Monday, November 5, 2007

What is Hypersomnia?

Hypersomnia is excessive sleepiness. It is an excessively deep or prolonged major sleep period. It may be associated with difficulty in awakening. It is believed to be caused by the central nervous system and can be associated with a normal or prolonged major sleep episode and excessive sleepiness consisting of prolonged (1-2 hours) sleep episodes of non-REM sleep.

What are the Symptoms?

  • Long sleep periods
  • Excessive sleepiness or excessively deep sleep
  • The onset is insidious (gradually, so you are not aware of it at first)
  • Typically appears before age 25
  • Has been present for at lest six months
How does a doctor determine that I have hypersomnia?

The first step is to consult a sleep specialist. The specialist will probably order a polysomnography test (sleep study) where you stay overnight while Technologists monitor your muscle movement, heartbeat, eye movement, leg movements and respiration. The specialist may also want to do a Multiple Sleep Latency Test (MSLT) that tests how sleepy you are.

How can it be treated?

Since the cause is still unknown, treatment consists of behavioral changes, good sleep hygiene and taking stimulants to help you be more alert. Limit your naps to one (preferably in the afternoon) lasting no longer than 45 minutes. Get at least 81/2 hours of sleep. Avoid shiftwork, alcohol and caffeine. Your doctor will determine the amount and type of stimulant you should take.

Sleep and Aging – Treatment for disorders

Because many factors influence the sleep-wake cycle, treatment must be individualized according to the patient's specific symptoms and findings from the patient's evaluation. Several generalizations are possible.

Implementation of good sleep habits and daily physical activity should help create an environment conducive to restorative sleep. Even if poor sleep habits are not responsible for insomnia, elimination of such habits can minimize their perpetuating influence.

Daily exercise and exposure to daylight can help reinforce the circadian cycle. These measures have the greatest potential for improving the quality of sleep in elderly persons. Exposure to bright light for 30 to 60 minutes in the evening may benefit patients with early bedtimes who complain of early-morning awakening.

Patients may be advised to avoid going to bed until they feel as though they can easily fall asleep. An extended wakeful time in bed (e.g., more than 30 minutes) should be avoided to minimize further reinforcement of hyperarousal. In addition, patients should plan relaxing nighttime activities before bedtime.

Low dosages of sedating antidepressants are especially helpful in patients with depressive symptoms. While potentially valuable in offering relief of insomnia, hypnotic agents should not be regarded as the ultimate solution to a sleep problem.

They should be used under limited circumstances, following evaluation of the patient's symptoms and in the context of good sleep habits. Consultation with a sleep disorders specialist should be considered in patients with marked daytime sleepiness, because this symptom can be dangerous.

Guidance regarding the management of chronic insomnia and sleep-related behavioral problems also may be obtained from a sleep disorders specialist. Formal sleep studies are appropriate when a primary sleep disorder is suspected.

Circadian rhythm

Another common age associated sleep change relates to the circadian rhythm of the typical sleep period. Although exceptions exist, elderly persons tend to go to sleep earlier in the evening and to awaken earlier in the morning. Early morning awakening is a common complaint in the elderly.

Some people find it annoying to awaken spontaneously at 4:30 a.m. instead of at 6:30 a.m. In these persons, if the onset of evening sleeps is not correspondingly earlier, sleep deprivation and excessive daytime sleepiness may result.

Daytime napping may compound the problem by reducing the drive for sleep at the usual bedtime hour, resulting in delayed sleep onset and a further decrease in the duration of nighttime sleep.

Sleep and Aging

Several generalizations can be made regarding sleep and aging characteristics. Compared with younger persons, elderly persons tend to achieve less total nighttime sleep. However, it cannot be assumed that elderly persons require less sleep.

Sleep related complaints and use of sedative hypnotics are more common in the older population than in younger patients. As with most bodily functions, sleep deteriorates as we age.

Several primary sleep disorders are associated with aging. Primary sleep disorders may delay sleep onset, cause multiple arousals and awakenings, and promote excessive daytime sleepiness.

Wandering behavior and confusional arousals may occur, especially in patients with dementing disorders. In rare instances, behaviors emanating from sleep may result in serious injury to the patient or bed partner.

Although the elderly spend more time in bed, they have more awakenings, less slow-wave sleep, lower sleep efficiency, and are more easily aroused from sleep. Increased daytime sleepiness may be the effect of such a pattern.

Why Does the Body Need Sleep?

It is not clear exactly why the body requires sleep, although inadequate sleep can have severe detrimental effects on health. Studies have shown that sleep is essential for normal immune system function and to maintain the ability to fight disease and sickness. Sleep also is essential for normal nervous system function and the ability to function both physically and mentally. In addition, sleep is essential for learning and for normal, healthy cell growth.

Stages of Sleep

There are five stages of sleep that cycle over and over again during a single night's rest: stages 1, 2, 3, 4 and REM (rapid eye movement). Stages 1 through 4 are also known as non-rapid eye movement sleep (NREM). About 50% of sleep time is spent in stage 2 and about 20% is spent in REM (normally more than 2 hours a night in adults). A complete sleep cycle, from the beginning of stage 1 to the end of REM, usually takes about an hour and a half.

Stage 1 is light sleep during which the muscles begin to relax and a person can be easily awakened. During stage 2, brain activity slows down and eye movement stops. Stages 3 and 4 comprise deep sleep, during which all eye and muscle movement ceases. It can be difficult to wake a person during deep sleep. Stage 3 is characterized by very slow brain waves (delta waves), interspersed with small, quick waves. In stage 4, the brain waves are all delta waves.

It is during deep sleep that some people sleepwalk and children may experience bedwetting. It is during REM sleep that dreams occur. The muscles of the body stiffen, the eyes move, the heart rate increases, breathing becomes more rapid and irregular, and the blood pressure rises.

Sleep Disorders

Sleep is absolutely essential for normal, healthy function. Scientists and medical professionals do not fully understand this complicated, necessary, physiological phenomenon. According to the National Institute of Neurological Disorders and Stroke, about 40 million people in the United States suffer from chronic long-term sleep disorders each year and an additional 20 million people suffer occasional sleep problems.
There are more than 70 different sleep disorders that are generally classified into one of three categories:

  • lack of sleep (e.g., insomnia),
  • disturbed sleep (e.g., obstructive sleep apnea), and
  • excessive sleep (e.g., narcolepsy).

In most cases, sleep disorders can be easily managed once they are properly diagnosed. Insomnia is the most common sleep disorder. It occurs more often in women and in the elderly.

The amount of sleep that a person needs to function normally depends on several factors (e.g., age). Infants sleep most of the day (about 16 hours); teenagers usually need about 9 hours a day; and adults need an average of 7 to 8 hours a day. Although elderly adults require about as much sleep as young adults, they usually sleep for shorter periods and spend less time in deep stages of sleep. About 50% of adults over the age of 65 have some type of sleep disorder, although it is not clear whether this is a normal part of aging or a result of medications that older people commonly use.

Falling asleep and waking up are controlled by various chemical changes in the brain and in the blood. Foods and medicines that alter the balance of these chemicals also affect how well we sleep. Caffeine, for example, can cause insomnia (lack of sleep). Antidepressants can cause a loss of REM (rapid eye movement) sleep, as can smoking and alcohol. Smoking and alcohol also can result in a loss of deep sleep. Both REM and deep sleep are essential parts of the normal sleep cycle.