TIAs Are Not Just Mild Strokes

The study was presented at the 27th International Stroke Conference in San Antonio (TX, USA).

Although the symptoms of stroke and TIAs are similar, TIAs don't leave any permanent disability. Danish researchers decided to look for differences in the causes of TIAs. Based on data from the Copenhagen Stroke Study, they compared the risk factor profiles and short- and long-term outcomes of 154 patients who had experienced TIAs with 482 patients who had experienced mild strokes. They did find differences. TIA patients were half as likely to have diabetes and half as likely to have narrowing of the leg arteries. If TIAs are not caused by blood clots, then aspirin therapy cannot help prevent them, note the researchers.

In spite of having different risk factors, both TIAs and strokes can be deadly. Short-term mortality rates indicated that 1.3% of TIA patients died, as did 2.3% of patients with minor strokes. However, after five years, the survival rates were virtually the same for both.

"It is clear that many transient ischemic attacks are due to blood clots,” said Tom S. Olsen, M.D., Ph.D., chairman of the department of neurology, Gentofte University Hospital (Hellerup, Denmark). "But it could be that some of them are due to spasm of brain arteries instead of a clot.”