RecruitingPhase 3Drug trialImmediate Versus Delayed Treatment With Azathioprine or Rituximab in Anti-MOG Antibodies Associated Acute Demyelinating Syndromes in Children: a Randomized Controlled Clinical TrialAmong all non viral encephalitis, myelin oligodendrocytes glycoprotein antibody associated diseases (MOGAD) are the second most frequent diagnosis in children. Risk of relapses varies according to studied cohorts and cognitive and academic difficulties are more and more detected in children without knowing if these sequelae are related to the first attack or relapses. The hypothesis is that earlier treatment would induce reduction of sequelae after the first attack and the number of relapses which would be also associated with a subsequent reduction of disability occurrence on the long term.