1. Departments of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
2. Division of Neurology, Saga University Faculty of Medicine, Saga 849-8501, Japan
3. Department of Internal Medicine and Advanced Comprehensive Functional Recovery Center, Saga University Faculty of Medicine, Saga 849-8501, Japan
4. Departments of Immunology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA