A transient ischemic attack (TIA) is the result of a temporary interruption of blood flow to the brain. TIAs are sometimes referred to as "mini-strokes," though the medical community discourages the use of this term because it can imply that a TIA is an insignificant medical event, which it is not.

TIAs are caused by one of two factors. In about 80 percent of cases, a blockage has occurred in an artery that supplies oxygen-rich blood to the brain. The blockage is usually due to material that has traveled through the bloodstream from another location and lodged in the artery (cerebral embolism). The blockage may also be due to a blood clot that has formed within the artery (thrombus) or to narrowing of the artery as a result of atherosclerosis.

The other 20 percent of TIAs are caused by minor bleeding in the brain. This bleeding may be a warning sign of an expanding aneurysm, or it may be the result of cerebral artery disease.

In both types of TIA, the lack of oxygen to the brain causes the same symptoms as those produced during a full stroke. These might include confusion, numbness or weakness in the face, blurred vision, severe headache, dizziness or trouble walking. TIAs differ from strokes only in the fact that these symptoms are temporary and clear up relatively quickly. Most symptoms from a TIA last only a few minutes, although some attacks can last for hours.

No matter how long the symptoms last, a TIA is a potentially dangerous event that can result in permanent brain damage and should be treated seriously. Anyone who experiences the symptoms of TIA should seek immediate medical help.

TIAs are one of the most accurate indicators of future stroke. Research suggests that a high percentage of individuals who experience a TIA have a stroke within the two weeks following the event.

The primary treatment goal with TIA is stroke prevention. Patients may be prescribed medication and/or procedures may be recommended to restore blood flow through narrowed arteries. The treatment depends on the underlying cause of the TIA. Physicians will also likely recommend lifestyle changes aimed at reducing the risk of stroke, including quitting smoking, losing weight, cutting down on saturated fat and beginning a regular exercise program.