Department of Nursing, Huizhou Health Sciences Polytechnic, Huizhou, Guangdong, China. Department of Neurology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, Guangdong, China. Department of Basic Courses, Huizhou Health Sciences Polytechnic, Huizhou, Guangdong, China. Department of Neurology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, Guangdong, China. tangym@mail.sysu.edu.cn.