Home Healthy Lifestyles Articles Life After Dark: The Secret World of Sleep
Life After Dark: The Secret World of Sleep
Wednesday, May 19, 2010 08:49 AM

We all need sleep. If you've ever nodded off during a meeting or felt your head droop at your desk, you know how important it is. The way we sleep has a direct impact on our mental and physical condition while we're awake.

The Science of Sleep

You may think of sleep as a period of dormancy, when the body and mind shut down. In reality, it's quite the opposite. While much about sleep is still unknown, we do know that the brain remains very active.

Chemicals in the brain, called neurotransmitters, control whether we are awake or asleep. They act on specific neurons in the brain stem (the base of the brain), which send the signals that cause us to fall asleep. Other neurons in the brain stem generate signals that keep us awake.

There are five phases of sleep, stages 1, 2, 3, 4, and REM (rapid eye movement), that form a sleep cycle. The cycle moves from stage 1 to REM then starts over again, continuing throughout the night. Most people experience five complete cycles each night, each cycle lasting from 90 to 110 minutes.

Stage one is light sleep. Most people drift in and out of stage one and can be easily awakened. Muscle and eye movements slow, and some people experience hypnic myoclonia, sudden muscle contractions often preceded by a sensation of falling. In stage two, eye movement stops and brain waves slow. There are occasional bursts of brain activity, known as sleep spindles, that are unique to this stage. By stage three, the brain begins to produce even slower waves called delta waves. At stage four, the brain produces delta waves exclusively and eye and muscle movement stop completely. Together, stages three and four are called deep sleep. It is very difficult to wake someone from deep sleep, and they may be disoriented for several minutes after waking up.

REM sleep begins 70 to 90 minutes after falling asleep. During this stage, eye movements become quick and irregular, breathing becomes rapid and shallow, heart rate and blood pressure increase, and muscles in the arms and legs become paralyzed. This is when we start to dream.

As the night progresses, the length of REM stages increases and the length of time spent in deep sleep (stages three and four) decreases. By morning, nearly all sleep is stage one, two or REM. The REM stage of the night's first cycle usually lasts about 10 minutes. The REM stage of the final cycle lasts about one hour. If you are awakened during REM sleep, the regular sleep cycle is disrupted. The next time you doze off you will go directly into REM sleep.

Sleep Is Essential

Not getting enough sleep can be detrimental to your work performance, relationships and health. Sleep deprivation is know to cause irritability, poor concentration, impaired memory and decreased hand-eye coordination. One study showed that sleep deprived drivers perform as poorly or worse than intoxicated drivers. The National Highway Traffic Safety Administration estimates that 100,000 motor vehicle accidents and 1,500 deaths are the direct result of sleep deprivation.

Exactly why we need sleep to survive is unknown, but animal studies have shown a breakdown in the immune system and a severely shortened life span in sleep-deprived rats. Other studies show that human cells produce more proteins during sleep. These proteins are necessary for cell growth and damage repair. In children, growth hormones are released during sleep.

When Good Sleep Goes Bad

For more than 40 million Americans, getting a good night's sleep is just a dream. Chronic sleep disorders reek havoc on careers, school, relationships and emotional health. Some of the most common sleep disorders are sleep apnea, insomnia, restless leg syndrome and narcolepsy.

Sleep Apnea

The most common sleep disorder, sleep apnea affects up to 18 million Americans, although few of them are ever diagnosed. Often brought about by physical changes related to age or obesity, sleep apnea causes the sleeper to stop breathing momentarily many times during the night.

During an episode of sleep apnea, the sleeper's upper airway is narrowed by fat buildup or relaxed muscles in the back of the throat. When the sleeper struggles to inhale, he creates suction and causes the airway to collapse. The sleeper is then unable to breathe for 10 seconds to one full minute. In response to the buildup of carbon dioxide in the blood, the brain wakes the sleeper up just enough to tighten the muscles in the airway and reopen it. The sleeper may snort or gasp as he begins to breathe again.

Sleep apnea causes loud snoring, daytime sleepiness, irritability, depression, headaches and mental confusion. In extreme cases it can even lead to sudden respiratory arrest and death. Because they are sleepy during the day, people with untreated sleep apnea are two to three times more likely than the general population to have a motor vehicle accident.

Once diagnosed, some sufferers can eliminate the problem with weight loss or sleeping on their sides instead of their backs. Others may find relief with a device called a CPAP machine. The CPAP device creates positive pressure in the upper airway while the person sleeps so the airway cannot collapse. It is important that a person with sleep apnea never take sleeping pills or sedatives because they can inhibit the ability to wake up and breathe.

