Fifty-seven patients with transient ischemic attacks in the carotid territory had CTs 3 to 28 days after the last episode. Sixteen (28%) showed an infarct appropriate to the symptoms. Infarcts were more likely with longer mean duration of attacks, longer duration of the longest attack, longer total duration of symptoms, and smaller number of attacks. Age, sex, type and extent of hemisphere symptoms, and vascular risk factors had noinfluence.If attacks lasted more than 45 to 60 minutes, the risk of infarction was more than 80%; most were actually infarcts. So-called TIAs included two subgroups, true TIA and CITS (cerebral infarction with transient signs), which corresponded respectively to a short (mean, 21 minutes) or long (mean, 6 hours) duration of attack.