Vol 11 Issue 5, October 2002
Full text and pictures available at http://www.aafp.org/afp/991115ap/2279.html
LYLE D. VICTOR, M.D.
Oakwood Hospital, Dearborn, Michigan
O
bstructive sleep apnea is a disorder in which complete or partial obstruction of the airway during sleep causes loud snoring, oxyhemoglobin desaturations and frequent arousals. As a result, affected persons have unrestful sleep and excessive daytime sleepiness. The disorder is associated with hypertension, impotence and emotional problems. Because obstructive sleep apnea often occurs in obese persons with comorbid conditions, its individual contribution to health problems is difficult to discern. The disorder has, however, been linked to angina, nocturnal cardiac arrhythmias, myocardial infarction, stroke and motor vehicle crashes.Even though obstructive sleep apnea is fairly common, it often remains undiagnosed in primary care practice. Because the disorder is associated with significant morbidity and even some mortality, family physicians need to be familiar with its clinical presentation and treatment.
Pathophysiology
Obstructive sleep apnea is caused by repetitive upper airway obstruction during sleep as a result of narrowing of the respiratory passages. Patients with the disorder are most often overweight, with associated peripharyngeal infiltration of fat and/or increased size of the soft palate and tongue. Some patients have airway obstruction because of a diminutive or receding jaw that results in insufficient room for the tongue. These anatomic abnormalities decrease the cross-sectional area of the upper airway. Decreased airway muscle tone during sleep and the pull of gravity in the supine position further decrease airway size, thereby impeding air flow during respiration.
Initially, partial obstruction may occur and lead to snoring. As tissues collapse further or the patient rolls over on his or her back, the airway may become completely obstructed. Whether the obstruction is incomplete (hypopnea) or total (apnea), the patient struggles to breathe and is aroused from sleep. Often, arousals are only partial and are unrecognized by the patient, even if they occur hundreds of times a night. The obstructive episodes are often associated with a reduction in oxyhemoglobin saturation.
With each arousal event, the muscle tone of the tongue and airway tissues increases. This increase in tone alleviates the obstruction and terminates the apneic episode. Soon after the patient falls back to sleep, the tongue and soft tissues again relax, with consequent complete or partial obstruction and loud snoring.
Cycles of sleep, snoring, obstruction, arousal and sleep occur throughout the night. Some patients with severe apnea may have episodes of upper airway obstruction a hundred or more times in one hour. Multiple arousals with sleep fragmentation are the likely cause of excessive daytime sleepiness in patients with obstructive sleep apnea.Patients often complain of unrestful sleep and sometimes lament that they are sleepier in the morning than when they go to bed at night.
Sites of Airway Obstruction
Airway obstruction can occur in many areas of the nasopharynx, oropharynx and
hypopharynx. Although the contribution of nasal polyps and septal deviation to
obstructive sleep apnea remains controversial, some investigators believe that
partial or total nasal obstruction can lead to hypopnea and apnea.
More commonly, airway obstruction occurs in the oropharynx. Redundant peripharyngeal tissue reduces the size of the posterior airway, which increases the chance of obstruction during sleep. An elongated soft palate and enlarged uvula may further compromise the airway. As mentioned previously, decreased muscle tone during sleep also contributes to airway collapse.
The base of the tongue is a common site of hypopharyngeal obstruction in sleep apnea. Patients with a small or receding jaw are at increased risk for obstruction. Occasionally, obstruction may be caused by an enlarged tongue. In this setting, obstruction occurs when the base of the tongue impinges on the airway just above the glottis.
Prevalence and Characteristic Features
Obstructive sleep apnea is more common than was previously thought. Reported prevalence rates vary widely, and asymptomatic sleep apnea is more common than symptomatic, clinically significant obstructive sleep apnea. Population-based studies suggest that 2 percent of women and 4 percent of men over the age of 50 years have symptomatic obstructive sleep apnea.
