Loud snoring, growling, and gasping can be a sign of obstructive sleep apnea, a serious condition that causes repeated, short pauses of breath (apnea) throughout the night. It can make people sleepy and depressed, putting them at risk for: high blood pressure, heart disease and other health problems†
If this sounds like you or a bed partner, a recent spate of ads for mask-free treatment for the condition may have caught your eye. Known medically as a hypoglossal nerve stimulator, the pacemaker-like device moves the tongue forward during sleep. That helps reopen a collapsed airway — the cause of obstructive sleep apnea. But how does it compare to other treatments and who could be a good candidate?
A second-choice therapy for sleep apnea
Marketed under the name Inspire, the device was approved by the FDA in 2014. It is a second-choice therapy intended only for people who cannot tolerate positive airway pressure (known as PAP or CPAP), according to Dr. Rohit Budhiraja, a lung and sleep specialist at Harvard-affiliated Brigham and Women’s Hospital.
“Sleep apnea causes the muscles in the back of the throat to collapse, leading to pauses in breathing that wake you up again and again,” he says. PAP, the gold standard therapy for sleep apnea, prevents airway collapse by using a small bedside machine attached to a tube that blows air through a face mask.
This can improve a measurement called the Apnea Hypoxia Index (AHI) by about 90%, dropping it below 5 in most people. The AHI is a score that measures the severity of sleep apnea. An AHI between 5 and 14 is considered mild; between 15 and 29 is moderate; 30 and above is serious.
Targeting tongue muscles is less effective
Inspire only targets the muscles of the tongue rather than the entire airway, so it’s not as effective as PAP. In fact, the company’s stated treatment goal is to lower a person’s AHI by as little as 50% (or less than 20), although some people may do better.
Because PAP is more effective, sleep specialists encourage people to stick with it by trying different strategies† But research shows that a quarter to a third of people have trouble using PAP (see here and here† If so, Inspire may be an alternative, says Dr. Budhiraja.
Who Should Consider Hypoglossal Nerve Stimulation?
In addition to trying PAP unsuccessfully, you should also:
- have moderate to severe sleep apnea (an AHI score of 15 to 65)
- have a body mass index (BMI) of 32 or below (although some centers allow BMI values up to 35), meaning the device is not suitable for people in certain weight classes.
If you meet these criteria, you can ask your doctor for a referral to a sleep specialist or an ear, nose, and throat surgeon. The next step is sleep endoscopy. While you are sedated, a doctor will pass a tube with a light and a small video camera on one end through a nostril to examine your upper airway. Up to a quarter of people have a pattern of airway collapse that cannot be corrected with Inspire, notes Dr. Budhiraja on. And, as noted, others have too high an AHI score to try.
A surgical procedure requiring general anesthesia
The device is implanted during a short procedure performed on the same day under general anesthesia. A generator is placed just below the collarbone, a breath sensor on the side of the chest near the ribs, and a stimulation electrode around the hypoglossal nerve under the tongue.
As with all surgeries, potential risks include bleeding and infection. Some people experience tongue weakness, which can lead to slightly slurred speech and minor swallowing difficulties. But this usually goes away within a few days, or for most people, within a few weeks.
The device must be activated in a sleep lab one month after surgery. The respiratory sensor monitors your breathing and, if necessary, tells the generator a small electrical pulse to the electrode to cause the tongue muscles to contract. The stimulation moves your tongue forward so you can breathe normally.
How does it feel?
“Some people describe a slight tingling sensation, but most say the feeling is hard to describe,” says Dr. Budhiraja.
At home, you use a small remote control to switch the device on in the evening and off in the morning. The Remote Control is set to gradually increase the stimulation level once or twice a week, as tolerated, until you reach the highest level. You will then return to the sleep lab for an examination to determine your optimal range. The remote will then be programmed to that range.
Some people begin to notice a difference in their sleep quality, even at the lowest stimulation levels. After that, annual checks are recommended and the replaceable battery will last approximately 11 years. Medicare and most major insurance plans cover Inspire.
Once it works, hypoglossal nerve stimulation certainly comes in handy: no maintenance, cleaning, or buying supplies as required with a PAP machine. “But because Inspire is less effective, it’s not considered a replacement for PAP,” says Dr. Budhiraja.