In 2015, the International Panel for NMO Diagnosis has developed a new nomenclature defines the unifying term NMOSD (divided into NMOSD with or without AQP4-IgG), which included ON, acute myelitis, area postrema syndrome, acute brainstem syndrome, acute diencephalic clinical syndrome, and symptomatic cerebral syndrome [15]. The gene discussed is AQP4; the disease is neuromyelitis optica.