Sleep disturbance and pain - Padda Institute Center for Interventional Pain Management

Sleep disturbance and pain


There is a dramatic upsurge of diseases and related conditions resulting from the Sleep Apnea and the Obesity Epidemic.  According to the National Sleep Foundation, 75 million Americas are affected by some type of sleep disorder and more than 18 million suffer from obstructive sleep apnea (OSA) alone.  It is estimated that a staggering percentage of those affected, 92% of women and 80% of men remain undiagnosed.  Complications from untreated sleep disorders include excessive daytime sleepiness and neurocognitive deficits including decreased intellectual capacity and psychomotor vigilance (such as the ability to drive).  Additionally, patients with untreated OSA are at increased risk for diabetes, hypertension, heart failure, stroke, and other co-morbidities.

 

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Symptoms of significant sleep disturbance include:

  • Loud nighttime snoring
  • Daytime sleepiness
  • Insomnia
  • Narcolepsy
  • Obstructive sleep apnea
  • Restless leg syndrome
  • REM behavior disorder (abnormal body movements during dreaming)

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If you’re not sure if you need to have a sleep test, the Epworth Sleepiness Scale might help you decide. It  is a useful measurement of daytime sleepiness that doctors use to initially evaluate patients for sleep disorders.

People with sleep apnea experience cessations in breathing during sleep, and the condition is associated with a range of serious side effects and illnesses. It used to be that you had to go into a sleep lab to have polysomnography, or a sleep test, in order to diagnose sleep apnea. At home testing is also now possible if ordered by your physician, so you can take the test discreetly, in the comfort and privacy of your own home.

Linkage of pain to sleep disturbance

Sleep disturbance is perhaps one of the most prevalent complaints of patients with chronically painful conditions.  Of all medical conditions, pain is the number one cause of insomnia. With chronic pain problems, difficulty falling asleep is one of the most prevalent types of sleep disruption.  However, awakening during the night and awakening earlier than desired are also frequent problems.

Research surveys of those with chronic pain problems have found that 65% report that they are awakened during the night due to pain and 62% report waking too early due to pain. In addition, many patients with chronic back pain problems do not feel “refreshed” in the morning when they awaken, a sleeping problem termed “non-restorative sleep.”  The National Sleep Foundation reports that 2/3 of chronic pain sufferers experience sleep problems. Approximately 15% of all people have sleep problems. Compounding the problem of disturbed sleep in people who hurt is the fact that some chronic pain medications tend to disrupt sleeping patterns.

 

Chronic pain sufferer experiences fragmented sleep due to:

  • Positional discomfort
  • Elevated Epinephrine/ Norepinephrine from stress responses as part of a flight or fight reaction, with secondary cortisol release.
  • Excessive carbohydrate consumption from ingestion analgesia and from sodium retention due to cortisol elevation
  • Obesity which occurs due to reduced Basal Metabolic Rate and due to excessive ingestion and preferential visceral fat deposition due to cortisol

Fragmented sleep leads to a vicious cycle– sleep disruption caused by chronic pain exacerbates the pain and obesity, which in turn interrupts sleep. With repetition, this becomes a hardwired pattern, a concept called neuroplasticity (the brain’s ability to reorganize itself by forming new neural connections throughout life is often referred to as  neuroplasticity and is the basis of learned behavior).  Sleep deprivation increases neuroplasticity-related gene expression, strengthening synapses in brain regions involved in mood regulation, creating a hard wiring of pain-insomnia-obesity behavior.

 

Normal Sleep Patterns

Sleep is divided into 2 different phases – Rapid Eye Movement Sleep (REM) and Non Rapid Eye Movement Sleep (NREM).  Microarousals are quite common.

We spend about 70% of our time in NREM sleep and 30% in REM sleep. The proportion of each changes through our lives from infancy to senility.

