Changfeng Chai1, Victor Li2, Xiaoying Bi3. 1. Department of Neurology, Shanghai Changhai Hospital, Shanghai, China. 2. Djavad Mowafaghian Centre for Brain Health and Department of Medicine, Vancouver Coastal Health Research Institute, University of British Columbia, Vancouver, BC, Canada. 3. Department of Neurology, Shanghai Changhai Hospital, Shanghai, China. bxiaoying616@sina.com.