Articles on the Science of Sleep

If you're interested in articles about improvements in the science of sleep, this is the place!  Please check back  as we update articles frequently.

Interview with iSideSleep CEO John Schultz on Txchnologist.com sponsored by GE

Txchnical Improvements is our way to track the depth of innovation streaming through the United States. Every week, to highlight the creative spirit and the people who are bringing new things into the world, we bring you the short story of an inventor who was just awarded a new patent.

Click Here:  http://txchnologist.com/post/33432483866/txchnical-improvements-changing-the-shape-of-sleep

Medical Cost of Undiagnosed Sleep Apnea

Obstructive sleep apnea is an under-diagnosed, but common disorder with serious adverse consequences.aged adults, we estimate that untreated sleep apnea may cause $3.4 billion in additional medical costs in the U.S.

Click Here:  http://www.ncbi.nlm.nih.gov/pubmed/10505820

Tele-health Helping Patients Sleep Better Interview with iSideSleep CMO Lee A. Surkin MD FACC FCCP FASNC

As medical technologies and health IT evolve, so too is the use of web-based, remote diagnostic and monitoring tools that allow clinicians to test and track patients for illnesses at home. But for some patients, telehealth advancements are also bringing a better night"s sleep.

Click Here:  http://www.informationweek.com/government/leadership/telehealth-helping-patients-sleep-better/d/d-id/1090565?

The Study of The Influence of Sleep Position On Sleep Apnea

Sleep position is one of most important factors affecting OSA. Patients with OSA were found to have at least twice as many apnea episodes in the supine(back) than in the lateral position (side).

Click Here:  http://www.rcjournal.com/abstracts/2003/?id=OF-03-249

 

High-Tech Alternatives to High-Cost Care Interview

with iSideSleep CMO Lee A. Surkin MD FACC FCCP FASNC

Dr. Lee Surkin, with his wife, Elizabeth Webster, uses a Watermark Medical device
to record patients’ sleep patterns, which specialists interpret and summarize for him.

Click Here:  http://www.watermarkmedical.com/news/High-Tech-Alternatives-to-High-Cost-Care-NYT-5-23-2010.pdf

The Effect of Polysomnography on Sleep Position:

Possible Implications on the Diagnosis of Positional Obstructive Sleep Apnea

Sleep Clinics may over-diagnose Sleep Apnea, patients with positional obstructive sleep apnea would have more apnea respiratory events while lying on their backs than on their sides.....

Click Here:  http://216.134.204.126/sleep-disorders/archives/Snoring_apnea_abstract12.htm

 

Can You Die of Insomnia?

Consistently sleeping less than six hours a night has been linked to impairments in cognitive functioning, specifically a loss of concentration.

Click Here:  insomnia/?_php=true&_type=blogs&emc=eta1&_r=0

Testing a $50,000 Mattress

I hadn’t slept this badly on an assignment since I spent the night on a tuna boat.

Click Here:  http://www.nytimes.com/2010/09/23/garden/23roadtest.html?emc=eta1

Lateral sleeping position reduces severity of central sleep apnea / Cheyne-Stokes respiration.

The influence of sleeping position on obstructive sleep apnea severity is well established.

Click Here:  http://www.ncbi.nlm.nih.gov/pubmed/16944673

Treatment Options for Adults with Obstructive Sleep Apnea

Positional Therapy: Sleep on your side!

Click Here: http://sleepapnea.org/treat/treatment-options.html

 

Term: Paresthesia - Hand or Arm Fallling "Asleep" Dead Arm

Sensation is carried to the brain by neurons (nerve cells) running from the outer parts of the body to the spinal cord in bundles called nerves. In the spinal cord, these neurons make connections with other neurons that run up to the brain. Paresthesias are caused by disturbances in the function of neurons in the sensory pathway. This disturbance can occur in the central nervous system (the brain and spinal cord), the nerve roots that are attached to the spinal cord, or the peripheral nervous system (nerves outside the brain and spinal cord).

Peripheral disturbances are the most common cause of paresthesias. "Falling asleep" occurs when the blood supply to a nerve is cut off--a condition called ischemia. Ischemia usually occurs when an artery is compressed as it passes through a tightly flexed joint. Sleeping with the arms above the head or sitting with the legs tightly crossed frequently cause numbness and tingling.

Direct compression of the nerve also causes paresthesias. Compression can be short-lived, as when a heavy backpack compresses the nerves passing across the shoulders. Compression may also be chronic. Chronic nerve compression occurs in entrapment syndromes. The most common example is carpal tunnel syndrome. Carpal tunnel syndrome occurs when the median nerve is compressed as it passes through a narrow channel in the wrist. Repetitive motion or prolonged vibration can cause the lining of the channel to swell and press on the nerve. Chronic nerve root compression, or radiculopathy, can occur in disk disease or spinal arthritis.
--From HealthCares.net.

