Myelin Oligodendrocyte Glycoprotein (MOG) Antibody-Associated CNS Demyelination: Clinical Spectrum and Comparison with Aquaporin-4 Antibody Positive Neuromyelitis Optica Spectrum Disorder.

BACKGROUND: The clinical phenotypes of myelin oligodendrocyte glycoprotein (MOG) antibody disease, its disease course, and treatment are poorly understood and much work needs to be done towards this. OBJECTIVE: To characterize the clinico-radiologic spectrum and treatment outcomes of MOG antibody disease and differentiate it from aquaporin-4 (AQP-4) antibody positive neuromyelitis optica spectrum disorders (NMO-SD). METHODS: A single-center, observational study from Western India during 2017-2019, of 48 patients with either MOG antibody positive (21 patients) or AQP-4 antibody positive (27 patients) central nervous system demyelination. RESULTS: MOG antibody group had median age 32.2 years, no gender bias, median disease duration 40 months, relapses in 9 patients (43%), and median 2.5 (1-16) episodes per patient. Onset phenotypes included isolated bilateral optic neuritis (ON) (43%), isolated unilateral ON (19%), acute brainstem syndrome (19%), simultaneous ON with myelitis (9%), isolated myelitis (5%), and acute disseminated encephalomyelitis optic neuritis (ADEM-ON) (5%). Characteristic neuroimaging abnormalities were anterior segment longitudinally extensive ON, upper brainstem, and thoracic cord involvement (both short and long segment lesions). Most patients (86%) responded well to steroids, only 3/21 required rescue immunotherapy. In total, 6 out of 46 eyes affected developed permanent visual disability, while one patient had motor disability. The features differentiating MOG from AQP-4 antibody group were: no female predilection, preferential optic nerve involvement, characteristic neuroimaging abnormalities, and favorable therapeutic response and outcome. CONCLUSIONS: MOG disease commonly presents as severe ON, myelitis, acute brainstem syndrome, ADEM or their combinations. Early identification, treatment, and maintenance immunosuppression are necessary. It can easily be differentiated from NMO-SD using clinico-radiological features and therapeutic response.