1. Department of Neurosurgery, Linyi People's Hospital, Linyi, Shandong 276000, P.R. China
2. Department of Clinical College, Binzhou Medical University, Yantai, Shangdong 264000, P.R. China
3. Department of Neurology, Linyi People's Hospital, Linyi, Shandong 276000, P.R. China