Parasomnias are disorders resulting in abnormal events during the night such as sleepwalking, sleep terrors and bruxism (tooth-grinding).
Most can be divided into disorders that affect either rapid-eye movement (REM) or non-rapid eye movement (NREM) sleep. Some parasomnias are not confined to any particular sleep stage.
The table below shows a list of what are considered completely normal events during NREM and REM sleep.
Table 1: Normal Events during NREM and REM sleep
| NREM sleep | REM sleep |
|---|---|
| Sleep starts | Isolated sleep paralysis |
| Exploding head syndrome (see links below) | Isolated hypnagogic/ hypnopompic hallucinations |
| Explosive tinnitus (see links below) |
Both sleep paralysis and hypnagogic hallucinations occurring in isolation are strongly associated with anxiety, poor sleep hygiene and retiring to bed in the early hours of the morning.
Which events are abnormal during sleep?
Table 2 shows a list of what are considered abnormal events during NREM and REM sleep.
Table 2: Abnormal Events during NREM and REM sleep
| NREM sleep | REM sleep |
|---|---|
| Sleep-sex | REM sleep behaviour disorder |
| Confusional arousals | REM-related painful erections |
| Sleepwalking | REM-related painful erections |
| Sleep terrors | |
| Sleep-related eating disorder |
What are the disorders that occur throughout sleep?
Other parasomnias include nocturnal groaning; bruxism (tooth grinding); enuresis (bed-wetting); rhythmic rocking movement disorder and sleep talking.
Be alert for the possibility of sleep-related epilepsy.
What can trigger an abnormal event during sleep?
A number of factors can trigger a parasomnia or make it occur more frequently. These include fever, alcohol, prior sleep deprivation, physical activity, emotional stress and various medications. Parasomnias can also be worsened by pregnancy or menstruation and sleep-disordered breathing. There is often interaction between genetic and environmental factors to cause these problems.
When should medical help be sought with a parasomnia?
We recommend that further advice is sought if behaviours are potentially violent/injurious; disruptive to household or family; result in complaints of excessive daytime sleepiness or are associated with medical, psychiatric or neurological symptoms and findings.
REM-behaviour disorder – special note
This is a disorder that can occur at any age and both sexes but is more common in middle-aged to older men. It occurs during REM sleep when a person tries to act out their dreams, usually in a violent or disturbing manner. Instead of the body being paralysed, it is active and acting out the dream. People with REM-behaviour disorder can often injure themselves and their partners, sometimes seriously. REM-behaviour disorder can occur spontaneously, secondary to some medications, in the context of trauma and cPTSD/PTSD or as the first sign of other neurological disorders such as Parkinson’s disease. The disorder can be treated but should always be diagnosed and managed by a sleep specialist.
Is there any treatment for sleep-talking, sleep-walking and night terrors?
Treatment should be discussed with a medical expert. If the behaviours occur infrequently, then no specific treatment is usually necessary. If the behaviours are causing problems, then there are a number of medications that can be used to treat them. Occasionally, psychotherapy, progressive relaxation and hypnosis can be useful.
Who can refer:
All healthcare professionals who have concerns about a parasomnia affecting their patient
Who to refer:
Any patient who is experiencing considerable distress secondary to a parasomnia
Any patient with:
- potentially violent/injurious behaviour
- behaviours disruptive to household or family
- behaviour resulting in complaints of excessive daytime sleepiness
- behaviours associated with medical, psychiatric or neurological symptoms and findings
We welcome advice only referrals
Who not to refer:
Isolated sleep paralysis – please explore principles of sleep hygiene and issues with anxiety
Isolated hypnogogic/hypnopompic hallucinations
Rarely occurring or isolated/situational behaviours e.g. one episode on holiday in a new hotel
NREM-parasomnia behaviours considered to be ‘normal’
Bruxism (tooth-grinding)
Behaviours occurring only in the context of significant alcohol intake
How to refer:
Sci-Gateway: RIE > Respiratory Sleep > LI Sleep Referral
Or via headed letter to:
Department of Sleep Medicine
Royal Infirmary of Edinburgh
51 Little France Crescent
Old Dalkeith Road
Edinburgh
EH16 4SA
Please discuss and ensure that the patient is following principles of good sleep hygiene, discuss alcohol and drug intake, smoking and caffeine containing drinks. Regular bed-times and exercise are also helpful.
Many parasomnias are linked to issues with anxiety and mood dysregulation.
If there are significant mental health issues, please refer or treat appropriately through mental health pathways.
Medications useful in the treatment of stress-related and situational parasomnias e.g. rare episodes of sleepwalking, confusional arousals: zopiclone as needed, low-dose amitriptyline starting at 10-20 mg, other low-dose tricyclic anti-depressants, trazadone starting at 50mg nocte.
Counselling on bedroom safety and safety in the house. Ensure no sharp or dangerous objects next to bed, mattress on floor if necessary, bolster between co-sleepers, locks on doors and windows etc.
Please stop any medications that are likely to induce or exacerbate a parasomnia, cause severe nightmares etc. The biggest culprits are beta-blockers, statins and SSRIs.
Bruxism is generally addressed by dental professionals.
However, it is associated with stress and anxiety. Addressing these concerns and lifestyle may lead to improvement. If the bruxism is very severe, referral for botox treatment and for construction of a mandibular advancement device by an orthodontist is appropriate (may not be NHS funded).
