Hypoglossal Stimulation Research Articles

The role of neuromuscular function in sleep apnea pathogenesis and management: A consensus of experts

Study objectivesAlthough the importance of upper airway assessment in the consideration of obstructive sleep apnea (OSA) is recognized, there are current limitations in our approach to assessment.MethodsWe convened a group of experts in upper airway neuromuscular physiology and anatomy, sleep apnea endophenotypes, novel therapeutics and sleep epidemiology to summarize existing literature and delineate future opportunities to utilize and incorporate innovative and less invasive techniques focused on upper airway neuromuscular physiology to assess and manage OSA.ResultsIn OSA, genioglossus electromyogram (EMG) activity is reduced during sleep onset with higher levels observed during wakefulness compared to controls. Surface EMG recordings are limited due to distance from the actual muscle and while needle EMG offers more direct assessment, this approach is more invasive. Novel alternatives overcoming these limitations to assess upper airway neuromuscular physiology in OSA may therefore prove beneficial. Specifically, such an approach would facilitate identification of upstream prognostic biomarkers of OSA clinical trajectory and offer more informative mechanistic data. Novel approaches to neuromuscular assessment in OSA would enhance phenotyping to predict better tolerance to positive airway pressure therapy and set the stage to target neuromuscular function and upper airway anatomy. A quantifiable and repeatable neuromuscular physiologic metric has potential to facilitate a precision medicine strategy and personalize treatment, including measuring treatment response to neurophysiologic-focused interventions including hypoglossal nerve stimulation (HGNS), myofunctional therapy and neuromuscular electrical stimulation. A key area for future investigation is whether observed neuromuscular changes can identify patients at future risk of OSA, facilitating early intervention or prevention strategies.ConclusionsOverall, recognizing the critical contributions of abnormalities of upper airway neuromuscular function to the pathophysiology of OSA, it may be important to find accurate and reproducible neurophysiological assessments to address existing knowledge gaps in OSA assessment and management.

Insomnia in Patients Undergoing Hypoglossal Nerve Stimulation Therapy for Obstructive Sleep Apnea.

Hypoglossal nerve stimulation (HGNS) is a treatment for obstructive sleep apnea (OSA) patients with intolerance of positive airway pressure therapy. Comorbid insomnia is quite prevalent in OSA patients. We investigated the impact of insomnia and excessive daytime sleepiness (EDS) on polysomnography metrics after HGNS treatment. Data of 27 consecutive patients (9 female; mean age 55.52 ± 8.6 years) were retrospectively evaluated. Insomnia was assessed using the ISI (insomnia severity index) and EDS using the Epworth sleepiness scale (ESS). The median ISI was reduced significantly 3 months after HGNS activation (preoperative: 19; postoperative: 14; p < 0.01). Significant correlations emerged between preoperative ISI and postoperative AHI (apnea/hypopnea index; Spearman's rho = 0.4, p < 0.05), ∆ AHI (r = -0.51, p < 0.01) and ∆ ODI (oxygen desaturation index; r = -0.48, p < 0.05). ISI correlated strongly with EES both preoperatively (r = 0.46; p < 0.02) and postoperatively (r = 0.79; p < 0.001). Therefore, HGNS therapy is associated with a significant reduction of insomnia-related symptoms, in addition to the improvement in respiratory metrics in OSA. Nonetheless, the preoperative severity of patient-reported insomnia symptoms was inversely correlated with the respiratory PSG-outcomes after HGNS. Insomnia should be considered in studies of EDS in OSA patients, especially those treated with HGNS.

