Thursday, 2 February 2012

Rare and Unusual Sleep Disorders

Parasomnias are unpleasant or undesirable behavioral or experiential phenomena that occur predominately or exclusively during sleep.[1] About 10% of Americans are believed to have 1 or more parasomnias.[2] These disorders may occur in either slow-wave (non-rapid eye movement [NREM]) sleep or rapid eye movement (REM) sleep. The most recognized parasomnias include sleepwalking and -talking, as well as night terrors, which are most commonly experienced by children.
Nocturnal eating and driving disorders[3] are rare parasomnias that were given increased scrutiny after being linked to zolpidem (Ambien®) several years ago. Likewise, the successful use of the "sleep defense" in recent murder and rape trials has brought attention to other unusual parasomnias, such as sleep violence and sleep sex.[4,5]

NREM Sleep Disorders
Disorders of arousal, such as sleepwalking and -talking, occur most often during NREM sleep and are the result of incomplete arousal from slow-wave sleep and sometimes from stage 2 sleep.[5] Some people are predisposed to confusional arousals, but certain drugs, caffeine and alcohol use before bedtime, and sleep deficit are also considered to be triggers.
Diagnosis of NREM sleep disorders should be done in a laboratory. Behavioral modification and talk therapy have been recommended for long-term management of NREM parasomnias. Pharmacologic agents should be considered only if the behaviors are hazardous or extremely disruptive.[5]

REM Behavior Disorders
A sleep disorder that occurs during REM sleep is known as a "REM behavior disorder" (RBD). Normal REM sleep is associated with skeletal muscle inhibition. When this inhibition becomes impaired, it can result in individuals acting out their dreams.
Unless triggered by pharmacologic agents, such as antidepressants, RBD is generally related to damage of pontomedullary brainstem structures.[6] It is estimated that 40%-65% of persons with an RBD will eventually develop a neurodegenerative disease, such as Parkinson disease or Lewy body dementia.[6] Because RBD can result in bodily injury or destruction of property, it is often treated with clonazepam and melatonin.[7] One study found that persons with RBD who do not respond to traditional therapy may benefit from a customized bed alarm.[8]

Sleep Violence
Sleep-related violence is aggressive behavior that stems from a disturbance or dysfunction during the sleep state. Less than 2% of the population is believed to exhibit signs of sleep violence. The condition is a concern, however, because it may result in physical harm of people or destruction of objects in the environment.[5] The condition is more likely to occur during NREM sleep, but it occasionally manifests as an RBD.
The evaluation of nocturnal violence should begin with a thorough history and detailed neurologic exam. Polysomnography should be used, and patients should be assessed for seizure activity and receive video monitoring. Treatment can range from behavioral modification to medication, depending on the severity of the condition and whether it occurs during NREM or REM sleep.

Sexsomnia[9] is characterized by uncontrolled and unaware sexual behaviors during sleep. These behaviors may involve masturbation and sexual behaviors with a partner. The term "sexsomnia" was coined by Shapiro and colleagues in research published in the Canadian Journal of Psychiatry in 2003.[10]
The journal Sleep looked at 31 published case reports of sleep sex in a 2007 review of parasomnias[11] and found that 48% of sexsomnia events included sleeptalking and moaning; 19.4% included groping, fondling, and attempts at intercourse with a partner; and 29% involved no behaviors other than pelvic movements by the sleeper. Treatment may include behavioral modifications and medication, such as clonazepam.
In August 2007, a jury acquitted a British Royal Air Force mechanic accused of raping a 15-year-old girl after he claimed sleepwalking and sexsomnia as a defense.[4]

Night Terrors
Night terrors,[12] sometimes called "sleep terrors," occur when a person, usually a child, awakens suddenly from sleep in a terrified state. These parasomnias mostly occur during NREM sleep and are more common in boys. Although it is rare in adults, some do experience night terrors. Alcohol use increases the likelihood of night terrors in adults.
Night terrors typically last only a few minutes, but they may be accompanied by thrashing movements; running; or other potentially hazardous motor activity, such as kicking or punching.[13]
For infrequent night terrors, treatment includes comforting the child. More frequent cases may require therapy or counseling. Benzodiazepines administered at bedtime may reduce night terrors but are rarely used as a treatment.[12]

Somniloquy (Sleeptalking)
Somniloquy, or sleeptalking, occurs in about 50% of children and about 5% of adults.[14] The talking can range from gibberish to more complex dialogues.[2] It may occur on its own or in combination with other sleep disorders, such as sleepwalking, sleepeating, sleep terrors, and RBD.[14]
Sleeptalking is typically harmless and does not require medical attention unless it is particularly dramatic or emotional. Refraining from consumption of alcohol and heavy meals before bed may reduce the incidence of sleeptalking. Stress reduction also may help alleviate this condition. In general, no treatment is required for this disorder.[2]

