Non-REM parasomnias
Sleep terrors, confusional arousals and sleepwalking are disorders of arousal from non–rapid eye movement (non-REM) sleep. During these parasomnias, which typically occur during the first half of sleep, a person appears to be awake and asleep at the same time. Upon waking, the event is usually not remembered.
A sleep terror (night terror) is characterised by an intense feeling of fear often accompanied by screaming and crying, violent thrashing movements and autonomic activation (eg sweating and tachycardia). The person may not wake during the sleep terror but, if they do, can be disorientated.
A confusional arousal is characterised by confusion upon arousal from sleep. The person may sit up in bed, look around and speak, but appear confused and unaware of their surroundings. These episodes are short; the person usually returns to sleep.
Sleepwalking occurs when a person who is asleep walks and potentially engages in an activity (eg talking, driving, cooking, moving furniture).
Non-REM parasomnias are common and most frequently occur in children. Stress, sleep deprivation, drugs (especially alcohol, zolpidem, lithium), physical illness and other sleep disorders (eg sleep-disordered breathing, periodic limb movements) can be precipitants. If a non-REM parasomnia first presents in adulthood, it is likely to be caused by an adverse drug effect, stress or a neurological disorder (eg sleep-related epilepsy).
Manage a non-REM parasomnia by educating the person and their significant other(s) about the condition. Patient information on sleep terrors and sleep walking is available on the Sleep Health Foundation website. The Royal Children’s Hospital provides advice for parents with children who have sleep terrors (see here) or sleepwalk (see here).
As people do not usually recall non-REM parasomnias, distress may be minimised by not waking them during an episode. If a drug is suspected to be causing the parasomnia, reduce the dose or stop the drug if possible. If lack of sleep is a likely precipitant, see here for advice for adults and the Raising Children website for advice for children and adolescents.
If sleepwalking is frequent or dangerous to the patient or others, make the sleeping environment safe. As relevant, recommend:
- locking windows and external doors
- removing breakable objects
- lowering the patient’s mattress to the floor
- for the patient to use a bedroom on the ground floor or, if this is not possible, to place a barrier at the top of stairs.
Refer the patient to a sleep specialist, and in the case of children, a paediatrician, if:
- sleepwalking is dangerous
- sleep terrors are severe and recurrent
- episodes of sleepwalking, sleep terrors or confusional arousals persist despite the interventions described above.
Pharmacotherapy is rarely required for non-REM parasomnias. However, sleep specialists will sometimes use a benzodiazepine if sleepwalking or sleep terrors are significantly affecting the patient’s quality of life or placing them or those around them in danger, and other interventions are ineffective.