Neuromyelitis optica (NMO), also known as Devic’s syndrome, is a diverse condition consisting of the simultaneous inflammation and demyelination of the optic nerve (optic neuritis) and the spinal cord (myelitis). While MS and NMO are similar, they are considered to be different diseases due to the specific regions under inflammatory attack in NMO. In NMO it known that the immune system targets a protein called AQP4 whereas the target in MS is unknown.