1. Department of Neurosurgery, Jinan First People's Hospital, Ji'nan, Shandong 250012, P.R. China
2. Department of Emergency, Jinan First People's Hospital, Ji'nan, Shandong 250012, P.R. China
3. Department of Neurology, The 960th Hospital of The Chinese People's Liberation Army, Ji'nan, Shandong 250031, P.R. China