Treatment of Comorbid Obstructive Sleep Apnea by Upper Airway Stimulation Results in Resolution of Debilitating Symptoms of Restless Legs Syndrome

Impact of continuous positive airway pressure therapy on restless legs syndrome in patients with coexistent obstructive sleep apnea: A qualitative systematic review

INTRODUCTION

Obstructive sleep apnea (OSA) is characterized by repetitive episodes of complete or partial upper airway collapse during sleep. Restless legs syndrome (RLS) is a sleep-related movement disorder characterized by an uncomfortable urge to move the legs, especially during inactivity and evenings. Both OSA and RLS are common with significant overlap: RLS is present in up to 36% of those with OSA. Treatment of OSA with continuous positive airway pressure (CPAP) therapy may influence RLS outcomes. We performed a systematic review to evaluate the impact of CPAP therapy on RLS symptoms and RLS medication usage in individuals with both OSA and RLS.

METHOD

A comprehensive literature search was conducted in MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews from inception to December 7, 2024. The outcomes of interest were the improvement in RLS symptom severity, as measured by standardized scales such as the International RLS Study Group RLS Severity Scale (IRLS), and changes in the usage of RLS medications. The review included clinical trials and observational studies. Inclusion criteria were: studies with a control group or comparison period before CPAP usage, adult participants diagnosed with OSA and RLS, measurements of RLS severity using standardized scales such as the IRLS, and reports on medication usage before and after CPAP therapy. Data extraction included study characteristics, participant demographics, exposure and outcome measurements, and adjusted effect estimates. Exclusion criteria included non-primary research articles such as reviews, editorials, commentaries, letters, studies without standardized assessments of RLS symptoms, and non-English articles. The quality of included studies was assessed using the Newcastle-Ottawa Quality Scale (NOS), and the risk of bias was evaluated using the ROBINS-I tool. The systematic review was registered in PROSPERO (ID: CRD42024550240).

RESULTS

The search identified 2,046 articles, with 291 undergoing full-text review, and three studies (3 observational, 0 RCTs) meeting the inclusion criteria, which included 479 patients. CPAP therapy was associated with improvements in RLS symptoms and a reduction in medication usage among patients with coexistent RLS and OSA. The magnitude of these effects varied, with some studies reporting significant improvements while others showed probable changes. The variability in results can be attributed to differences in study designs, sample sizes, and adjustments for confounding factors. These factors highlight the need for more rigorous research to evaluate the benefits of CPAP therapy in patients with coexistent RLS and OSA.

CONCLUSION

CPAP therapy appears beneficial for improving RLS symptoms and reducing medication usage in patients with coexistent OSA and RLS. However, further research with standardized diagnostic and treatment criteria, larger sample sizes, and robust adjustment for confounding factors is necessary to confirm these findings and better understand the underlying mechanisms.

The Effect of Mindfulness-Based Stress Reduction on Restless Legs Syndrome in Hemodialysis Patients: A Randomized Clinical Trial

Background: There is currently no definitive cure for restless legs syndrome (RLS), and the common treatments are only used to reduce symptoms. Mindfulness-based stress reduction (MBSR) is an intervention that has shown beneficial effects in many mental and physical disorders.Purpose: This study aimed to determine the effect of MBSR on RLS in hemodialysis patients.Methods: This study was a randomized clinical trial involving 60 hemodialysis patients with RLS recruited by convenience sampling each group. Inclusion criteria were patients with RLS diagnosis, age 18-65, Hb>10, no cognitive disorders, ability to read and write, no vision or hearing problems, and history of hemodialysis ≥6 months. The intervention group received eight sessions of the MBSR program, and the control group received routine care in a government dialysis center. International Restless Legs Syndrome Scale and Restless Legs Syndrome Severity Scale were used to measure RLS. Statistical analyses were conducted using independent and pair t-test and ANCOVA.Results: Significant difference was found in the severity the RLS (Mean(SD) score) between the intervention group (12.90(4.58)) and the control group (22.27(4.19)) (95% CI:-11.66 to -7.08, p<0.0001). The effect size between groups was obtained based on Cohen’s d of 2.13.Conclusion: MBSR showed a significant reduction in the severity of RLS in hemodialysis patients. This preliminary study suggests that MBSR can be a promising treatment option in the management of RLS patients.

