ABCs of Sleep || Gastroesophageal Reflux Disease (GERD)

Gastroesophageal Reflux Disease (GERD) is a condition in which acid rises from the stomach and breaches the valve separating the bottom of the esophagus from the top of the stomach. This valve, also known as a sphincter, is meant to keep stomach acid out. If it comes into contact with the stomach acid on a regular basis, it can become damaged and no longer prevent the "reflux" of stomach acid from rising back into the esophagus and even into the trachea and other parts of the upper airway. 

The highly corrosive nature of stomach acid means it will wreak havoc on other parts of the body outside the stomach as they are not lined with the heavy mucosal barrier like the stomach. If allowed to enter the airways, stomach acid reflux can lead to, trigger or aggravate respiratory disorders like chronic cough, wheezing and asthma. 

Other common complaints of GERD include chest pain; problems with the ears, nose and throat, such as postnasal drip, vocal cord damage, upper airway resistance and congestion; and inflammatory diseases like bronchitis and pneumonia, in which particles of stomach acid are accidentally aspirated (inhaled) into the lungs. 

Researchers are also looking into relationships between GERD and obesity as well as obstructive sleep apnea (OSA) as each of these conditions relates to physiologically challenged upper airways.

GERD can happen at any time of day and to nearly anyone at any age and of any size. But at nighttime, it can be especially troublesome. People laying completely flat (and especially while supine) are most susceptible to the creeping up of stomach acid. 

This can make bedtime frustrating because GERD leads to frequent awakening, requiring its sufferers to rise out of bed, take an antacid, and even sit in a chair in order to fall asleep again, as the gravity of a vertical position can help pull the acid back into the stomach where it belongs. 

However, sleeping is hardly easy or comfortable to achieve in an upright position. GERD may be a key reason why many older people sleep in reclining chairs, as they have the flexibility of raising and lowering the back of the chair to suit their issues with GERD. 

There are several things a person with GERD can do to help prevent their condition from interrupting with their nightly sleep. 


Elevate the head of the bed by 3 inches. This increases the angle of the bed enough to help use gravity to one's advantage without being too noticeable for people sleeping in bed. Individuals might consider sleeping in a reclining chair or using a wedge pillow that helps them sleep more upright. 

Quit smoking. Smoking exacerbates any issues with asthma or other pulmonary conditions that could develop as a result of GERD.

Dietary changes. Eating a low-fat diet, avoiding high acid foods, eating lighter meals at dinner and eating at least two hours before bedtime can help alleviate GERD and improve sleep quality.

Avoid alcohol. Alcohol relaxes the body's muscles, which increases the chance that the sphincter which serves to keep stomach acid out of the esophagus will lose its ability to seal. 

Sleep on your left side. This sleeping position is most likely to support the closure of the sphincter between the esophagus and the stomach; sleeping on the right side is more likely to break that important seal.

Treat GERD. There are a number of approaches to managing reflux disease; some are over-the-counter, while others are more aggressive prescription approaches that should be monitored by a healthcare professional.

SLEEP STUFF: Anti-snoring nasal products

For some people, the worst thing about their sleeping life truly is their snoring. It's loud enough to keep their sleeping partner awake, and it leads to discomfort in the nasal tissues and airway, dry mouth and sore throat. 

For those who snore but do not have sleep apnea*, the options for treatment are a bit different. It may be that they have other issues causing their airway resistance, such as a deviated septum, chronic allergies, narrow passageways or other physiological problems, such as overlarge tonsils or swollen turbinates.

Many of these people qualify for surgical approaches to repair their physiological challenges, but these can be expensive procedures, difficult for adults to recover from and may still not completely eradicate the problem.

Treatment of allergies is generally limited to nasal steroid sprays and medications, yet chronic post-nasal drip associated with allergies--even when treated--can still contribute to snoring.

There are small companies out there manufacturing various kinds of mechanical devices which promise to help physically open up the nasal passages via the nostrils in order to facilitate better breathing.

Some users swear by these products, while others try them and find no relief. Fortunately, most of them are inexpensive and promise to be a one-time purchase, so if they do work, the promise of a simple inexpensive solution delivers.

Listed below are four products out on the market that have been created to assist those people with sleep breathing problems that are not related to apnea or upper airway resistance that can be linked to a clinically identified respiratory system condition.

