What are transient ischemic attacks (TIAs)?

Causes and Symptoms

A transient ischemic attack (TIA) is very similar to a stroke. Most physicians define a TIA as an episode of strokelike symptoms that fully resolves within twenty-four hours. A stroke, on the other hand, is defined as an episode that produces neurological symptoms that are permanent.

Strokes and TIAs are caused when the blood supply to the brain is interrupted. This interruption may occur because of a hemorrhage in an artery in the brain. Other causes of stroke or TIA may include a blood clot or piece of plaque that breaks loose from somewhere else in the body and eventually lodges in an artery that feeds the brain, or from severe narrowing in an artery that feeds the brain. Symptoms from a stroke or TIA that originates in the carotid arteries
(the main arteries in the front of the neck) include weakness or numbness on one side of the body, temporary loss of vision in one eye, and difficulty speaking. When the back of the brain is damaged, symptoms such as dizziness, difficulty walking, or a drop attack (sudden loss of leg strength) may occur.

One might think that since the symptoms of a TIA go away, such an attack is not a serious condition. However, a TIA is often a warning signal of an impending stroke. For this reason, anyone suffering a TIA should immediately seek medical attention.

The risk factors for TIA and stroke are similar. They include high blood pressure, high cholesterol, smoking, diabetes mellitus, advancing age, cardiac disease (especially irregular heart rhythm problems), stress, and lack of physical activity. Genetics can make one more likely to have a stroke or a TIA as well.

Treatment and Therapy

A person experiencing symptoms of a TIA should call paramedics in order to be seen in an emergency room immediately. Doctors can assess the patient’s situation and determine whether treatment can be initiated that will limit the amount of time that the brain is starved of oxygen. A stroke has been referred to as “brain attack” to underscore the need to seek prompt medical attention quickly, as one would for a heart attack.

Diagnostic tests will likely include magnetic resonance imaging (MRI) of the brain to check for hemorrhage or damage. Other tests may include magnetic resonance angiography (MRA) of the arteries or an ultrasound of the arteries that serve the brain. If these studies show a narrowing of the carotid arteries, then surgery can be done to remove the narrowed section before it causes more damage.

In some cases, medications will be used to lessen the risk of a full-blown stroke. They may include anticoagulants (blood thinners) and antiplatelet drugs such as aspirin, clopidogrel (Plavix), ticlopidine, and dipyridamole (Aggrenox). Drugs that lower cholesterol may also be prescribed.

Bibliography

Adams, Harold P., Jr., Vladimir Hachinski, and John W. Norris. Ischemic Cerebrovascular Disease. New York: Oxford University Press, 2001.

American Stroke Association. http://www.stroke association.org.

Chaturvedi, Seemant, and Steven R. Levine, eds. Transient Ischemic Attacks. Malden, Mass.: Blackwell Futura, 2004.

Kikuchi, H., ed. Strategic Medical Science Against Brain Attack. New York: Springer, 2002.

Parker, James N., and Philip M. Parker, eds. The Official Patient’s Sourcebook on Transient Ischemic Attack. Rev. ed. San Diego, Calif.: Icon Health, 2004.

"Transient Ischemic Attack (TIA)." Mayo Clinic, March 3, 2011.

"Transient Ischemic Attack (TIA)." National Stroke Association, 2013.

Wood, Debra. "Transient Ischemic Attack." Health Library, September 30, 2012.