[1] Nagoya Med Ctr, Natl Hosp Org, Dept Neurosurg, Nagoya, Aichi, Japan
[2] Japanese Red Cross Nagoya Daiichi Hosp, Dept Neurosurg, Nagoya, Aichi, Japan
[3] Fujita Hlth Univ, Sch Med, Dept Neurosurg, Toyoake, Aichi 47011, Japan
[4] Nagoya Med Ctr, Natl Hosp Org, Dept Resp Med, Nagoya, Aichi, Japan
[5] Nagoya Univ, Grad Sch Med, Dept Neurosurg, Nagoya, Aichi 4648601, Japan