Hypoglossal Nerve Stimulator Explantation Technique and Outcomes: A Retrospective Case Series

Introduction: Upper airway stimulation via the hypoglossal nerve stimulator (HGNS) implant is a surgical method for treating obstructive sleep apnea. However, patients may need the implant removed for a variety of reasons. The purpose of this case series is to assess surgical experiences with HGNS explantation at our institution. We report on surgical approach, overall operative times, operative and postoperative complications, and discuss relevant patient-specific surgical findings when removing the HGNS. Methods: We performed a retrospective case series of all patients that underwent HGNS implantation at a single tertiary medical center between January 9, 2021, and January 9, 2022. Subjects included adult patients who presented to the sleep surgery clinic of the senior author for surgical management of previously implanted HGNS. Patient clinical history was reviewed to determine the timing of the patient’s implant, reasons for explant, and postoperative recovery course. Operative reports were reviewed to determine overall duration of surgery and any associated difficulties or deviations from the general approach. Results: Between January 9, 2021, and January 9, 2022, 5 patients had an explantation of their HGNS implant. Explantation occurred between 8 and 63 months of their original implant surgery. The average operative time from incisional start time to close was 162 min for all cases with a range of 96–345 min. No significant complications were reported including pneumothorax and nerve palsy. Conclusion: This reported case series outlines the general steps for Inspire HGNS explantation as well as details the experiences in a case series of 5 subjects explanted over the year at a single institution. The results from the cases suggest that the explantation of the device can be performed efficiently and safely.

Otorhinolaryngology - New alternative treatments for obstructive sleep apnea at the CHUV: unilateral or bilateral hypoglossal nerve stimulation

Hypoglossal nerve stimulation is an alternative treatment for obstructive sleep apnea syndrome (OSAS) in patients intolerant to CPAP. The INSPIRE system (unilateral hypoglossal nerve stimulation) available since 2014 and the NYXOAH system (bilateral hypoglossal nerve stimulation) available since 2019 help to treat OSAS via activation of the genioglossus muscle causing protrusion of the tongue during sleep. We present in this article the two types of hypoglossal nerve stimulators through a recent review of the literature.

Supine Pharyngeal Width Is Associated With Complete Concentric Palatal Collapse During Drug-Induced Sleep Endoscopy and Hypoglossal Nerve Stimulator Outcomes.

Hypoglossal nerve stimulation (HNS) implantation in the US requires preoperative drug-induced sleep endoscopy (DISE) screening for complete concentric palatal collapse (CCC) to establish treatment candidacy. We hypothesized that supine pharyngeal width (SPW) in awake patients is associated with CCC and HNS therapy outcomes. Adults with moderate to severe obstructive sleep apnea underwent awake measurement of SPW followed by DISE screening for CCC. Eligible patients electing for HNS implantation underwent postoperative polysomnography per standard of care. SPW was measured in 73 patients. For SPW >20mm, the positive likelihood ratio for absence of CCC was 6.67 with pre- and post-test odds of 6.3 and 42.0, respectively. Postoperative PSG data were available from 31 of 44 (70.5%) patients subsequently implanted with HNS. Patients with SPW >20mm had a greater rate of HNS response than those with SPW ≤20 (62 vs 30%; P < .05). Only SPW and BMI were significantly associated with CCC and HNS response in regression models. In a retrospective cohort study, SPW was significantly associated with CCC and postoperative apnea-hypopnea index following HNS implantation. SPW may be a viable screening tool for HNS candidacy.

Moving toward standardization: physician reporting of sleep studies.

Lastra AC, Ingram D, Park J, etal. Moving toward standardization: physician reporting of sleep studies. J Clin Sleep Med. 2023;19(3):595-603.

Short-Term Outcome of Unilateral Inspiration-Coupled Hypoglossal Nerve Stimulation in Patients with Obstructive Sleep Apnea

