Chen, John J.

Neuromyelitis optica spectrum disorder (NMOSD) is a severe autoimmune disease that predominantly affects the optic nerves and spinal cord, which is a distinct disease process from multiple sclerosis (MS) and myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease. The most common neuro-ophthalmologic manifestation of NMOSD is atypical optic neuritis (ON), characterized by severe vision loss with a higher propensity toward bilateral involvement, longitudinal enhancement of the optic nerve, and chiasmal involvement than MS-related optic neuritis. Due to the severity of disease, high recurrence rate, and significant risk of permanent deficits, early recognition of neuro-ophthalmologic signs and short- and long-term management with immunosuppressive therapies is critical. In this article, we will review the characteristic neuro-ophthalmologic findings in NMOSD, serologic markers, neuroimaging findings, and current approaches to both acute and long-term treatment.

Purpose of review The purpose of this article is to provide a review of neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), with a focus on what renders optic neuritis “atypical” in these two conditions. Clinical features, diagnostic criteria, and epidemiology are outlined. Acute treatments for optic neuritis, as well as immunotherapy for NMOSD and MOGAD are discussed. Recent findings Updates in NMOSD and MOGAD are highlighted, with an emphasis on novel work including the new 2023 MOGAD diagnostic criteria, our evolving understanding on the epidemiology of these conditions, and recently FDA-approved NMOSD treatments. Pipeline therapies are also discussed. Summary A thorough history and examination, supported by ancillary testing, continues to be the mainstay of optic neuritis diagnosis. Stratifying typical versus atypical optic neuritis is paramount. Within the atypical category, NMOSD and MOGAD are important considerations. Clues can point towards these diagnoses and guide steps for treatment, which is increasingly becoming targeted to individual diseases, as the pathophysiology is different for these disorders.