Recurrent Optic Neuritis and Acute Encephalopathy with Myelin Oligodendrocyte Glycoprotein Antibodies in a Korean Child

ABSTRACT

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated diseases are reported to have distinct pathogenic mechanisms, clinical courses, and therapeutic implications in comparison to other acquired demyelinating syndromes. Here, we report the case of a 6-year-old Korean girl with recurrent steroid-responsive optic neuritis (ON) and an episode of acute disseminated encephalomyelitis (ADEM) with a high MOG antibody titer. Initially, she suffered from left ON with subclinical brain lesions including magnetic resonance imaging hyperintensities in the bilateral frontal subcortical white matter, the left thalamus, and the right cerebral peduncle. Her vision improved dramatically after steroid therapy; however, 3 months after the 1st episode, she developed acute encephalopathy with extensive newly developed ADEM-like lesions and resolution of previous hyperintensities. Despite regular interferon β-1a injection after steroid tapering, she developed a 3rd episode presenting as a right ON. Throughout these three episodes, serological tests associated with autoimmune diseases, viral markers, anti-aquaporin-4 antibodies, and cerebrospinal fluid oligoclonal bands were negative, with the immunoglobulin G index in the normal range. After the 3rd episode, anti-MOG antibody testing was performed and higher titer was detected. Testing for anti-MOG antibodies is highly recommended for relapsing inflammatory demyelinating central nervous system diseases in pediatric patients, in order to define early an adequate long-term treatment.