Who sleeps walks

Moonlit walks, do you enjoy them? It is true that a night walk has its advantages and offers a different perspective on the world around us, not to mention the mysterious, even romantic side of it. However, have you ever taken a walk… while sleeping? You will agree, that is a whole different story. This story is what people subject to sleepwalking experience, this singular sleep disorder leading to unconscious actions while one is asleep. What do we really know about sleepwalking? What does this kind of "unconscious awakening" correspond to? Beyond a few myths and urban legends associated with it, sleepwalking is a very interesting subject on which we will try to shed some light. So, are you ready for a little night walk but well illuminated by our investigation?

Sleepwalking, a short path between myths and scientific facts

What is sleepwalking?

Many pathologies or unusual manifestations have sparked all sorts of assumptions or popular beliefs. Just like night terrors or sleep paralysis, sleepwalking is a perfect example, spectacular and difficult to grasp. Before addressing the urban legends related to it, let's be more down to earth: what exactly is sleepwalking? It is a somewhat particular sleep disorder. Indeed, it is classified as a parasomnia because it occurs at the boundary between sleep and wakefulness, during the deep slow-wave sleep phase, and it involves abnormal and undesirable motor or psychomotor behavior.

How does sleepwalking manifest?

You may be wondering what a "undesirable" behavioral event could refer to. In this case, imagine for a moment that you wake up in the middle of the night and, to your great surprise, your beloved is no longer next to you in your bed. Could he (or she, let's respect parity) have gone out without your knowledge? It is then that you hear a noise coming from your garage. You go there and, to your astonishment, you see your partner getting into the car and starting it, completely ignoring your questions and the sound of your voice... because he is asleep! Or more precisely, he is in that famous unconscious waking state. Examples like this are diverse and varied. A sleepwalker can exhibit multiple behaviors ranging from simply sitting on the bed to scan the room with their gaze, to doing the dishes, cleaning, or any other activity, even taking a random walk, sometimes even leaving their home. It is true that this can present certain advantages, especially for those who lack motivation to tackle household chores, but it can also pose risks in certain situations! In practice, a sleepwalker can perform almost any daily action, and they will generally have no memory of it. Furthermore, it is not possible to interact with a person experiencing a sleepwalking episode. Indeed, despite their "awake" appearance, they are very much unconscious, and may only respond in a completely incoherent or incomprehensible manner.

A sleepwalking episode generally begins between 1 and 3 hours after falling asleep and can last from 5 to 30 minutes on average, which, as you can imagine, leaves quite a bit of time to wander or do all sorts of things, even mischief!

Who can be affected by sleepwalking?

This parasomnia can affect anyone. However, sleepwalking tends to concern children more and becomes rarer as one reaches adulthood. Studies estimate on average the prevalence of sleepwalking¹ at 2% of adults and 5% of children. The peak prevalence² for children would be around the age of 10, with an average of 13% of our young toddlers facing sleepwalking episodes.

As for gender, sleepwalking would be quite equal if we believe a Finnish study³, since it reveals a prevalence of 3.9% in men and 3.1% in women. However, other research⁴ may highlight a slightly higher incidence in men than in women, although the difference is not truly significant.

Do we know the causes of sleepwalking?

Throughout history, sleepwalking has raised scientific questions and popular beliefs. While it is an interesting, even fascinating subject, the exact causes of sleepwalking remain uncertain, at least until a few years ago. Fortunately, some recent studies have shed light on the sometimes obscure and mysterious path of sleepwalking.

