Sleep disorder

A sleep disorder, or somnipathy, is a medical disorder of the sleep patterns of a person or animal. Some sleep disorders are serious enough to interfere with normal physical, mental and emotional functioning. Polysomnography is a test commonly ordered for some sleep disorders.

Disruptions in sleep can be caused by a variety of issues, from teeth grinding (bruxism) to night terrors. When a person suffers from difficulty in sleeping with no obvious cause, it is referred to as insomnia.^[1] In addition, sleep disorders may also cause sufferers to sleep excessively, a condition known as hypersomnia. Management of sleep disturbances that are secondary to mental, medical, or substance abuse disorders should focus on the underlying conditions.

Common disorders

The most common sleep disorders include:

• Primary insomnia: Chronic difficulty in falling asleep and/or maintaining sleep when no other cause is found for these symptoms.
• Bruxism: Involuntarily grinding or clenching of the teeth while sleeping.
• Delayed sleep phase syndrome (DSPS): inability to awaken and fall asleep at socially acceptable times but no problem with sleep maintenance, a disorder of circadian rhythms. (Other such disorders are advanced sleep phase syndrome (ASPS), non-24-hour sleep-wake syndrome (Non-24), and irregular sleep wake rhythm, all much less common than DSPS, as well as the transient jet lag and shift work sleep disorder.)
• Hypopnea syndrome: Abnormally shallow breathing or slow respiratory rate while sleeping.
• Narcolepsy: Excessive daytime sleepiness (EDS) often culminating in falling asleep spontaneously but unwillingly at inappropriate times.
• Cataplexy: a sudden weakness in the motor muscles that can result in collapse to the floor.
• Night terror: Pavor nocturnus, sleep terror disorder: abrupt awakening from sleep with behavior consistent with terror.
• Parasomnias: Disruptive sleep-related events involving inappropriate actions during sleep; sleep walking and night-terrors are examples.
• Periodic limb movement disorder (PLMD): Sudden involuntary movement of arms and/or legs during sleep, for example kicking the legs. Also known as nocturnal myoclonus. See also Hypnic jerk, which is not a disorder.
• Rapid eye movement behavior disorder (RBD): Acting out violent or dramatic dreams while in REM sleep (REM sleep disorder or RSD)
• Restless legs syndrome (RLS): An irresistible urge to move legs. RLS sufferers often also have PLMD.
• Situational circadian rhythm sleep disorders: shift work sleep disorder (SWSD) and jet lag.
• Sleep apnea, and mostly obstructive sleep apnea: Obstruction of the airway during sleep, causing lack of sufficient deep sleep; often accompanied by snoring. Other forms of sleep apnea are less common. The air is blocked from entering into the lungs, causing the individual to unconsciously gasp for air. The individual will pause for an average of ten seconds in order to breathe. This is commonly found in overweight, middle-aged men but is also found in people who have suffered from stroke.
• Sleep paralysis: is characterized by temporary paralysis of the body shortly before or after sleep. Sleep paralysis may be accompanied by visual, auditory or tactile hallucinations. Not a disorder unless severe. Often seen as part of narcolepsy.
• Sleepwalking or somnambulism: Engaging in activities that are normally associated with wakefulness (such as eating or dressing), which may include walking, without the conscious knowledge of the subject.
• Nocturia: A frequent need to get up and go to the bathroom to urinate at night. It differs from Enuresis, or bed-wetting, in which the person does not arouse from sleep, but the bladder nevertheless empties.^[2]
• Somniphobia: a dread of sleep.

Types

• Dyssomnias - A broad category of sleep disorders characterized by either hypersomnolence or insomnia. The three major subcategories include intrinsic (i.e., arising from within the body), extrinsic (secondary to environmental conditions or various pathologic conditions), and disturbances of circadian rhythm. MeSH
  • Insomnia: Insomnia is often a symptom of a mood disorder (i.e., emotional stress, anxiety, depression) or underlying health condition (i.e., asthma, diabetes, heart disease, pregnancy or neurological conditions). ^[3]
  • Narcolepsy: A chronic neurological disorder (or dyssomnia), which is caused by the brain's inability to control sleep and wakefulness.^[4]
  • Sleep Disordered Breathing (SDB), including (non exhaustive):
    • Several types of Sleep apnea
    • Snoring
    • Upper airway resistance syndrome
  • Restless leg syndrome
  • Periodic limb movement disorder
  • Hypersomnia
    • Recurrent hypersomnia - including Kleine-Levin syndrome
    • Posttraumatic hypersomnia
    • "Healthy" hypersomnia
  • Circadian rhythm sleep disorders
    • Delayed sleep phase syndrome
    • Advanced sleep phase syndrome
    • Non-24-hour sleep-wake syndrome
  • Parasomnias - A category of sleep disorders that involve abnormal and unnatural movements, behaviors, emotions, perceptions, and dreams in connection with sleep.
  • REM sleep behaviour disorder
  • Sleep terror (or Pavor nocturnus)- Characterized by a sudden arousal from deep sleep with a scream or cry, accompanied by some behavioral manifestations of intense fear.^[5]
  • Sleepwalking (or somnambulism)
  • Bruxism (Tooth-grinding)
  • Bedwetting or sleep enuresis.
  • Sleep talking (or somniloquy)
  • Sleep sex (or sexsomnia)
  • Exploding head syndrome - Waking up in the night hearing loud noises.
• Medical or Psychiatric Conditions that may produce sleep disorders
  • Psychosis (such as Schizophrenia)
  • Mood disorders
    • Depression
    • Anxiety
  • Panic
  • Alcoholism
• Sleeping sickness - a parasitic disease which can be transmitted by the Tsetse fly.

