Low-Positive Myelin Oligodendrocyte Glycoprotein (MOG)-Immunoglobulin G (IgG) in Pediatric Demyelinating Disease: How Imaging Features Can Support a MOG Antibody-Associated Disease (MOGAD) Diagnosis.

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a rare inflammatory demyelinating disorder that can affect children and remains challenging to diagnose. Neuroimaging plays a key role, as MRI patterns in the brain, optic nerves, and spinal cord differ from those of multiple sclerosis and Aquaporin-4 (AQP4)‑positive neuromyelitis optica spectrum disorder (NMOSD). The 2023 international consensus criteria require a compatible core clinical phenotype, positive serum MOG‑immunoglobulin G (IgG), and exclusion of a better alternative diagnosis, with supportive MRI features when needed. The authors recently managed a pediatric patient with an acute demyelinating syndrome, positive serum MOG‑IgG, and characteristic compatible lesions. This case illustrates key clinical and imaging features of pediatric MOGAD, shows how the 2023 criteria can be applied in practice, and highlights radiologic clues that help distinguish MOGAD from other demyelinating disorders.