Considering the prevalence rates, most family physicians probably have a number of patients with undiagnosed sleep apnea. The way to find these patients is to be aware of the common signs and symptoms of obstructive sleep apnea and to carefully examine any patient who complains of snoring or daytime sleepiness. Because the patient is often unaware of the nocturnal arousals, it may be helpful to have the bedroom partner also complete the questionnaire.
Typical Obstructive Sleep Apnea
The patient with obstructive sleep apnea is often brought to the physician's
office by a family member or bedroom partner who is being disturbed by the
patient's loud snoring. The bedroom partner may describe episodes in which the
patient stops breathing and then gives a loud gasp or snort when aroused by the
apnea. The snoring and apneic episodes may be worse after the patient drinks
alcohol or takes sleeping pills, because these sedatives decrease pharyngeal
muscle tone and can exacerbate obstructive sleep apnea.
Daytime fatigue and sleepiness are the most significant complaints of the patient with obstructive sleep apnea. Frequently, the patient falls asleep during sedentary activities, such as watching television or sitting in a movie theater. Near-miss automobile crashes may occur because the patient dozes off behind the wheel.
As daytime sleepiness becomes more excessive, the patient may report falling asleep in embarrassing situations, such as during meals or when sitting in a car stopped at a traffic light. The patient also complains of being tired on awakening in the morning. The patient often has to nap during the day but typically wakes up unrefreshed.
Many patients with obstructive sleep apnea have lower-face abnormalities,
which may include a small chin, maxilla and
mandible, as well as a large tongue. These findings may not be obvious in some
patients, but a receding jaw with 2 mm or more of overbite resulting in a
prominent mental cleft or curling of the lower lip may be more readily discerned
by the family physician.
Uncommon Causes
Occasionally, obstructive sleep apnea can be caused by less common medical
problems, including hypothyroidism, acromegaly and renal failure. Neuromuscular
disorders such as postpolio syndrome can result in inadequate neuromuscular
control of the upper airway and lead to obstructive sleep apnea. Restrictive
lung disease from scoliosis has also been associated with the disorder.
Laboratory Testing
Nocturnal polysomnography is the gold standard for diagnosing obstructive sleep
apnea. In this technique, multiple physiologic parameters are measured while the
patient sleeps in a laboratory. Typical parameters in a sleep study include eye
movement observations (to detect rapid-eye-movement sleep), an
electroencephalogram (to determine arousals from sleep), chest wall monitors (to
document respiratory movements), nasal and oral air flow measurements, an
electrocardiogram, an electromyogram (to look for limb movements that cause
arousals) and oximetry (to measure oxygen saturation). Apneic events can then be
documented based on chest wall movement with no air flow and oxyhemoglobin
desaturations.
Medical Complications
Cardiovascular disease is common in patients with obstructive sleep apnea. Hypertension and obesity increase the risk of cardiac disease and are frequent findings in patients with this sleep disorder. Although hypertension is the best documented cardiovascular condition in obstructive sleep apnea, some studies have shown that patients with the disorder are also at increased risk for cardiac arrhythmias, including severe bradycardias, during apneic episodes. Furthermore, the prevalence of angina and myocardial infarction is increased in patients with apnea. Obstructive sleep apnea has been shown to cause dilated cardiomyopathy, which is reversible with successful treatment of the sleep disorder.
Patients with sleep apnea who are smokers may also have coronary artery disease and obstructive airway disease. More severe oxyhemoglobin desaturations occur during apneic episodes in patients with both sleep apnea and chronic obstructive pulmonary disease. In some patients, repetitive severe nocturnal desaturations may lead to persistent pulmonary hypertension and right-sided heart failure (cor pulmonale).
Cerebrovascular diseases may also be more prevalent in patients with obstructive sleep apnea. One large population-based study found an increased incidence of cerebral infarction in patients with habitual snoring. Another study reported an increased number of strokes in patients who had obstructive sleep apnea.
Psychosocial problems are common in patients who have sleep apnea. These patients often have depression, mood changes, poor memory, irritability and impaired concentration. Nocturnal panic attacks have also been associated with sleep apnea.
