This phenomenon can largely be attributed to the absence of modern diagnostic criteria before the year 2000, limited availability of advanced neuroimaging, and, most importantly, the still not yet described related neuroinflammatory demyelinating disorders such as neuromyelitis optica spectrum disorder (NMOSD), MOG antibody-associated disease (MOGAD), or autoimmune encephalitis [35,36]. This evidence concerns the gene MOG and autoimmune encephalitis.