Sleep disorders in patients with multiple sclerosis

Objective: Poor sleep is a frequent symptom in patients with multiple sclerosis (MS). The objective of the study was to assess the relationship between nocturnal polysomnographic (PSG) findings and quality of sleep, fatigue, and increased daytime sleepiness among patients with MS.

Methods: Clinical characteristics were collected. Pittsburgh Sleep Quality Index (PSQI), Fatigue Severity Scale (FSS), Epworth Sleepiness Scale (ESS), and International Restless Legs Syndrome Rating Scale were used to assess quality of sleep, fatigue, excessive daytime sleepiness, and the presence of restless legs syndrome (RLS). All patients underwent nocturnal diagnostic PSG examination.

Results: Fifty patients with MS were enrolled into the study. Age was the only independent variable significantly determining apnea-hypopnea index and desaturation index (DI) (beta = 0.369, p = 0.010, beta 0.301, p = 0.040). PSQI and ESS score were significantly higher in a population with RLS (p = 0.004, p = 0.011). FSS significantly correlated with DI (r = 0.400, p = 0.048). Presence of RLS was the only independent variable significantly determining PSQI and ESS (p = 0.005, p = 0.025). DI and presence of RLS were independent variables determining FSS (p = 0.015, p = 0.024).

Conclusion: Presence of RLS seems to be the main factor determining poor sleep, fatigue, and daytime somnolence. Sleep disordered breathing and its severity influences only fatigue in patients with MS.