AQP4 and neuromyelitis optica: To date, it is suggested that clinical manifestations in MOGAD differ from multiple sclerosis (MS) (5) but overlap with aquaporin-4 antibody seropositive neuromyelitis optica spectrum disorder (NMOSD AQP4+) (6, 7); optic neuritis and acute myelitis in MOGAD have similarities with clinical manifestations of NMOSD and can only be distinguished by detecting MOG antibodies.