Two Pediatric Cases of Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease Predominantly Presenting as Cortical Encephalitis: A Case Report and Literature Review

Objective To analyze and summarize the clinical characteristics of pediatric patients with myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) presenting with cortical encephalitis as the predominant clinical phenotype, thereby enhancing clinical awareness and facilitating early diagnosis and treatment. Methods We retrospectively analyzed the clinical data of two pediatric MOGAD cases with a predominant cortical encephalitis phenotype admitted to Wuxi Children's Hospital from March 2024 to March 2025. Their clinical presentations, treatments, and prognoses were summarized alongside a relevant literature review. Results In Patient 1, the patient initially presented with convulsive status epilepticus (March 2024) and normal cranial MRI, diagnosed as "severe encephalitis." After initial improvement, follow-up MRI two months later revealed frontotemporal cortical swelling, followed by another episode of status epilepticus one week subsequently. At that time, CSF was positive for MOG-IgG (titer 1:1), but serum was negative. The patient improved with immunotherapy. In March of this year, despite being asymptomatic, routine MRI again showed frontotemporal cortical swelling, and serum MOG-IgG was positive (titer 1:10+; live CBA). Acute treatment included IVIG and pulsed steroids, and the patient is now maintained on corticosteroids and mycophenolate mofetil. Patient 2 presented with prolonged fever,convulsions, headache, vomiting, and limb numbness. Serum MOG-IgG titer was 1:100+ (CBA), and MRI showed diffuse cerebral cortical swelling. The patient improved following IVIG and pulsed steroid therapy. Neither patient had relapsed at the one-year follow-up. Conclusion Pediatric myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) can manifest as cortical encephalitis, typically presenting with core symptoms including fever, headache, and seizures. The cortical encephalitis phenotype of MOGAD is more commonly observed in older children. Patients generally respond well to acute-phase treatment with intravenous immunoglobulin (IVIG) and pulsed methylprednisolone; however, a subset may experience relapses, necessitating timely initiation of second-line immunosuppressive therapy. When neuroimaging reveals features suggestive of cortical encephalitis, MOG antibody testing should be performed to confirm the diagnosis, preferably using a live cell-based assay (CBA) which offers higher sensitivity.