CLUSTERING TRANSIENT ISCHEMIC ATTACKS

The aims of this retrospective-prospective study were to investigate the presumed etiology and the risk of stroke following clustering transient ischemic attacks (TIAs). Among all patients with TIAs examined in a 5-year period, 70 had multiple (> 2) TIAs recurring at intervals of less than 24 h. TIAs were either in the carotid (repetitive hemiplegia in 46 subjects, amaurosis fugax in 6 and aphasia in 7) or the vertebrobasilar (11 patients) territory. A potential cardiac source of embolism was disclosed in 7 (10%) patients. Extracranial vessel disease was considered the most plausible etiology of the TIAs in 12 patients. Intracranial vascular abnormalities were found in 5 subjects. Twenty-seven patients presented with TIAs which were brief expressions of classic lacunar syndromes. Fourteen had an appropriate lacunar infarct on CT. Patients with amaurosis fugax had the highest prevalence of extracranial vessel disease. Twenty-one patients suffered an ischemic stroke within 48 h of the last TIA, despite 5 being on heparin. The highest rate of stroke (32%) was found among patients with repetitive attacks of hemiplegia. On follow-up (mean 13.1 months) 18 subjects had recurrent TIAs but only 2 suffered a stroke. In conclusion, in the majority of cases, clustering TIAs are related to small-vessel disease and carry a high risk of immediate stroke. Clustering TIAs are one of the clinical presentations of single-perforator-vessel-territory ischemia.