NASAL DILATORS
These products use plastic or medical grade stainless steel with silicone to physically widen, or dilate, the nostrils in order to increase airflow while sleeping. The applications vary, but all of them require inserting a portion of the dilator into the nostrils. The user adjusts the device following instructions provided by the manufacturer to achieve a widening of the nasal passages. Some of these devices are meant to be cleaned and reused repeatedly, while others are disposable and recommended for up to three uses in a row before disposing. These products are generally marketed toward people who struggle with nasal congestion, allergies, deviated septum or sinusitis, all of which can interfere with breathing during sleep. Price ranges are all across the map; cheaper dilators tend to be all-plastic and disposable, while more expensive ones that incorporate stainless steel wire run closer to $30. Some brands available include Airmax, Brez, ClipAir, Nozovent, Respitec, Rhyno and SleepRight. FDA approval depends upon the product.

NOSE CONES
These are a different variety of device which are shaped exactly as they sound, like tiny conical shaped cage-like inserts for the nostrils. They also purport to prevent nasal collapse while sleeping and can be found in both disposable and reusable options. Some brands available include Max-Air, SinusCones and Snorepin. FDA approval depends upon the product.

NASAL STRIPS
You're probably most familiar with these products, BreatheRight being the most popular brand. These external nasal passage wideners are applied across the bridge of the nose, and usually incorporate tension from the adhesive with or without a wire insert to stretch open the upper passage of the nose. They come in a wide variety of options, including some with fragrances, color choices, variations in strength and special adhesive for sensitive skin.

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*The only way to know whether a snoring condition is related to sleep apnea is to undergo a sleep evaluation from a sleep health professional. Not all snorers have sleep apnea and not all people with sleep apnea snore. SHC encourages its readers to seek the advice of a medical professional and resist the urge to diagnose themselves. 

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A friendly reminder that links to websites offering products does not imply endorsement by SleepyHeadCENTRAL.com.

SleepyHeadCENTRAL strongly encourages people with ongoing sleep health problems to approach a medical professional to determine appropriate differential diagnoses and treatment. This post, like all other posts on SHC, is not intended to substitute for medical advice.  

The Wisdom of Sleep || Anthony Burgess

"Snore" (2007) by blogger Sue Ling.

LAUGH and the world laughs with you; 

SNORE and you sleep ALONE. 

—Anthony Burgess, author (1917-1993)

WOMEN & SLEEP || Adventures in Sleep for the Pregnant Woman, Part Two: The Second Trimester

See Also:
Adventures in Sleep
for the Pregnant Woman, Part One:
The First Trimester
---
Adventures in Sleep
for the Pregnant Woman, Part Three:
The ThirdTrimester
---
Adventures in Sleep
for the Pregnant Woman, 
Postpartum Edition

So you've made it through the first 13-14 weeks, congratulations! You may find the second trimester much easier to cope with in regard to sleep issues. Less nausea and more energy are common improvements women enjoy as they move into the middle of their pregnancy. But sleep may still be disrupted, at least compared with how you slept before pregnancy. 

Potential sleep disruptions during the second trimester include: 

1. Sleep breathing problems
2. Charleyhorses and restless legs
3. Vivid dreams 

Let's take a closer look.

Sleep breathing issues can become more apparent during the second trimester. At this point, the pregnant woman has gained some necessary weight, and swelling and fluid retention have likely become the new "norm." 

Sleep breathing issues that can emerge include snoring, nasal congestion, upper airway resistance and obstructive sleep apnea. 

Body tissues during pregnancy soften due to hormone changes and retain more fluid, making the airway a target for airflow resistance. Mucus membranes may in fact be generating even more mucus than normal, which contributes to that resistance. Snoring reflects the vibrations and sounds that come from the friction inside the airway as the person breathes in and out. Nasal and sinus congestion can also be blamed on these hormonal shifts. Blood vessels will also expand, crowding your airway passages as well. 

Upper airway resistance syndrome is a sleep disorder in which the pattern of snoring and friction through the nasal passages and upper airway in general leads to micro-arousals, mini waking sessions which disrupt the architecture of sleep and can lead to sleep fragmentation, a cause of excessive daytime sleepiness. 

Finally, if the airway becomes blocked, either partially or completely, by enlarged or swollen tissues or due to fluid retention in the neck, obstructive sleep apnea can occur. OSA is especially concerning for pregnant women because it leads to lower blood oxygen saturation during the night which can have negative impacts on both mother and baby.

