Moyamoya Disease in China

Background and Purpose— Here we describe the clinical features and outcomes of patients with moyamoya disease who were surgically treated at a single institution in China. Methods— Our cohort included 802 patients with moyamoya disease. Demographic and clinical characteristics were obtained by retrospective chart review; follow-up information and outcome were obtained through clinical visits, telephone, or letter interview. We used the Kaplan-Meier methods to estimate stroke risk by treatment status. Results— The median age for the onset of symptoms was 28 (range, 0.5–77) years. Two definite peaks in age distribution were found. The ratio of women to men was 1:1 (398/404). Familial occurrence of moyamoya disease was 5.2%. The initial symptom was ischemia, hemorrhage, or others in 564, 113, and 125 patients, respectively. Twenty-nine of the 802 patients (3.6%) received conservative management. The remaining 773 patients (96.4%) underwent neurosurgical revascularization procedures, and 502 of these were bilateral. The median follow-up after surgery (n=773) or conservative management (n=26) was 26.3 months (range, 6.0–101.9 months). Most subsequent ischemic events appeared in the first 2 years after surgery. The Kaplan-Meier estimated stroke risk was 10.1% in the first 2 years, and the 5-year-Kaplan-Meier risk of stroke was 12.7% after surgery for all patients treated with surgical revascularization. Conclusions— This study on the clinical features of moyamoya disease in mainland China indicated bimodal incidence distribution with women-to-men ratios of 1:1 and lower rate of hemorrhages in adults compared with in children. Patients had low rates of postoperative ischemic or hemorrhagic strokes, and the majority of patients had preserved functional status after revascularization.