Rheumatoid Meningitis: Diagnostic and Therapeutic Observations.

A 75-year-old female with untreated rheumatoid arthritis presented with two weeks of behavioral changes and cognitive decline. A neurologic examination showed severe encephalopathy, brisk reflexes, and bilateral Babinski sign. A contrast-enhanced brain MRI demonstrated right meningeal enhancement and periventricular white matter disease. A computed tomographic angiogram (CTA) of the head and neck was negative for vasculitis. The cerebrospinal fluid (CSF) demonstrated lymphocytic pleocytosis. The patient's serum rheumatoid factor levels were elevated. A biopsy of the leptomeninges and cortex showed lymphocytic vasculitis of the cortical tissue and patchy lymphoplasmacytic infiltrates of dural small vessels consistent with rheumatoid meningitis. The patient received pulse-dose steroids followed by cyclophosphamide infusions. At her three month follow-up appointment, the patient's mental status had improved mildly. A follow-up brain MRI showed resolution of enhancement, but progression of subcortical bihemispheric white matter disease. Subsequently, the patient developed a respiratory infection and passed away. In rheumatoid arthritis, symptoms of encephalopathy, headaches, seizures, or focal neurologic deficits should raise suspicion for CNS involvement. This potentially treatable disease warrants prompt diagnosis.