P048 A rare case of rheumatoid leptomeningitis presenting with transient neurological symptoms

Leptomeningitis is a rare but serious neurological complication of rheumatoid arthritis (RA), predominantly seen in patients with established disease. Its clinical presentation varies, often posing significant diagnostic and therapeutic challenges, with potentially fatal outcomes.

This case report describes a 67-year-old woman with seropositive RA, previously treated with adalimumab, who presented with transient episodes of limb numbness followed by headaches. Initial MRI revealed subcortical oedema in the fronto-parietal white matter, but the diagnosis remained uncertain. She unfortunately later sustained a femoral fracture leading to hospital admission and suspension of her Adalimumab. Symptoms progressed when she was seen by the stroke team a few months later now describing intermittent episodes of upper limb peripheral numbness which ascended to the left side of her face and finally expressive dysphasia. Concerns about adalimumab-related demyelination led to continued suspension of the medication, though her neurological symptoms persisted.

Further MRI imaging demonstrated leptomeningeal enhancement of bilateral fronto-parietal regions in addition to previous changes, while lumbar puncture results, mycobacterial culture and serum ACE were unremarkable. After much deliberation at a regional connective tissue disease multi-disciplinary team (MDT) meeting, the next step suggested was a brain biopsy which revealed nonspecific chronic inflammation initially. Further discussion in a histopathology MDT meeting suggested that the biopsy findings were in keeping with a florid inflammatory process with mixed T and B cell lymphocyte infiltration, and a polytypic pattern of light chain expression by plasma cells leading to a diagnosis of rheumatoid leptomeningitis. After treatment with rituximab, her symptoms completely resolved.

This case underscores the challenges of diagnosing rheumatoid leptomeningitis with often non-specific findings on investigation. Utilising a multidisciplinary approach, integrating clinical, radiological plus histopathological findings can aid in early diagnosis. Timely diagnosis and initiation of immunosuppressive therapy, such as corticosteroids/rituximab, are key factors for optimal patient outcomes.

Z.M. Iftikhar: None. K. Dasigan: None. O. Jones: None.