1. Department of Neurosurgery, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
2. Department of Neurology, Hongda Hospital of Jiamusi University, Jiamusi, Heilongjiang, China
3. Department of Neurosurgery, The First Hospital of Jilin University, Changchun, Jilin, China
4. Department of Neurosurgery, Shanghai Seventh People's Hospital, Shanghai, China