1. Insititute of Nervous System Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Jiangsu 221002, China
2. Jiangsu Key Laboratory of Bone Marrow Stem Cell, Xuzhou Medical University, Jiangsu 221002, China
3. Department of Neurosurgery, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221002, China