[1] Natl Hosp Org Okayama Med Ctr, Dept Neurol, Okayama, Japan
[2] Natl Hosp Org Okayama Med Ctr, Dept Hematol, Okayama, Japan
[3] Natl Hosp Org Okayama Med Ctr, Clin Lab, Okayama, Japan
[4] Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Dept Neurol, Okayama, Japan