Highly Aggressive Relapsing Course of Myelin Oligodendrocyte Glycoprotein (MOG) Antibody-Associated Disease Requiring Intensive Care Unit Treatment and Quadruple Immunotherapy.

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an autoimmune-mediated demyelinating disorder of the central nervous system (CNS). Clinical manifestations and disease courses range from involvement of the optic nerve, spinal cord, or brainstem to acute disseminated encephalomyelitis (ADEM), and from monophasic to relapsing or progressive forms. Diagnosis can be challenging; repeated testing is sometimes required to establish the diagnosis, particularly in atypical clinical presentations. First-line therapy in the acute setting consists of corticosteroids, whereas steroid-sparing agents are used for long-term management in relapsing cases. Various therapeutic strategies, particularly in aggressive courses, have been described in case reports. We report a challenging case of a 34-year-old woman with a severe relapsing disease course requiring intensive care unit (ICU) support. Anti-myelin oligodendrocyte glycoprotein-immunoglobulin G (anti-MOG IgG) was detected only after repeated testing using different assays. Brain biopsy identified an unidentified viral pathogen of uncertain clinical relevance. The disease demonstrated marked refractoriness to standard therapies.