Nonsurgical Approaches
Weight loss is the simplest treatment for obstructive sleep apnea in obese
patients. Even a modest 10 percent weight loss may eliminate apneic episodes by
reducing the mass of the posterior airway. Unfortunately, however, this
treatment option is usually not successful because only a small fraction of
people can permanently lose weight. Moreover, success may be limited if patients
also have anatomic deficits in the jaw.
CPAP treatment is used in most patients who have obstructive sleep apnea. With CPAP, the patient wears a snugly fitting nasal mask attached to a fan that blows air into the nostrils to keep the airway open during sleep. Because most people sleep with their mouth closed, the mouth usually does not have to be covered, but a chin strap can be used if necessary.
Sneezing and rhinorrhea are mild but common complications of CPAP but can usually be alleviated with steroid nasal sprays. Some patients develop dry mucus membranes from the continuous positive air flow. This problem may be reduced by humidification. Another frequent problem is dermal irritation from the mask rubbing the face. Dermal irritation is most commonly reduced by changing the mask size or trying a different kind of mask.
Perhaps the biggest problem with CPAP therapy is noncompliance. Frequently, patients use the machine for only a few hours a night or a few days a week. Sneezing, nasal discharge and dryness sometimes result in noncompliance, but CPAP failure may also be caused by perceived discomfort, claustrophobia and panic attacks. Patients with more severe apnea and debilitating daytime sleepiness are often more compliant, because they are motivated by the prompt reversal of their symptoms. The cost of a CPAP machine is substantial (usually around $1,000) but is covered by most insurance carriers.
Tongue-retaining devices or bite guards can be used to bring the lower jaw forward and thereby alleviate posterior airway obstruction during sleep. These devices are not as consistently successful as CPAP treatment, but they may be useful in selected patients with mild sleep apnea who cannot tolerate CPAP13 or do not want to undergo surgery. Tongue-retaining devices may also be of some use in patients who snore heavily but do not have significant apnea.
An early study indicated that oxygen therapy was somewhat beneficial in reducing the frequency of apneic episodes and the incidence of apnea-induced bradycardia. These results were not borne out in later studies.
Surgical Treatments
Younger patients and those who cannot tolerate CPAP may be candidates for
surgical intervention to alleviate obstructive sleep apnea.
Uvulopalatopharyngoplasty (UPPP) involves the removal of part of the soft
palate, uvula and redundant peripharyngeal tissues, sometimes including the
tonsils. This procedure is often effective in eliminating snoring; however, it
is not necessarily curative for obstructive sleep apnea, because areas of the
airway other than the soft palate also collapse in most patients with this sleep
disorder. Patients who undergo UPPP must be hospitalized for a few days.
Furthermore, they may experience the annoying complication of nasal
regurgitation of liquids following the removal of palatal tissues.
Laser-assisted uvulopalatoplasty (LAUP) can be performed in a series of office treatments and thus has become more popular than UPPP in recent years. The clinical indications for this procedure, as well as its effectiveness, have not yet been clearly defined. Some sleep experts recommend the use of LAUP in patients who have snoring and mild apnea or patients who have no significant apnea but want to alleviate snoring.
Gastric surgery might be a consideration in some morbidly obese patients with obstructive sleep apnea. How weight loss causes a lessening of apnea is not clear, but it is presumably through a reduction in the adipose level of parapharyngeal tissues.
Jaw surgery is the most invasive surgical procedure used to treat obstructive sleep apnea. Patients who have a small, retrognathic mandible and have failed more conservative treatments may be candidates for this approach. The surgical procedure may be limited to pulling the tongue forward (genioplasty). An extensive procedure may entail moving both the mandible and maxilla. Extensive jaw surgery has a higher complication rate and a longer recovery time.
In noncompliant patients with extremely severe apnea, tracheostomy may be considered. Because of its high associated morbidity, this procedure is now seldom used.
The Author
LYLE D. VICTOR, M.D.,
is director of the sleep disorders center at Oakwood Hospital, Dearborn, Mich.,
where he is also program director of the transitional-year residency program. In
addition, he serves as clinical associate professor of medicine at the
University of Michigan Medical School, Ann Arbor, and the Wayne State University
School of Medicine, Detroit. Dr. Victor received his medical degree from Mount
Sinai School of Medicine of the City University of New York.