Solutions? Speak to your doctor about nighttime congestion, excessive daytime sleepiness or any reports from your sleep partner about gasping, loud snoring or choking sounds you might be experiencing during sleep. Other signs you might have a sleep breathing issue include waking up with dry mouth in the morning, headaches upon waking, and elevated blood pressure that can't be explained by anything else. 

Snoring and congestion can usually be corrected by simple treatments or behaviors like positional therapy or saline nasal spray. Try elevating the head of your bed by three inches to help with postnasal drainage, and learn how to sleep on your side, if you haven't already.

If your doctor suspects UARS and/or OSA, they may have you participate in a home sleep study and/or an overnight sleep study to identify what's going on so they can give you appropriate treatment.  This can include a trial on PAP (positive airway pressure) therapy or an oral device to reposition your jaw so that your airway remains clear throughout the night.

Nighttime leg cramps, sometimes called "charleyhorses," are a common complaint among women who are pregnant. You're sleeping just fine, then WHAM! your toe or calf muscle seizes up, sending you out of your bed to massage the rock-hard spasm or walk it off. The experience is painful and highly disruptive to sleep.
Similar to these leg cramps are restless legs. They occur just as you are going to bed; your legs begin to feel restless and you are compelled to walk to calm them down. Some people describe the feeling as crawling, tingling or burning sensations or an undeniable need to move the legs. As many as 16 percent of all pregnant women experience restless legs. Restless legs can happen during the day as well, especially after long periods of sitting. At night, however, they become a nuisance because they can force a delay in sleep onset and pregnant women need to get as much sleep as possible.

In either case, leg cramping may indicate a dietary imbalance in minerals like potassium, calcium, magnesium or iron. It could be that your enlarged blood vessels in your legs experience more pressure than usual, leading to these kinds of discomfort. Surges in estrogen and progesterone can lead to the experience of restless legs. Finally, restless or cramping legs may present in a way that is similar to "growing pains" in children. Many pregnant women literally feel their body growing while pregnant and these sensations in the legs might reflect that phenomenon. 

Solutions? Some simple habit changes can go a long way to help you prevent leg cramps at night, such as standing for long periods or sitting in a way that prevents good blood flow. You would be better off moving your body from sitting to standing to walking to elevating your feet throughout the day to improve circulation in your legs. Stretching your calves and moving your feet in circles in both directions also offers some relief; so does massage. Left side sleeping improves blood circulation while you sleep. 

Don't forget to drink you water as dehydration can be a direct cause of leg cramps. If you drink a lot of tea or coffee during the day, you may rethink this habit; both have a diuretic effect on the body and can lead to unintentional dehydration. If you don't want to exclude these beverages from you diet, at least consider chasing each glass or cup of tea or coffee with an equal amount of water to replace your fluids. Remember, dehydration can also lead to ongoing fatigue.

How to fix a charleyhorse: Stand upright and straighten your affected leg, flexing your heel so that your toes are pointed back toward your shins. Breathe through the pain this might cause at first; it will subside as the spasm lets go of the affected calf muscle. Walking a few minutes to improve mobility of the muscle, or using a hot pad or heating ointment on the muscle can also help.

Be wary of any swelling or tenderness in your leg that may accompany the cramping. With the larger volume of blood circulating in your blood vessels, the odds naturally increase for blood clots. Though these are rare, they still require immediate identification and treatment. 

For people with restless legs, a massage or warm shower at bedtime can be extremely helpful for calming those uncomfortable sensations. Taking a short, slow walk can also help. It may be that an increase in light exercise during the day can counteract some of the restlessness that some feel in their legs at night.

Finally, many women will swear on supplements for minerals like magnesium, calcium, potassium or iron; you are best advised to discuss these possibilities with your doctor. For most pregnant women taking an iron-fortified prenatal vitamin, the amounts dosed in this daily supplement should be enough to supplement their needs. However, eating foods high in these minerals is still a better way to improve their levels in your bloodstream, since eating mineral-rich foods makes many minerals and vitamins more bio-available, which is better for both mother and baby. 

A vivid dream life may continue into your second trimester (see our comments on what this means in Part One). Again, go with the flow and try not to let this bother you. Dreams are a great release for anxiety and you shouldn't worry about them too much.

