Neuromyelitis optica (NMO) is a heterogeneous condition consisting of the inflammation and demyelination of the optic nerve (optic neuritis) and the spinal cord (myelitis). It can be monophasic or recurrent. Currently at least three different kinds are proposed based on the presence of autoantibodies thought to produce the disease: anti-AQP4, anti-MOG and anti-NF. All the cases are considered autoimmune diseases.Neuromyelitis optica (NMO) is a central nervous system disorder that primarily affects the eye nerves (optic neuritis) and the spinal cord (myelitis). NMO is also known as neuromyelitis optica spectrum disorder or Devic's disease.