1. Department of Neurology Medicine, Tianjin 4th Center Hospital, Tianjin, Hebei 300052, P.R. China
2. School of Public Health, Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
3. Department of Neurology Medicine, Tianjin Medical University General Hospital, Tianjin, Hebei 300052, P.R. China