1. Department of Neurology, The Fifth Affiliated Hospital, Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
2. Department of Neurophysiology, Oilfields General Hospital in Daqing, Daqing, Heilongjiang 163001, P.R. China
3. Department of Neurology, Ya'an Hospital, Ya'an, Sichuan 625000, P.R. China