Sleep microstructure and clinical characteristics of patients with restless legs syndrome

STUDY OBJECTIVES

Restless legs syndrome (RLS) is a sleep-related movement disorder, often accompanied by sleep disruption. Obstructive sleep apnea (OSA) has a controversial prevalence among patients with RLS. We evaluated the clinical and sleep features of patients who attended our sleep clinic considering RLS and OSA.

METHODS

In this cross-sectional study, we obtained health records of 1,497 patients during 2015-2019 who underwent polysomnography (PSG). Baseline characteristics, sleep-related and RLS questionnaires, and sleep microstructure were assessed. Descriptive and analytical assessments were performed. RLS was assessed according to the International Restless Legs Syndrome Study Group criteria.

RESULTS

RLS was found in 19.4% of patients, with more prevalence among women (26.9% vs 16.4%). RLS affected 19.1% of patients with OSA. Patients with RLS were significantly older with higher insomnia and depression and worse PSG results. As the respiratory disturbance index increased, the odds of RLS slightly decreased (adjusted odds ratio [95% confidence interval]: 0.80 [0.67-0.94]). The odds of OSA (respiratory disturbance index ≥ 5) was not affected by RLS. OSA in patients with RLS was significantly associated with a higher limb movement index. RLS in patients with OSA was significantly associated with higher insomnia, depression, and limb movement index (men and women), higher wake after sleep onset and percentage of N1 sleep (men), and lower sleep efficiency (men).

CONCLUSIONS

Patients with RLS had worse PSG results, higher insomnia, and depression. Although men with OSA+/RLS+ had worsened PSG results, PSG parameters in women with OSA+/RLS+ did not differ from the OSA+/RLS- group. Patients with either OSA or RLS should be evaluated for possible comorbidities, including insomnia and depression. Notably, sex-specific characteristics need more consideration in sleep clinics.

CITATION

Amirifard H, Jameie M, Akbarpour S, et al. Sleep microstructure and clinical characteristics of patients with restless legs syndrome. J Clin Sleep Med. 2022;18(11):2653-2661.

Hypoglossal Nerve Stimulation Therapy

Hypoglossal nerve stimulation (HNS) has been shown to be a safe alternative in the treatment of moderate-to-severe obstructive sleep apnea (OSA). A recent meta-analysis of 12 studies by Costantino et al. indicated the surgical success rates at 55-75%, a reduction of the apnea hypopnea index (AHI) of 18 events/h, and a reduction of the Epworth Sleepiness Scale (ESS) of 2.9-5.3. After animal studies in the 1970s, the first trial on humans to decrease upper airway resistance by transcutaneous electrical stimulation of the genioglossus was reported in 1989. A separate stimulation of protruding and retracting muscles was realized in 1995 by fine-wire electrodes that were placed into the tongue transoral. Over the next years, several companies developed implantable devices for hypoglossal stimulation in OSA. Initially, devices were developed that used unilateral stimulation of the hypoglossal nerve. In 2014, a device for unilateral respiratory frequency-controlled hypoglossal stimulation finally received FDA approval after a successful phase III trial. In recent years, a device for bilateral breath rate-independent stimulation of the hypoglossal nerve has been added to these approaches as a new development. Accordingly, hypoglossal nerve stimulation, on the one hand, is now an established tool for patients with OSA when standard treatments are not satisfactory. Beyond that, hypoglossal stimulation is undergoing a continuous and impressive development like hardly any other field of surgical therapy for OSA.

