Parasomnias

Also called Sleepwalking, Night terrors, Nightmares, Sleep paralysis, REM sleep behaviour disorder

Odd things happening during sleep. Common and harmless in children; in an older adult, acting out dreams is an early warning worth knowing about.

What it is

Unwanted events during sleep. Several distinct things are grouped here because they are confused with each other.

**Night terrors** occur in the first few hours of sleep, usually in children. The child screams, appears terrified, is unresponsive, and remembers nothing afterwards. Nightmares are different: they occur later in the night, the person wakes properly, and they remember.

**Sleepwalking** also occurs early in the night, is common in children, runs in families, and is usually outgrown. The person is not aware and should be guided gently back to bed rather than woken.

**Sleep paralysis** is being unable to move on falling asleep or waking, sometimes with vivid hallucinations. It is frightening, harmless, and very common.

**REM sleep behaviour disorder** is the one that matters most in adults. Instead of being paralysed during dreaming, the person acts the dream out: shouting, punching, kicking, leaping from bed, sometimes injuring themselves or a partner. It occurs mainly in men over 50, and it is strongly associated with later development of Parkinson's disease, Lewy body dementia or multiple system atrophy, often many years ahead. It needs neurological assessment and, above all, making the bedroom safe.

Triggers for the childhood parasomnias are sleep deprivation, illness, fever, stress and a full bladder, and fixing those usually fixes the events.

Signs you might notice

Night terrors: screaming or thrashing in the first few hours, eyes open but unresponsive, sweating and a racing heart, no memory next day.

Sleepwalking: getting up and walking, glazed expression, clumsy or inappropriate actions, no memory.

Nightmares: waking distressed later in the night, with clear recall.

Sleep paralysis: unable to move for seconds to minutes on waking or falling asleep, sometimes with a sense of presence or hallucinations.

REM sleep behaviour disorder: shouting, swearing, punching or kicking during sleep; falling out of bed; injuring self or partner; and clear dream recall matching the actions.

See a doctor for: any injury; events that begin in adulthood; anything suggesting a seizure such as stereotyped repetitive movements, tongue biting or incontinence; excessive daytime sleepiness suggesting sleep apnoea or narcolepsy; or acting out dreams at any age.

How it can affect day-to-day life

For children, the reassurance is genuine: night terrors and sleepwalking are common, harmless and usually outgrown, and the child is not distressed even though the parent is.

The instinct to wake a sleepwalking or terrified child is wrong. It prolongs the episode and causes confusion. Guiding gently and staying quiet is better.

Safety is practical: locking external doors, stair gates, moving keys, and clearing the route.

Scheduled awakening, waking a child briefly around 15 to 30 minutes before the usual time of an event, works well for predictable episodes and is a simple intervention few families are told about.

For REM sleep behaviour disorder, the bedroom must be made safe immediately: padding, removing sharp furniture, a mattress on the floor, and sometimes partners sleeping separately, which is a real loss and should be acknowledged.

Telling somebody that a sleep disorder predicts a future neurological condition needs care and consent; some people want to know and some do not, and it should be their choice.

Supporting someone well

Protect sleep. Sleep deprivation is the biggest trigger for the childhood parasomnias; a regular routine and enough hours resolves most of them.

Do not wake a sleepwalker or a child in a night terror. Guide them gently, speak calmly, and keep them safe.

Make the environment safe: doors, stairs, windows, and clearing obstacles.

Try scheduled awakening for predictable episodes.

Treat what disturbs sleep underneath: a full bladder, fever, sleep apnoea, restless legs, reflux, and stress.

For acting out dreams, make the bedroom safe now and ask for referral to a sleep or neurology service.

For sleep paralysis, reassure: it is harmless, and improving sleep regularity reduces it.

Get any adult-onset event, injury, or possible seizure assessed properly.

Where to get help

A GP practice for events causing injury, adult-onset parasomnias, or possible seizures.

A sleep clinic or neurology service for REM sleep behaviour disorder.

Narcolepsy UK and the sleep charities for information on sleep disorders.

Parkinson's UK on 0808 800 0303 for the association with REM sleep behaviour disorder.