To compare MOG positive and negative patients with ADEM as relates to demographic features, neuroimaging and laboratory features, hospital course, treatments, and relapse rate.

MOG antibody disease is an increasingly recognized etiology for acute disseminated encephalomyelitis (ADEM). ADEM is a condition that predominately affects children and presents with multifocal neurological symptoms and encephalopathy. Positive MOG antibodies strongly argues against later development of multiple sclerosis or NMOSD. The distinguishing characteristics of ADEM, as defined by MOG positive or negative status has not been well studied.

Children with the initial diagnosis of ADEM were consented to participate in a study of ADEM related outcomes. Their demographic features, clinical presentation, laboratory and imaging results, and clinical course are presented, highlighting differences in MOG positive and negative cohorts.

37 children in the study were assessed for MOG IgG. 18 children were MOG positive (49%) and 19 children were MOG negative (51%). Average age and race/ethnicity were similar between cohorts but the MOG positive group showed equal male/female ratio while MOG negative cohort showed male predominance (74%).

The MOG negative cohort had greater number of individuals with normal nucleated cells in CSF (0-5 cells/mm3) than MOG positive cohort: 7/19 (37%) vs 2/18 (11%). Neuroimaging features, need for ICU stay and acute rehabilitation were similar between cohorts. A greater number of MOG positive patients required ICP management (4/18 vs 1/19) and one MOG positive child died.

6/18 (33%) MOG positive patients had relapses compared to 3/19 (16%) MOG negative patients. 90% of the 29 patients who had neuropsychological testing scored within the normal range.