AQP4 and optic neuritis: As a result, MOG antibodies have been found in patients with optic neuritis, acute myelitis, neuromyelitis optica spectrum disorders (NMOSD) without aquaporin 4 (AQP4) antibodies (17, 18), acute disseminated encephalomyelitis (ADEM) (19, 20), and brainstem (21–23) and cerebral cortical encephalitis (24–26).