Background: The natural history of amaurosis fugax and of hemispheric transient ischemic attacks (TIAs) may be different. We analysed the ischemic risk factors, carotid status and prognosis with respect to future ischemic events in a cohort of patients who presented with either of these transient ischemic episodes.
Methods: The charts of patients who presented to our institution between February 1983 and April 1995 with amaurosis fugax or hemispheric TIAs were reviewed. Patients under the age of 45 years with a history of migraine or previous carotid surgery were excluded. Follow-up by a clinical visit or telephone interview was performed. Information was obtained regarding demographic features, presenting symptoms, ischemic risk factors, carotid status (as measured by duplex ultrasonography), type of medical treatment prescribed and occurrence of subsequent ischemic events. Outcome ischemic events were graded as major (myocardial infarction, cerebrovascular accident or death due to either of these) or minor (recurrent amaurosis fugax or hemispheric TIA).
Results: A total of 141 patients were followed for a mean of 47 months. Risk factors were more prevalent in patients with hemispheric TIAs than in those with amaurosis fugax. Most patients had a low degree of carotid stenosis. There was no statistically significant difference in the occurrence of major outcome events between the two groups. Kaplan-Meier survival curves were similar for the two groups.
Interpretation: Amaurosis fugax and hemispheric TIA both carry a risk for future ischemic events. However, we did not find a statistically significant difference in prognosis between the two groups.