According to Stephen Layne, M.D., Pulmonologist and Medical Director of the EJGH Sleep Disorders Program, patients often live with sleep apnea for years before seeking a diagnosis. When they finally do seek treatment, it's usually because they've gotten a push from a bed partner.

"Many patients minimize it. They're used to being tired during the day and think this is the way it's supposed to be," says Dr. Layne. "It's not until their spouse throws them out of the bedroom that they seek help."

In addition to the strain loud snoring can cause in a relationship, those with sleep apnea are at a higher risk for high blood pressure, a risk factor for heart disease and stroke. Also, studies have found that patients with sleep apnea are more likely than the general population to have congestive heart failure (CHF). While one does not cause the other, having both conditions together can be deadly.

"When a patient has CHF, the heart is already working harder than it should," says Dr. Layne. "Adding the stress of sleep apnea really over taxes the heart."

Insomnia

Almost everyone has suffered through bouts of insomnia. It is usually caused by stress, intense emotional states or even eating too close to bedtime. For some people though, insomnia is not tied to a specific event. Nearly 60 million Americans (40 percent of women and 30 percent of men) experience long-term insomnia.

For short-term insomnia, a doctor may prescribe sedatives or sleeping pills. These medications are not a solution to long-term insomnia, as they tend to lose their effectiveness after a few weeks. Currently, some physicians are working with light therapy and chrono-therapy (changing the person's circadian rhythms) to combat long-term insomnia. If insomnia is associated with clinical depression, antidepressant medications often help.

Restless Leg Syndrome

Restless Leg Syndrome (RLS) is a disorder that may run in families and affects up to 12 million Americans. It causes uncomfortable crawling, tingling or prickling sensations in the sleeper's legs along with the urge to move the legs for relief. RLS is most common in seniors, but can begin as early as childhood. Women may also develop symptoms of RLS during pregnancy. Once diagnosed, a physician can prescribe medication to combat the disorder.

Narcolepsy

About 250,000 Americans suffer the frequent 'sleep attacks' associated with narcolepsy. The attacks happen at various times throughout the day, even if the person slept adequately the night before. They may last several seconds or be as long as 30 minutes. Another symptom is cataplexy, a sudden loss of muscle control that often occurs with an emotional moment. Laughter is a common trigger for cataplexy. Hallucinations, temporary paralysis upon awakening, and disrupted nighttime sleep are also common.

While narcolepsy is not fully understood, it seems to be caused by a blurring of the borders between the stages of sleep and wakefulness. One stage invades another causing normal things to happen at abnormal times. For example, the temporary loss of muscle control in cataplexy may be the muscle paralysis of REM sleep occurring during wakefulness.

In 1999, a narcolepsy gene was discovered, meaning a cure for the disorder may be on the horizon. For now, patients with narcolepsy can be treated with medications, including stimulants and antidepressants, that decrease daytime sleepiness and prevent sleep attacks at inappropriate times. Naps at set times during the day can also help.

Good Habits for a Good Night's Sleep

  • Stick to a schedule. Go to bed at the same time each night and get up at the same time each morning.
  • Exercise daily, but not too close to bedtime.
  • Avoid caffeine in the late afternoon and evening. In addition to coffee, caffeine can be found in black tea, chocolate, soft drinks, diet pills, and some pain killers made for headache relief.
  • Don't drink alcohol close to bedtime. Although alcohol may make you feel sleepy, it actually interferes with deep sleep and REM sleep.
  • Relax before going to bed. Read, have a warm bath or meditate before you turn in. Call the Wellness Center at 849-6868 for information on Meditation and Stress Management classes.
  • Wake up with sunlight. Exposure to morning sunlight helps to reset your internal clock and may help you maintain a regular sleep schedule.
  • If you can't sleep, don't lie in bed awake. Move to another room and read, watch TV or listen to music until you feel tired then go back to bed.
  • Keep your bedroom at a comfortable temperature. It's difficult to fall asleep and stay asleep in a room that is too hot or cold.
  • If you continue to have trouble falling asleep or staying asleep, or if you always feel sleepy during the day, talk to your doctor. He or she may be able to help, or may refer you to a sleep specialist.

To Sleep Perchance to Dream

You arrive at your office on a Monday morning clad only in your underwear. Your final exam is tomorrow and you haven't attended the class all semester. You're flying high above the treetops or floating peacefully in a tropical lagoon. These are the kinds of places our dreams take us. But what does it all mean? The answer depends on whom you ask.

