All animals require sleep. Sleep restores the body and the mind. Why do human beings sleep? All metabolic processes require restoration of their function, which is achieved through sleep. In 1834, MacNish stated: “Sleep is the intermediate state between wakefulness and death;” wakefulness being regarded as the active state of all the animal and intellectual functions and death as that of their total suspension. Rodents die within about 21 days if completely sleep deprived and it is theorized that humans would die after about 180 days of sleep deprivation.
What are the stages of sleep?
As Dr. William Dement, the first physician board certified in sleep and founder of the Stanford University Sleep Disorders Center, stated: “The interest in sleep and dreams has existed since the dawn of history and perhaps only ‘love’ and ‘human conflict’ have received more attention from poets and writers.” There are three distinct physiological states of the human body: awake, non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. The brain waves and the status of the neuromuscular system are different in each of these states. Alterations in the “normal” state of sleep has produced over 160 diagnosis of sleep pathology.
The awake state has a predominance of alpha activity as well as low voltage, mixed frequency pattern. Stage I sleep is the transition from the awake state to stage II sleep, shown by diminished or disappearance of alpha activity and a relatively low voltage, mixed frequency EEG pattern, often in the presence of slow-rolling eye movements. Stage II sleep has K-complexes and sleep spindles with a mixed frequency background. Slow wave sleep reveals high amplitude (>75 microvolts) delta waves with a frequency of 0.5 to 2 Hertz, that is between one-half to two seconds in duration. Delta sleep occurs more commonly in the first one third of the night and decreases with age.
REM sleep is scored having three criteria: First, EEG returns to relatively low voltage, mixed frequency pattern with no K-complexes or sleep spindles. Some patients also reveal a “sawtooth” EEG pattern. Second, chin EMG decreases in amplitude to its lowest levels, and third, EOG reveals rapid eye movements. REM is more prominent in the last third of the night. Although one can dream in all stages of sleep, dreams in REM sleep are much more vivid and may have “phasic” body movements associated with them. This is commonly observed when one’s dog is dreaming and chasing a feline friend with the extremities moving, the eyes fluttering and the dog barking or panting. REM sleep occurs 90-120 minutes after sleep onset and approximately every 90 minutes thereafter.
One needs to understand normal sleep before under taking diagnosing and treating sleep disorders. There are four sections in the classification of sleep disorders:
- Dyssomnias, which comprises disorders that cause a complaint of either insomnia or excessive sleepiness.
- Parasomnias, which comprises disorders that intrude into or occur during sleep.
- Medical and psychiatric disorders associated with sleep disturbance.
- Proposed sleep disorders of new and rapid advances in sleep disorders, such as short and long sleepers and fragmentary myoclonus.
These are either intrinsic sleep disorders such as insomnia, narcolepsy, sleep apnea, periodic limb disorder or restless legs syndrome or extrinsic sleep disorders such as inadequate sleep hygiene, insufficient sleep disorder, or drug or alcohol dependent sleep disorder; and circadian rhythm disorders, such as jet lag, shift work sleep disorder, delayed or advanced sleep phase syndrome.
These are further divided into arousal disorders such as sleepwalking and sleep terrors; sleep-wake transition disorders, such as sleep starts or sleep talking; parasomnias usually associated with REM sleep, such as nightmares, sleep paralysis and; other parasomnias, such as sleep bruxism, primary snoring and sudden infant death syndrome.
Insomnia is the most common sleep disorder with almost everyone having at least one episode in any given year. It is either initiating insomnia (while attempting to go to sleep with a duration greater than 20 minutes) or maintenance insomnia (awaking after sleep onset and having difficulty returning to sleep).
Obstructive sleep apnea occurs in 24% of adult men and 9% in adult women. The pathology is the upper airway collapsing during sleep. This syndrome usually causes excessive daytime sleepiness and there are numerous associated symptoms and risks including socially disruptive snoring, depression, decreased cognitive functioning, personality changes, gastroesophageal reflux, hypertension, and diabetes with an increased risk of stroke and heart attacks. Almost 70% of these sleep apnea patients are over their ideal body weight, however, 30% are at or below their ideal body weight and are usually associated with a deficient facial bony structure or larger soft palate.
When one receives less sleep than genetically determined to require, it produces a state of sleep deprivation, which usually causes excessive daytime sleepiness. This can be due to voluntary schedule changes, sleep disruption of any cause including pain.
Musculoskeletal Issues of Sleep
Stress and pain are the two most common causes of both initiating and maintenance insomnia. However, pain can also produce numerous other alterations in sleep, as noted above. In conclusion, pain reduces sleep efficiency. In order to diminish pain during sleep one can perform activities before and during sleep.
Before going to bed and daily activities that can improve one’s severity of pain are the following:
- Non-steroidal anti-inflammatory medications. If muscle spasm is observed, muscle relaxants, such as diazepam or other muscle relaxants may be of benefit.
- Daily exercise, stretching and range of motion exercises, however, this activity should be performed at leas five hours before going to sleep to prevent delaying sleep onset.
- Chiropractic manipulations and massage therapy.
- Soaking in a warm bath, which often improves sleep onset.
Improving the sleep environment:
- A quite sleep room, this can be attained through double pane glass windows. Some patients prefer back round noise, such as the sound of running water or soft music.
- A dark sleep room, this can be facilitated by special draperies blocking outside light. Avoid the use of a television in the bedroom.
- A mattress with adequate head and body support is probably the most important physical variable during sleep.
Sleep is a state of being that encompasses one third of our life’s time and is essential for restoring both our mind and body. Understanding normal sleep, sleep disorders and the benefits of chiropractic care on sleep, may shape another chapter to your medical practice.