1. Department of Nuerosurgery, Shandong University, Jinan, Shandong Province, P. R. China
2. Department of Neurosurgery, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui Province, P. R. China
3. Department of Neurosurgery, Anhui Provincial Institute of Stereotactic Neurosurgery, Hefei, Anhui Province, P. R. China
4. Department of Neurosurgery, Anhui Provincial Hospital Affiliated to Anhui Medical University, Hefei, Anhui Province, P. R. China