Somnambulism (Sleepwalking)
Somnambulism, or sleepwalking, is a parasomnia that typically occurs during deep sleep. Sleepwalkers usually have no memories of their actions and are difficult to arouse.[15] Like night terrors and sleeptalking, sleepwalking is more common in children. Occasional sleepwalking is believed to affect about 40% of children. After 10 years of age, the prevalence of sleepwalking declines.[16]
In some cases, sleepwalkers may talk; display inappropriate behavior, such as urinating in closets or next to toilets; scream, when walking occurs concurrent with a night terror; or violently attack someone trying to rouse them during a sleepwalking episode.[15]
Treatment of sleepwalking may include the use of antidepressants or sedative-hypnotics.[15] Hypnosis has also been shown to be effective in some cases.[17]

Nocturnal Eating Disorders
There are 2 types of nocturnal eating disorders: sleep-related eating disorder (SRED) and nocturnal eating syndrome (NES). The conditions are believed to be a combination of sleep disorder and eating disorder.[18] The term "NES" was coined in a 1955 study by eating disorder specialists, whereas SRED was identified by sleep researchers and is believed to be a parasomnia.[19]
SRED involves episodes of eating after an arousal from nighttime sleep, followed by amnesia.[20] SRED typically occurs in conjunction with other sleep disorders, such as sleepwalking, and has been identified as a potential side effect of some sleep medications.[3] NES, in contrast, may be considered an abnormality in the circadian rhythm of meal timing with a normal circadian timing of sleep onset.[20]
The antiseizure medication topiramate has been shown to be effective for treatment of both disorders.[18,20]

Sleepdriving is a poorly understood condition. It is believed to occur concurrently with somnambulism or as a result of certain sedating medications, such as zolpidem, eszopiclone, and zaleplon. Like sleepwalking and -eating, sleepdriving is a complex task that occurs while a person is asleep. As with other parasomnias, sleepdrivers often have no memory of this behavior once awakened.[21]
The link between zolpidem and sleepdriving has been scrutinized in several studies. One case series involving 8 clinical patients and 6 legal defendants charged with driving under the influence found that the concomitant ingestion of other sedating drugs, taking a higher dose of zolpidem, ingestion of zolpidem at times other than bedtime or when sleep is unlikely, poor management of pill bottles, a history of parasomnia, and living alone increased the risk for sleepdriving.[22] 

  1. Mahowald MW, Bornemann MC, Schenck CH. Parasomnias. Semin Neurol. 2004;24:283-292.
  2. Schenck CH. Sleep and parasomnias. National Sleep Foundation. Accessed January 5, 2011.
  3. DeNoon DJ. Ambien linked to 'sleep eating.' WebMD. March 15, 2006. Accessed November 3, 2011.
  4. Goldman R. Accused rapist's defense: 'I was sleepwalking.' ABC News. August 25, 2007. Accessed November 3, 2011.
  5. Morris S. Devoted husband who strangled wife in his sleep walks free from court. The Guardian. November 20, 2009. Accessed November 3, 2011.
  6. Postuma RB, Gagnon JF, Montplaisir JY. REM sleep behavior disorder: from dreams to neurodegeneration. Neurobiol Dis. 2011 Oct 14. [Epub ahead of print]
  7. Zadra A, Pilon M. NREM parasomnias. Handb Clin Neurol. 2011;99:851-868.
  8. Howell MJ, Arneson PA, Schenck CH. A novel therapy for REM sleep behavior disorder (RBD). J Clin Sleep Med. 2011;7:639-644A.
  9. Della Marca G, Dittoni S, Frusciante R, et al. Abnormal sexual behavior during sleep. J Sex Med. 2009;6:3490-3495.
  10. Shapiro CM, Trajanovic NN, Fedoroff JP. Sexsomnia -- a new parasomnia? Can J Psychiatry. 2003;48:311-317.
  11. Schenck CH, Arnulf I, Mahowald MW. Sleep and sex: what can go wrong? A review of the literature on sleep related disorders and abnormal sexual behaviors and experiences. Sleep. 2007;30:683-702.
  12. Kaneshiro NK. Night terror. MedlinePlus. Accessed January 4, 2012.
  13. Hoban TF. Sleep and its disorders in children. Semin Neurol. 2004;24:327-340.
  14. Sleep talking. American Academy of Sleep Medicine. Accessed January 5, 2012.
  15. Sleepwalking. National Sleep Foundation. Accessed January 5, 2012.
  16. Laberge L, Tremblay RE, Vitaro F, Montplaisir J. Development of parasomnias from childhood to early adolescence. Pediatrics. 2000;106(1 Pt 1):67-74.
  17. Hypnosis may help people with parasomnias such as nightmares, sleepwalking. American Academy of Sleep Medicine. Accessed January 5, 2012.
  18. Winkelman JW. Treatment of nocturnal eating syndrome and sleep-related eating disorder with topiramate. Sleep Med. 2003;4:243-246.
  19. Winkelman JW. Sleep-related eating disorder and night eating syndrome: sleep disorders, eating disorders, or both? Sleep. 2006;29:876-877.
  20. Inoue Y, Komada Y. [Sleep related eating disorder]. Seishin Shinkeigaku Zasshi. 2010;112:912-920.
  21. Kiume S. What drives sleep driving? PsychCentral. Accessed January 4, 2012.
  22. Poceta JS. Zolpidem ingestion, automatisms, and sleep driving: a clinical and legal case series. J Clin Sleep Med. 2011;7:632-638.

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