Transient Ischemic Attacks (TIAs)

A transient ischemic attack (TIA), also called a mini-stroke, is a temporary loss of normal neurological function caused by a transient interruption of blood flow to the brain. The only difference between a TIA and a full-blown stroke is that in a TIA, blood flow is restored before brain tissue actually dies.

If you have had a TIA, you are at a greatly increased risk of having a full stroke. So, if you think that you might have had a TIA, it is critical that you seek medical care quickly.

What Are The Symptoms of A TIA?

The symptoms of a TIA are identical to the symptoms of stroke, except that the symptoms of a TIA go away within minutes to hours. The precise symptoms can vary tremendously, and depend on which part and how much of the brain is being deprived of blood flow. The most common symptoms of TIA include:

• Weakness in the hand, arm, leg, face, tongue, or face
• Numbness in the hand, arm, leg, face, tongue, or face
• Inability to speak coherently
• Unexplained dizziness, often with vertigo (the sensation that the room is spinning)
• Double vision, partial loss of vision, or other sudden visual disturbances

A TIA only becomes a TIA when the symptoms resolve by themselves. Until that moment, for all practical purposes, you are having a stroke. If you or a loved one experience any of these symptoms, you need to get medical care immediately -- don't wait to see if things get better on their own.

What Causes TIAs?

TIAs are caused by the same disease processes that produce stroke -- blockage of the arteries to the brain, mostly due to atherosclerosis or embolism.

• Read about the causes of stroke.

The only difference is that in stroke, the blockage persists long enough to produce the death of brain tissue, whereas in TIA the blockage is transient. TIAs are therefore analogous to unstable angina, a condition in which transient blockages in the coronary arteries produce chest pain. And just as unstable angina often heralds a full myocardial infarction, the occurrence of a TIA indicates that a full stroke is likely.

Because the risk of stroke is highest in the first few days to weeks after a TIA, a delay in seeking medical help can be catastrophic.

How Is TIA Treated?

Since the symptoms of TIA resolve by themselves, the main goal of therapy is to prevent a stroke. So, after a TIA, your doctor will do the testing necessary to identify what caused the TIA and institute preventive treatments. Identifying the cause of a TIA often includes the following testing:

• Brain imaging with CT or MRI scanning
• Imaging of the major blood vessels that supply the brain, either with CT scanning or by catheterization
• Heart testing, usually with echocardiography, to look for a source of blood clots that could embolize to the brain

The preventive treatment that your doctor institutes after this evaluation will depend largely on what has been found. That treatment very often includes:

• Aggressively treating the risk factors that produce atherosclerosis, such as treating hypertension and cholesterol, getting excellent control of diabetes, and encouraging (demanding, if possible) smoking cessation.
• Antiplatelet therapy to inhibit the formation of abnormal clots within the arteries, with aspirin, aspirin plus dipyridamole, or Plavix (clopidogrel).
• Anticoagulation therapy with Coumadin (warfarin).
• If a significant blockage in a carotid artery is found, your doctor may recommend "carotid endarterectomy" (surgical repair of the blockage). Stenting of the carotid artery, while it is done, has not been shown definitively to be as safe or effective as surgical repair.

Summary

A TIA is a very serious medical problem, even though the symptoms resolve on their own. By seeking immediate medical care after a TIA, you can greatly reduce your odds of having a full stroke.

• Read more about stroke.

_Sources:

_{Easton, JD, Saver, JL, Albers, GW, et al. Definition and evaluation of transient ischemic attack. AHA/ASA Scientific Statement. Stroke 2009; 40:2276.}

_{Johnston, SC, Nguyen-Huynh, MN, Schwarz, ME, et al. National Stroke Association guidelines for the management of transient ischemic attacks. Ann Neurol 2006; 60:301.}