[1] Univ Occupat & Environm Hlth, Sch Med, Dept Neurosurg, Yahatanishi Ku, Kitakyushu, Fukuoka 8078555, Japan
[2] Univ Occupat & Environm Hlth, Sch Med, Dept Internal Med, Yahatanishi Ku, Kitakyushu, Fukuoka 8078555, Japan
[3] Univ Occupat & Environm Hlth, Sch Hlth Sci, Dept Hlth Informat Sci, Yahatanishi Ku, Kitakyushu, Fukuoka 8078555, Japan
[4] Univ Hosp Occupat & Environm Hlth, Div Hyperbar Med, Kitakyushu, Fukuoka, Japan
[5] Akita Res Inst Brain & Blood Vessels, Dept Radiol, Akita, Japan