General principles of treatment

Treatments for sleep disorders generally can be grouped into four categories:

• Behavioral and psychotherapeutic treatment

• Rehabilitation and management

• Medication

• Other somatic treatment

None of these general approaches is sufficient for all patients with sleep disorders. Rather, the choice of a specific treatment depends on the patient's diagnosis, medical and psychiatric history, and preferences, as well as the expertise of the treating clinician. Often, behavioral/psychotherapeutic and pharmacological approaches are not incompatible and can effectively be combined to maximize therapeutic benefits. Management of sleep disturbances that are secondary to mental, medical, or substance abuse disorders should focus on the underlying conditions.

Medications and somatic treatments may provide the most rapid symptomatic relief from some sleep disturbances. Some disorders, such as narcolepsy, are best treated pharmacologically. Others, such as chronic and primary insomnia, may be more amenable to behavioral interventions, with more durable results.

Chronic sleep disorders in childhood, which affect some 70% of children with developmental or psychological disorders, are under-reported and under-treated. Sleep-phase disruption is also common among adolescents, whose school schedules are often incompatible with their natural circadian rhythm. Effective treatment begins with careful diagnosis using sleep diaries and perhaps sleep studies. Modifications in sleep hygiene may resolve the problem, but medical treatment is often warranted.^[6]

Special equipment may be required for treatment of several disorders such as obstructive apnea, the circadian rhythm disorders and bruxism. In these cases, when severe, an acceptance of living with the disorder, however well managed, is often necessary.

Some sleep disorders have been found to compromise glucose metabolism.^[7]

Sleep medicine

Due to rapidly increasing knowledge about sleep in the 20th century, including the discovery of REM sleep and sleep apnea, the medical importance of sleep was recognized. The medical community began paying more attention than previously to primary sleep disorders, such as sleep apnea, as well as the role and quality of sleep in other conditions. By the 1970s in the USA, clinics and laboratories devoted to the study of sleep and sleep disorders had been founded, and a need for standards arose.

Sleep Medicine is now a recognized subspecialty within internal medicine, family medicine, pediatrics, otolaryngology, psychiatry and neurology in the United States. Certification in Sleep Medicine shows that the specialist:

"has demonstrated expertise in the diagnosis and management of clinical conditions that occur during sleep, that disturb sleep, or that are affected by disturbances in the wake-sleep cycle. This specialist is skilled in the analysis and interpretation of comprehensive polysomnography, and well-versed in emerging research and management of a sleep laboratory."^[9]

Competence in sleep medicine requires an understanding of a myriad of very diverse disorders, many of which present with similar symptoms such as excessive daytime sleepiness, which, in the absence of volitional sleep deprivation, "is almost inevitably caused by an identifiable and treatable sleep disorder", such as sleep apnea, narcolepsy, idiopathic central nervous system (CNS) hypersomnia, Kleine-Levin syndrome, menstrual-related hypersomnia, idiopathic recurrent stupor, or circadian rhythm disturbances.^[10] Another common complaint is insomnia, a set of symptoms which can have a great many different causes, physical and mental. Management in the varying situations differs greatly and cannot be undertaken without a correct diagnosis.

Sleep dentistry (bruxism, snoring and sleep apnea), while not recognized as one of the nine dental specialties, qualifies for board-certification by the American Board of Dental Sleep Medicine (ABDSM). The resulting Diplomate status is recognized by the American Academy of Sleep Medicine (AASM), and these dentists are organized in the Academy of Dental Sleep Medicine (USA).^[11] The qualified dentists collaborate with sleep physicians at accredited sleep centers and can provide oral appliance therapy and upper airway surgery to treat or manage sleep-related breathing disorders.^[12]

In the UK, knowledge of sleep medicine and possibilities for diagnosis and treatment seem to lag. Guardian.co.uk quotes the director of the Imperial College Healthcare Sleep Centre: "One problem is that there has been relatively little training in sleep medicine in this country – certainly there is no structured training for sleep physicians."^[13] The Imperial College Healthcare site^[14] shows attention to obstructive sleep apnea syndrome (OSA) and very few other sleep disorders.

See also

• Chronotypes
• Environmental noise health effects
• International Classification of Sleep Disorders
• National Sleep Foundation
• Reversed vegetative symptoms
• Sleep hygiene
• Sundowning (dementia)
• White noise machine
• Sleep medicine
• Polysomnography
• Polysomnographic technician

References

External links

• Sleep Problems - information leaflet from mental health charity The Royal College of Psychiatrists
• List of sleeping disorders
• Sleep Disorders ePatient website