MOG and viral encephalitis: Myelin oligodendrocyte glycoprotein autoantibodies (MOG-Ab) have been identified in patients with various central nervous system (CNS) demyelinating diseases, including single or recurrent optic neuritis (ON), transverse myelitis (TM), acute disseminated encephalomyelitis (ADEM), encephalitis, and brainstem encephalitis (1, 2).