Hypoglossal nerve stimulation (HGNS) is a therapeutic option for patients with obstructive sleep apnea (OSA) and intolerance of positive airway pressure (PAP) therapy. Most reported data are based on multicentre pivotal trials with selected baseline core clinical features. Our aim was to investigate polysomnography (PSG)-based outcomes of HGNS-therapy in a patient cohort with higher average AHI and BMI than previously reported. Data of 29 consecutive patients (nine female; mean age: 55.52 ± 8.6 years, mean BMI 30.13 ± 3.93 kg/m2) were retrospectively evaluated. Numerical values of PSG- based metrics were compared before and after intervention using Wilcoxon's rank-sum test. AHI (38.57/h ± 12.71, 24.43/h ± 13.3, p < 0.001), hypopnea index (24.05/h ± 9.4, 15.27/h ± 8.23, p < 0.001), apnea index (14.5/h ± 12.05, 9.17/h ± 10.86, p < 0.01), snoring index (262.68/h ± 170.35, 143.48/h ± 162.79, p < 0.001), cortical arousal index (20.8/h ± 10.34 vs. 14.9/h ± 8.36, p < 0.01) and cumulative duration of apnea and hypopnea during sleep (79.79 min ± 40.32 vs. 48.62 min ± 30.56, p < 0.001) were significantly lower after HGNS. HGNS provides an effective therapy option for selected patients not tolerating PAP-therapy with higher average AHI and BMI than usually reported. HGNS-therapy appears to suppress central nervous system arousal circuits while not eliciting peripheral autonomous sympathetic activation. Such metrics as the snoring index and the cumulative duration of respiratory events during sleep may be considered in future HGNS studies.

Persistent Treatment-Emergent Central Sleep Apnea (TECSA) Following Hypoglossal Nerve Stimulation.

Since 2001, hypoglossal nerve stimulators (HNS) have been used worldwide to treat patients with obstructive sleep apnea (OSA). Recently, a few studies reported treatment-emergent central sleep apnea (TECSA) with spontaneous resolution following HNS. However, the evidence of persistent development of TECSA during long-term care visits was lacking. As a result, this study first report two patients with persistent TECSA and describe their development phenotype during more than two years of follow-up visits to help explore the influencing factors and underlying mechanisms. This retrospective study included twenty-seven patients who underwent HNS implantation from 2016 to 2021. Their demographic data, pre- and postoperative sleep study characteristics, and device use settings were collected. The possible factors associated with post-operative elevated CSA (central apnea index ≥5) were evaluated. Moreover, the development phenotype of the TECSA was observed and followed up with a titration trial study. Among overall 27 patients with OSA, 3 patients with an increased preoperative Epworth Sleepiness Score (ESS) got an elevated CSA (CAI ≥ 5). Two of these 3 patients developed a persistent TECSA with a significant negative correlation between obstructive apnea index (OAI) and central and mixed sleep apnea index (CMAI) (R = -0.745, P = 0.021). These development phenotypes might be associated with different stimulation amplitudes of the HNS device. Furthermore, the following titration trial study also suggested that different amplitudes would influence the development of TECSA following HNS. OSA patients with severe daytime sleepiness are more likely to have elevated CSA following HNS. An inappropriate stimulation amplitude might influence the development course of TECSA in such patients.

Obstructive Sleep Apnea and Positive Airway Pressure Usage in Populations with Neurological Disease.

Obstructive sleep apnea (OSA) is characterized by repetitive episodes of complete or partial upper airway obstruction during sleep, with a worldwide estimate of 936 million sufferers. Treatments of OSA include continuous positive airway pressure (CPAP), weight loss, positional therapy, oral appliances, positive upper airway pressure, oro-maxillofacial surgery, hypoglossal nerve stimulation, and bariatric surgery, and others, with CPAP being the most commonly prescribed treatment. In this review, the neurologic conditions of stroke, cognitive decline, epilepsy, and migraines will be discussed as they relate to OSA. Additionally, the literature regarding improvement in these conditions following treatment with CPAP will be explored.

Cost-Effectiveness of Continuous Positive Airway Pressure Therapy Versus Other Treatments of Obstructive Sleep Apnea.

Obstructive sleep apnea (OSA) is a common disorder that is increasing in prevalence, both in the United States and worldwide. Continuous positive airway pressure (CPAP), the gold-standard treatment for OSA, is cost-effective from both a payer and societal perspective. Alternative treatments of OSA, including oral appliance therapy, various surgeries, and hypoglossal nerve stimulation have also been evaluated from a cost-effectiveness perspective although results are less consistent. Some studies directly compare these alternative therapies with CPAP. This review will discuss the available literature for cost-effectiveness analysis in the treatment of OSA.

