Chenlong Yang1, Jingyi Fang2, Yulun Xu1. 1. Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, No. 6, Tiantan Xili, Dongcheng District, Beijing 100050, China; China National Clinical Research Center for Neurological Diseases, Beijing 100050, China. 2. Department of Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, No. 6, Tiantan Xili, Dongcheng District, Beijing 100050, China.