Neuromyelitis Optica is an inflammatory autoimmune disease causing demyelination of the central nervous system with degradation of the insulating sheath of at least one optical nerve (Neuritis nervi optici) and at the same time or few months later the spinal cord (Myelitis). Highly specific serum autoantibody markers are found very frequently in NMO, while they are not detected in Multiple sclerosis (MS) or healthy subjects.