Editor’s Note: This article was originally posted on Neurology Advisor on 07/01/2021. Neuromyelitis optica (NMO) is an uncommon inflammatory autoimmune disease of the central nervous system that has a clinical and radiologic presentation similar to multiple sclerosis (MS).1-3 Unlike MS, however, NMO is mediated by an antibody response to aquaporin-4 (AQP4), a water channel located in…