Sleep disorders are a frequently reported yet poorly characterized aspect of myasthenia gravis(MG), a chronic autoimmune neuromuscular disorder marked by fluctuating muscle weakness. Beyond motor impairment, MG patients often experience systemic fatigue, mood disturbances, and impaired daily functioning, all of which may be compounded by disrupted sleep. Upper-airway and respiratory muscle weakness, medication effects, and autonomic changes plausibly contribute to insomnia, obstructive sleep apnea, restless legs syndrome and excessive daytime sleepiness.Despite their potential impact, these manifestations remain underrecognized, and the accuracy of standard screening tools in this population continues to represent a major clinical challenge.

A systematic search of PubMed, Embase, and PsycInfo was conducted from inception to April 2025. Observational studies reporting on sleep disorders in clinically diagnosed MG patients were included. Study quality was assessed using the Joanna Briggs Institute tools. 

Of 812 unique records, 27 studies (n= 3,889 participants) were included. The prevalence was 15-79% for obstructive sleep apnea (OSA) and 38-77% for poor sleep quality (PSQI >5). Restless leg syndrome (5-47.6%) and excessive daytime sleepiness (12-75%) were also highly prevalent. Higher Body mass index and male sex were significant risk factors for OSA and sleep-disordered breathing. A critical finding was the significant discrepancy between subjective questionnaires and objective polysomnography (PSG). Subjective questionnaires overestimated OSA risk due to symptom overlap, while objective polysomnography provided more specific diagnoses. Notably, most studies found no significant association between MG disease severity scores and sleep disorders. Sleep disorders were strongly correlated with worsened MG-specific quality of life, fatigue, and depression scores.

Sleep disorders are exceedingly common in MG, but their assessment is confounded by the inherent limitations of subjective questionnaires. The dissociation from disease severity suggests a distinct, multifactorial pathophysiology.