AQP4 and encephalitis: MOG-Ab-associated diseases and AQP4-Ab-positive NMOSD share some clinical phenotypes, but MOG-Ab-associated diseases do have some distinct clinical features from AQP4-Ab-positive NMOSD: a higher proportion of males, fewer relapses, better recovery, more bilateral simultaneous ON, more symptomatic brain disease appears manifest as seizures or encephalitis, and a wider spectrum of MRI features [13, 29–34].