[1] Juntendo Univ, Sch Med, Dept Neurol, Bunkyo Ku, Tokyo 1138421, Japan
[2] Kanto Rosai Hosp, Kawasaki, Kanagawa, Japan
[3] Natl Utano Hosp, Ctr Neurol Dis, Clin Res Sect, Kyoto, Japan
[4] Kagawa Prefectural Cent Hosp, Dept Neurol, Takamatsu, Kagawa, Japan
[5] Sagamihara Natl Hosp, Dept Neurol, Sagamihara, Kanagawa, Japan
[6] Toyama Med & Pharmaceut Univ, Fac Med, Div Biostat, Toyama, Japan
[7] Kitasato Univ, Tokyo, Japan