Redefining Success by Focusing on Failures After Pediatric Hypoglossal Stimulation in Down Syndrome

Advances in the Use of Hypoglossal Nerve Stimulator in Adolescents With Down Syndrome and Persistent Obstructive Sleep Apnea-A Systematic Review

INTRODUCTION

The Hypoglossal Nerve Stimulator (HNS) is a novel therapy that has been extensively studied in adults and more recently, it has been incorporated in children with Down Syndrome (DS) with persistent obstructive sleep apnea after adenotonsillectomy and trial of continuous positive airway pressure treatment. This systematic review article aims to examine the existing literature on HNS use in children to explore the benefits, efficacy, and parental experiences.

METHODS

MEDLINE, Web of Science and EMBASE were searched to include all studies published up to March 2nd, 2023, on the topic of HNS use in pediatric population under 21 years old.

RESULTS

A total of 179 studies were initially identified from which 10 articles were consistent with the inclusion criteria. Nine articles addressed outcomes after implantation of the HNS device in children with DS and 1 article explored the parental experiences. Findings were similar across studies where after implantation of HNS, there was marked improvement in polysomnographic outcomes and quality of life scores with high level of compliance.

CONCLUSIONS

HNS holds promise as an effective treatment option for pediatric patients with DS and persistent OSA after AT and CPAP trials. It significantly improves sleep-disordered breathing, quality of life, and neurocognitive measures, leading to substantial and sustained benefits for these children. While the findings are encouraging, further research is needed to explore the potential of HNS in other pediatric populations without DS and to raise awareness among healthcare providers about this treatment option. Overall, HNS may offer significant long-term benefits for the overall well-being and health of pediatric patients with DS and persistent OSA.

Hypoglossal nerve stimulation in adolescents with down syndrome and obstructive sleep apnea: A systematic review and meta-analysis

Objective

To evaluate the efficacy and adverse effects of hypoglossal nerve stimulation in adolescents with down syndrome and obstructive sleep apnea.

Methods

A systematic search was conducted using PubMed, Web of Science, Embase, and Scopus databases. The systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A comprehensive search strategy used a combination of Medical Subject Headings and free words with “OR” and “AND.” Articles were screened to extract data reporting apnea-hypopnea index, quality of life, voltage, follow-up duration, and complications. All included participants were adolescents with down syndrome and obstructive sleep apnea.

Results

A total of 92 articles were identified, of which 9 articles met the inclusion criteria. A total of 106 patients were included. All the studies showed that patients receiving hypoglossal nerve stimulation experienced a significant decrease in apnea-hypopnea index (at least 50%). The pooled AHI was significantly lower in patients following treatment (mean AHI reduction 17.43 events/h, 95% confidence interval 13.98–20.88 events/h, P < 0.001) after 2 case reports were excluded. The pooled OSA-18 were significantly decreased in 88 patients after treatment (mean OSA-18 reduction 1.67, 95% confidence interval 1.27–2.08, P < 0.001) after excluding 5 studies. Four investigations examined the necessity to optimize stimulation voltage for arousal during treatment. The most common complication was pain or discomfort in the tongue or mouth. Most studies had relatively short patient follow-up periods, with the most extended follow-up being 44–58 months.

Conclusion

Hypoglossal nerve stimulation significantly reduces apnea-hypopnea index and improves the quality of life; and thus, could be a potential alternative therapy for obstructive sleep apnea in adolescents with down syndrome. The adolescent's age, potential complications, adverse events, long-term efficacy, and comfort, needs to be considered while performing hypoglossal nerve stimulation.

Management of Pediatric Obstructive Sleep Apnea After Failed Tonsillectomy and Adenoidectomy

Pediatric obstructive sleep apnea (OSA) represents a different entity from its adult counterpart and therefore requires a different therapeutic approach. Adenotonsillectomy (AT) is the primary treatment of pediatric OSA, and evidence shows it is very effective. However, there is a growing understanding that residual OSA is common, and next steps for patients who fail primary AT are less certain. This article reviews current methods of evaluating and treating these complex patients.

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.

Aging with Down Syndrome-Where Are We Now and Where Are We Going?

Down syndrome (DS) is a form of accelerated aging, and people with DS are highly prone to aging-related conditions that include vascular and neurological disorders. Due to the overexpression of several genes on Chromosome 21, for example genes encoding amyloid precursor protein (APP), superoxide dismutase (SOD), and some of the interferon receptors, those with DS exhibit significant accumulation of amyloid, phospho-tau, oxidative stress, neuronal loss, and neuroinflammation in the brain as they age. In this review, we will summarize the major strides in this research field that have been made in the last few decades, as well as discuss where we are now, and which research areas are considered essential for the field in the future. We examine the scientific history of DS bridging these milestones in research to current efforts in the field. We extrapolate on comorbidities associated with this phenotype and highlight clinical networks in the USA and Europe pursuing clinical research, concluding with funding efforts and recent recommendations to the NIH regarding DS research.

Long-term stability of hypoglossal nerve stimulation for the treatment of obstructive sleep apnea in children with Down syndrome

IMPORTANCE

Obstructive sleep apnea (OSA) occurs in 55-97% of people with Down syndrome (DS). Even after adenotonsillectomy, residual OSA often persists into adulthood due, in part, to tongue base collapse. Implantable hypoglossal nerve stimulators are being investigated in children and young adults with DS and persistent, moderate to severe OSA. However, the long-term necessity for such an intervention-especially as patients mature and voltage adjustment becomes warranted-has not been previously reported in the pediatric DS population.

OBJECTIVE

To assess the long-term need for implantable hypoglossal nerve stimulators and the necessity for voltage adjustment in children and young adults with Down syndrome.

DESIGN

This is a case series from an ongoing clinical trial assessing safety and efficacy of hypoglossal nerve stimulation among 42 children and young adults with DS and persistent OSA, despite adenotonsillectomy and trialed positive airway pressure (PAP) therapy. We focus here on the first 4 participants who have undergone implantation by age 13 and have completed at least 44 months of follow-up.

PARTICIPANTS

4 participants (2 male, 2 female; ages 10-13 years) with DS and persistent, severe OSA (AHI > 10 events/h) underwent hypoglossal nerve stimulator implantation and were followed for 44-58 months.

SETTING

Participants completed in-lab sleep studies at baseline (before implantation), 1 year postoperatively, and 44-58 months postoperatively. During their most recent follow-up, 2 participants completed split-night sleep studies in which assessment was done with the device both on and off.

INTERVENTIONS

Hypoglossal nerve stimulator implantation.

MAIN OUTCOMES AND MEASURES

Stability in titrated and untitrated OSA as measured by the apnea-hypopnea index (AHI); growth measures including BMI; and quality of life as measured by the OSA-18 questionnaire.

RESULTS

Compared to baseline, all 4 participants maintained reductions of at least 50% in AHI over the course of follow-up. At recent follow-up, two participants had persistent, moderate OSA despite stimulation therapy. The other two participants achieved 100% reductions in AHI with stimulation therapy; when they underwent split-night sleep studies, the severe OSA persisted with the device turned off. Improvement in OSA-18 quality of life scores was observed in three of the four participants.

CONCLUSION

and Relevance: Hypoglossal nerve stimulation continues to effectively control OSA in children with DS as they mature, while their underlying untitrated OSA appears to persist into adulthood.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT2344108.