[1] Kobe City Med Ctr Gen Hosp, Dept Gen Internal Med, 2-1-1 Minami Machi,Chuo Ku, Kobe, Hyogo 6500047, Japan
[2] Natl Inst Neurosci, Natl Ctr Neurol & Psychiat, Dept Neuromuscular Res, Tokyo, Japan
[3] Kobe City Med Ctr Gen Hosp, Dept Pathol, Kobe, Hyogo 6500047, Japan
[4] Akashi Med Ctr, Dept Gen Internal Med, Akashi, Hyogo, Japan