Clinical Decisionmaking

Distinct differences found in transient ischemic attacks with and without infarction

Transient ischemic attacks (TIAs), also called "mini strokes," caused by limited blood supply to the brain, can cause symptoms ranging from temporary vision loss and difficulty speaking to weakness or numbness on one side of the body. If symptoms last longer than 24 hours, they are considered to be a stroke. However, TIAs with infarction (tissue death due to lack of blood supply) appear to have unique features separate from TIAs without infarction and ischemic stroke and should be considered a separate clinical syndrome, transient symptoms with infarction (TSI), suggests a new study.

The study was supported in part by the Agency for Healthcare Research and Quality (HS11392) and led by Walter J. Koroshetz, M.D., of Harvard Medical School. His team studied clinical and imaging features of 87 patients with TIA and 74 patients with ischemic stroke to establish similarities and differences among patients with ischemic stroke, TIA without infarction, and TSI.

Although TIA-related infarcts were smaller than those associated with ischemic stroke (mean 0.7 vs. 27.3 ml), there was no lesion size that distinguished ischemic stroke from TSI. Duration of symptoms did not distinguish TIA from TSI. Third, symptoms in patients with TIA or TSI were short, usually lasting a few minutes, and only very rarely longer than 200 minutes. Stroke, on the other hand, is defined as ischemic symptoms lasting more than than 24 hours.

A history of recent prior TIA (within 30 days), non-penetrator artery location, and small infarct size were independent predictors of recovery. Most importantly, in this group, patients with TSI appeared to have substantially greater risk for recurrent ischemic stroke than patients with TIA without infarction or ischemic stroke.

More details are in "Transient ischemic attack with infarction: A unique syndrome," by Hakan Ay, M.D., Dr. Koroshetz, Thomas Benner, Ph.D., and others, in the May 2005 Annals of Neurology 57(5), pp. 679-686.

Return to Contents
Proceed to Next Article