Rheumatoid Meningitis a Rare Extra-Articular Manifestation of Rheumatoid Arthritis: Report of 6 Cases and Literature Review

Objectives. Central neurological manifestations of rheumatoid arthritis (RA) like rheumatoid meningitis (RM) are rare, little known and have a high rate of morbi-mortality. METHODS. We described six cases of RM that were directly related to RA activity after exhaustive assessment. RESULTS. They were mainly women, aged of 50 to 69. All were positive for anti-cyclic citrullinated peptide antibodies and half for rheumatoid factors. RA activity, duration, and treatments were heterogeneous including oral steroids, conventional synthetic disease modifying anti-rheumatic drugs (DMARDs) and biologic DMARDs. Symptoms were various, with acute or progressive beginning; main were: generalized or focal seizure (4/6), fever (3/6), headaches (3/6), and frontal syndrome (2/6). Imaging lesions were four leptomeningitis, one pachymeningitis, and one association of both. MRI usually showed hypersignal in various territories in T2-FLAIR (fluid attenuated inversion recovery) mode, and enhancement in T1-weighted mode after gadolinium injection. All patients had lumbar puncture that found sterile cerebrospinal fluid, no neoplasic cell, elevated cell count in 5/6 cases and elevated proteins concentration in 3/6 cases. Cerebral biopsy was possible for three patients, and definitively confirmed the diagnosis of aseptic lepto- or pachymenintis, excluding vasculitis and lymphoma. Different treatments were used like intravenous high dose steroids, immunoglobulins or biologic DMARDs, with variable clinical and imaging outcome: one death, one complete recovery, and four recoveries with sequelae. Conclusions. Clinical symptoms, imaging, lumbar puncture, and serological studies are often nonspecific, only histologic examination can confirm the diagnosis of RM. Any central neurological manifestation in RA patients, even in quiescent and ancient RA, should warn the physician.