Exploring Sleep Architecture in Polish Patients with Multiple Sclerosis: A Polysomnography Study

Background: Sleep disturbances are a prevalent phenomenon in patients with multiple sclerosis (PwMS). The present study employs polysomnography (PSG) to quantify sleep efficiency and architecture in PwMS, aiming to elucidate the relationships between PSG parameters and factors including gender, disability level, brain lesion location, and subjective measures of insomnia, excessive daytime sleepiness (EDS), fatigue, pain, and mood disorders. Methods: The study cohort comprised 51 adult PwMS, of whom 31 underwent overnight PSG. The demographic and clinical characteristics, including age, gender, and Expanded Disability Status Scale (EDSS), were collated. The Athens Insomnia Scale, the Epworth Sleepiness Scale, the Fatigue Severity Scale, the Modified Fatigue Impact Scale (MFIS), the Numerical Pain Rating Scale, and the Hospital Anxiety and Depression Scale were employed for the assessment of insomnia, EDS, fatigue, pain, and mood disorders. The brain and spinal cord magnetic resonance imaging (MRI) were evaluated. Results: A reduced sleep efficiency was observed among 30 PwMS (aged 38.9 +/- 12.9), with a mean of 80 +/- 12%, especially in those with brainstem demyelinating lesions. In those PwMS aberrant sleep onset latency (SOL) and wake after sleep onset were also noted (p < 0.05). The prevalence of sleep fragmentation, as measured by the total arousal index, was greater in male PwMS than in female (p < 0.05). Higher disability according to the EDSS correlated with longer SOL (rho = 0.48, p < 0.05), and reduced N2 sleep stage correlated with cognitive fatigue according to MFIS (rho = -0.46, p < 0.05). Age, disease duration, insomnia, EDS, physical fatigue, and mood disorders did not impact PSG parameters. Conclusions: The study demonstrated the disruption of sleep architecture in PwMS, and highlighted the importance of a comprehensive PSG assessment of sleep disturbances in this population.