Perspectives and therapeutic options for the treatment of myelin oligodendroglial antigen-associated disease (MOGAD): case report and literature review

Abstract

Case Presentation: An 11-year-old female from Salvador, Brazil, first presented at 4 years of age with intense headache preceded by fever, nausea, and diarrhea. Cerebrospinal fluid analysis revealed lymphocytic pleocytosis with normal glucose and protein, leading to initial treatment for suspected meningoencephalitis. Despite antimicrobial therapy, she developed transient appendicular ataxia and convergent strabismus. Brain MRI demonstrated multifocal, bilateral T2/FLAIR hyperintense lesions involving periventricular white matter, corpus callosum, basal ganglia, brainstem, and cerebellum, without contrast enhancement, raising concern for a demyelinating disorder, initially considered multiple sclerosis versus acute disseminated encephalomyelitis. She subsequently evolved with truncal and gait ataxia and ocular apraxia, responding well to high-dose intravenous methylprednisolone. Two months later, she experienced severe bilateral optic neuritis with significant visual loss. Given this presentation, myelin oligodendrocyte glycoprotein antibody–associated disease (MOGAD) and neuromyelitis optica spectrum disorder were considered. Anti–aquaporin-4 antibodies were negative, while anti-MOG antibodies returned positive, confirming the diagnosis of MOGAD. Immunosuppressive therapy with azathioprine and oral corticosteroids was initiated, resulting in temporary clinical stability. However, attempts at corticosteroid tapering were followed by recurrent optic neuritis, despite optimized azathioprine dosing. Rituximab was subsequently introduced, but the patient developed recurrent infections and further optic neuritis relapses, with MRI evidence of optic nerve edema and enhancement. Due to ongoing disease activity and treatment-related complications, therapy was switched from rituximab to monthly intravenous immunoglobulin (IVIG) in May 2025, with maintenance corticosteroids. Since initiating IVIG, the patient has remained relapse-free. Ophthalmologic evaluation demonstrated temporal retinal nerve fiber layer thinning on optical coherence tomography, more pronounced in the right eye, despite preserved visual acuity (20/20 bilaterally). At last follow-up, she remains neurologically stable on monthly IVIG, with plans for gradual corticosteroid tapering and reassessment of immunoglobulin dosing. Discussion: MOG antibody–associated disease (MOGAD) typically responds well to glucocorticoids during acute attacks. Due to the absence of randomized trials, treatment strategies are extrapolated from MS and NMOSD. About half of patients have a monophasic course, while relapse risk may reach 40% within two years. Acute therapy relies on high-dose intravenous corticosteroids, with plasma exchange or IVIg used in refractory cases. Maintenance therapy is reserved for relapsing disease or severe first attacks and includes azathioprine, mycophenolate, rituximab, tocilizumab, and IVIg, with variable effectiveness. Final Comments: Maintenance therapy in MOGAD is unclear; IVIg and tocilizumab show promise; AZA/MMF need overlap.