[Neuromyelitis Optica Spectrum Disorders].

Neuromyelitis optica spectrum disorders (NMOSD) are inflammatory autoimmune disorders of the central nervous system, that primarily cause optic neuritis and myelitis. Aquaporin-4 (AQP4) antibody is the key in NMOSD pathophysiology, which causes astrocytopathy, demyelination, and neuropathy through complement activation and cell-mediated immunity. Currently, biopharmaceutical agents are introduced for preventing relapse with high efficacy, expected to reduce side effects derived from long-term steroid therapy, and improve patients' quality of life.