Study Purpose: This research looks at how a treatment called the Inspire Upper Airway Stimulation (UAS) System helps young people with Down syndrome and sleep apnea. Sleep apnea causes breathing to stop and start during sleep. The study checks if the treatment helps thinking skills (cognition) and speaking abilities.

What Will Happen: 57 young people aged 10-21 will have a small device implanted to help with breathing. They will be monitored for one year. Participants will need to visit the lab five times and do sleep studies and language tests. Before the implant, they will answer questions about their life and take tests. After the implant, they will have more tests at 6 and 12 months.

Eligibility: Participants must have Down syndrome, be aged 10-21, and have had their tonsils removed. They must have severe sleep apnea and be unable to use other treatments. Parents and children must speak English and agree to visits and tests.

• Study lasts for 12 months with 5 visits.
• Participants must be okay with having a small device implanted.
• Participants will not be able to join if they have other major health issues.