1. Department of Neurology, JA Toride Medical Center, Toride City, Ibaraki, Japan,
2. Department of Public Health, Saitama Medical University Faculty of Medicine, Moroyama-Machi, Iruma-Gun, Saitama, Japan,
3. Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyo-Ku, Tokyo, Japan, and
4. Department of Medicine and Rheumatology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyo-Ku, Tokyo, Japan