaches
 * Smoking
 * Diabetes
 * Increasing age.

When to seek urgent medical care?
A TIA is a medical emergency. Call 911 or another local emergency number immediately. Do not ignore symptoms just because they go away. They may be a warning of a future stroke.

Diagnosis
TIAs do not show brain changes on CT or MRI scans. (Most strokes do show changes on such tests.) Because symptoms and signs may have completely disappeared by the time you get to the hospital, a diagnosis of a TIA may be made on based on your medical history alone.

A physical examination should include a neurological exam, which may be abnormal during an episode but normal after the episode has passed.

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. In some cases, low blood pressure may be seen before symptoms of a TIA occur.

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


 * You almost always will have a head CT scan or brain MRI.
 * You may have an angiogram, CT angiogram, or MR angiogram.
 * 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. Cerebral arteriogram reveals which blood vessels is blocked or bleeding.
 * You may have EKG and heart rhythm monitoring tests to check for irregular heart beats.

Additional tests and procedures may include:


 * Blood clotting tests to rule out a blood disorder
 * Blood chemistry
 * Complete blood count (CBC)
 * C-reaction protein
 * ECG
 * ESR (Sedimentation rate)
 * Serum lipids
 * Tests for syphilis, Lyme disease, and other infections

Your doctor may use these tests to check high blood pressure, heart disease, diabetes, high cholesterol, and peripheral vascular disease.

Treatment options
The goal is to prevent a stroke from occurring.

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

Underlying disorders such as high blood pressure, heart disease, diabetes, and blood disorders, should be treated appropriately.

Blood thinners, such as aspirin, may be prescribed to reduce blood clotting. Others include dipyridamole, clopidogrel, Aggrenox or heparin, Coumadin, or other similar medications. You may be treated for an indefinite time period.

Surgery (carotid endarterectomy) may be appropriate for some people who have clogged neck arteries.

If you smoke, you should stop.

Your health care provider may recommend a low-fat, low-salt diet. Other dietary changes may be recommended.

Where to find medical care for Transient ischemic attack?
Directions to Hospitals Treating Transient ischemic attack

What to expect (Outlook/Prognosis)?
TIAs do not cause lasting damage to the brain.

However, they are a warning sign that you may have a true stroke some day. Over 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 recurrent episodes.

Your chances of a future stroke can be reduced by close follow-up with your health care provider to manage risk factors.

Possible complications
Complications of TIA include:


 * Death of brain cells due to too little blood flow to the brain
 * Injury that occurs from falls
 * Stroke

Prevention
Prevention of TIAs includes controlling risk factors, such as high blood pressure, diabetes, heart disease, and other associated disorders. Smoking should be stopped.