Stroke recurrences in patients with symptomatic vs asymptomatic middle cerebral artery disease

Background: Although the natural history of extracranial carotid artery disease has been investigated systematically, limited data are available on the course of middle cerebral artery (MCA) disease. Methods: The authors observed 102 consecutive patients (67 men, 35 women; mean age 61.9 years) with significant MCA stenosis or occlusion as demonstrated by transcranial Doppler and transcranial color-coded duplex ultrasonography. Forty-six patients entered the study after TIA (n = 17) or stroke (n = 29); 56 patients were asymptomatic. Neurologic and ultrasound investigations were performed at regular intervals with a mean follow- up of 31 (range 6 to 117) months. Patients were continuously treated with either platelet inhibitors (n = 75) or anticoagulation (n = 27). Results: Nineteen cerebral ischemic events (11 strokes, 8 TIAs) occurred during follow- up, resulting in an overall annual rate of 7.3%. Thirteen events (8 strokes, 5 TIAs) were attributable to the vascular territory ipsilateral to MCA disease. Patients with symptomatic MCA disease at study entry had an overall stroke risk of 12.5% per year (ipsilateral: 9.1%), whereas the annual incidence in primarily asymptomatic MCA disease was only 2.8% (ipsilateral: 1.4%; p < 0.01). Symptomatic MCA disease was an independent predictor for overall (hazard ratio [HR] 7.91, 95% CI 2.03 to 30.79; p < 0.01) and ipsilateral (HR 9.66, 95% CI 1.5 to 62.25; p = 0.02) cerebrovascular events. Conclusions: Compared with asymptomatic middle cerebral artery disease, there was a high and continuous recurrence rate of ischemic events in symptomatic patients, which was even higher than in patients with symptomatic extracranial carotid artery disease.