Rheumatoid leptomeningitis: magnetic resonance imaging and pathologic findings--a case report

Rheumatoid arthritis (RA) is a chronic inflammatory multisystem disease with articular and extra-articular manifestations. Intracranial manifestations of RA are rare. Purpose of this article is to report on a rarely described leptomeningeal involvement in RA, and on its neuroimaging features, including diffusion-weighted imaging (DWI).

The authors describe the case of a 74-year-old woman with a 5-year history of RA presenting with progressive left-side weakness and hypoesthesia. The patient underwent laboratory investigation and brain contrast-enhanced MRI, also with DWI, before undergoing brain biopsy.

Neuroimaging revealed abnormal high T2-signal in right frontal and parietal lobes, restricted diffusion in the subarachnoid space, and diffuse thick linear leptomeningeal contrast-enhancement. These findings were interpreted as rheumatoid leptomeningitis, and brain biopsy confirmed this diagnosis.

In summary, rheumatoid meningitis is a rare neurological complication of RA, but it should be considered in the proper clinical setting when patient presentation and laboratory results fail to support the other differential diagnostic possibilities proposed by the MR imaging findings.