Isolated rheumatoid arthritis-associated cerebral vasculitis: a diagnostic challenge.

Central nervous system involvement in rheumatoid arthritis is uncommon. In order of frequency, published cases have reported rheumatoid nodules, meningeal vasculitis, and cerebral vasculitis (CV). The frequency of vasculitic cerebral involvement in rheumatoid arthritis is unknown. However, it is known that it is more common in patients with seropositive, long-standing rheumatoid arthritis, and in those with concomitant systemic vasculitis. We report the case of a 47-year-old woman with an 11-year history of seropositive rheumatoid arthritis without any extra-articular manifestations, with the exception of secondary Sjogren's syndrome, presenting with mental status changes and tonic-clonic seizures as symptoms of isolated CV. Magnetic resonance imaging (T2) showed hyperintense white-matter lesions in the frontal and temporal lobes, as well as in the hippocampus and cerebellum. Transcranial Doppler ultrasound findings were consistent with CV. Other differential diagnoses were ruled out. The patient responded favorably to methylprednisolone and intravenous gammaglobulin therapy.