PCR11 Quality of Life Analysis of Hypoglossal Nerve Stimulation with INSPIRE® Device in the Treatment of Patients With Obstructive Sleep Apnea Intolerant to Continuous Positive Airway Pressure Therapy

PCR11 Quality of Life Analysis of Hypoglossal Nerve Stimulation with INSPIRE® Device in the Treatment of Patients With Obstructive Sleep Apnea Intolerant to Continuous Positive Airway Pressure Therapy

PCR126 Patient-Reported Experience With Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea – Results From a Pilot Study in Germany

PCR126 Patient-Reported Experience With Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea – Results From a Pilot Study in Germany

OMS residents' obstructive sleep apnea-related education, knowledge, and professional behavior: A national survey.

Oral and maxillofacial surgeons (OMS) treat adult and pediatric patients with obstructive sleep apnea (OSA). Objective 1 assessed sleep apnea-related education, knowledge, and professional behavior of OMS residents in the United States. Objective 2 was to compare the responses of junior versus senior residents and residents in single- versus dual-degree programs. OMS residents in the United States received a recruitment email with a link to an anonymous online survey; 81 residents responded. The survey included 20 questions to assess respondents' OSA-related education, knowledge, attitudes, and professional behavior. Respondents generally agreed that they had received OSA-related didactic-based education (5-point scale with "5"=agree strongly: mean=3.62) and clinical training (mean=3.75). Clinical and classroom educational gaps were identified in relation to treatment with oral appliances and hypoglossal nerve stimulation. The residents scored on average 10.38 out of 18 (58%) possible correct answer pointsfor the knowledge questions. Findings about pediatric OSA suggest that only 43.8% of residents understand diagnostic criteria for pediatric OSA, with only 26.6% screening pediatric patients for OSA. A case analysis showed that only 1.5% of residents correctly identified an apnea-hypopnea index of 17 as moderate sleep apnea. This survey found knowledge gaps in several areas that can be improved upon. It identifies deficiency in objective knowledge about OSA among OMS residents and a specific lack of clinical training and confidence with hypoglossal nerve stimulation and management of pediatric patients with OSA. Junior and senior residents and single- and dual-degree residents showed no statistically significant differences in any category except senior residents in regard to surgical management of OSA, particularly with maxillomandibular advancement.

A Review of a Recent Meta-Analysis Study on Obstructive Sleep Apnea

This paper summarizes a recent meta-analysis of various topics in obstructive sleep apnea (OSA). In addition to cardiovascular disease and neurocognitive dysfunction, a wide variety of diseases have been associated with OSA, and associations with cancer have also been reported. Although continuous positive airway pressure is a very effective treatment, the results have shown that it does not reduce the incidence of various complications. It has been reported that uvulopalatopharyngoplasty was effective, and robotic surgery for the tongue root and hypoglossal nerve stimulation were also effective. The effectiveness of various medications to reduce daytime sleepiness has also been demonstrated. Although exercise lowered the apnea-hypopnea index, it was not related to changes in body composition, and it was also reported that exercise combined with weight control were effective. Additionally, interesting and clinically meaningful meta-analysis results were summarized and presented.

Caregiver knowledge of obstructive sleep apnoea in Down syndrome.