Address correspondence to Lyle D. Victor, M.D.,
Department of Medical Education
Oakwood Hospital
18101 Oakwood Blvd.
Dearborn, MI 48124.
Reprints are not available from the author.
Sometimes it's important to work for that pot of gold. But other times it's essential to take time off and to make sure that your most important decision in the day simply consists of choosing which color to slide down on the rainbow.
~Douglas Pagels, These Are the Gifts I'd Like to Give to You
Circle of Friends
David Ege, M.D.
Mary,
I just finished the last issue of CLSF news. By publishing these particular articles together, are you raising the question of sleep apnea as a cause of cardiomyopathy? Certainly they go together. Do the published articles you cite mention the possibility of chronic hypoxia as a cause of the cardiomyopathy? Is it possible that (once again) you have found something that, if addressed appropriately, could improve the lives of many CLS kids and their families? This topic has been of interest to me for a while. I studied the effects of hypoxia on rats' hearts in Medical School. (Yes, they had rats back then.) It will be interesting to review the articles you quote.
I cried when I read the story of Gabrielle. Thanks for the reminder of what a huge responsibility I have to people. I try not to take it lightly, but get selfish sometimes.
Once again, you letter has been one of the most informative and motivating professional journals I read each month.
Dave Ege
Thank you so much. That means a lot to me. According to Dr. Loube of the Swedish sleep center, there is definitely a correlation between apnea and congestive heart failure due to the fact that an otherwise normal heart has to work so much harder. He did not mention cardiomypathy specifically. According to what I found at http://www.ninds.nih.gov/health_and_medical/disorders/anoxia_doc.htm, hypoxia (chronic oxygen deprivation)can cause all kinds of nasty symptoms that we've seen in CLS kids. I don't know that we have enough evidence to say that there is a correlation, but it certainly looks suspicious. I was hoping that maybe Davis's drop attacks would improve when he got on the bi-pap, but I haven't noticed any improvement there yet. If anything, they have been worse in the last week, but he has natural fluctuations in frequency and severity, so it's just too soon to tell. I should add Dr. Loube to my mailing list. Maybe he'd like to get involved with this. - MCH
Denise Christian
Charles City, VA
August 21,2002
Dear Mary,
Brandon has missed a lot of days out of school, a total of 72 days because of increasing episodes of Tachycardia, sweating, diaphoresis, weakness, some type of seizure. I felt that Brandon might have had a heart blockage but his Pediatric Cardiology did not want to perform the test on Brandon, saying it was to intensive, so she wouldn't do the test. I took him to another Cardiologist at the Medical College of Virginia in Richmond, where Dr. Louise Robertson did a Cardiac Cauterization on him February 28, 2002. He was diagnosed with Cardiomyopathy and Brandon is not a candidate to receive a heart because his heart muscle is to weak to under go surgery, if we tried, I was told he wouldn't make it through surgery. So all I can do now is put it in God's hands.
Brandon now takes Furosemide 10mg orally and Enalapril, one pill to help strengthen his heart muscle. So far it's working and he hasn't had the seizure type episodes (sweating, clammy, pale weakness and rapid heart beat).
On May 23, 2002, he had a sleep study done and was diagnosed with steep apnea, so he now sleeps with a CPAP. Brandon is less tired and the snoring is better. I recommend, if you have doubts, get your child checked because I was told that Brandon stops breathing 25 times within an hour. I was shocked and had no idea it was that serious. I have to agree with the Bellosi family, when Dana said each child is and angel from God, because they are so special in their own little way. There's never a dull moment around the house, so cherish your kids today because tomorrow isn't promised.
Grange S. Coffin MD
Berkeley, CA
Letter to James and Dana Bellosi
That was a touching letter in CLSF News. I have special feelings about the story of Gabrielle, because people who have the syndrome that I discovered seem sometimes to be like my own children. I can sense how much you have suffered, and you have my deepest sympathy. There is a good side of the story: it shows a charming and lively girl, and parents who loved here and did everything that they could possibly do to help her, then somehow did a little more. It was good to keep on trying the drugs for seizures. And it was wise to have the autopsy: a full report of the results could help us to understand other children’s disabilities.
