Neuromyelitis optica (NMO), characterised by longitudinally extensive transverse myelitis (LETM), was previously thought to be a variant of multiple sclerosis.
PURPOSE: The anti-aquaporin-4 (AQP4) antibody was recently reported to be associated with neuromyelitis optica (NMO). Optic nerve involvements in many NMO cases are bilateral and the prognosis is poor