Chapter 52 - NREM parasomnias
Introduction
Parasomnias are undesirable physical or behavioral phenomena that occur during entry into sleep, within sleep, or during partial arousals from sleep (American Academy of Sleep Medicine, 2005). The focus of this chapter is confusional arousals, sleepwalking (somnambulism), and sleep terrors. These sleep disorders constitute the prototypic nonrapid-eye-movement (NREM) sleep parasomnias and are collectively termed “disorders of arousal” (Broughton, 1968) because of the autonomic and motor arousal that propels the patient towards partial wakefulness. A summary and comparison of the main features of NREM and REM sleep parasomnias are presented in Table 52.1.
Disorders of arousal are more common in childhood than in adulthood and their prevalence rate decreases significantly with age. However, whereas the occurrence of NREM parasomnias in children is frequently viewed as a relatively benign and common event that will resolve spontaneously, these disorders often pose greater problems, including social inconvenience and sleep-related injury, in affected adults. In fact, injurious NREM sleep parasomnias in adults may be more prevalent than commonly believed (Schenck et al., 1989, Ohayon et al., 1999, Mahowald and Schenck, 2000c).
The symptoms and manifestations of these NREM parasomnias can be considered along a spectrum. For instance, the patient's affective expression can range from calm to extremely agitated, and the actual physical behaviors can range from simple and isolated actions (e.g., sitting up in bed, mumbling, fingering bed sheets) to complex behaviors (e.g., rearranging furniture, inappropriate sexual activity, playing a musical instrument, driving an automobile). Moreover, an episode can be comprised of two overlapping disorders, such as a sleep terror followed by sleepwalking.
Disorders of arousal share a number of characteristics. Most episodes arise from sudden but incomplete arousal from slow-wave (stages 3 and 4) sleep (Jacobson et al., 1965, Kavey et al., 1990, Espa et al., 2000) and sometimes from stage 2 sleep (Kavey et al., 1990, Zucconi et al., 1995, Joncas et al., 2002). Consequently, these parasomnias tend to occur in the first third of the sleep period when slow-wave sleep (SWS) is predominant. Episodes are generally characterized by misperception and relative unresponsiveness to external stimuli, mental confusion, automatic behaviors, and variable retrograde amnesia. This state is indicative of a high arousal threshold. A common genetic component is also suspected, as a positive family history is often reported by people with an arousal disorder (Hublin et al., 1997, Hublin et al., 2001, Hublin and Kaprio, 2003).
Factors that deepen sleep, such as intense physical activity (Vecchierini, 2001), hyperthyroidism (Ajlouni et al., 2005), fever (Dorus, 1979, Kales et al., 1979, Larsen et al., 2004), sleep deprivation (Rauch and Stern, 1986, Mayer et al., 1998, Joncas et al., 2002), and neuroleptics (Charney, 1979, Landry and Montplaisir, 1998) or medications with depressive CNS effects (Lee-Chiong, 2002, Mahowald, 2002), can facilitate or precipitate NREM parasomnias in predisposed individuals. Factors that fragment sleep, including sleep-disordered breathing (Guilleminault et al., 1998, Espa et al., 2002, Guilleminault et al., 2005a), periodic leg movement syndrome (Guilleminault et al., 2003), stress (Kales et al., 1980b, Klackenberg, 1982, Crisp et al., 1990, Ohayon et al., 1999), and environmental or endogenous stimuli (Gastaut and Broughton, 1965, Kales et al., 1966, Broughton and Gastaut, 1974), can have similar effects. Hormonal factors may also influence the frequency with which women experience parasomnias, as sleep terrors and injurious sleepwalking can emerge premenstrually (Schenck and Mahowald, 1995b), and sleepwalking may decrease during pregnancy, particularly in primiparas (Hedman et al., 2002).
Some researchers (Mahowald and Schenck, 1992, Mahowald and Schenck, 1999, Mahowald and Schenck, 2005) have cogently argued that a proper understanding of many parasomnias rests on the appreciation that sleep and wakefulness are not always mutually exclusive states and that various variables implicated in generation of wakefulness, REM sleep, and NREM sleep (the three primary states of being) may occur simultaneously, interact dynamically, or oscillate rapidly. It should also be noted that NREM parasomnia-related behaviors are not unlike the natural occurrence of clinically wakeful behavior during physiological sleep documented in the animal kingdom (Almanar and Ball, 1994, Rattenborg et al., 1999).
Section snippets
Clinical features
That people sometimes experience confused awakenings from deep sleep in which they appear to be partially awake and partially asleep was noted over 150 years ago – a condition termed “ivresse du sommeil” (French) or “sleep drunkenness”. Other terms used to describe this disorder include Schaftrunkenheit (German) and Elpenor syndrome (derived from the story of Elpenor, who broke his neck during such an episode in Homer's The Odyssey).
