The most extreme of all the sleep disorders, sleep walkers usually confine themselves to simple tasks like dressing or washing, but not always.
My brother used to sleepwalk.
In his case he would get out of bed in the dead of night, go downstairs, sit on the living room sofa and watch a blank TV screen for 20 minutes or so before returning to bed.
I know this because at that time we shared a bedroom and I would follow him to make sure he didn’t hurt himself.
I always had in mind that one shouldn’t wake a sleepwalker, I had no idea why not or whether that information was even valid. I probably gleaned it from a Carry On film or read it in the Beano, but it was gospel as far as I was concerned.
It turns out it is actually official advice, according to the NHS, whose counsel is to avoid shocking or stressing the walker, but try to gently guide them back to bed and settle them down; only then should you gently wake them so that you break the sleep cycle they are in.
It also turns out that around 25% of children experience at least one episode of sleepwalking.
Despite being so widespread very little is really known about what triggers the condition which has been shown to cluster in families making it much more likely that you might experience an episode if another member of your family has displayed a tendency to sleepwalk.
Freud claimed that sleepwalking was an expression of sexual desire and that the unconscious subject was seeking to find a suitable sleeping partner but, in this as in so many of his later pronouncements, this probably says more about Freud than it does about the condition.
Luckily, most of us grow out of it and less than 4% of adults in a 2012 study by Stanford University reported sleepwalking of any kind.
For those who are prone to somnambulism (or noctambulism) as sleepwalking is known the consequences can be dire.
In 2013 Kelly Jackson was an otherwise healthy 24 year old when one night she left her bed and walked out of the house to get into her mini car.
While still asleep she started the vehicle and drove away only to crash at speed into a tree less than half a mile away from her house in Birmingham.
Kelly lost a leg, was severely disfigured and suffered significant brain damage as a result of the collision.
When she was found trapped in the wreckage she was still in her pyjamas and to this day cannot recall anything of the evening after saying goodnight to her family and retiring to bed.
In 2014 a 27 year old man who was staying at a country house hotel in Hertfordshire was found lying in the grounds suffering from head injuries and severe hypothermia.
Rob Williams had a history of regular sleepwalking, much to the amusement of friends and family, but it is thought that in the unfamiliar surroundings of the hotel room he walked in his sleep straight out of a window in his third floor room.
Tragically, he never recovered consciousness and died five days later.
There are also plenty of recorded incidents when a sleepwalker has caused harm to others and the law struggles to make accommodation for the possibility that a person is acting unconsciously in such cases.
As recently as 2008 a husband who killed his wife while ‘dreaming’ he was being attacked by intruders had the charges against him dropped and walked out of court a free man.
Meanwhile a similar defence offered by Scott Falater, in another case where a wife was brutally murdered by her ‘sleeping’ husband, failed because the jury considered changing clothes and hiding the murder weapon in a car to be those of a guilty man, not an unconscious one.
There is no ‘cure’ or standardised treatment for sleepwalking and the NHS even advises that an occasional minor event does not require any medical intervention.
Healthy and regular sleeping patterns should help to prevent it, as over-tiredness and interrupted sleep can make it worse.
For those who have to deal with it, however, it can be a distressing experience to know that their body has been functioning, however briefly, without their knowledge.
For children, parents should do everything to ensure that their environment is as hazard free as possible using child-proof gates at the top of stairs as well as the bottom for example.
Of course in the vast majority of the cases reported from around the world no harm is done and no tragedies occur; it is simply another medical mystery, another reminder that however smart we think we are, we’re a long way from knowing everything.
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