Epidemiology of moyamoya disease in China: a single-center, population-based study.

BACKGROUND: To our knowledge, no previous study has described the nationwide epidemiological features of moyamoya disease in China. We describe the epidemiological features, including the relative prevalence, age distribution, gender distribution, and initial clinical manifestations of patients with moyamoya disease treated at a single institution in China.

METHODS: Our cohort included 4,128 patients with moyamoya disease. Their demographic and clinical characteristics were obtained by retrospective chart review.

RESULTS: The median age for the onset of symptoms was 30.36 years. The age distribution of patients with MMD was bimodal, with the highest peak detection rate at 35-45 years of age and a smaller peak at 5-9 years of age. The ratio of female to male patients was 1:1. The disease occurred mainly in the Han people and was rarely seen in minority nationalities. In our cohort, transient ischemic attack was the most common initial clinical manifestation (48.13%). The other initial manifestations included infarction (22.62%), hemorrhage (16.45%), and headache 230/4128 (5.57%). In north and northeast China, the ischemic type was more predominate while the hemorrhagic type was relatively rare. However, the percentage of hemorrhagic type in East China was higher than anywhere else in China.

CONCLUSIONS: This study confirmed some unique epidemiological features as the studies previously reported in China, but also it revealed some new sight and tendency about moyamoya in China. As a lack of national epidemiologic studies, this study indicated the outline of moyamoya in China.