1. Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
2. Department of Neurology, The Fifth Central Hospital of Tianjin, Tianjin 300450, P.R. China
3. Department of Pathology, The Fifth Central Hospital of Tianjin, Tianjin 300450, P.R. China
4. Department of Neurosurgery, The Fifth Central Hospital of Tianjin, Tianjin 300450, P.R. China
5. Central Laboratory, The Fifth Central Hospital of Tianjin, Tianjin 300450, P.R. China