[1] Sunshine Union Hosp Shandong Prov, Brain Ctr, Weifang 261000, Peoples R China
[2] Weifang Maternal & Child Hlth Hosp, Dept Anesthesiol, Weifang 261000, Peoples R China
[3] Weifang Med Univ, Dept Neurosurg, Affiliated Hosp, Weifang 261000, Peoples R China
[4] Weifang Chinese Med Hosp, Dept Neurosurg, Weifang 261000, Peoples R China