The borderland of neuromyelitis optica.
Matthews LAE., Baig F., Palace J., Turner MR.
Neuromyelitis optica (NMO), also known as Devic's disease, is an emerging clinical and pathological entity originally thought to be a variant of multiple sclerosis. Characterised by episodes of demyelination confined to the optic nerve and spinal cord, the discovery in such patients of antibodies to the aquaporin-4 channel has been largely responsible for defining the phenotype to date. Recently it has become clear that there is a borderland where there are patients with optic neuritis-only and myelitis-only forms of the disease, and these may be seronegative in the early phase. We describe two cases of optic neuritis-only NMO, and explore the current understanding of the diagnosis and spectrum of NMO disorders.