Papers of the Week

Rheumatoid Meningitis (RM) is a rare complication of Rheumatoid Arthritis (RA) that can manifest as stroke-like episodes. We present the case of a 63-year-old woman with a past history of Overlap Syndrome (OS) and clinical manifestations suggestive of Amyopathic Dermatomyositis, Rheumatoid Arthritis, and Systemic Lupus Erythematosus. She presented to the emergency department with sudden onset right-sided clumsiness and numbness and a 2-week history of left hemicraneal headache. Laboratory workup revealed positive serum Antinuclear Antibodies (ANA), anti-Ro antibodies, Anti-Citrullinated Peptide Antibodies (ACPA), and elevated Rheumatoid Factor (RF). Lymphocytic pleocytosis, positive ACPA and anti-Ro antibodies with passive diffusion pattern, and negative microbiological studies were demonstrated in the CSF. Brain MRI showed predominant left fronto-parieto-occipital leptomeningeal and pachimeningeal enhancement. We diagnosed RM and started methylprednisolone IV mg/kg once daily. Stroke-like episodes in the setting of a patient with lymphocytic pleocytosis in CSF and meningeal enhancement should raise suspicion of RM. In this context, serum RF and ACPA levels should always be measured and ACPA should also be measured in CSF. To our knowledge, this is the first reported case of RM in the context of an OS. ACPA levels in CSF could be a relevant diagnostic clue in the setting of central nervous system (CNS) disturbance and overlapping autoimmune conditions that include RA. In our case, the presence of a suggestive clinical scenario of RM reinforces the probable pathogenic role of ACPA when it is present in the CNS, even without intrathecal synthesis evidence.