Weidong Yu1, Zheng Feng1, Conghai Zhao1, Chao Fu2. 1. From the Department of Neurosurgery (W.Y., C.Z., C.F.) and Pediatrics (Z.F.), China-Japan Union Hospital of Jilin University, Changchun, Jilin Province, People's Republic of China. 2. From the Department of Neurosurgery (W.Y., C.Z., C.F.) and Pediatrics (Z.F.), China-Japan Union Hospital of Jilin University, Changchun, Jilin Province, People's Republic of China. fc616@126.com.