  • REM sleep has the following features:-
    • Rapid eye movements associated with typical saw tooth brain wave patterns on EEG (Electro-encephalogram)
    • A rise in heart rate, blood pressure, associated with an irregular breathing pattern
    • Susceptibility to being woken by sensory stimuli – light, noise, touch, pain
    • Paralysis of all muscles except the diaphragm
  • NREM sleep can be divided into 2 phases – transitional and deep:-
    • Transitional sleep is divided into stages 1 and 2
      • Stage 1 – The transition from wake to sleep occurs within minutes of the onset of slow rolling eye movements. The subject is less aware of their surroundings then just a few minutes ago. They may waken by a whisper, or noise. They are relaxed, their breathing is more regular and there is slower, rolling eye movement noticed. There may also be  “hypnogogic experiences” – dream-like sensations of falling, hearing voices, or seeing flashes of pictures. It takes 5 – 10 minutes to progress to Stage 2. Stage 1 accounts for only about 5% of the total sleep time.
      • Stage 2 – Stage two is the first stage of true sleep and accounts for about 50% of total sleep. The subject is even less aware of their surroundings and is characterized by as light sleep since individuals are easily aroused from this sleep state. Stage 1 & 2 are “transitional” stages of sleep. It takes approximately 30 minutes to complete these stages and enter Stage 3.
    • Deep sleep is divided into stages 3 and 4
      • Stages 3 and 4 are also referred as Slow Wave Sleep (Delta Waves). As the subject is in a very relaxed state, they have a slow, regular heartbeat and respiratory rate. Their muscles are very relaxed. It is very difficult to arouse a patient in “Slow Wave Sleep”. If they are awakened, they are confused and slow to react. It is normally easy for them to go back to sleep.
  • Normal Sleep Cycles
    • Cycling  from deep sleep to REM sleep and back again occurs several times during a normal nights sleep. There is tendency to have more deep sleep at the beginning of the sleep period and increasing amounts of REM later in the period.

 

Diagnosing sleep apnea

Sleep apnea is an under-diagnosed condition that results in breathing cessations during sleep, up to hundreds of times a night, which can critically lower blood oxygen levels. If left untreated, sleep apnea is associated with a host of problems including daytime sleepiness, increase in car accidents and serious illnesses such as heart disease, stroke, and diabetes.

Symptoms of sleep apnea can be hard to define because they are vague and often can be explained away by a patient’s overall condition. Snoring and daytime sleepiness are two hallmarks of sleep apnea, but do not in and of themselves prove someone has the condition. The first step in evaluating those symptoms is for your doctor to rule out other medical reasons for sleepiness such as interrupted sleep due to environmental reasons, narcolepsy, night shift work, etc.

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Additional indicators of sleep apnea that merit a sleeping test or an evaluation by a sleep specialist include:

  • Sleepiness that is dangerous to others (pilots, truck drivers, and anyone who drives).
  • Sleepiness that affects quality of life.
  • Partner reports of choking and gasping spells during sleep.
  • The presence of strongly associated conditions such as high blood pressure or diabetes.
  • Children who snore loudly and have difficulty with concentration and paying attention in school.

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The best options for diagnosing sleep apnea are either an overnight polysomnography, which is conducted in a sleep lab, or a home sleeping test. Both tests evaluate the various sleep stages patients go through, and both monitor changes in breathing, episode of apnea (breathing cessation) and blood oxygen levels. Sleep lab studies are more labor-intensive and expensive, and home tests offer significant savings and patient comfort. However, home tests may not be appropriate for evaluating other sleep disorders, so if the results are unclear, a full polysomnography in a sleep lab may be necessary.

Many people prefer home sleep testing because it is more private, more comfortable, and is accurate in evaluating for the number of apneas, drops in oxygen, and heart rate variability. People with certain kinds of jobs such as pilots and truck drivers may choose home testing because it is more discreet and participation in a sleep study is less likely to be known to employers.

No matter where or how you get tested, greater than five episodes of apnea lasting longer than 10 seconds is considered significant sleep apnea if you are sleepy, and more than 15 episodes regardless of how sleepy you are. The good news is that there is effective treatment for sleep apnea, including CPAP or Continuous Positive Airway Pressure. Lifestyle changes such as losing weight may also help the condition. The most important thing for symptomatic people to do is get tested, either at home or in a sleep lab, so sleep apnea doesn’t interfere any further with their quality of life.

 

What is polysomnography?

Polysomnography is considered the “gold standard” for diagnosing obstructive sleep apnea or OSA. OSA is a common but under-diagnosed condition in which breathing ceases temporarily during sleep, up to hundreds of times per night, resulting in lowered blood oxygen levels.  Polysomnography is a study of how you sleep, or how you try to sleep. It is usually performed to evaluate sleep problems and diagnose possible sleep disorders.

Trained sleep specialists perform Polysomnography at a sleep lab or sleep center. Patients sleep in beds at the center, at their usual bedtime, in a comfortable bedroom. They are monitored both visually and electronically. The test is done at night in order to study normal sleep patterns.

Electrodes are placed on the chin, scalp, and outer edges of the eyes, and monitors are placed on the body to record heart rate and breathing. The sleep specialists directly watch patients while they sleep and record changes in position, breathing and heart rate. Episodes of apnea, or cessations in breathing, are also recorded. A video camera records position changes throughout the night. In addition, airflow through the nose and mouth, blood pressure, and blood oxygen levels are monitored.