You may wonder—as do I– why God allow such tragic things to happen. Here is an old saying that begins to answer that big question, “Earth has no sorrow that heaven can no heal.”
Earnest best wishes,
Grange Coffin
Mark Hawthorne
Bangor Co. Down, Northern Ireland
Hello Mary
An update on Matthew, he has made progress in the last year with his speech. He is filling out and loves eating, is there a thing with CLS that they don't know when they are full? We are expecting a new arrival soon in about four weeks to be exact, things getting stressful at home. We feel very lonely over here as we have no real support.
Mark
I've heard of the appetite problem with Prader-Willi syndrome, but not with CLS. Those parents often have to put locks on their refrigerators. Maybe he's just getting ready for a growth spurt! :-) - MCH
Erin Dolan
Loraine, OH
8/17/2002
Dear Mary,
At 17-1/2 months old, Mark saw Dr. Cassidy at the North Olmsted site for Genetics. He has developmental delay, hypotonia and dysmorphic physical features. Dr. Cassidy saw him on 8/23/1994. Her clinic notes summarized physical examination. There is kyphosis of the lower thorax. 12/27/1994 Dr. Liebman of Pediatric Cardiology noted a soft ejection murmur. From his physical examination: “His ears are big and his eyes slant down somewhat. His hair is coarse and straight. His lips are thick and pouty. The ears have thick helices and protrude from the head. When Mark walks he drags or slide one foot. Mark has drop attacks at times and when he wakes up from a bad dream or nightmare he cries so hard that he stops breathing and his body goes stiff.”
Erin Dolan
The following was translated from the original French by a co-worker at Microsoft. Thanks, Francois! - MCH
Annie et Alain Huet
Bailleulval, France
We are the proud parents of Florian who is affected by CLS. We live in the north of France. We have three children: Sebastien 21 yo, Christophe 11˝, Florian 9˝.
Florian is a very gentle boy. Pregnancy and birth happened without any problems. At birth, no abnormalities were detected. At one month, Florian underwent surgery for twisted inguinal hernia. He had repeated colds. At 5 months Florian was not reacting like my other children, he was rather slow. No physician diagnosed any illness.
Florian started walking at 13 months – although he had a slight balance problem. At 2 years, he underwent surgery for twisted inguinal hernia again. At that time we realized his bone development was late.
Florian joined nursery school a 2 ˝ yo. He spoke very little and his teacher said that he was too quiet.
When Florian turned 4, having consulted with a number of paediatricians and specialists, we turned to CHU Jeanne des Flandres in Lille (hospital complex in north of France). There we were met by a fantastic team of specialists who ran a number of tests and for the first time we heard about the disease. In 2001, we had the confirmation: Florian has CLS.
Following major sleep apnoea episodes, Florian underwent amygdalectomy and adenoidectomy. Since then, his nights are peaceful and we no longer hear him snore.
Currently Florian is 9 ˝, since age 6 he goes to a school that provides specialist care. He doesn’t speak very well yet but if you pay attention, it is possible to make out what he’s saying. He progresses at his own space. He is very sociable and he is very cuddlesome.
For the last two years we’ve been facing a new issue: Florian falls down at the slightest emotional or shock or surprise. He has tried three remedies without any results. Our neurologist and we ourselves are a bit bewildered. He falls more and more frequently, so much so that Florian is scared to walk in case he might fall, he starts to move on all fours again quite frequently.
We would like to know if you know other children with the same problem and if so, is there any effective treatment?
In France, very few people know this disease and I’ve been trying in vain for three years to get in touch with people affected by CLS.
Thank you for your consideration.
French-speaking families are encouraged to contact Annie and Alain.
If it weren't for the fact that the TV set and the refrigerator are so far
apart, some of us wouldn't get any exercise at all. ~Joey Adams
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Coffin-Lowry Syndrome Foundation
c/o Mary Hoffman
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