Synopsis
Differentiate common non-REM and REM parasomnias from seizures and other nocturnal events, prioritise environmental safety, and refer new, injurious or diagnostically uncertain presentations appropriately.
- Parasomnias are unwanted behaviours, experiences or autonomic events arising from sleep, sleep-stage transitions or partial arousal.
- Non-REM disorders of arousal usually occur in the first third of the night, with incomplete waking, confusion and little detailed recall.
- Nightmares usually arise from REM sleep later in the night and are vividly recalled after full awakening without complex dream enactment.
- REM sleep behaviour disorder causes loss of normal REM atonia with dream enactment and may injure the person or bed partner.
- First address safety, sufficient sleep and triggers including sleep deprivation, alcohol, sedatives, stress, fever and untreated sleep apnoea.
- During an ordinary night terror or sleepwalking episode, remain calm, guide away from danger and avoid forceful waking or restraint.
- Video, witness description and timing are useful; video-polysomnography is considered for suspected REM behaviour disorder, epilepsy or atypical injury.
- New adult REM behaviour disorder warrants sensitive neurological review because it can precede a neurodegenerative syndrome, but risk is discussed without deterministic prediction.
Key red flags
New adult-onset dream enactment, recurrent injury or complex violent behaviour requires sleep-specialist assessment for REM sleep behaviour disorder.
Highly stereotyped frequent episodes, daytime seizures, focal signs, tongue injury or prolonged post-event confusion raises concern for nocturnal epilepsy.
Snoring, witnessed apnoeas, choking or marked daytime sleepiness suggests sleep-disordered breathing that may precipitate arousals.
Leaving the home, weapons, falls, fire risk, safeguarding concerns or an unsafe bed partner requires immediate environmental risk reduction.
Investigation priorities
Establish clock time, interval from sleep onset, duration, behaviour, responsiveness, recall, recovery, triggers and injury.
Management branches
A nocturnal behaviour could lead to falls, injury, leaving home or harm to another person.
- Clear sharp objects, secure stairs, doors and windows, remove weapons and fire hazards, and consider temporary separate sleeping if needed.
- During an event, stay calm, avoid forceful restraint or abrupt waking, and gently guide the person away from danger if feasible.
- Assess injury and breathing, seek urgent help for prolonged altered awareness or instability, and document an emergency plan for recurrence.