Background: Multiple sclerosis (MS) patients often suffer from fatigue. Objective: We evaluated the relationship of obstructive sleep apnea (OSA) to fatigue and sleepiness in MS patients. Methods: Ambulatory MS patients without known sleep disorders and healthy controls underwent diagnostic polysomnography and a multiple sleep latency test (objective sleepiness measure). Fatigue was measured with the Fatigue Severity Scale (FSS) and the Multidimensional Fatigue Inventory (MFI), and subjective sleepiness by Epworth Sleepiness Scale. Covariates included age, sex, body mass index, Expanded Disability Status Scale (EDSS), depression, pain, nocturia, restless legs syndrome, and medication. Results: OSA (apnea–hypopnea index ≥15) was found in 36 of 62 MS subjects and 15 of 32 controls. After adjusting for confounders, severe fatigue (FSS ≥5) and MFI-mental fatigue (>group median) were associated with OSA and respiratory-related arousals in MS, but not control subjects. Subjective and objective sleepiness were not related to OSA in either group. In a multivariate model, variables independently associated with severe fatigue in MS were severe OSA [OR 17.33, 95% CI 2.53–199.84], EDSS [OR 1.88, 95% CI 1.21–3.25], and immunomodulating treatment [OR 0.14, 95% CI 0.023–0.65]. Conclusions: OSA was frequent in MS and was associated with fatigue but not sleepiness, independent of MS-related disability and other covariates.

Obstructive sleep apnea (OSA) is a prevalent disorder characterized by recurrent upper airway obstruction during sleep resulting in intermittent hypoxemia and sleep fragmentation. Research has recently increasingly focused on the impact of OSA on the brain’s structure and function, in particular as this relates to neurodegenerative diseases. This article reviews the links between OSA and neurodegenerative disease, focusing on Parkinson’s disease, including proposed pathogenic mechanisms and current knowledge on the effects of treatment.

Background: We recently reported that sleep disorders are significantly associated with fatigue in multiple sclerosis (MS). Objective: The objective of this paper is to assess the effects of sleep disorder treatment on fatigue and related clinical outcomes in MS. Methods: This was a controlled, non-randomized clinical treatment study. Sixty-two MS patients completed standardized questionnaires including the Fatigue Severity Scale (FSS), Multidimensional Fatigue Inventory (MFI), Epworth Sleepiness scale (ESS) and Pittsburgh Sleep Quality Index (PSQI), and underwent polysomnography (PSG). Patients with sleep disorders were offered standard treatment. Fifty-six subjects repeated the questionnaires after ≥ three months, and were assigned to one of three groups: sleep disorders that were treated (SD-Tx, n=21), sleep disorders remaining untreated (SD-NonTx, n=18) and no sleep disorder (NoSD, n=17). Results: FSS and MFI general and mental fatigue scores improved significantly from baseline to follow-up in SD-Tx ( p <0.03), but not SD-NonTx or NoSD subjects. ESS and PSQI scores also improved significantly in SD-Tx subjects ( p <0.001). Adjusted multivariate analyses confirmed significant effects of sleep disorder treatment on FSS (-0.87, p = 0.005), MFI general fatigue score ( p = 0.034), ESS (p = 0.042) and PSQI (p = 0.023). Conclusion: Treatment of sleep disorders can improve fatigue and other clinical outcomes in MS.