The myelin oligodendrocyte protein is expressed on myelin sheaths of oligodendrocytes. The exact biology of MOG antibody remains unclear, but animal studies show it is an encephalitogenic protein. Myelin oligodendrocyte antibody disease is a newly recognized demyelinating disorder that has not been fully elucidated. It is possible MOG-antibody associated encephalomyelitis is a separate demyelinating entity with overlapping features of other pediatric demyelinating disorders: acute disseminated encephalomyelitis, neuromyelitis optica spectrum disorder, and multiple sclerosis.

The mean (SD) patient age was 12.5 (4.7) years; age at disease onset was 8.6 (4.8) years, and number of relapses was 1.1 (1.6). Patient demographics: 25% male, nine (56.3%) White patients, six (37.5%) Hispanic patients, and one (6.25%) African American patient. Three patients tested positive for oligoclonal bands, one had an elevated IgG index, two had elevated IgG synthesis rates, and all were negative for AQP4. Fever was noted in 43.8% of presentations. No associated autoimmune disorders. Spine MRI showed central longitudinally extensive transverse myelitis and conus involvement. Brain MRI findings were more often bilateral than unilateral, lesions in the brachium pontis and subcortical white matter were larger than typical MS lesions, and midbrain abnormalities often involved periaqueductal gray matter.