1. Department of Neurology, Beijing Tiantan HospitalCapital Medical University Beijing China
2. China National Clinical Research Center for Neurological Diseases Beijing China
3. Center of StrokeBeijing Institute for Brain Disorders Beijing China
4. Beijing Key Laboratory of Translational Medicine for Cerebrovascular Disease Beijing China
5. Department of NeurologyDuke University Medical Center Durham NC
6. Department of Epidemiology, School of Public Health and Tropical MedicineTulane University New Orleans LA