Down syndrome (DS) population has a very high prevalence of obstructive sleep apnoea (OSA), but this remains underdiagnosed. Hence, we aimed to evaluate caregiver's knowledge of OSA and related sociodemographic factors that could contribute to OSA screening patterns in this population. An online survey though the LuMind IDSC Foundation focused on OSA diagnosis, treatments and the number of sleep studies performed. Data were compared between subjects born before and after the American Academy of Pediatrics (AAP) recommendations for OSA screening. Of the caregivers, 724 (parents 96.3%), responded to the survey. The median [interquartile (IQR)] age of the subjects with DS was 12 [20;7] years. The majority (84.3%) had sleep apnoea diagnosis, and half of them were initially referred for a sleep study due to disturbed sleep symptoms. Only 58.7% of the responders were aware of the AAP recommendations. This was linked to higher socioeconomic and/or educational level and to an earlier OSA diagnosis. The median (IQR) age of OSA diagnosis was lowered after the AAP guidelines publication compared with before its publication (3 [4;2] years vs. 10 [18;5] years, P<0.000). Adenotonsillectomy (81.9%) and continuous positive airway pressure (61.5%) were the most commonly prescribed treatments. Few had discussed other new therapies such as hypoglossal nerve stimulation (16.0%). Only 16.0% of the subjects repeated the sleep study to monitor OSA with ageing, and 30.2% had to wait more than 4years between studies. This study reinforces the need to improve OSA knowledge of caregivers and clinicians of individuals with DS to promote an earlier diagnosis and optimal treatment of OSA in this population.

Surgical Treatment Options for Epiglottic Collapse in Adult Obstructive Sleep Apnoea: A Systematic Review.

The critical role of epiglottis in airway narrowing contributing to obstructive sleep apnoea (OSA) and continuous positive airway pressure (CPAP) intolerance has recently been revealed. This systematic review was conducted to evaluate available surgical treatment options for epiglottic collapse in adult patients with OSA. The Pubmed and Scopus databases were searched for relevant articles up to and including March 2022 and sixteen studies were selected. Overall, six different surgical techniques were described, including partial epiglottectomy, epiglottis stiffening operation, glossoepiglottopexy, supraglottoplasty, transoral robotic surgery, maxillomandibular advancement and hypoglossal nerve stimulation. All surgical methods were reported to be safe and effective in managing selected OSA patients with airway narrowing at the level of epiglottis. The surgical management of epiglottic collapse can improve OSA severity or even cure OSA, but can also improve CPAP compliance. The selection of the appropriate surgical technique should be part of an individualised, patient-specific therapeutic approach. However, there are not enough data to make definitive conclusions and additional high-quality studies are required.

Abstract 11871: Hypoglossal Nerve Stimulation as a Treatment for Sleep Apnea Does Not Lower Blood Pressure

Introduction: Obstructive sleep apnea (OSA) effects up to 30% of men and 15% of women in North America. Untreated, OSA is associated with the development of hypertension, heart failure, coronary artery disease, cardiac arrhythmia, and stroke. Treatment reduces these risks. The American Academy of Sleep Medicine outlines the first line treatment of OSA as continuous positive airway pressure (CPAP). However, many patients are unable to tolerate CPAP. One of the newest therapies approved in 2014 is implantation of a hypoglossal nerve stimulator (HNS) which functions by stimulating the tongue protrudor muscles to reduce upper airway obstruction. However, there is minimal research investigating HNS's effects on comorbidities. Currently there are two published studies showing improved blood pressure control and heart rate variability, but each study only included 46 patients. Several factors warrant a comparison including the lack of data, procedural risks, and procedural cost; especially, when considering the proven efficacy and low cost of CPAP. We present a retrospective analysis of blood pressure after HNS implantation. Hypothesis: We hypothesize that HNS implantation will improve blood pressure control. Methods: All cases of HNS implantation at MercyOne North Iowa Mason City, Iowa were retrospectively reviewed. Each case was manually reviewed for pre- and post-surgery blood pressure, heart failure exacerbations, arrhythmia, hemoglobin A1c, stroke, and acute coronary syndrome. Results: Fifty-nine patients had a mean change in blood pressure of +1.76 systolic and +0.76 diastolic with a standard error of 2.10 and 1.29 respectively. The mean follow-up time was 5.7 months after the fine-tuning sleep titration study. Five patients needed one less blood pressure medication and 6 patients needed one more. Preliminary regression analysis does not support gender, age, apnea-hypopnea index, or body mass index being predictive of change in blood pressure with HNS implantation. There was no statistically significant effect on other comorbidities. Conclusion: This study showed no clinically significant change in blood pressure after HNS implantation. Limitations include the small sample size and only one follow-up blood pressure.