First of all, as reported by the referenced site "Sleep Foundation"⁵ correlations have been established between sleepwalking and the following factors or pathologies:

• lack of sleep : it leads to spending more time in deep sleep to "recover", thus increasing the risks of sleepwalking episodes
• medication use : medications such as sleeping pills cause an excess of sleep favorable to sleepwalking
• alcohol consumption : adverse effects on sleep quality with disturbances during different phases, leading to fragmentation of slow waves conducive to sleepwalking
• stress : promotes sleepwalking due to fragmented sleep

Regarding the factor "lack of sleep", a study⁶ went further by concluding that beyond the risks associated with sleep deprivation, a forced or abrupt awakening could significantly increase the chances of being a victim of a sleepwalking episode… for predisposed individuals! It is indeed important to clarify this point because it is the discovery of this "predisposition to sleepwalking" that has advanced the understanding, and which, hopefully, may allow for a better understanding of this parasomnia in the coming years.

For those who are not familiar with the "schmilblick" (and its established expression), it would be appropriate to do some research. A bit of general knowledge is always good to have!

A genetic predisposition to sleepwalking?

The discovery of a hereditary factor has shed light on what is undoubtedly, along with lack of sleep, the main cause of sleepwalking. According to a study from 2003⁷, it is estimated that there are family histories in nearly 80% of sleepwalkers. Moreover, as revealed by an article from "Medical Express"⁸, researchers from the neurology department of the prestigious "Washington University School of Medicine" have managed to highlight and identify the chromosome that would be responsible for a genetic transmission predisposing to sleepwalking: it would be chromosome "20q12-q13.12" (gene "HLA DQB1*05", involved in the regulation of the immune system). Furthermore, their study⁹ determined that an individual prone to sleepwalking episodes possessing this particular form of chromosome 20 had nearly a 50% chance of passing it on to their offspring.

This is interesting and could help prevent, or at least limit, certain untimely nighttime walks or activities in the future!

Sleepwalking in popular beliefs

In order to continue our nighttime stroll on a lighter note, but still well-lit, let's pause for a moment on some popular beliefs about sleepwalking. Which ones are true, which ones are false? Here are some elements of answers just for you, dear night rebels:

• "A sleepwalker can die if you wake them up": no, however, they could find themselves in a state of more or less strong confusion that could lead to abrupt and disorderly reactions.
• "Sleepwalkers always keep their eyes closed": no, otherwise how could they move? In reality, their eyes are sometimes not always completely open, but a sleepwalker moving with their eyes closed is only to scare in certain movies!
• "People who are prone to it experience episodes of sleepwalking every day": no, not necessarily. Indeed, the frequency of episodes mainly depends on the level of stress factors and lack of sleep.
• "Sleepwalkers cannot hurt themselves": should we really respond? Of course, sleepwalkers are not superheroes; they can hurt themselves, injure themselves, or even hurt someone (we will return to this!).

In addition to these few beliefs (among others), sleepwalking has also been the subject of mystification over the centuries. Imagine, a few hundred years ago, the incredulous or fearful reactions to a person walking in their sleep, even though today we still struggle to explain it through science. People spoke of spirits and possession: "The emergence of the myth of possession dates back to the Middle Ages," explains Édouard Collot, a psychiatrist specialized in hypnotherapy and author, with Bertrand Hell, of Soigner les âmes (Dunod). "This type of belief rooted in the cultural foundation means that the sleepwalker can be equated with a possessed person."

Art, and literature in particular, has been influenced by certain sleep disorders, including sleepwalking. For example, the character of MacBeth in the eponymous novel by William Shakespeare (second cultural point!). This is also the case in the 7th art, where some horror films and thrilling thrillers have featured (sometimes) very inspired sleepwalkers ("The Sleepwalker", a 1997 film by John Cosgrove, starring Hillary Swank)!

How can sleepwalking be treated?

While it is inspiring for literature, cinema, or some urban legends, sleepwalking should not be taken lightly. Indeed, it can lead to sometimes comical scenes, but in some cases, it can be distressing, and even dangerous. This is referred to as risky sleepwalking. The sleepwalker can indeed be dangerous to themselves, by falling down stairs, jumping out of windows, cutting themselves with a knife, or through many other actions. Unfortunately, they can also be dangerous to those around them: some sleepwalkers exhibit aggressive behaviors, may perform violent and erratic gestures, or simply be clumsy.