JUST BREATHE: No, there are no magic pills for sleep apnea, and some magic pills just make it worse

Sorry, I cannot provide you a link to purchase these for your sleep apnea because they don't exist.
 

It would be so nice to just pop a pill and be done with sleep apnea, right? Except that because sleep apnea (the obstructive variety, anyway) is an issue of physiological mechanics, no pill can fix that.

(Not sure what sleep apnea is? Check out this great 3-minute video to learn how to differentiate snoring from sleep apnea.)

So there aren't any magic pills for OSA. Fine, you say. But wait! There are still plenty of drugs that can actually aggravate OSA (whether you have been diagnosed or not). This goes for all kinds of sleep disordered breathing, not just apnea.

Alcohol--Can't share this one enough. Alcohol may help you fall asleep, but you will always have a withdrawal effect a couple of hours later, after you metabolize your nightcap, which disrupts the remainder of your sleep all night. On top of that, it relaxes the airway structures in a way that encourages them to collapse.

Muscle relaxants--Makes sense, right? You have soft tissues in your airway but you also have muscles there, too. The muscles help keep the soft tissues from collapsing. Relax those muscles and you have more chances to develop an obstructed airway when you're asleep.

Sedatives--Sleep medications play a lot of tricks on your brain to get it to fall into a sleep-like state. One of the problems with sedatives is that they interfere with the neurochemical messages that your brain processes with relation to your blood's oxygen/carbon dioxide balance. Your brain normally startles you awake so that you take a breath when that imbalance hits a certain threshold. If you are taking sedatives, it will take longer for your brain and lungs to work together to avoid this depression of the respiratory system. The result will be more apneas; if you already have OSA, the result will be more severe apneas.

Cigarettes--So maybe a smoke relaxes you at bedtime. What's the harm? It also introduces irritants into the airway which cause the tissues there to swell in response, creating obstruction.

JUST BREATHE: Upper airway resistance. It's a thing. And it matters.

Graphic courtesy Dallas Center for Sleep Disorders

Upper airway resistance is a problem for people who don't have full-blown sleep apnea. It's essentially a form of obstructive breathing during sleep which only yields a partial blockage of the airway.

This is essentially snoring, right?

Well... it includes snoring. But it may also happen in the absence of the log cutting you might be lucky enough not to hear all night long from your sleep partner.

What's the problem with silent snoring? With upper airway resistance, the airway narrows so much that the muscles of breathing along the ribcage and the diaphragm work double duty to inhale. These create what the Ohio Sleep Medicine Institute refers to as "snore arousals."

In technical terms, these are called RERAs (Respiratory Event Related Arousals); they differentiate from apneas primarily in that they do not result in the reduction in blood oxygen that makes Obstructive Sleep Apnea (OSA) so dangerous.

However, when many of these arousals take place over the course of the night, snoring is no longer the root cause of the patient's problem.

People with UARS (Upper Airway Resistance Syndrome) have frequent RERAs all night long which interfere with their ability to sleep deeply; they suffer the dreaded "fragmented sleep" that is the same demon behind insomnia, sleep apnea and other sleep disorders. Fragmented sleep is dangerous; it leads to health and relationship problems and can be the cause behind traffic and work accidents.

UARS is a 'thing'

Unfortunately, people with UARS can be left undiagnosed because, well, if it's not sleep apnea, then a Positive Airway Pressure (PAP) device or other treatment to alleviate UARS may not happen: traditionally, insurance companies have been unwilling to acknowledge UARS as a legitimate sleep breathing disorder. This, despite its prevalence, weighing in at about 1 in 7. Match that with the growing numbers of people being diagnosed with OSA, and it's not hard to imagine a relationship between the two. Clinical studies continue to bear this out empirically as well.

The discovery of UARS as a certifiable sleep breathing issue took place in 1993 at Stanford, but diagnosing and treating it has been inconsistent at best. The initial identification of the syndrome came as a result of sleep lab patients having disruptions in their breathing that didn't quite fall into the apnea category. They were still tired, still suffering physically and mentally even if they didn't "qualify" for PAP therapy. But they don't always get therapy for this problem.

Why not?

It turns out that UARS is a sleep breathing disorder that sleep medicine may not more actively identify as a legitimate problem due to the lack of doctors who recognize it, and the insurance companies who fail to acknowledge it is "a thing."

