Neuromyelitis Optica Spectrum Disorder in a 19-Year-Old Female with Systemic Lupus Erythematosus and Positive Aquaporin-4 Immunoglobulin G: A Case Report

Neuromyelitis optica spectrum disorder (NMOSD) is a rare, severe autoimmune demyelinating, inflammatory relapsing disease of the central nervous system that preferentially targets the optic nerve, spinal cord, and specific brain regions. The aim is to report a case of aquaporin-4-positive NMOSD in a 19-year-old female in Port Harcourt, Nigeria. A 19-year-old female first presented to our clinic in April 2023 on account of blurry distance vision. She had previously been diagnosed with systemic lupus erythematosus (SLE). Visual acuity was 6/6 and 6/9 on the right and left, respectively, and examination findings were normal. She was diagnosed with refractive error and spectacles were prescribed. She presented again in July 2023 with acute bilateral painless visual loss. Visual acuity was hand motion on the right and no light perception on the left. She had a left total afferent pupillary defect. There was bilateral optic disc swelling with temporal disc pallor. Brain magnetic resonance imaging was unremarkable, while antinuclear antibodies and aquaporin-4 were elevated. A diagnosis of NMOSD in the background of SLE was made. She was treated with intravenous methylprednisolone followed by oral prednisolone, with some visual improvement. She was subsequently lost to ophthalmic follow-up but continued care with the pediatric nephrology team, who commenced her on maintenance immunosuppression with mycophenolate mofetil. Early diagnosis of NMOSD coexisting with SLE is critical to enable early institution of appropriate therapy and the achievement of favorable treatment outcomes.