1. Department of Geriatrics, Xuanwu Hospital of Capital Medical University, Xicheng District, Beijing 100053, China
2. Department of Vascular Ultrasound, Xuanwu Hospital of Capital Medical University, Xicheng District 100053, Beijing, China
3. Evidence Based Medicine Center, Xuanwu Hospital of Capital Medical University, 45 Changchun Street, Xicheng District, Beijing 100053, China
4. Department of Neurology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Changping District, Beijing 102218, China
5. Department of Geriatrics, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
6. Department of Neurology, Xuanwu Hospital of Capital Medical University, 45 Changchun Street, Xicheng District, Beijing 100053, China
7. School of Clinical Medicine, Tsinghua University, 30 Shuangqing Road, Haidian District, Beijing 100084, China