[1] Kyorin Univ, Sch Med, Dept Neurosurg, Mitaka, Tokyo 1818611, Japan
[2] Kyorin Univ, Sch Med, Dept Stroke & Cerebrovasc Med, Mitaka, Tokyo 1818611, Japan
[3] Fuji Brain Inst & Hosp, Dept Neurosurg, Shizuoka, Japan
[4] Natl Ctr Geriatr & Gerontol, Ctr Comprehens Care & Res Memory Disorders, Aichi, Japan