Multiple Sclerosis, Fatigue, Expanded Disability Status Scale: A Cross-Sectional Exploration of Sleep Efficiency and Quantitative Sleep Parameters

BACKGROUND: Poor sleep quality and sleep disorders are more prevalent in individuals with multiple sclerosis (MS) than in the general population. Poor sleep has been correlated with worse MS outcomes. Sleep efficiency (SE) is one of the most sensitive markers of sleep quality. There is very little written about SE and other polysomnography (PSG) parameters and MS measures. METHODS: This is a retrospective review of 280 consecutive individuals with MS evaluated by PSGs and other standardized MS measures over 13 years at a comprehensive MS center. In addition, the cohort was assessed with 2 fatigue scales, the Epworth Sleepiness Scale, and the Expanded Disability Status Scale. A comparison of means test (independent t test) and a correlation coefficient (r) were used. RESULTS: The PSG measures of SE and Total Sleep Time were significantly different between a group of individuals with MS with a disease duration of more than 5 years vs a group of individuals with MS with a disease duration less than or equal to 5 years. Prevalence of obstructive sleep apnea was 63%, higher than reported in the literature while the prevalence of moderate to severe obstructive sleep apnea was 33.4%, which was lower than reported. CONCLUSIONS: Longer disease duration and worse disability correlate with sleep quality as measured by SE.