AQP4 and erythema multiforme: Whereas persistent severe motor impairment after acute myelitis is more suggestive of AQP4-IgG-positive NMOSD than of MOG-EM/MOGAD, persisting sphincter disturbance/sexual dysfunction is more commonly seen in MOG-EM/MOGAD, as the latter disorder more often affects the conus than does NMOSD [36].