Parental experience of hypoglossal nerve stimulator implantation in adolescents with Down Syndrome and obstructive sleep apnea

PurposeThe purpose of this study is to explore the experience of parents in deciding whether to participate in a clinical trial of the insertion of the Hypoglossal Nerve Stimulator (HNS) to treat their adolescent with Down Syndrome (DS) and Obstructive Sleep Apnea (OSA). Design and methodsA qualitative descriptive design with interviews was used to gather parental experiences from those who consented to HNS for their adolescent with DS and OSA. Interviews were conducted, audiotaped, and transcribed. Basic content analysis was followed to interpret the data. Using a process of data debriefing/engagement, codes were generated, and field/reflective notes were used to assure trustworthiness of the data. ResultsParents, 13 mothers/2 fathers, participated. Three themes were identified: Parents experience desperation about acceptance of standard of care for their adolescent with DS and OSA. This desperation led parents to seek information/insights from social media and they came to rely on those sites to explore options, ultimately leading them to HNS clinical trial. Finally, parents had a desire to share experience with HNS implantation. ConclusionsParents described being desperate at acceptance of standards of care for OSA. They shifted reliance on experts and parents by searching social media pages to explore options for treatment of OSA. Parents wished to share experiences with the HNS implantation. Practice implicationsNurses play a role in preparing for the HNS by instructing/educating parents. Nurses can identify supportive social media sites for parents during the HNS decision and suggest ways to measure outcomes of HNS.

Quality of Life Impact of Hypoglossal Nerve Stimulation with Inspire® Device in Patients with Obstructive Sleep Apnea Intolerant to Continuous Positive Airway Pressure Therapy.

Patients with obstructive sleep apnea (OSA) that do not tolerate/accept continuous positive airway pressure (CPAP) are candidates for surgical alternatives. Hypoglossal nerve stimulation (HNS) through the implantation of the Inspire® device constitutes a minimally invasive operative option. The main objective of this study is to estimate, under real-world clinical practice conditions, the 3-month impact on the quality of life (IQoL) of the HNS in patients with moderate/severe OSA who do not tolerate or accept CPAP, compared to patients who did not receive HNS. As a baseline, the unadjusted EuroQol utility index was 0.764 (SD:0.190) in the intervention group (IGr) and 0.733 (SD:0.205) in the control group (CGr); three months later, the indexes were 0.935 (SD: 0.101) and 0.727 (SD:0.200), respectively. The positive impact on quality of life was estimated to be +0.177 (95% CI: 0.044-0.310; p = 0.010). All dimensions in the IGr improved compared to CGr, especially for usual activities (p &lt; 0.001) and anxiety/depression (p &gt; 0.001). At the end of the follow-up, there was no significant difference in the quality of life between the general Spanish population and the IGr (difference: 0.012; CI95%: -0.03 to -0.057; p = 0.0578) for the same age range; however, there was a difference concerning the CGr (difference: -0.196; CI95%: -0.257 to -0.135; p &lt; 0.001). In conclusion, patients with moderate/severe OSA implanted with the Inspire® device showed a positive IQoL.

A Closed-Loop Approach to Fight Coronavirus: Early Detection and Subsequent Treatment.

The recent COVID-19 pandemic has caused tremendous damage to the social economy and people’s health. Some major issues fighting COVID-19 include early and accurate diagnosis and the shortage of ventilator machines for critical patients. In this manuscript, we describe a novel solution to deal with COVID-19: portable biosensing and wearable photoacoustic imaging for early and accurate diagnosis of infection and magnetic neuromodulation or minimally invasive electrical stimulation to replace traditional ventilation. The solution is a closed-loop system in that the three modules are integrated together and form a loop to cover all-phase strategies for fighting COVID-19. The proposed technique can guarantee ubiquitous and onsite detection, and an electrical hypoglossal stimulator can be more effective in helping severe patients and reducing complications caused by ventilators.