Unusual central nervous system involvement of rheumatoid arthritis: successful treatment with steroid and azathioprine

Central nervous system involvement of rheumatoid arthritis (RA) frequently develops in patients who had a long-term history of RA, irrespective of the disease activity of systemic arthritis, and it has a high mortality rate despite treatment. Since clinical symptoms and radiologic signs are rather nonspecific, in short of doing biopsy, the diagnosis of rheumatoid meningitis is one of exclusion. However, the strongly positive rheumatoid factor in the cerebrospinal fluid is quite specific. We here report a 70-year-old man who had not been diagnosed as RA before he was admitted with neurological findings, who was diagnosed as RA later and successfully treated with prednisolone and azathioprine.