Term: Shoulder Impingement

Impingement syndrome is a common condition affecting the shoulder often seen in aging adults. This condition is closely related to shoulder bursitis and rotator cuff tendonitis. These conditions may occur alone or in combination.

In virtually all parts of your body, bones are the innermost structures and are surrounded by muscles. When an injury occurs to the rotator cuff muscles, they respond by swelling. However, because the rotator cuff muscles are surrounded by bone, when they swell, a series of other events occur.

The pressure within the muscles increases, which results in compression and loss of blood flow in the small blood vessels. When the blood flow decreases, the muscle tissue begins to fray like a rope. Motions such as reaching up behind the back and reaching up overhead to put on a coat or blouse, for example, may cause pain.
--From WebMD.

Term: Sleep Apnea

The Greek word "apnea" literally means "without breath." There are three types of apnea: obstructive, central, and mixed; of the three, obstructive is the most common. Despite the difference in the root cause of each type, in all three, people with untreated sleep apnea stop breathing repeatedly during their sleep, sometimes hundreds of times during the night and often for a minute or longer.

Obstructive sleep apnea (OSA) is caused by a blockage of the airway, usually when the soft tissue in the rear of the throat collapses and closes during sleep. In central sleep apnea, the airway is not blocked but the brain fails to signal the muscles to breathe. Mixed apnea, as the name implies, is a combination of the two. With each apnea event, the brain briefly arouses people with sleep apnea in order for them to resume breathing, but consequently sleep is extremely fragmented and of poor quality.

Sleep apnea is very common, as common as adult diabetes, and affects more than twelve million Americans, according to the National Institutes of Health. Risk factors include being male, overweight, and over the age of forty, but sleep apnea can strike anyone at any age, even children. Yet still because of the lack of awareness by the public and healthcare professionals, the vast majority remain undiagnosed and therefore untreated, despite the fact that this serious disorder can have significant consequences.

Untreated, sleep apnea can cause high blood pressure and other cardiovascular disease, memory problems, weight gain, impotency, and headaches. Moreover, untreated sleep apnea may be responsible for job impairment and motor vehicle crashes. Fortunately, sleep apnea can be diagnosed and treated. Several treatment options exist, and research into additional options continues.
-From the American Sleep Apnea Association

Term: Snoring

Snoring, like all other sounds, is caused by vibrations that cause particles in the air to form sound waves. For example, when we speak, our vocal cords vibrate to form our voice. When our stomach growls (borborygmus), our stomach and intestines vibrate as air and food move through them.
While we are asleep, turbulent airflow can cause the tissues of the nose and throat to vibrate and give rise to snoring. Essentially, snoring is a sound resulting from turbulent airflow that causes tissues to vibrate during sleep.

Sleeping position and snoring

When we are asleep, we are usually (though not always) lying down. Gravity acts to pull on all the tissues of the body, but the tissues of the pharynx are relatively soft and floppy. Therefore, when we lie on our backs, gravity pulls the palate, tonsils, and tongue backwards. This often narrows the airway enough to cause turbulence in airflow, tissue vibration, and snoring. Frequently, if the snorer is gently reminded (for example, with a gentle thrust of the elbow to the ribs or a tickle) to roll onto his or her side, the tissues are no longer pulled backwards and the snoring lessens.

How common is snoring?

Any person can snore. Studies estimate that 45% of men and 30% of women snore on a regular basis. Frequently, people who do not regularly snore will report snoring after a viral illness, after drinking alcohol, or when taking some medications.

People who snore can have any body type. We frequently think of a large man with a thick neck as a snorer. However, a thin woman with a small neck can snore just as loudly. In general, as people get older and as they gain weight, snoring will worsen.

What causes snoring?

While we are breathing, air flows in and out in a steady stream from our nose or mouth to our lungs. There are relatively few sounds when we are sitting and breathing quietly. When we exercise, the air moves more quickly and produces some sounds as we breathe. This happens because air is moving in and out of the nose and mouth more quickly and this results in more turbulence to the airflow and some vibration of the tissues in the nose and mouth.


When we are asleep, the area at the back of the throat sometimes narrows. The same amount of air passing through this smaller opening can cause the tissues surrounding the opening to vibrate, which in turn can cause the sounds of snoring. Different people who snore have different reasons for the narrowing. The narrowing can be in the nose, mouth, or throat.

The function of the nose in normal breathing

For breathing at rest, it is ideal to breathe through the nose. The nose acts as a humidifier, heater, and filter for the incoming air. When we breathe through our mouth, these modifications to the air entering our lungs occur to a lesser extent. Our lungs are still able to use the colder, drier, dirtier air; but you may have noticed that breathing really cold, dry, or dirty air can be uncomfortable. Therefore, our bodies naturally want to breathe through the nose if possible.

