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

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 ofenrollment

• Approval from at least two of the three physician reviewers based upon the resultsof a routine drug-induced sleep endoscopy (DISE) having occurred within 12 months ofenrollment

• Subjects must have either tracheotomy or be ineffectively treated with CPAP due tonon-compliance, discomfort, un-desirable side effects, persistent symptoms despitecompliance use, or refusal to use the device

• Children and their parents/guardians must be willing to have stimulation hardwarepermanently 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 theirchild is capable of communicating feelings of pain or discomfort. They must alsoconfirm they are able to assess their child for adverse effects related to deviceimplantation

• 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 heartfailure, recent open heart surgery, immunosuppression, or chronic lung disease oraspiration)

• Presence of another medical condition requiring future magnetic resonance imaging (MRI) of the chest

• Patients with another implantable device which could interact unintentionally withthe Inspire system

• Any contraindication for general anesthesia

• History of bleeding or clotting disorders and those on blood thinning or NSAIDmedications for the week prior to implantation surgery. Subjects will be asked torefrain from the use of NSAIDS for two weeks after implantation or any revisionsurgeries

• 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 testingprocedures 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