[1] Univ Tokyo, Dept Neurol, Tokyo, Japan
[2] Kyorin Univ, Dept Neurol, Tokyo, Japan
[3] Tokyo Metropolitan Geriatr Hosp, Dept Neurol, Tokyo, Japan
[4] Jichi Med Univ, Saitama Med Ctr, Dept Neurol, Saitama, Japan
[5] Int Univ Hlth & Welf, Dept Neurol, Otawara, Tochigi, Japan
[6] Natl Def Med Coll, Dept Neurol, Saitama, Japan
[7] Natl Ctr Neurol & Psychiat, Dept Neurol, Tokyo, Japan
[8] Tottori Univ, Dept Neurol, Tottori, Japan
[9] Kyorin Univ, Dept Cytophysiol, Tokyo, Japan