Sleep Disorders
Sleep disorders involve any difficulties related to sleeping, including difficulty falling or staying asleep, falling asleep at inappropriate times, excessive total sleep time, or abnormal behaviors associated with sleep.
Causes, incidence, and risk factors
More than 100 different disorders of sleeping and waking have been identified. They can be grouped in four main categories:
- Problems with falling and staying asleep
- Problems with staying awake
- Problems with adhering to a regular sleep schedule
- Sleep-disruptive behaviors
PROBLEMS WITH FALLING AND STAYING ASLEEP
Insomnia includes any combination of difficulty with falling asleep, staying asleep, intermittent wakefulness and early-morning awakening. Episodes may be transient (come and go), short-term (lasting as long as 2 to 3 weeks), or chronic (long-lasting).
Common factors associated with insomnia include:
- Physical illness
- Depression
- Anxiety or stress
- Poor sleeping environment such as excessive noise or light
- Caffeine
- Alcohol or other drugs
- Use of certain medications
- Heavy smoking
- Physical discomfort
- Daytime napping
- Early bedtimes
- Excessive time spent awake in bed
- Psychophysiological insomnia (learned insomnia)
- Delayed sleep phase syndrome - where a patient's internal clock is constantly out of synch with the "accepted" day / night phases; for example, patients feel best if they can sleep from 4AM to noon
- Hypnotic-dependent sleep disorder - insomnia resulting from building tolerance to, or stopping, certain types of sleep medications
- Stimulant-dependent sleep disorder - insomnia resulting depending on, or stopping, certain types of stimulants
Disorders of excessive sleepiness are called hypersomnias. These include:
- Sleep apnea
- Narcolepsy
- Restless leg syndrome
- Periodic limb movement disorder
- Obstructive sleep apnea
- Central sleep apnea
- Idiopathic hypersomnia
- Respiratory muscle weakness associated sleep disorder
Sleep apnea more commonly affects obese people, but it may affect anyone with a short neck or a small jaw, regardless of weight. The disorder causes breathing to stop intermittently during sleep, resulting in the person being awakened repeatedly. People with sleep apnea often have difficulty achieving prolonged deep sleep. This results in excessive daytime sleepiness.
Narcolepsy is a condition of daytime sleep attacks as well as other features that may include sleep paralysis and hypnagogic hallucinations (hallucinations that happen at the time between wakefullness and sleep). Sleep attacks occur despite adequate sleep at night. A person with narcolepsy may suddenly fall asleep in any situation, without warning.
Restless leg syndrome is characterized by an uncomfortable sensation, usually in the legs, that occurs primarily at night and when a person is relaxed. The uncomfortable sensation diminishes when the legs are moved. This is commonly associated with periodic limb movement disorder, in which a patient has limb movements during sleep. It usually causes insomnia and may cause daytime sleepiness.
PROBLEMS WITH ADHERING TO A REGULAR SLEEP SCHEDULE
Problems may also occur when maintaining a consistent sleep and wake schedule is disrupted. This occurs when traveling between times zones and with shift workers on rotating schedules, particularly nighttime workers.
Sleep disruption disorders include:
- Sleep state misperception (the person actually sleeps a different amount than they think they do)
- Shift work sleep disorder
- Natural short sleeper (the person sleeps less hours than normal but suffers no ill effects)
- Chronic time-zone-change syndrome
- Irregular sleep-wake syndrome
Abnormal behaviors during sleep are called parasomnias and are fairly common in children. They include:
- Sleep terror disorder
- Sleep walking
- REM behavior disorder (a type of psychosis related to lack of REM sleep and lack of dreaming)
In adults, sleepwalking may also be caused by an organic brain syndrome, reactions to drugs, psychological disorders, and certain medical conditions.
Symptoms
- Awakening in the night
- Difficulty falling asleep
- Excessive daytime drowsiness
- Loud snoring
- Episodes of stopped breathing
- Sleep attacks during the day
- Daytime fatigue
- Depressed mood
- Anxiety
- Difficulty concentrating
- Apathy
- Irritability
- Loss of memory (or complaints of decreased memory)
- Lower leg movements during sleep
- Polysomnography (recording brain activity, muscle activity and breathing during sleep)
- Multiple sleep latency test - a daytime test that uses polysomnography during multiple brief nap periods
INSOMNIA
The treatment is related to the cause, if the cause can be determined. If there is an obvious physical or psychological disorder causing insomnia, it should be treated. Depression is a very common cause of insomnia and can usually be treated with medication, cognitive behavioral therapy, or interpersonal therapy.
Attempts to control environmental and lifestyle factors should be made; these factors include:
- Erratic hours of wakefulness
- Too much light
- Too much noise
- Too much caffeine or other stimulants
HYPERSOMNIA
Sleep apnea is treated with weight reduction and the administration of air under pressure through the nose. Occasionally, surgery or other measures may be needed.
Narcolepsy is treated by use of stimulating medications during the daytime. A new medication called modafanil seems to have fewer side effects than traditional stimulants. It is FDA-approved for narcolepsy and has recently been approved for shift work sleep disorder .
Restless leg syndrome is treated by treating the underlying disorder and with opiate or dopaminergic agonists -- these are medications that work by stimulating the receptors for dopamine and opiates in the brain.
PARASOMNIA
Night terrors are treated with hypnosis, guided imagery techniques and benzodiazepines, but safety measures may be needed to prevent people from harm during nighttime walking.
Sleep disorder clinics often are able to help people restore normal sleeping patterns through various techniques.
Expectations (prognosis)
The outcome varies with the type of disorder. Some disorders may clear up on their own.
Complications
A complication is dependence upon sedatives or other medications prescribed for sleep disorders.
Prevention
Maintaining regular sleep habits and a quiet sleep environment may prevent some sleep disorders.
Informations obtained from National Institute of Health.