The electrodes send signals indicating the two states of sleep; Rapid Eye Movement (REM) sleep and Non-rapid eye movement (NREM) sleep. REM sleep is associated with dreaming, and NREM has four different stages that the electrodes can detect. Normally, REM and NREM sleep alternate approximately every 90 minutes during the night. That means most people have four to five cycles of REM and NREM each night.

People with a normal sleep patterns will show normal brain waves and muscle movements during sleep, and no significant breathing difficulties. Abnormal results can lead to diagnosis of a sleep disorder. Reduced airflow through the nose and mouth, along with a fall in blood oxygen levels, may indicate sleep apnea.

Sleep disorders are associated with serious complications and effective treatment is available, so polysomnography is a highly useful tool for people who suspect they have sleep apnea or another sleeping problem.

 

Linkage of Obstructive Sleep Apnea (OSA) to obesity.

New research reveals that obstructive sleep apnea (OSA) may cause more severe consequences in overweight people than in people of normal weight. A study, published in the October 15 issue of the American Journal of Respiratory and Critical Care Medicine, found that greater oxygen depletion occurred in the blood of overweight people with OSA both during and after apnea events.

Apnea events are cessations in breathing during sleep that can happen up to hundreds of times a night, and that can cause significant reductions in blood oxygen levels. These reductions appear to be greater in overweight people, possibly leading to more severe outcomes. Since sleep apnea is related to the development of serious conditions such as heart disease and stroke, as well as daytime sleepiness and increased automobile accidents, all of these risks could be greater among overweight people with OSA. The study revealed that overweight people have more frequent episodes of apnea during sleep.

The researchers were careful to account for age, gender, and body position during sleep, so they can be sure it was body weight that contributed to the severity of oxygen saturation reductions in the people with OSA. They note that it isn’t just obese people that suffer from more severe episodes of apnea; anyone above the normal maximum Body Mass Index (BMI) of 25 is at increased risk. A 10% increase in BMI led to a 10% increase in oxygen depletion associated with sleep apnea. In other words, the greater your weight, the greater the consequences.

This study adds to the growing body of evidence that excess weight is a significant risk factor for the development, progression, and severity of OSA. Doctors and sleep specialists need to be aware that their overweight patients might be suffering from greater oxygen depletion related to OSA, even if they have the same number of sleep apnea events during the night as normal weight patients. People with sleep apnea who are overweight should keep in mind that any reduction in body weight would be beneficial to reducing the severity of their sleep apnea events, and to improving overall blood oxygen levels during sleep.

 

Improved sleep leads to better weight loss.

It may come as no surprise that being overweight causes sleep problems, but new research shows that the reverse may also be true! Sleep problems may be the reason you are putting on weight or unable to reduce weight with diet and exercise.

There are several explanations for why sleep loss causes weight gain.  Two key players are the hormones leptin and ghrelin.  Leptin suppresses appetite while ghrelin does just the opposite – it stimulates it. In just a few weeks of not sleeping well, your leptin levels can decrease by as much as 15%. Instead of registering that you are no longer hungry, your brain receives the message, ‘Hey! I am hungry. I need to eat.’  Uh oh!

A few years ago there was great hope in the obese community that leptin would be the magic weight loss solution everyone was looking for – but this proved not to be the case. Obese patients typically suffer from a condition called leptin resistance where despite having high leptin levels, which should help them lose weight, they no longer respond to the hormone effectively. To regain leptin sensitivity, patients first need to decrease body fat, because leptin is produced by adipocytes and the brain becomes resistant to the excessive leptin production in obese individuals.

Once sleep apnea is treated, you will be able to lose weight.   Getting a good night’s rest contributes to proper hormone function as well as providing energy for exercise – both of which are essential for effective weight loss. Patients need to recognize the importance of sleeping well for long-term weight control, as well as for overall good health.  Many people unknowingly suffer from sleep disorders. Sleep apnea, the most common sleep disorder, affects over 20 million Americans, yet the majority remains undiagnosed. A person who suffers from sleep apnea typically stops breathing for periods of 10 to 60 seconds, possibly hundreds of times throughout the night, resulting in a very poor quality of sleep.

 

Taking a pill will not improve your sleep; it will just make you forget you slept poorly.

