Every night, before he goes to sleep, Al Pierce, whose thunderous snoring used to drive his wife out of their bedroom, uses a small remote control to turn on an electronic sensor implanted in his chest. The sensor detects small changes in his breathing pattern—early signs that Pierce's airway is beginning to collapse on itself. When the device senses these changes, it triggers a mild jolt of electricity that travels through a wire going up his neck. The wire ends at a tiny electrode wrapped around a nerve that controls muscles in his tongue. The nerve, stimulated by the charge, activates muscles that thrust Pierce's tongue forward in his mouth, which pulls his airway open.
Throughout the night the 65-year-old plumber in Florence, S.C., gets hundreds of little jolts, yet he sleeps quietly. In the morning, rested and refreshed, Pierce uses the remote to turn off the device.
This new technology, called upper-airway electronic stimulation and approved by the U.S. Food and Drug Administration last summer, offers much more than relief from an annoying noise. Pierce's loud snoring was the most obvious symptom of obstructive sleep apnea, a drastically underdiagnosed disorder shared by an estimated 25 million Americans. It can lead to high blood pressure, heart disease, diabetes, depression and an impaired ability to think clearly. Overall, people with severe sleep apnea have triple the risk of death from all causes as compared with those without the disorder.
Yet help has not been easy for sufferers to find. One very effective option, a strap-on mask that gently pushes air into the throat to hold it open, is rejected by a great many of the people who try it because the device is uncomfortable. Other alternatives offer only mixed results. So a surgical implant and nerve stimulation, as extreme as it may sound, could be the answer for many. In a study published last January in the New England Journal of Medicine, the technique reduced episodes of severe apnea by about two thirds. The fda approval opens the door to insurance coverage for the treatment.
Doctors, for several reasons, have not been pushing to find apnea therapies. Patients tend not to bring serious apnea up with physicians as a problem, for one thing. And doctors may have their own reasons for treating the disorder lightly. “Sleep apnea is not on a death certificate,” says Patrick J. Strollo, Jr., a sleep specialist at the University of Pittsburgh Medical Center. “While it may contribute to death, it's not really a direct cause.” So, he says, “there is less urgency from primary care doctors and other doctors to address this problem.”
Pierce found out that he had apnea only because his wife, Gail, asked her doctor for a prescription for sleeping pills. He asked why, and Gail explained that she needed them because of her husband's snoring. About half of the people who snore loudly have sleep apnea, according to the National Sleep Foundation. The doctor told her that if things were that bad, her husband should come in for a sleep study: an overnight observation period during which various sensors are attached to a patient. The study revealed that Pierce was having as many as 30 apnea episodes an hour. Despite years of feeling tired all the time, he was stunned that he had an actual medical problem. “I thought that was the way everyone lived. I didn't know any different,” Pierce recalls.
Obstructive sleep apnea often develops when people age or put on extra weight. Fat narrows the tube of the airway, and the muscles in the mouth and throat also can lose their tone. When these muscles further relax during sleep, the airway becomes constricted and blocks the flow of air to the lungs. Some people with severe apnea stop breathing altogether, for up to a minute or two, as many as 600 times a night. This oxygen deprivation forces the heart to work harder and creates surges of adrenaline, which in turn cause blood pressure to spike. In addition, fluctuating oxygen levels can cause cell and tissue damage in the lungs and other organs.
Major interventions such as reconstructive throat surgery have often been ineffective. Physicians frequently recommend lifestyle-based changes such as losing weight and sometimes even playing the didgeridoo, a large Australian wind instrument that strengthens and tones the muscles of the tongue. Nose strips and generic mouthpieces, readily available over the counter, target snoring, the symptom, rather than sleep apnea, the underlying problem. The trouble is, what helps one patient may fail another completely. Plus, anything designed to go into the mouth or throat during sleep, to prop the airway open, can bother the patient and actually disrupt sleep. Any treatment has to be comfortable, easy to use and reliable.
Difficulty meeting all those criteria is what bedevils the strap-on mask, called CPAP, for continuous positive airway pressure. The oxygen mask covers the nose (or the nose and mouth) and is held in place by straps that wrap around the head. A small bedside pump delivers a steady flow of pressurized air to the mask through plastic tubing. The therapy, available since the early 1980s, almost guarantees relief from obstructive sleep apnea symptoms, and research shows that it lower rates of cardiovascular disease and death in patients who use it.
Use is the key: fully half of the people who try the mask abandon it. Pierce is one of them. “I was miserable,” he says. Like so many others, Pierce could not sleep easily while wearing something over his face, and he did not like the way the tubing restricted his movements in bed.
Strollo is a strong CPAP advocate but has long recognized the need for an alternative. Upper-airway electronic stimulation could be that option, he says. Strollo led a large study of the new treatment, a yearlong safety and efficacy trial involving 126 people with moderate to severe obstructive apnea. The participants all had a body mass index (BMI) of 32 or less (a man who is five feet, 10 inches in height and 223 pounds in weight has a BMI of 32), had tried CPAP first and had no history of cardiovascular disease. In last January's New England Journal of Medicine study, Strollo and his colleagues reported that the therapy, with a device made by Inspire Medical Systems, reduced subjects' sleep apnea events by 68 percent, from a median of 29.3 events an hour to nine an hour, basically turning severe apnea into a mild case. (CPAP, after adjustment, can do even better. It can cut the number of severe apnea events to fewer than five an hour, on average, but only in patients who stick with it.)
Alan R. Schwartz, a sleep specialist at Johns Hopkins University who did much of the early work on nerve stimulation—he showed in animals that jolting the tongue-controlling nerve would open their airway—says he is pleased but cautious. “We've still got a lot to learn,” he notes, pointing out that overweight and obese people, who make up a significant percentage of the obstructive apnea population, are not considered good candidates for the procedure because of their excess airway tissue.
What is more, stimulation involves an invasive procedure. The surgery to implant the device takes about two hours. A head and neck surgeon, working through an incision in the side of the neck, under the patient's jaw, places an electrode on the hypoglossal nerve, which controls the muscles of the tongue. The surgeon also puts a battery pack and a sensor in the chest and connects them to the electrode with a wire lead. The patient usually can go home a day later; the device is turned on and adjusted after a month.
Researchers are investigating more alternatives, such as medication. In a six-week trial involving 120 patients, David W. Carley, a physician at the University of Illinois at Chicago, is testing a drug called dronabinol, which is a synthetic version of an active compound in marijuana. He is comparing people who get the drug with those who do not. Dronabinol may prevent or reduce sleep apnea episodes by stimulating certain neurotransmitter activity in the brain. Other researchers are looking at the role played by leptin, a hormone that suppresses appetite and may improve respiratory function. A small study of 26 obese subjects with BMIs greater than 45 suggests that certain levels of leptin may minimize upper-airway collapse.
Schwartz is also trying to modify the stimulation technique, testing a device that eliminates the sensor. Instead it sends a repeated charge to the nerve in the tongue during the night to keep the airway open. This refinement should simplify the surgery and reduce parts that could fail, Schwartz says.
Pierce, however, is quite happy with the system he has. When he is awake—or quietly sleeping—he does not even notice it.