Sleep-related Symptoms and Phenotypes in Neuromyelitis Optica and Myelin Oligodendrocyte Glycoprotein Antibody-associated Diseases

Background and objective: Sleep dysfunction is an under-recognized but debilitating non-motor symptom of central nervous system (CNS) demyelinating disorders.While the sleep architecture of multiple sclerosis (MS) is well-documented, the distinct sleep profiles of neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) remain poorly characterized.This study aimed to identify whether antibody status dictates specific sleep disorder phenotypes and their correlation with neurological disability. Materials and methods:In this observational analytical cross-sectional study, 77 patients (NMOSD, n = 39; MOGAD, n = 29; double-seronegative, n = 9) underwent a comprehensive sleep evaluation using the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Insomnia Severity Index (ISI), and International Restless Legs Syndrome (IRLS) Rating Scale.Disease severity was quantified using the Expanded Disability Status Scale (EDSS).Results: The total cohort demonstrated a high burden of sleep dysfunction (mean global PSQI: 7.8 + 3.4).Patients with NMOSD reported the highest burden of insomnia (n = 28) and daytime sleepiness (n = 12), which achieved statistical significance compared to the other groups.However, a significant divergence was observed in restless legs syndrome (RLS) prevalence (p = 0.001); 38.5% of patients in the NMOSD group had moderate-to-severe RLS, whereas 55.2% of MOGAD patients were asymptomatic.Conclusion: Sleep disturbances, particularly insomnia and RLS, are highly prevalent among patients with CNS demyelinating disorders.Distinct clinical associations were observed across subgroups, including a higher frequency of moderate-to-severe RLS in NMOSD and an association between insomnia severity and disability (EDSS) in MOGAD.Given these associations, routine screening for sleep impairment is valuable in clinical practice, though larger longitudinal studies are required to determine whether antibody-specific management strategies are warranted.