Myelin oligodendrocyte glycoprotein antibody–positive acute disseminated encephalomyelitis following hepatitis A infection: A paediatric case report

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated demyelinating disorder that follows viral infections, but is uncommon after hepatitis A virus (HAV) infection, especially in children. Only three paediatric cases have been reported worldwide, and none of them mentions myelin oligodendrocyte glycoprotein (MOG) antibody positivity, which is the first documented case of MOG antibody-positive ADEM following HAV infection in the paediatric population. Thus, it expands the existing knowledge regarding post-HAV infection neurological sequelae in children. A 13-year-old boy presented with a 1-week history of confusion, gait instability, left eye blurring, headache, and dysarthria, 3 weeks after a self-resolving episode of febrile jaundice. Examination showed mild encephalopathy, unilateral disc oedema, and cerebellar signs. Magnetic resonance imaging (MRI) revealed multifocal demyelinating lesions involving bilateral cerebellar hemispheres, basal ganglia, and subcortical white matter. Serum anti-MOG and hepatitis A immunoglobulin M antibodies were positive. Cerebrospinal fluid analysis was normal. Differential diagnosis, including paediatric multiple sclerosis, was considered, but the MRI and clinical history supported ADEM. The patient received intravenous methylprednisolone for 5 days, following which he was transitioned to oral prednisolone, which was tapered over the course of 6 weeks. There was significant clinical improvement, and no new neurological signs during the follow-up visit 3 months later. ADEM can rarely complicate HAV infection, and clinicians need to be vigilant during follow-up. This case also highlights the importance of checking for anti-MOG antibodies in post-infectious demyelination. Also, it adds new evidence to the limited literature on HAV-associated ADEM in the paediatric population.