The nose is made up of two parallel passages, one on each side, called the nasal cavity. They are separated by a thin wall in the middle (the septum), which is a relatively flat wall of cartilage, bone, and lining tissue (called the nasal mucosa). On the lateral side (the wall of the nose closer to the cheeks) of each passage, there are three nasal turbinates, which are long, cylindrical-shaped structures that lie roughly parallel to the floor of the nose. The turbinates contain many small blood vessels that function to regulate airflow. If the blood vessels in the turbinates increase in size, the turbinate as a whole swells, and the flow of air decreases. If the vessels narrow, the turbinates become smaller and airflow increases.

Everyone has a natural nasal cycle that generally will shift the side that is doing most of the breathing about every eight hours. For example, if the right nasal turbinates are swollen, most of the air enters the left nasal passage. After about eight hours, the right nasal turbinates will become smaller, and the left nasal turbinates will swell, shifting the majority of breathing to the right nasal passage. You may notice this cycle when you have a cold or if you have a chronically (long standing) stuffy nose. The turbinates may also swell from allergic reactions or external stimuli, such as cold air or dirt.

Mouth breathing and snoring

As discussed above, we naturally want to breathe through our noses. Some people cannot breathe through their noses because of obstruction of the nasal passages. This can be caused by a deviation of the nasal septum, allergies, sinus infections, swelling of the turbinates, or large adenoids (tonsils in the back of the throat).

In adults, the most common causes of nasal obstruction are septal deviations from a broken nose or tissue swelling from allergies.

In children, enlarged adenoids (tonsils in the back of the throat) are often the cause of the obstruction.

People with nasal airway obstruction who must breathe through their mouths are therefore sometimes called "mouth breathers." Many mouth breathers snore, because the flow of air through the mouth causes greater vibration of tissues.

The soft palate and snoring

The soft palate is a muscular extension of the bony roof of the mouth (hard palate). It separates the back of the mouth (oropharynx) from the nasal passages (nasopharynx). It is shaped like a sheet attached at three sides and hanging freely in the back of the mouth.

The soft palate is important when breathing and swallowing.

During nasal breathing, the palate moves forward and "opens" the nasal airway for air to pass into the lungs.

During swallowing, the palate moves backward and "closes" the nasal passages, thereby directing the food and liquid down the esophagus instead of into the back of the nose.The uvula is the small extension at the back of the soft the palate. It assists with the function of the soft palate and also is used in some languages (Hebrew and Farsi) to produce the guttural fricative sounds (like in the Hebrew word "L"chaim"). English words do not use the guttural fricative sounds.

The palate and attached uvula often are the structures that vibrate during snoring and surgical treatments for snoring may alter these structures and prevent guttural fricative sounds. Therefore, if you speak a language that uses guttural fricative sounds, a surgical treatment for snoring may not be recommended or appropriate for you.

Narrowed airways and snoring

The tonsils are designed to detect and fight infections. They are located at the back of the mouth on each side of the throat (oropharynx). They are also called the palatine tonsils. Like other infection-fighting tissue, the tonsils swell while they are fighting bacteria and viruses. Often, the tonsils do not return to their normal size after the infection is gone. They can remain enlarged (hypertrophied) and can narrow the airway vibrate, and cause snoring.

The soft palate, as described above, is the flap of tissue that hangs down in the back of the mouth. If it is too long or floppy, it can vibrate and cause snoring.

The uvula is suspended from the center and back of the soft palate. An abnormally long or thick uvula also can contribute to snoring.

The base of the tongue is the part of the tongue that is the farthest back in the mouth. The tongue is a large muscle that is important for directing food while chewing and swallowing. It also is important for shaping words while we are speaking. It is attached to the inner part of the jaw bone (mandible) in the front and to the hyoid bone underneath.

The tongue must be free to move in all directions to function properly. Therefore, it is not attached very tightly at the tip or top of the tongue. If the back of the tongue is large or if the tongue is able to slip backwards, it can narrow the space through which air flows in the pharynx, which can lead to vibrations and snoring.

Stage of sleep and snoring

Sleep consists of several stages, but in general they can be divided into REM (rapid eye movement) and non-REM stages. Snoring can occur during all or only some stages of sleep. Snoring is most common in REM sleep, because of the loss of muscle tone characteristic of this stage of sleep.

During REM sleep, the brain sends the signal to all the muscles of the body (except the breathing muscles) to relax. Unfortunately, the tongue, palate, and throat can collapse when they relax. This can cause the airway to narrow and worsen snoring.


--From MedicineNet.com