Effects of Hypoglossal Nerve Stimulation on Cognition and Language in Down Syndrome and Obstructive Sleep Apnea

This study is a prospective, single-arm study conducted under a common implant and follow-up protocol. The objective will be to follow fifty-seven (57) adolescents and young adults (10-21 years of age), with Down syndrome, moderate to severe sleep apnea, and post-adenotonsillectomy, for 12 months after undergoing implant of the Inspire Upper Airway Stimulation (UAS) System. The study is being conducted in order to evaluate objective change in cognition and expressive language after implant and therapy with the Inspire UAS System.

Prior to implant subjects will be required to meet eligibility criteria, complete quality of life questionnaires and undergo neurocognitive testing (NCT) and expressive language sampling. Eligibility criteria will be determined via review of medical records, an in-lab polysomnography (sleep study), and a drug-induced sleep endoscopy (DISE).

After implant of the Inspire UAS System, subjects will undergo five (5) study visits. Four (4) of the visits will include an in-lab sleep study (PSG). Follow-up expressive language sampling and neurocognitive testing will be performed at 6 months post-implant. Follow-up quality of life questionnaires will be completed at 12 months post-implant.

Subjects will conclude their participation in the study at the end of their 12 month study visit.

Inclusion criteria

• Diagnosis of Down syndrome
• Age 10-21 years
• Prior adenotonsillectomy
• Severe OSA (AHI > 10, AHI < 50, no more than 25% AHI attributable to central events) based on prior in-lab PSG performed after adenotonsillectomy and within 18 months of enrollment
• Approval from at least two of the three physician reviewers based upon the results of a routine drug-induced sleep endoscopy (DISE) having occurred within 12 months of enrollment
• Subjects must have either tracheotomy or be ineffectively treated with CPAP due to non-compliance, discomfort, un-desirable side effects, persistent symptoms despite compliance use, or refusal to use the device
• Children and their parents/guardians must be willing to have stimulation hardware permanently implanted, and be willing to participate in follow-up visits, postoperative PSG, and questionnaire completion
• Children's parents/guardians must complete a questionnaire confirming that their child is capable of communicating feelings of pain or discomfort. They must also confirm they are able to assess their child for adverse effects related to device implantation
• Children and their parents/guardians must be proficient in English

Exclusion criteria

• Body mass index (BMI) above the 95th percentile for subject's age
• Circumferential airway collapse at the level of the velopharynx observed during DISE
• Other medical conditions resulting in medical instability (eg. congestive heart failure, recent open heart surgery, immunosuppression, or chronic lung disease or aspiration)
• Presence of another medical condition requiring future magnetic resonance imaging (MRI) of the chest
• Patients with another implantable device which could interact unintentionally with the Inspire system
• Any contraindication for general anesthesia
• History of bleeding or clotting disorders and those on blood thinning or NSAID medications for the week prior to implantation surgery. Subjects will be asked to refrain from the use of NSAIDS for two weeks after implantation or any revision surgeries
• Subject is currently taking muscle relaxant medication
• Life expectancy less than 12 months
• Subject's inability to communicate pain or discomfort to their caretaker/parent, based on parental or investigator assessment
• Nonverbal candidates will be excluded due to an inability to complete testing procedures including expressive language sampling
• Subjects with a co-occurring diagnosis of autism spectrum disorder
• Subjects that have a positive β-HCG
• Subjects deemed unfit for participation by the investigator for any other reason