Rheumatoid meningitis: an autopsy report and review of the literature.

We report the clinical and autopsy findings of a 71-year-old Japanese woman with rheumatoid meningitis. This patient developed subacute meningitis during an inactive stage of rheumatoid arthritis (RA), and despite intensive examinations no causative agents or underlying disease could be identified except for RA. Based on persistent hypocomplementaemia and increased serum levels of immune complexes she was suspected of having vasculitis, and was treated with intravenous methylprednisolone (1000 mg/day for 3 days) followed by oral prednisolone. Soon after beginning treatment with corticosteroid her symptoms improved, in parallel with a decrease in cell counts and interleukin-6 in the cerebrospinal fluid. During tapering of oral prednisolone she died of a subarachnoid haemorrhage which was ascribed to a relapse of the meningitis. Autopsy demonstrated infiltration of mononuclear cells, including plasma cells, in the leptomeninges, mainly around small vessels, leading to a definite diagnosis of rheumatoid meningitis. When RA patients manifest intractable meningitis with a subacute course, this disease is important as a possible diagnosis even if the arthritis is inactive, and intensive treatment, including corticosteroid and immunosuppressants, should be positively considered as a therapeutic option as soon as possible because of the poor prognosis.