Confusional arousals, often seen in children, consist of
Clinical features
Like some other parasomnias, sleepwalking was once thought to be a behavioral manifestation of dreaming-related processes. Sleepwalking is now considered a disorder of arousal involving a physiological dysfunction in the neural regulation of generalized cortical activation. Somnambulistic actions may be complex, such as dressing, playing a musical instrument, or driving a car, and may be performed with substantial dexterity; more often, however, they are mundane, stereotyped, and accompanied by
Clinical features
Sleep terrors, also known as night terrors, are sometimes called “pavor nocturnus” in children. As outlined by Broughton (2000), the term sleep terror is preferable to night terror, because episodes can occur during daytime sleep or naps. Historically, sleep terrors have been confused with nightmares, a distinct REM sleep parasomnia (see Chapter 53 for details of REM sleep parasomnias). Gastaut and Broughton (1965) first observed polysomnographically that sleep terrors were not associated with
Clinical Variants
The behaviors manifested during an arousal disorder can be relatively distinct and specialized. Two variants of NREM parasomnias involve sleep-related eating and sleep-related sexual behaviors.
NREM Parasomnias Associated with Primary Sleep Disorders
Several lines of evidence indicate that in both children and adult populations sleep terrors and sleepwalking can be secondary to sleep respiratory events, such as obstructive sleep apnea (OSA) and upper airway resistance syndrome, or to other sleep disorders. Parent-reported parasomnias in children with OSA suggest that sleep terrors and sleepwalking are more frequent in sleep-disordered children than in normative controls (Owens et al., 1997). Similar results were reported by Ipsiroglu et al.
NREM Parasomnias Associated with Medical Conditions
Rarely, NREM parasomnias may develop as a result of medical or neurological conditions. De novo sleep terrors have been reported in association with a right thalamic lesion (Di Gennaro et al., 2004) and a brainstem lesion (Mendez, 1992). De novo somnambulism has been described in patients presenting with thyrotoxicosis caused by diffuse toxic goiter or Graves' disease (Ajlouni et al., 2001, Ajlouni et al., 2005). Disorders of arousal can also be triggered by medication. These include
Diagnostic Considerations
The DSM-IV and ICSD-II clinical criteria for sleepwalking and sleep terrors are presented in Table 52.2. Diagnosis of NREM parasomnias can often be made based on a detailed history, including complete description of the time course and content of sleep-related behaviors. Given that variable retrograde amnesia characterizes disorders of arousal, descriptive information from family members or a bed partner can be particularly valuable. Similarly, home video recording may also be helpful in
Treatment
Several factors must be taken into account while considering treatment options for disorders of arousal. These include the frequency and chronicity of the episodes, the potential danger to the patient or to others, and the disruptive nature of the disorder for the patient, bed partner, or family. When the episodes are benign and not associated with harm potential, treatment is often unnecessary (Mahowald and Schenck, 1996). Reassuring the patient and significant others about the generally
References (185)
- et al.
Sleepwalking associated with hyperthyroidism
Endocr Pract
(2005) - et al.
Posttraumatic stress disorder in the spouse of a patient with sleep terrors
Sleep Med
(2003) - et al.
SPECT during sleepwalking
Lancet
(2000) - et al.
Sleep in children with episodic sleep phenomena: a comparison with the normal child
Electroencephalogr Clin Neurophysiol
(1978) - et al.
Sleepwalking: diagnosis and treatment through the life cycle
Psychosomatics
(1986) - et al.
The value of sleep recording in evaluating somnambulism in young adults
Electroencephalogr Clin Neurophysiol
(1991) Sleep-related violence: does the polysomnogram help establish the diagnosis?
Sleep Med
(2000)- et al.
Assessment and treatment of nocturnal panic attacks
Sleep Med Rev
(2005) - et al.
Night terrors associated with thalamic lesion
Clin Neurophysiol
(2004) - et al.
