Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is a recently defined inflammatory demyelinating disease of the central nervous system, affecting both children and adults. MOGAD pathologically differs from multiple sclerosis and neuromyelitis optica spectrum disorder (NMOSD). In this review, observational studies highlight an often-monophasic disease without an evident progression course and suggest, for a better recovery, the need for early and active anti-inflammatory action during attacks. We aim to specify hallmarks for the risk of relapse and long-term prognosis. Innovative clinical, biological and imaging biomarkers have been tested. Questions to be resolved are the optimal management of each attack and the definition of the window of opportunity to treat, looking to modify the risk of a potential relapsing disease course, with cumulative disability.