Elderly‐Onset Neuromyelitis Optica Spectrum Disorders

To the Editor: Neuromyelitis optica (NMO), also known as Devic disease, is a demyelinating disorder of the central nervous system primarily affecting the spinal cord and optic nerve. Since the discovery of the NMO-immunoglobulin (Ig)G antibody or aquaporin-4 antibody, it has been discovered that there are different variants of NMO, classified as NMO spectrum disorders (NMOSDs). A case of elderly-onset NMOSD is reported.