AQP4 and optic neuritis: Conformation-sensitive antibodies against MOG are detectable in patients with optic neuritis, myelitis, opticomyelitis, acute or multiphasic disseminated encephalomyelitis (ADEM/MDEM) and brainstem/cerebral cortical encephalitis, although they are rarely detected in patients with prototypic multiple sclerosis or anti-aquaporin 4 (AQP4) antibody-positive neuromyelitis optica spectrum disorders (NMOSDs) (1–13).