Pharmaceutical Neuromyelitis optica spectrum disorder (NMOSD) – also known as neuromyelitis optica (NMO) and Devic’s disease – is a rare, chronic autoimmune condition that affects the central nervous system (CNS), especially the optic nerve and spinal cord. The estimated prevalence is 1 to 10 per 100,000 individuals worldwide, with the condition more common among Hispanic, Black and Asian populations. 7 April 2025