[1] Shiga Gen Hosp, Dept Neurosurg, 5 4 30,Moriyama, Moriyama, Shiga 5248524, Japan
[2] Hikari Hosp, Dept Rehabil, Otsu, Shiga, Japan
[3] Hikone Chuo Hosp, Dept Neurosurg, Hikone, Shiga, Japan
[4] Kitano Hosp, Tazuke Kofukai Med Res Inst, Dept Neurosurg, Osaka, Osaka, Japan