The Ohio Sleep Medicine Institute refers to UARS as "the orphan child of sleep medicine" because, let's face it, there's money in OSA, with PAP therapy leading the pack in treatment options; insurance acknowledges the existence of OSA. For UARS, the treatments are similar: PAP or oral devices are the common approaches, and other options like surgery can help. But doctors may fail to recognize UARS as a legitimate problem first. Even if they do recognize and diagnose it, it may not even matter. Only very recently have insurance companies accommodated UARS as a real diagnosis and reimbursed patients and doctors for its treatment.

Bottom line: If insurance doesn't believe it exists, then there is no money to pay for therapy.

Ultimately, UARS is "a thing" even if insurance payers aren't on board. In terms defined by the American Academy of Sleep Medicine (AASM), it has most certainly been a "thing" since 2005, as it is included in the ruling sleep research body's most recent updates on practice parameters, right alongside its popular sleep breathing disorder bedfellow, OSA.

Here's the kicker

Untreated UARS can evolve from its "harmless" position in the hierarchy of sleep breathing disorders--between snoring and apnea--into full blown Obstructive Sleep Apnea (OSA). We've already talked about what untreated OSA can do to the human body. (It's not pretty.)

UARS is also often misdiagnosed as Chronic Fatigue Syndrome (CFS), Fibromyalgia, depression, mood disorder, Attention Deficit Hyperactivity Disorder (ADHD) or migraine by primary care physicians who do not think to have their patients undergo a sleep study, where the imprint of UARS on respiratory recordings as RERAs is hardly a mystery. Whether a lab tech or a doctor counts RERAs or not in their diagnostic tests actually makes a difference in the final diagnosis; yet, even then, insurance companies may still not be satisfied and refuse to reimburse for treatments.

So... it would make sense to identify and treat UARS in order to prevent full-blown OSA (and all of these other problems), wouldn't it? As a form of preventive medicine?

The Ohio Sleep Medicine Institute explains the importance of diagnosing and treating UARS here: "Patients simply do not go to bed normal one night, only to awaken the next morning with obstructive sleep apnea. Instead, they typically go through natural progression over time or following weight gain from 'benign snoring,' to UARS, and finally to obstructive sleep apnea. This progression may take years or decades to occur."

Other impacts from untreated UARS include:

• Acid reflux, heartburn, Gastroesophageal Reflux Disease (GERD), Laryngopharyngeal Reflux Disease (LPRD)
• Bruxism (teeth grinding and jaw clenching)
• Chronic insomnia
• Excessive daytime somnolence
• Headaches
• Hypertension
• Hypotension
• Irritable Bowel Syndrome (IBS)
• Memory problems
• Morning nasal congestion
• Night sweats
• Nocturia
• Non-refreshing sleep (or, waking up tired)



This rendering of the Mallampati Scale
is one way doctors can screen for potential
 UARS. Notice the normal airway structure
structure in figure I, and how the oral cavity
can be crowded, either by the tongue, the
hard palate, the soft palate, the uvula or the
adenoids (tonsils). The higher the Mallampati
score, the more likely a patient will suffer
Upper Airway Resistance Syndrome (UARS).
[Graphic is public domain.]

• Parasomnias like confusional arousal, sleepwalking, sleeptalking, sleep paralysis

Dr. Steven Park is a popular activist on the subject of sleep-disordered breathing; his excellent podcast here gives very clear descriptions of what can happen if you let UARS go untreated.


What causes UARS? 

Like OSA, the causes of UARS are primarily mechanical in nature. The tongue is overlarge. The upper airway passages (nasal, pharyngeal) are congenitally narrow. The adenoids or the uvula get in the way. People with UARS often have a high narrow palate or an overbite. Other problems, like allergies, and chronic respiratory infections like rhinitis, swell the mucous membranes lining the airways, thereby narrowing them. A deviated septum might be the obvious source of UARS-related obstruction. Swollen turbinates or collapsing nasal valves can also lead to UARS. And edema anywhere in the body (even in that far-off location, the ankles) can be redistributed at night while the body is horizontal, sending more fluid up into the neck, creating weight and swelling there that can close off the space you need to breathe. Pregnant women suffer a lot from UARS, perhaps without even knowing it.

What distinguishes UARS from full-blown OSA, then?