On the other hand, a particular form of sleepwalking is associated with sexual behavior: it is called sexomania. During an "episode" of this particular sleepwalking, the individual may engage in sexual behaviors alone, just as she may become proactive, or even sexually aggressive towards someone. Numerous case studies have multiplied in recent years, notably by Prof. Shapiro¹⁰. Some cases of sexomania type assaults, akin to rapes, have even been the subject of legal proceedings.

As we can see, sleepwalking is not trivial. Some consequences of its manifestations can be serious (injuries, accidents, violent behaviors), even if risky sleepwalking is fortunately not the most common. In the face of the inconveniences and risks of certain behaviors related to it, is it possible to prevent or treat sleepwalking?

Unfortunately, there is no officially recognized treatment for sleepwalking. However, and this is fortunate, it is possible to limit the frequency and duration of sleepwalking episodes, even for the most severe cases. These cases are, however, quite rare in adults (less than 2%). In any case, before considering any medication, here are some tips to act on the main factors related to sleepwalking:

• adopt good sleep hygiene: avoid an excessive duration of deep sleep (conducive to sleepwalking) by having a sufficient daily amount of sleep so as not to have to 'catch up' on a lack of sleep
• carry out scheduled awakenings: 15 to 20 minutes before the usual observed start time of episodes, when possible
• treat sleep disorders or diseases that fragment deep sleep: sleep apnea, restless legs syndrome...
• resort to hypnosis sessions : the effectiveness of hypnosis to limit the impact of sleepwalking is recognized through numerous studies¹¹
• secure the environment: close doors and windows, hide car keys and dangerous objects...

In particularly difficult cases, resorting to medication, and more specifically to benzodiazepines or antidepressants, known to limit deep slow sleep, may be considered. However, be cautious of the risks of dependence and certain undesirable side effects.

A phenomenon as mysterious as it is spectacular, inspiring for popular culture and a source of increasingly numerous research for science, this parasomnia cannot be ignored and requires certain attention. Sleepwalking is a drowsy stroll that sometimes has nothing of a walk in the park! Also, let's bet that recent discoveries about genetic predispositions help us better understand it in the future.

In addition, to better illustrate the point of this article, we offer you a short and nice video, right here, published by the channel "Life Noggin".

Third cultural point, for those who would like to have some thrills watching an excellent Scandinavian thriller featuring sleepwalking as a central theme, we recommend the film "Sleepwalker".

Sources:

[1] Prevalence of Sleepwalking: A Systematic Review and Meta-Analysis, Helen M. Stallman and Mark Kohler, "Plos One", 2016 [2] Childhood Sleepwalking and Sleep Terrors: A Longitudinal Study of Prevalence and Familial Aggregation, Dominique Petit, Marie-Hélène Pennestri et al, "JAMA Pediatrics", July 2015 [3] Prevalence and Genetics of Sleepwalking, C. Hublin, J. Kaprio et al, "Neurology", January 1997 [4] Prevalence of sleepwalking in an adult population, Celestine Okorome Mume, "Libyan Journal of Medicine", January 2010 [5] Sleepwalking, site "Sleep Foundation", 2020 [6] Precipitating factors of somnambulism: impact of sleep deprivation and forced arousals, Mathieu Pilon, Jacques Montplaisir et al, "Neurology", June 2008 [7] HLA and genetic susceptibility to sleepwalking, M Lecendreux, C Bassetti et al, "Molecular Psychiatry", 2003 [8] Scientists find genetic basis for sleepwalking, site "Medical Xpress", February 2011 [9] Novel genetic findings in an extended family pedigree with sleepwalking, A.K. Licis, MD, D.M. Desruisseau et al, "Neurology", January 2011 [10] Sexsomnia: a new parasomnia?, Colin M Shapiro, Nikola N Trajanovic et al, "Revue Canadienne de Psychiatrie", June 2003