A rare concurrence: Antibodies against Myelin Oligodendrocyte Glycoprotein and N-methyl-D-aspartate receptor in a child

Background: Myelin Oligodendrocyte Glycoprotein antibodies (MOG) may be used as a biomarker for diagnosis of many demyelinating diseases. Especially, patients of acute disseminated encephalomyelitis (ADEM), multiple sclerosis (MS), aquaporin-4 (AQP4) seronegative neuromyelitis optica spectrum disorder (NMOSD), monophasic or recurrent optic neuritis (ON), transverse myelitis and N-methyl-D-aspartate (NMDA) receptor encephalitis (NMDARe) can overlap with Myelin Oligodendrocyte Glycoprotein antibodies. We present a child with autoimmune encephalitis in whom antibodies against Myelin Oligodendrocyte Glycoprotein (MOG) and N-methyl-Daspartate receptor (NMDAR) were simultaneously detected. The clinical manifestation was characteristic of NMDAR encephalitis, and cranial and spinal magnetic resonance imaging showed no signs of encephalomyelitis. On the other hand, complete recovery within first days of steroid treatment was more compatible with the course of MOG antibody-related disease. Conclusions: We emphasize the rarity of this antibody combination in children and suggest these patients, although clinically improved, may require longer follow-up due to the risk of recurrence of two autoimmune disorders.