Chronic relapsing aseptic meningoencephalitis in Sjögren's disease and cryoglobulinemia successfully treated with intrathecal dexamethasone: a case-based review.

Chronic relapsing aseptic meningoencephalitis is a rare but serious central nervous system (CNS) manifestation of Sjögren's disease (SjD), particularly when refractory to conventional immunosuppression. Cryoglobulinemia occurs in a subset of SjD patients and is associated with systemic vasculitis, but its role in driving refractory CNS inflammation remains poorly defined. A 54‑year‑old woman with SjD, rheumatoid arthritis, and persistent cryoglobulinemia presented with a 5‑year history of recurrent headaches resistant to prednisone, methotrexate, mycophenolate mofetil, and cyclophosphamide. CSF analysis showed protein elevation (peak 2,906 mg/L), mild pleocytosis (26 nucleated cells/µL), and elevated opening pressures (150-230 mmH₂O). MRI revealed diffuse white matter hyperintensities, cerebral atrophy, and ventriculomegaly. She received eight intrathecal dexamethasone (IT‑DEX) injections (10 mg each), each producing rapid headache relief (Numeric Pain Rating Scale 7‑8 → 1‑2)and progressive CSF protein decline (from 2,906 to 696 mg/L). At last follow‑up (March 2026), she remained in remission on prednisone 10 mg/day and intravenous cyclophosphamide 0.4 g every 4 weeks. A systematic review of 23 reported SjD‑associated recurrent aseptic meningitis cases identified universal CSF pleocytosis and elevated protein, but none reported concurrent cryoglobulinemia or progressive ventriculomegaly. This case expands the clinical spectrum of CNS‑SjD to include cryoglobulinemia‑driven refractory meningoencephalitis with hydrocephalus ex vacuo. IT‑DEX appears to be an effective rescue therapy for compartmentalized CNS inflammation when systemic immunosuppression fails.