1. Department of General Internal Medicine; Mito Kyodo General Hospital; Tsukuba University Hospital Mito Area Medical Education Center; Mito Ibaraki Japan
2. Department of Rheumatology; Mito Kyodo General Hospital; Tsukuba University Hospital Mito Area Medical Education Center; Mito Japan
3. Department ofNeurology; Mito Kyodo General Hospital; Tsukuba University Hospital Mito Area Medical Education Center; Mito Japan
4. Department of Medicine; Japan Community Healthcare Organization; Tokyo Japan
5. Department of Neurology; Tsukuba University Hospital; University of Tsukuba; Tsukuba Ibaraki Japan
6. Department of Internal Medicine; Faculty of Medicine; University of Tsukuba; Tsukuba Ibaraki Japan