[1] Natl Cerebral & Cardiovasc Ctr, Dept Cerebrovasc Med, Suita, Osaka, Japan
[2] Nippon Med Coll Hosp, Grad Sch Med, Dept Neurol Sci, Bunkyo Ku, Tokyo, Japan
[3] Kyorin Univ, Sch Med, Dept Neurosurg, Mitaka, Tokyo, Japan
[4] Kyorin Univ, Sch Med, Stroke Ctr, Mitaka, Tokyo, Japan
[5] Nakamura Mem Hosp, Dept Neurosurg, Sapporo, Hokkaido, Japan
[6] Natl Cerebral & Cardiovasc Ctr, Dept Neurol, Suita, Osaka, Japan
[7] Natl Cerebral & Cardiovasc Ctr, Div Stroke Care Unit, Suita, Osaka, Japan