1. Lanzhou University Second Hospital, The Second Medical College of Lanzhou University, Cuiyingmen No. 82, Chengguan District, Lanzhou 730030, China
2. Department of Neurosurgery, Second Hospital of Lanzhou University, Lanzhou 730030, China
3. Department of Anesthesiology, Second Hospital of Lanzhou University, Lanzhou 730030, China
4. Key Laboratory of Neurology of Gansu Province, Lanzhou University, Lanzhou 730030, China