A New York Times article reports that about 42 million prescriptions for sleep medication were issued in 2005. Aside from being over prescribed, sleep medications these days can have strange side effects (parasomnias) such as sleep driving, sleep-sex, and sleep eating.  Drug makers target and capitalize on the public perception that “modern day lifestyle” is frenetic, and that a restful eight hours of sleep is an absolute necessity; although physiologically our natural pattern of sleep is supposed to include short periods of microarousal.

Sleeping Pills (benzodiazepine family) are often used to treat insomnia, but long-term use is not recommended. They have been shown to disturb the normal NREM:REM sleep ratios during the night, causing the sufferer to awaken unrefreshed even though they’ve had a reasonable number of hours sleep. They also cause rebound sleeplessness on withdrawal, making them highly addictive. Sleeping pills also worsen obstructive sleep apnea.

These days, we all live with more stress than usual and it may be affecting your sleep. While it’s normal to have the occasional night when you can’t sleep very well, having those kind of nights more often can indicate a more serious problem. If you regularly take medications to fall asleep, even over-the counter medicines, you could be masking a sleep disorder – and not solving the problem causing it.

Insomnia is a symptom of an underlying issue, and is not an illness in itself. By simply taking pills and not dealing with the underlying causes of your sleeping problems, there’s little chance it will ever go away – and it could get worse. And if you are taking prescription sleep medications, there is the potential for addiction, which is a very difficult habit to break that may require professional help.

There are additional risks to allowing a sleep disorder to continue while simply taking sleeping pills at night. Sleep disorders are associated with serious health risks such as heart disease, diabetes, and stroke – not to mention quality of life issues such as daytime sleepiness, general fatigue, and increased car accidents.

If you find yourself needing sleeping pills more than very occasionally, it’s important to talk to your doctor about treating the cause of your sleeping problems. A good physician will do more than simply write a prescription. He or she will talk to you about what’s going on in your life, any other physical or emotional problems you are dealing with, and what might be affecting your ability to sleep well at night. You will also be evaluated for a possible sleep disorder such as sleep apnea. Sleep apnea is a very common sleep disorder in which a person’s breathing ceases for a period of time, up to hundreds of times a night. It is associated with a host of serious health problems but can be effectively treated – without pills.

You can also make some simple lifestyle changes to sleep better at night. Getting 30-60 minutes of moderate exercise each day is an excellent sleep enhancer. Avoid alcohol or caffeine within 5 hours of bedtime, and try to maintain a regular sleep schedule even on the weekends. Your body will get used to the routine and you will feel sleepier at night and better in the mornings.

If these changes don’t help and you continue to experience insomnia or symptoms of a sleep disorder (loud snoring, daytime fatigue, inability to concentrate) – don’t turn to pills to fix the problem. Talk to your doctor and get to the root of the problem, so you can eliminate it without having to turn to medications.

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How to sleep better with chronic pain:

  • Optimize pain relief by using interventional techniques and minimize benzodiazepines and narcotic analgesics.
  • Maintain a schedule – Go to bed and get up at the same time every day, including weekends and vacations, maintaining a circadian rhythm.
  • Regular exercise improves sleeping habits. Exercise between twenty to thirty minutes a day for the best results, but take care not to exercise within five hours of bedtime.
  • Don’t Lie Awake – If you cannot fall asleep, don’t lie in bed awake. Worrying about sleep actually keeps many people awake. Get up and do something else until you feel sleepy.
  • Limit Alcohol, Nicotine and Caffeine – Nicotine and caffeine are both stimulants, and should be avoided up to 12 hours before bedtime. Alcohol is a sedative, and may appear to promote sleep in the early part of the night, but may then cause a very disturbed sleep pattern for the rest of the night.
  • Eat and Drink Long Before Bedtime – A heavy meal before bed can cause indigestion, which can keep you up.
  • Drinking fluids before bed can interrupt your rest by causing you to get up to urinate. Try to avoid both food and fluids for at least two hours before bedtime.
  • Relax – Spending some down time before bed can relax you enough that falling asleep comes easier.
  • Meditation, relaxation techniques and breathing techniques may all work. Relaxation could be as simple as a warm bath, or quiet reading (but not in the bedroom).
  • Consider Melatonin supplements – Melatonin is a natural substance that builds up in the body as daylight fades, making people drowsy.
  • Taking a warm bath in the evening, which can relax muscles.
  • Stretching for three to five minutes before going to bed, which can loosen joints and make assuming a comfortable position in bed more likely.
  • Drinking a warm, non-caffeinated beverage about an hour before bedtime, such as warm milk, or herbal tea.
  • Keep the Bedroom for Two Things (sleeping and sex) – Watching television, paying the bills, reading a book, and listening to music in the bedroom are not recommended.

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