Behavioral intervention for childhood sleep terrors
Behav Ther
(1999)
Sleep architecture, slow wave activity, and sleep spindles in adult patients with sleepwalking and sleep terrors
Clin Neurophysiol
Sleep and wakefulness in somnambulism: a spectral analysis study
J Psychosom Res
Non-REM sleep instability in recurrent sleepwalking in pre-pubertal children
Sleep Med
Genetic aspects and genetic epidemiology of parasomnias
Sleep Med Rev
Self-reported organic and nonorganic sleep problems in schoolchildren aged 11 to 15 years in Vienna
J Adolesc Health
Serotonergic hypothesis of sleepwalking
Med Hypotheses
Predisposition to sleep-walking
Psychiatr Neurol (Basel)
Sleepwalking and recurrent sleeptalking in children of childhood sleepwalkers
Am J Psychiatry
De novo sleepwalking associated with hyperthyroidism
Sleep Hypn
Avian sleep
Sexual behavior in sleep, sleepwalking and possible REM behavior disorder: a case report
Sleep Res Online
ICSD-2: The International Classification of Sleep Disorders: Diagnostic and Coding Manual
Diagnostic and Statistical Manual of Mental Disorders: DSM-IV
Childhood migraine and somnambulism
Neurology
Somnambulism in children with Tourette syndrome
Dev Med Child Neurol
Sleepwalking in twins
Lancet
Disorders of arousal
Rev Neurol
Prevalence of sleep disorders in the Los Angeles metropolitan area
Am J Psychiatry
Conversion disorder revisited: severe parasomnia discovered
Aust N Z J Psychiatry
Sleep homeostasis and models of sleep regulation
Phasic and dynamic aspects of sleep: a symposium review and synthesis
NREM arousal parasomnias
Recent sleep research on enuresis nocturna, sleep walking, sleep terrors and confusional arousals: a review of dissociative awakening disorders in slow wave sleep
Homicidal somnambulism: a case report
Sleep
Sleep disorders: disorders of arousal?
Science
l-5-Hydroxytryptophan treatment of sleep terrors in children
Eur J Pediatr
Sleepwalking and indecent exposure
Med Sci Law
Treatment of pavor nocturnus with alprazolam
J Clin Psychiatry
Sleepwalking violence: a sleep disorder, a legal dilemma, and a psychological challenge
Am J Psychiatry
Sleep architecture in psychotropic-induced somnambulism
Am J Psychiatry
Somnambulistic-like episodes secondary to combined lithium-neuroleptic treatment
Br J Psychiatry
Elimination of sleepwalking in a seven-year-old boy
J Consult Clin Psychol
Treatment of coexistent night-terrors and somnambulism in adults with imipramine and diazepam
J Clin Psychiatry
Sleepwalking, night terrors, and consciousness
BMJ
Three cases of familial somnambulism
Ann Med Interne (Paris)
Sleepwalking and aggressive behavior in sleep
Sleep
The natural history of night terrors
Clin Pediatr (Phila)
Sleepwalking and febrile illness
Am J Psychiatry
Treating sleep terrors in children with autism
J Positive Behav Interv
The hypnotic treatment of sleepwalking in an adult
Am J Clin Hypn
Cited by (38)
The Clinical Spectrum of the Parasomnias
2024, Sleep Medicine ClinicsSleep in chronic pain and other pediatric conditions
2023, Encyclopedia of Sleep and Circadian Rhythms: Volume 1-6, Second EditionParasomnia versus epilepsy: An affair of the heart?
2018, Neurophysiologie CliniqueThe sleeping brain in Parkinson's disease: A focus on REM sleep behaviour disorder and related parasomnias for practicing neurologists
2017, Journal of the Neurological SciencesCitation Excerpt :Therefore, clues pointing to out-of-bed activities should prompt physicians to consider the possibility of sleepwalking in those patients, as the recognition of these episodes is vital to allow appropriate intervention that can improve the quality of sleep for both patients and caregivers as well as prevent possible injuries. Sleep terrors are characterized by a scream or a cry for help, associated with intense autonomic activation (tachycardia, tachypnea), and overwhelming anxiety and fear [49]. Sleep terrors may be accompanied by sleepwalking episodes, but this association has never been reported in PD patients.
Confusional arousals, sleep terrors, and sleepwalking
2014, Sleep Medicine ClinicsCitation Excerpt :These episodes are essentially confused awakenings whereby the patient might sit up in the bed and perform some movements with or without some vocalizations, with no ambulation. If awakened, the patient is confused and has little or no recollection of the event.27 Sleepwalking episodes may begin as confusional arousals or with the patient immediately leaving the bed after getting up.
Parasomnias and isolated sleep symptoms in Parkinson's disease: A questionnaire study on 661 patients
2014, Journal of the Neurological SciencesCitation Excerpt :According to the ICSD-3 the diagnosis of a typical parasomnia can be based on history and clinical examination. A polysomnography is not necessary, but in case of doubt it is recommended [4]. The diagnosis of RBD can be based on history but the definitive diagnosis of RBD requires polysomnographic (PSG) documentation as one of the essential diagnostic criterion is REM sleep without muscle atonia (RWA).