Current Management of Residual Excessive Daytime Sleepiness Due to Obstructive Sleep Apnea: Insights for Optimizing Patient Outcomes

Although excessive daytime sleepiness (EDS) attributable to obstructive sleep apnea (OSA) can be resolved by consistent usage of and effective treatment (often with the use of continuous positive airway pressure therapy), 12–58% of patients report residual EDS (REDS). While REDS is difficult to treat, a proportion of cases are possibly due to reversible issues, and wake-promoting medications can prove useful for the remaining cases. Given the challenges associated with effective management of REDS and its relationship to multiple comorbidities, multidisciplinary management of patients with REDS is often recommended. Here we aim to bridge the knowledge gap on the burden, risk factors, prevalence, and potential pathophysiologic mechanisms of REDS in patients with OSA after first-line treatment. The roles of primary care physicians and sleep specialists, as well as the importance of the use of objective assessment tools for the evaluation of REDS and the effective management of comorbidities, are discussed. An update of approved treatments and emerging candidate treatments is also presented.

Update on Persistent Excessive Daytime Sleepiness in OSA

OSA is a highly prevalent sleep disorder, and subjective excessive daytime sleepiness (EDS) is the cardinal symptom for which many individuals seek medical advice. Positive airway pressure (PAP) devices, first-line treatment for OSA, eliminates EDS in most patients. However, a subset of patients suffers from persistent EDS despite adherence to therapy. Multiple conditions, some reversible, could account for the residual sleepiness and need to be explored, requiring detailed history, review of PAP data from the smart card, and sometimes additional testing. When all known causes of EDS are excluded, in adequately treated subjects, the purported mechanisms could relate to long-term exposure to the OSA-related sleep fragmentation, sleep deprivation, and hypoxic injury to the arousal system, shifts in melatonin secretion, or altered microbiome. Independent of the mechanism, in well-treated OSA, pharmacological therapy with approved drugs can be considered. Modafinil is commonly prescribed to combat residual EDS, but more recently two drugs, solriamfetol, a dual dopamine-norepinephrine reuptake inhibitor, and pitolisant, a histamine H3 receptor inverse agonist, were approved for EDS. Solriamfetol has undergone randomized controlled trials for treatment of EDS associated with both OSA and narcolepsy, exhibiting robust efficacy. Solriamfetol is renally excreted, with no known drug interactions. Pitolisant, which is nonscheduled, has undergone multiple RCTs in narcolepsy, showing improvement in subjective and objective EDS and one OSA trial showing improvement in subjective EDS.

Impact of Positive Airway Pressure on International Restless Legs Syndrome Score in Sleep Disordered Breathing

Study Objective: Studies have shown increased prevalence of restless legs syndrome (RLS) in sleep disordered breathing (SDB), however limited data have focused on the impact of SDB therapy on RLS. We hypothesize that positive airway pressure (PAP) will improve the International Restless Legs Syndrome (IRLS) score among SDB patients compared to patients without PAP. Methods: Patients with AHI ≥ 5 who responded positively to a RLS qualifier question from January 2010 to May 2015 were included in this retrospective study. IRLS score was used to measure RLS symptom severity. Two-sample t-tests and one-way analysis of variance were used to compare changes in IRLS score and linear regression models were created to examine IRLS change with PAP use and PAP adherence (PAP usage ≥4 h nightly for ≥70% of nights), adjusting for potential confounders. Results: In 434 patients (51.9 ± 13.4years, 50.5% female, 77.6% Caucasian; 325 PAP, 109 control), IRLS scores improved from baseline to follow-up, with the PAP group achieving significant improvement after adjustment for covariates (difference in IRLS: −1.8 (CI −3.6,0.00), p = 0.050). In self-reported PAP adherent patients, IRLS improvement was greater than controls (−5.3 ± 7.4 vs. −2.7 ± 7.6 respectively, p = 0.045), and comparable to non-adherent patients (−5.3 ± 7.4 vs. −3.0 ± 7.0, p = 0.091). Conclusions: Among SDB patients with a positive RLS qualifier, those who used PAP therapy achieved significantly greater improvement in IRLS scores than patients who did not use PAP, with more significant changes in the PAP adherent group. This is the first large clinical study to examine these relationships, providing a basis for future prospective interventional trials and informing clinicians of expected improvement in IRLS score in PAP treated SDB populations.