• OSA prevails in men, but women are more likely to suffer from UARS
• OSA is more common in older people, while UARS occurs in patient of all ages, even the very young
• OSA often accompanies someone with obesity, whereas UARS sufferers often have normal BMI or are even underweight
• People with UARS suffer more from frequent awakenings and difficulty resuming sleep than those with OSA
• People with UARS do not always snore, whereas snoring or gasping is a common marker of OSA
• People with UARS do not have dangerous changes in their airflow during the night; those with OSA have remarkable shifts in which no breathing happens at all
• People with UARS do not have significant drops in their oxygen saturation; in OSA, patterns of low blood oxygen confirm apnea

Try breathing like this while you are awake, then
imagine spending 6-9 hours like this, asleep.

UARS is hardly "OSA Lite." As the website for the Center for Sound Sleep describes it, "To understand the difficulty that someone with UARS has with breathing, try to imagine breathing for an extended period of time through an opening no larger than a small soda straw."

How to breathe like a boss while you sleep

Treatments for UARS mirror those for OSA. Continuous Positive Airway Pressure (CPAP) therapy combined with cognitive behavior therapy for any underlying secondary behavioral issues is advocated by some; others promote surgical reshaping of the upper airway by removing excess tissue as a solution. Orthodontics can help pediatric patients breathe more easily and correct cranial issues to support healthy breathing in their future while their bodies are still growing. Oral devices, which force the lower jaw forward to open the airway enough to improve airflow, are popular and finally finding some support via reimbursement by insurance companies. Positional therapy for mild cases can work. Weight loss is always a good option as it shrinks the fat pads which store fluids in the neck, therefore freeing up pace for better breathing while asleep.

Still, given all this information we have on hand regarding the legitimate condition of UARS, there are still challenges being made to the ways in which it is assessed and treated. Some doctors demand that all RERAs (see definition above) be counted during a study, while others don't consider them until treatment happens. This ongoing debate about how to measure upper airway resistance (and here's another link) continues at the peril of thousands of untreated sufferers of UARS. Let's hope they can arrive at a consensus soon, and that insurance companies can find wisdom in reimbursing necessary preventive medicine.

___________________

Note to sleep activists:

KEEP YOUR EYES PEELED for the May 15, 2015 release of these two highly anticipated commentaries on the subject of diagnostic measures of UARS:

• "Scoring respiratory events in sleep medicine: who is the driver--biology or medical insurance?" by Thomas, Guilleminault, Ayappa and Rapoport
  
• "Capitulation or advocacy for sleep physicians and patients?" by Morgenthaler, Thomas and Berry

____________________

Sources

"Breathing Related Arousals: Call Them What You Want, but Please Count Them." Collop, N. Journal of Clinical Sleep Medicine. 2014 Feb 15; 10(2): 125–126.

"Frequency and Accuracy of 'RERA' and 'RDI' Terms in the Journal of Clinical Sleep Medicine from 2006 through 2012." Krakow B, Krakow J, Ulibarri VA, McIver ND. Journal of Clinical Sleep Medicine. 2014 Feb 15; 10(2): 121–124.

Center for Sound Sleep || Learn More about Upper Airway Resistance Syndrome (commercial site)

"Practice Parameters for the Indications for Polysomnography and Related Procedures: An Update for 2005." Kushida CA, Littner MR, Hirshkowitz M, et al. American Academy of Sleep Medicine, accessed on the web April 15, 2015. (PDF)

Cleveland Clinic || Sleep Disordered Breathing

Stanford Center for Sleep Sciences and Medicine || Stealthy Insomnia Cause? Upper Airway Resistance Syndrome Subtly Disturbs Breathing in Sleep (blog)

Dr. Steven Park || Upper Airway Resistance Syndrome (podcast transcription)

Ohio Sleep Medicine Institute || Upper Airway Resistance Syndrome (commercial site)

"Upper Airway Resistance Syndrome-One Decade Later." Bao B, Guilleminault C. Current Opinion in Pulmonary Medicine. 2004;10(6).

"Upper airway resistance syndrome: still not recognized and not treated." Palombini L, Lopes MC, Tufik S, Guilleminault C, Bittencourt LRA. Sleep Science. 2011;4(2):72-78.

SleepyHeadCENTRAL || What happens if I don't treat my sleep apnea?