Myelin-oligodendrocyte glycoprotein antibody-associated disease in Crohn's disease: an exceptional neurological manifestation.

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a rare demyelinating syndrome of the central nervous system (CNS). Its association with other autoimmune diseases is uncommon. We present a unique case of MOGAD in a 53-year-old man with Crohn's disease, highlighting significant diagnostic challenges. The patient had been diagnosed with Crohn's disease one year prior, with azathioprine treatment that was ineffective. He underwent surgery for ileal stenosis and an incidental hepatic hydatid cyst. Six weeks later, he developed bilateral optic neuritis and acute myelitis with significant neurologic deficits. After a thorough diagnostic workup and exclusion of other etiologies, including multiple sclerosis and neuromyelitis optica spectrum disorder (NMOSD), MOG-IgG seropositivity supported the diagnosis. Immediate high-dose corticosteroid therapy resulted in almost complete recovery of visual and motor functions. This case report highlights the importance of considering rare entities such as MOGAD in patients with Crohn's disease who present with severe, simultaneous bilateral optic neuritis and myelitis, a core clinical phenotype of MOGAD, even when some imaging features (e.g., orbital MRI) are atypical. Early diagnosis and appropriate management can significantly improve outcomes, as seen in this patient.