Aging Begins at 30

TIAs as Precursors to Strokes

A transient ischemic attack, or TIA, is a sudden localized blood deprivation in the brain that can produce problems such as weakness in the hand, face or leg; loss of vision in one eye; poor balance; slurred speech; or seeing double. It resembles a mini-stroke but it usually lasts only a few minutes and is all gone within 24 hours. It is pronounced TRANSient isKEEMick attack. A TIA really is a stroke that clears spontaneously and it identifies someone who is at substantial risk of a stroke, heart attack, and death. The risk of a more severe stroke is 5% during the first month after the TIA, 12% during the first year, and approximately 30% during the next five years. The 5% annual death rate after a TIA is mainly due to heart attacks and is the same as in people with angina, as both types of patients have ready-to-clot artery disease in the heart and brain. While doctors can’t treat a TIA, they can treat the cause of it. The most important feature of a TIA is that it is a warning of a serious stroke.

TIAs can be mimicked by tumors, seizures, low blood sugar, or balance-labyrinthine disorders. A careful diagnosis must be made. The character of the symptoms can suggest the cause and site such as the brain territory involved or whether it is low blood flow or embolic (migrating clot) in type. The carotid (or front brain) artery may lead to an episode of weakness or numbness of one side, slurred speech, or loss of vision in one eye. The vertebral-basilar (or hind brain) artery may cause blurred vision in both eyes, poor balance, weakness, numbness, incoordination, dizziness, or slurred speech. Small sized brain strokes can lead to similar occurrences but they last for more than 24 hours.

Survival after a TIA is 94% at 1 year and 87% at 5 years. There are three survival predictors; your age when the TIA occurs; your gender (young women survive best and older women have the worst survival rate); and your heart-contracted or systolic blood pressure (very low blood pressures are worst especially if you also have heart failure). Diabetes does not add to the risk of subsequent stroke. Only age, especially being over 70, is an independent predictor of stroke rather than death after a TIA. There is a 45% increase in risk of stroke for each 10-year increase of age. Multiple TIAs, especially five or more, increase the risk of subsequent stroke. TIAs exclusively affecting the sight of an eye are less likely to be followed by a stroke than those affecting the front part of the brain. TIAs involving the hind brain are also somewhat less likely to be followed by a stroke. On the other hand a TIA that lasts one hour or more carries a greater risk of stroke.

Stroke is the third largest cause of death in America at present. Just as important however: it is the leading cause of severe disability. Every effort should be made to prevent it.

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See related Patient Topics Brain and Nervous System, Heart and Circulation, Seniors' Health, Stroke or Transient Ischemic Attack.

See related Provider Topics Brain and Nervous System, Heart and Circulation, Seniors' Health or Stroke.

All contents copyright © 1992-2004 the Author(s) and The University of Iowa. All rights reserved.

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