Rheumatoid meningitis (RM) is a rare but serious complication of rheumatoid arthritis (RA) that affects the central nervous system (CNS) with varied symptomatology. RM has been reported to occur independent of active synovial disease or history of RA, and may serve as the initial presentation of subsequent disease. CSF studies can be normal or show a lymphocytic pleocytosis. Serum RA biomarkers, rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP), can support the diagnosis of RM however they alone are not diagnostic. MRI commonly shows meningeal thickening and enhancement with possible T2 changes within the subarachnoid space. Diagnosis is confirmed with biopsy. Here we present a case of RM in a woman without history or development of RA.

CSF profile was significant only for a WBC of 12 with lymphocytic predominance. Serum studies showed a highly elevated anti-CCP of 197.5 (reference 0-19 units). RF was negative. Review of previous MR images revealed progressive intrahemispheric meningeal thickening with subarachnoid signal intensity previously interpreted as ischemic changes. Dural biopsy ultimately revealed necrotizing granulomatous inflammation. Extensive infectious workup was unrevealing. She was treated with corticosteroids and cyclophosphamide with clinical improvement, and MR imaging demonstrated resolution of abnormal meningeal signal. Now one year later she continues to have no evidence of systemic rheumatoid disease.