Neuromyelitis optica

Neuromyelitis optica spectrum disorders (NMOSD) is an etiologically heterogeneous syndrome predominantly characterized by acute inflammation of the optic nerve (optic neuritis, ON) and the spinal cord (myelitis). Episodes of ON and myelitis can be simultaneous or successive. A relapsing disease course is common, especially in untreated patients. Rarely, NMO may occur in the context of other autoimmune diseases (e.g. connective tissue disorders, paraneoplastic syndromes) or infectious diseases. In some cases, the etiology remains unknown (idiopathic NMO).