Some researchers believe dreams to be nothing more than random firings of neurons in the brain during REM sleep. The cortex of the brain, the area responsible for thought, logic and organization of information, attempts to make sense of these random stimuli by putting them into an understandable context - a story. It may be disjointed and strange, but it is a story nonetheless.

Others believe that dreams are full of symbols that can be decoded. Once the code is broken, they offer a wealth of information that can enhance our understanding of ourselves and improve our daily lives. There are a number of dream dictionaries that claim to be the key to breaking the dream code.

Yet another school of thought defines a dream as an arena where issues can be examined and conflicts can be resolved. When problems arise during the day, they are often not easily solved because of the emotions and interpersonal dynamics involved. The dream provides a safe and private place to confront the people and situations that cause stress and anxiety during the day. If you can learn to direct these dreams, perhaps it is possible to make real progress in resolving a daytime problem.

One thing everyone can agree on, though, is that your dreams are uniquely your own. Whether you regard them as random brain activity or secret messages from your subconscious is entirely up to you.

Dreams That Go Bump in the Night

REM Behavior Disorder (RBD) is a sometimes bizarre and often dangerous sleep disorder. It causes sleepers to act out their dreams, especially when the dreams are scary or dramatic. They may walk, talk, shout, scream, punch or kick while still asleep. Many of these activities can be dangerous to the sleeper and to his or her bed partner.

As in narcolepsy, RBD seems to be a breakdown in the borders between the stages of sleep and wakefulness. During normal REM sleep the muscles of the chin, neck, limbs and torso are paralyzed to prevent the sleeper from acting out his dreams. In RBD, the sleeper can get up and move around unaware that he is dreaming. In the morning, he will have no idea of what transpired the night before.

EJGH Polysomnographic Technologist D.J. DeGruise has seen sleepers do some interesting things during REM sleep. One patient, a teacher, sat up and reviewed a recent exam with his students. Another had a long conversation with a friend. In both cases, the patients' eyes were open and they were speaking coherently in a normal tone of voice. In these cases, the patients didn't present a danger to themselves or a bed partner, but were experiencing daytime sleepiness they couldn't explain.

In other cases, RBD is dangerous. Dr. Layne has seen patients who have done things while sleeping that put their own and others' lives in jeopardy. One patient nearly burned his house down while trying to cook during REM sleep. Another had, on several occasions, gotten into her car and began driving to the grocery store.

Medications can help most people with RBD, but some patients develop a tolerance to these drugs over time. According to Dr. Layne, the most important thing is to make the sleep environment as safe as possible by removing anything sharp or breakable and placing a chain or latch-type lock on the bedroom door.

Studying Sleep

Sleep disorders can be accurately diagnosed through sleep studies conducted in a sleep laboratory. The Sleep Lab at EJGH has two bedrooms and a control room where technologists and therapists monitor patients throughout the night. The bedrooms are designed to be comfortable and home-like, so the patient can sleep as normally as possible. Patients can wear their own pajamas and are invited to bring their own pillows.

The Sleep Lab team is lead by Dr. Layne, a Diplomat of the American Academy of Sleep Medicine and specialist in diagnosing and treating sleep disorders. Overnight sleep studies are conducted by certified respiratory therapists and registered polysomnographic technologists (commonly known as sleep techs). The lab is accredited by the American Academy of Sleep Medicine and was the first facility in Jefferson Parish to achieve this distinction.

When a patient is scheduled for a sleep study, the Sleep Lab staff meets with him or her about one week prior to the study. The staff explains the study and follow-up process to ease any anxiety the patient might have and to ensure accurate results.

On the evening of the study, the patient reports to the lab between 7 and 8 p.m. to be connected to equipment that monitors brain activity, heart rhythm and muscle movement. Then the patient can watch television or read, whatever he or she normally does before going to sleep.

As the patient sleeps, technicians and therapists can see the patient through infrared cameras and hear the patient through a microphone in the bedroom. They can also monitor the patient's brain activity and heart rhythm throughout the study. Everything that goes on during the night is recorded for review by a physician. Based on this information, the physician can make a diagnosis and recommend an appropriate treatment.

If a sleep disorder is diagnosed, the patient doesn't have to face it alone. A.W.A.K.E. (Alert, Well And Keeping Energetic) provides support and education for those with sleep apnea and other disorders. Meetings are held quarterly and are free to attend. For more information on A.W.A.K.E, call the Sleep Disorders Program at (504) 849-8769.

 

 

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