Christopher Hartnick, MD, MS, director of the Division of Pediatric Otolaryngology at Mass Eye and Ear, is the senior and corresponding author and Brian Skotko, MD, MPP , the director of the Down Syndrome Program and Emma Campbell Endowed Chair on Down Syndrome at Massachusetts General Hospital, is a co-author of a paper published in the International Journal of Pediatric Otorhinolaryngology, " Hypoglossal nerve stimulator for obstructive sleep apnea in children with down syndrome younger than 13 ."
Q: How would you summarize your study for a lay audience?
Sleep apnea, or difficulty breathing at night, is common among children with Down syndrome—affecting up to 80% compared to just 5% of the general pediatric population. Sleep apnea can negatively impact any child's ability to function and learn, but for children with Down syndrome who have neurocognitive differences, good sleep may be even more crucial to their development. Standard treatments like tonsil or adenoid removal are often less effective for these children due to anatomical differences including a larger tongue that can block the airway during sleep.
We recently demonstrated the safety and efficacy of a hypoglossal nerve stimulator —an implant that acts like a tongue pacemaker by moving it forward to open the airway when apnea occurs—for patients with Down syndrome between the ages of 13 and 21. That data contributed to the device being approved by the FDA for this age group.
Since early school years are a crucial period for development, our new research aimed to determine if this treatment is also safe and effective for younger children with Down syndrome, potentially allowing them to gain key neurocognitive benefits.
Q: What question were you investigating?
The primary questions our study addressed were around the hypoglossal nerve stimulator's safety and therapy response. Safety was assessed by the number of adverse events the children experienced, including from the surgery and device itself. We need to collect data that shows the procedure can be done safely in a 4-year-old who has different anatomy than an adult or teen who undergoes the surgery, or whether there are surgical challenges unique to this age group that prevent success.
Then we needed to know whether the treatment was effective. Therapy response was defined as a reduction in their obstructive apnea-hypopnea index (OAHI) by 50% or more. OAHI is a measure of the number of apnea events, or time a child stops breathing, per hour.
Q: What methods or approach did you use?
Our study was a retrospective review of 29 children between the ages of 4 and 13 who underwent hypoglossal nerve stimulator implant surgeries at two hospitals: Mass Eye and Ear and Phoenix Children's Hospital. The children who received the surgeries had sleep studies performed before surgery and then at 1 to 3 months, 6 months, 1 year, and 3 years after surgery.
The Mass Eye and Ear patients were treated and monitored as part of a collaborative, multidisciplinary team at Mass General Brigham including clinicians at Massachusetts General Hospital who specialize in Down syndrome and pediatric sleep medicine. Children with Down syndrome have unique care needs, and we find this multi-disciplinary care approach vital.
Q: What did you find?
We found that the hypoglossal nerve stimulator surgery was safe in all 29 children, with no serious adverse events. One child had a minor adverse event with surgical wound healing that was resolved. There were no adverse events related to the device itself.
The children in our study showed striking reductions in their sleep apnea events. At 6 months post-operation, more than 95% of the children had an OAHI reduction of more than 50% or more. Prior to surgery the median OAHI was more than 18 apnea events per hour, and after surgery the median was nearly 4 events. That's a tremendous difference.
Q: What are the implications?
This research has major implications, first being that the safety results can alleviate concerns about whether this procedure is possible in young children. There had been concerns about whether the safety of the implant remains as a child grows, and by tracking children for three years, we saw it remained stable.
Next, based on these safety and efficacy results, we feel this research provides data that the FDA can review to approve the treatment for younger children.
We also feel this research offers a message of hope to parents of young children with Down syndrome who have worried about their children's sleep apnea.
Q: What are the next steps?'
These findings will allow our team to submit grants to fund trials that answer the question of whether neurocognition improves more for children with Down syndrome, the younger they receive the treatment.
Following our trial in teens and young adults, we received a five-year-grant from the National Institutes of Health (NIH) to study neurocognition and language outcomes in teens over 10 years of age with Down syndrome who underwent the surgery. That study is ending soon. We want to conduct a similar study in children between 4 and 10 years old.
When we speak to parents across child and adolescent ages, we often hear positive feedback, like they no longer have to worry all night about their child's breathing, and that their child is thriving in school, having fewer mood swings and behavioral issues, and speaking better than ever. But we need the data to support these qualitative reports, and our hope is to receive funding to pursue such research.
Authorship: In addition to Hartnick and Skotko, Mass General Brigham authors include Minjee Kim, Lucy J. Xu, E'Ching Shih and Kevin S. Gipson.
Paper cited: Kim, M,, et. al. "Hypoglossal nerve stimulator for obstructive sleep apnea in children with down syndrome younger than 13." International Journal of Pediatric Otorhinolaryngology. DOI: 10.1016/j.ijporl.2025.112497
Disclosures: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
