So I’ve just got back from an unusually showbiz morning.. a trip to the ITV studios to meet two women who have experienced bizarre bouts of cleaning and online shopping in their sleep.
We only had a few minutes on the This Morning couch for Anita and Kelly to share their stories, so I thought I’d explain a bit more about what causes sleepwalking, and how it is treated. You can watch the full interview with Mark and Rochelle here, or in the link below.
What are parasomnias?
Parasomnias are a group of sleep disorders characterised by abnormal behaviours during sleep. They happen because of faulty transitions between the stages of sleep, or between sleep and wakefulness. In sleepwalking, wakefulness, or arousal, interrupts deep sleep.
What type of parasomnia do I have?
There are two main families of parasomnias, depending on which stage of sleep is disrupted. In this post I’m going to focus on the most common non-REM parasomnias: sleep walking, confusional arousals, night terrors. (REM parasomnias include nightmares, sleep paralysis, and REM sleep behaviour disorder - or sleep aggression. I'll cover these in a separate post.)
We sleep in a series of 5 or 6 sleep cycles every night. Each cycle involves three stages of progressively deeper sleep (somewhat unimaginatively called: Stage 1, Stage 2 & Stage 3 non-REM sleep!), followed by a light phase of Rapid Eye Movement sleep, or REM sleep, which is associated with dreaming. We usually have more non-REM sleep in the first half of the night, so sleepwalking is more common before 2am, whereas nightmares are more common in the second half of the night.
1. Sleepwalking
Both Anita and Kelly describe sleepwalking, or somnambulism, which happens when arousal creeps into the deepest phase of sleep. When you meet a sleepwalker you might initially think they’re awake - their eyes are open, and they are partially responsive to sounds, but the parts of the brain responsible for rational thinking and conscious awareness are out of action. The sleepwalker will usually have no memory of the event.
Sleeperwalkers’ actions tend to be familiar and automatic, but can be surprisingly complex and are often entirely inappropriate. Anita was only prevented from a naked roam around Las Vegas by intervention from her lighter sleeping partner. Kelly’s involuntary online sleep purchases included a year’s worth of Haribo and a full size basketball court. (When I met Kelly, her petite stature suggested that she was not a basketball player.)
Unsurprisingly these events led to huge anxiety for Anita, Kelly and their families.
Other parasomnia behaviours include sending emails and texts, playing a musical instrument, climbing out of windows, sexual acts (sexsomnia), compulsive eating (sleep-related eating disorder) and even driving a car. Sleepwalking has even been used successfully as a defence in murder trials.
Q: Should you wake a sleepwalker?
Do try and wake them if they are at risk to themselves or others, otherwise guide them gently back to bed. Sleepwalkers will be very confused if they wake up, and may become anxious or aggressive, so be gentle and reassuring.
2. Confusional arousals
Confusional arousals often include sleep talking or mumbling, and are also termed ‘sleep drunkenness’. Like sleep walking, most episodes are short, but can persist for more than an hour.
3. Night terrors
If you’ve ever seen someone in the grips of a night terror, you will undoubtedly remember it - but they usually will not. More common in children, these usually start with a sudden cry of terror, followed by shaking, sweating, hysterics or attempting to run from a threat. If you try and wake the sleeper up, the symptoms may get worse. The best thing is to speak to them gently to try and help calm them down, and stop them jumping out of bed. The terror will pass, and remarkably, they are unlikely to remember it.
How many people experience non-REM parasomnias?
Parasomnias are most common in children, probably because their sleep-wake regulation is still not fully developed. Around 17% of children sleepwalk, and perhaps 7% experience night terrors. When parasomnias affect adults, it’s often a recurrence of an issue that started in childhood, but not always. We don’t know exactly how many people sleepwalk in adulthood, because there may be under-reporting, but it’s probably between 1 and 4% of the population.
What causes parasomnias?
Anything which disrupts natural sleep cycles could provoke parasomnias, especially in those with a genetic predisposition.
Triggers can include excess caffeine, or alcohol, a change in medication, pain, fever, noise or being under prolonged stress, which leads to lighter, more fragmented sleep. Sleeping pills and antidepressants are often a trigger.
If you’re short of sleep, parasomnias become more likely - it’s as if the brain is so desperate to catch up on lost sleep that it resists attempts to pull it fully from one stage to another.
While most parasomnias are benign, they may be symptoms of an underlying condition which warrants treatment (see below). Medical causes include sleep disorders, and some neurological and psychiatric conditions.
How are parasomnias treated?
If the parasomnia is an isolated event, and doesn’t cause any serious risk of harm, it usually doesn’t require any intervention, and will resolve itself. However, if you’re worried about safety, or the number of events is increasing without any clear cause, seek medical advice.
Safety is the first consideration. For sleepwalkers, remove sharp objects, don’t sleep near windows, and if necessary, keep phones/computers/food/musical instruments/car keys (or whatever tempts your sleeping brain) locked out of reach.
The next step is a thorough assessment to understand what exactly is happening, how often, and whether there are any changes in lifestyle, medication or stress which might be contributing. Hopefully you can then address the underlying cause. Cognitive behavioural therapy can be helpful in the case of stress-related sleep disturbances. For both treatment and prevention, getting sufficient sleep, and sticking to good sleep hygiene is incredibly important.
If there are no clear behavioural or psychological causes, it might be that there is an underlying sleep disorder, such as sleep apnea or restless leg syndrome, which is causing fragmented sleep. Sleep apnea is a condition in which temporary narrowing of the airways during sleep means there is less oxygen delivered to the brain. This causes multiple brief awakenings, and a shortage of deep sleep. In Kelly’s case, a sleep study showed that she stopped breathing over 100 times during the night. Once she started treating her sleep apnea (with a CPAP, or Continuous Positive Airway Pressure, machine), her parasomnias completely disappeared.
There are other potential causes of parasomnias which are rarer, but need to be ruled out, including some neurological disorders. There are also psychiatric disorders like posttraumatic stress disorder (PTSD) and panic attacks that can mimic parasomnias.
What can I do now?
If you, your partner, or your family experience parasomnias, start a diary to track dates, times, and exactly what happened during each event. This can help you to spot patterns and to help monitor the impact of any changes you make to your routine, or treatment.
If you’d like more information about parasomnias, these are review articles are open access:
Howell et al. Parasomnias: an updated review Neurotherapeutics (2012) 9:753–775
Singh et al. Parasomnias: a comprehensive review Cureus 10(12): e3807