Parasomnias are undesirable events occurring during sleep or during the transition into or out of sleep. They may occur during non-rapid eye movement (NREM) or rapid eye movement (REM) sleep, depending on the type of parasomnia.
They include abnormal behaviours (e.g., sleep-related eating) or dreams (e.g., nightmare disorder).
Diagnosis relies mainly on careful history from the patient or, more commonly, the bed partner or other household members.
Treatment is indicated if the parasomnia may result in injury to patient or bed partner or if sleep is significantly disrupted.
Management depends on the type of parasomnia and includes reassurance, sleep environment modification, cognitive therapy, and pharmacotherapy.
Parasomnias are undesirable sleep-related events that may occur during sleep or during the transition into sleep or out of sleep. They include abnormal behaviours (e.g., sleepwalking) and dreams (e.g., nightmares). Parasomnias may be transient and have no significant consequences on the patient's sleep health. However, in some cases they are severe or persistent enough to cause significant sleep disruption and distress or injury to the patient or bed partner.
History and exam
Key diagnostic factors
- known condition causing sleep fragmentation/deprivation
- normal physical examination between episodes
- cognitive disturbance during event (confusional arousals, sleep terrors, and sleepwalking)
- cognitive disturbances in between episodes (rapid eye movement sleep behaviour disorder)
- sensation of a sudden loud noise in the head (exploding head syndrome)
- vigorous or violent behaviour during episode (confusional arousals, sleepwalking, sleep terrors, and rapid eye movement sleep behaviour disorder)
- episodes of inability to move during episode (recurrent isolated sleep paralysis)
- eating behaviour during the night (sleep-related eating disorder)
- evidence of external injuries (rapid eye movement sleep behaviour disorder)
- evidence of fear during episode demonstrated by autonomic hyperactivity (sleep terrors, nightmare disorder)
Other diagnostic factors
- abnormal facial expression during episode (confusional arousals, sleepwalking, sleep terrors, rapid eye movement sleep behaviour disorder)
- parkinsonian signs (rapid eye movement sleep behaviour disorder)
- history of childhood parasomnias (non-rapid eye movement parasomnias)
- age >60 years (rapid eye movement sleep behaviour disorder)
- male sex (rapid eye movement sleep behaviour disorder)
- female sex (nightmare disorder, isolated recurrent sleep paralysis)
- family history (confusional arousals, sleepwalking, sleep terrors)
- presence of human leukocyte antigen gene DQB1 (sleepwalking)
- obstructive and central sleep apnoea (mainly non-rapid eye movement sleep parasomnias)
- periodic limb movement disorder (mainly non-rapid eye movement sleep parasomnias)
- sleep deprivation (sleepwalking and sleep paralysis)
- stress (nightmare disorder)
- psychiatric disorders (nightmare disorder, sleep paralysis)
- neurological disorders (rapid eye movement sleep behaviour disorder)
- medicines such as venlafaxine, SSRIs (rapid eye movement sleep behaviour disorder, nightmare disorder)
- forced awakenings
- eating disorder (sleep-related eating disorder)
- history of sleepwalking, sleeptalking, and periodic limb movements of sleep (sleep-related eating disorder)
1st investigations to order
- polysomnography (PSG) (in rapid eye movement sleep behaviour disorder [RBD])
Investigations to consider
- PSG (in confusional arousals)
- PSG (in sleepwalking)
- PSG (in nightmare disorder)
- PSG (in sleep terrors)
- PSG (in all other parasomnias)
- electroencephalogram (EEG)
- urine drug screen
non-rapid eye movement (NREM) parasomnia
rapid eye movement (REM) parasomnia
Hrayr Attarian, MD
Director of the Center for Sleep Disorders
HA is an author of a number of references cited in this topic.
Dr Hrayr Attarian would like to gratefully acknowledge Dr Pierre Giglio, a previous contributor to this topic.
PG declares that he has no competing interests.
Bobbi Hopkins, MD
Baylor College of Medicine
Texas Children's Hospital
Clinical Care Center
BH declares that she has no competing interests.
Mark Mahowald, MD
Professor and Chairman
Department of Neurology
Hennepin County Medical Center
MM is an author of a number of references cited in this topic.
- seizures (sleep related)
- nocturnal dissociative disorder
- BAP consensus statement on evidence-based treatment of insomnia, parasomnias and circadian rhythm disorders: an update
- Position paper for the treatment of nightmare disorder in adults
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