Transient ischemic attacks and stroke.

Transient ischemic attacks (TIAs) constitute the most specific and powerful warnings of impending stroke. They are defined as brief, focal neurological events of sudden onset. Their proper recognition and treatment rank second only to the modification of risk factors in importance for stroke prevention. Carotid endarterectomy, although widely used to treat TIAs, remains unproven; randomized clinical trials are attempting to define its role. Anticoagulant therapy appears worth while for suspected cardiac embolism and possibly for disabling TIAs. Acetylsalicylic acid is the only agent that has been found to be effective in controlled trials, but questions persist about its dosage, its efficacy in women and its use after stroke. Another platelet inhibitor, ticlopidine hydrochloride, is being investigated and may prove to be an effective alternative.