Parasomnias – with thanks to Dr Sophia Datsopoulos

A group of sleep disorders that are paroxysmal, predictable in timing in the sleep cycle and characterized by retrograde amnesia. Polysomnography (type of sleep study in which various parameters are measured in order to rule in or out various sleep disorders), if performed, is abnormal. Diagnosis is based on a thorough history; extensive work-up seldom necessary.

Focus on: ‘Pavor Nocturnus’ or Night Terrors

Children aged three to eight years, M>F. Often family history of night terrors or sleepwalking. Occur approximately 90 minutes into sleep,
during non-REM sleep.

Presentation: Child suddenly sits bolt upright, screams, and is inconsolable for up to 15 minutes, before relaxing and falling back to sleep
with no memory of the event the next morning. Tachycardia, tachypnoea and other signs of autonomic arousal are apparent.


– Reassure families that they have a benign course and are self-limiting

– Advise them not to attempt to wake the child during an episode and that comforting during the episode may delay its recovery

– Explore and alleviate any stress in the child’s environment. Encourage a relaxing bedtime routine

– If frequent and occurring at a specific times every night, behavioural interventions such as scheduled awakenings (see may be beneficial

– More severe forms may benefit from treatment with benzodiazepines (e.g., clonazepam) under direction of specialist services.

Main differential: nightmares – these can occur at any age, during the lighter stage of sleep when dreaming, and so tend to be later in the night.  Seizures due to temporal lobe epilepsy can appear similar to night terrors but the seizures are usually brief (30 seconds to a few minutes) and are more common in older children and adults.


Comparison: Night Terrors and Nightmares

Factor Sleep Terrors Nightmares
Age 3 – 8 years Any age
Gender M>F Either
Occurrence in sleep cycle NREM REM
Arousable? No Yes
Memory for event No Yes
Exacerbated by stress Yes Yes

REM = rapid eye movement; NREM = non-rapid eye movement.


Next month: Focus on: Somnambulism (sleep waking) and Somniloquy (sleep talking)


One thought on “Parasomnias

  1. There is a useful information leaflet that can be found through the Gillette children’s speciality healthcare website, an organisation based in the USA.

    The website has some useful links to various conditions, one of which is a leaflet for medical professionals looking at a comparison between night terrors and nocturnal frontal lobe epilepsy. It can be found at:

    Scroll down to the bottom of the page and click on “publications for medical professionals.”
    It can then be found as a publication under the date “2011.”

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