Why sleepwalking is not a sleep disorder, but a wakefulness disorder, how to treat it, is it possible to distinguish an unintentionally committed murder in a dream from an attempt to avoid responsibility, how does the activity of the human brain during sleepwalking differ from the activity of the brain of an ordinary patient, and how to measure it if during episode of a person cannot be put into a tomograph? All this in an interview with Indicator. Ru tells a specialist in neurology and sleep disorders, MD, professor at the Department of Neurology at the University of Bern and director of the Southern Swiss Neurocenter Claudio Bassetti.
The title of Bassetti's talk at the VI International Forum "Sleep" at Moscow State University - "Sleep and Aggression" - may remind you how people become angry and irritable from lack of sleep. However, the talk is about a rare and much more interesting disorder - aggressive behavior that occurs during sleep. We also decided to discuss this issue with the researcher.
Tell us, what types of aggressive behavior during sleep are most common?
- There are different types of violent sleep activities. There is sexual aggression (sexual assault), cases of murder or attempted murder, cases or attempted suicide. There are also less severe forms of violence - blows, which can lead to injury to patients or people nearby. It must be understood that a wide range of sleep behaviors that we can call violent, aggressive, can lead to injury.
But are there any differences in the frequency of such cases in different populations?
- Now there are no large-scale studies that would show the frequency of such cases among people with different origins or genetic characteristics. The largest studies on this topic were conducted in the United States, and they included 100-200 patients.
Is there a dependence on the sex or age of a person? For example, as far as I know, sleepwalking is more common in children than in adults. Is there a similar dependence for aggression in a dream?
- It should be said that violence is usually committed by males, they are more likely to cause injury, and women are often victims. Perhaps these results are not surprising: if you look at cruelty and violence in general, it is statistically more likely to be committed by men against women. But this is on average. There are male victims and female aggressors.
As far as age is concerned, you're right. Aggression in a dream can occur at different ages, both by children and the elderly, but this depends on the reason, which lies in physiology. The result can be injury, fracture, accident, but the potential causes are different at different ages.
What sleep phases are associated with aggression?
- It depends on the reason. If you look at the violence associated with sleepwalking or sleepwalking, aggressive behavior can manifest itself in the first couple of hours of sleep. But in some cases, it can be caused by epileptic seizures, which can happen during different phases of sleep. In addition, there is a behavior disorder during REM sleep. This pathology manifests itself during the so-called REM or REM-sleep (literally rapid eye movements, or sleep with rapid eye movement), which is characteristic of the latter part of the night. Also, various factors affect acts of aggression in a dream, including the intake of excessive amounts of alcohol, stressful situations. Different phases may be affected depending on the cause.
What areas of the brain show high activity during sleepwalking and how is research done on this topic? The movements of the sleepwalking patient are quite unpredictable. How difficult is it to study his brain during an episode of aggression?
- Yes. This is hard. 19 years ago, we were the first in the world to conduct such experiments. For the study, we used the method of single photon emission tomography (SPECT). We injected a radioisotope marker into the bloodstream and got an image showing which areas are most supplied with blood. The advantage of single photon emission tomography is that you can reconstruct a 3D image of the blood flow an hour ago. You cannot put patients in a tomograph and get an image while they are moving, and thanks to this method, you can see which areas were active while he was still sleeping. We learned that there are areas that are suppressed, just like during normal sleep. An example is the frontal lobe, which guides our thoughts and our actions.
And does it influence decision making?
- Yes, and attention and control. The centers of proprioception (body position in space) in the parietal lobe, temporal lobes, where data on touch are processed, were also suppressed. But the motor centers in the cerebellum and in the cingulate gyrus (lat.cingulum) were active. We have been able to show that during sleepwalking, some areas of the brain continue to sleep while others are already awake. And these waking centers are associated with movement control. For this reason, sleepwalking is referred to as arousal and wakefulness disorder - a state between wakefulness and sleep, when you wake up, but not completely, and stop somewhere halfway. Usually, when you wake up at night (for example, go to the toilet or drink water), both your body and your thoughts turn on. You may be unsteady on your feet asleep, but you will find your way to the kitchen or bathroom. But with somnambulism, your motor system is highly agitated, while your consciousness is not awakened.
And during normal sleep, motor functions are suppressed
- Yes, but we are not completely paralyzed, because then we would get injured from constant pressure of the body weight on the same areas, bedsores. We toss and turn in bed about every 15 minutes. If we watch a video of a person's sleep, we will see that we are not completely immobilized: we turn over like a small skewer with a kebab.
A funny comparison. Are there any differences between the brain of patients with sleepwalking and the brain of healthy people?
- This is a very interesting question, because in the past it was believed that sleepwalking was a sleep disorder. No one even thought that the brain of a patient with sleepwalking could be any different. In the past five to ten years, researchers have begun to look at the brains of patients and find differences in daytime activity. We began to realize that there are differences in motion control, emotion control, and cognitive function.
Are the differences visible only at the level of physiology, or at the level of anatomy too?
- Good question! Scientists have such assumptions, but the answer is still unknown.
And if you look at the brain of a person with a tendency to sleepwalking, which does not lead to violence or injury, and the brain of a person with aggressive behavior during sleep, will there be a difference?
- It's not clear yet. But if you are a man and you are an adult, your behavior will be more aggressive on average. Sleep aggression is less likely if you are a child or woman.
Genetic predispositions are also unknown?
- Yes it is.
And how does the law treat people who have committed a crime during sleepwalking? Is it possible to prove that a person is lying about an attack of sleepwalking in order to avoid punishment?
- In my report, I touched on this topic. She is very ambiguous. As I have already noted, during sleepwalking and other sleep problems, a person can harm others and even commit murder or suicide. Such cases did happen, although there are not very many of them. But they must be distinguished from attempts to mislead the court, when a person pretends to be a sleepwalker so as not to bear criminal responsibility.
I gave two similar cases. In one, a person was found not guilty, and the investigation concluded that the murder of the person was committed during sleepwalking. The outcome of another case was the opposite. It was a woman who killed two children, but there were signs that she might have done it on purpose. In the end, she confessed.
There are many factors that need to be considered in such an investigation: possible motives, family history, history of previous episodes, results of medical diagnosis.
Is there a way to distinguish between such cases? Is there any analysis done?
- Not only medical analysis, but also psychological and psychiatric research, because an interdisciplinary approach is required. The problem is that you can never be present when what is happening: you have a lot of random evidence, coincidences, and you need to reconstruct events in the past. Guilt or innocence is very difficult to define, but a decision must be made.
Can we find out if the person at that moment had a conscious goal, or his behavior was random?
- The movements of a person in a lunatic state are not chaotic. He can go to the kitchen or the balcony, talk, drive. Actions have some ultimate goal, they are not completely random, but partially arbitrary. This is not just some random set of movements - in a sense, a person understands what he is doing, but not completely. An intermediate state, twilight.
Some people believe that during sleepwalking you can become stronger than in everyday life. Is it true?
- I don’t think it’s so. The truth is, they are not aware of the circumstances, the context of their actions. They are awake, but not fully conscious. And if you get in touch with them, they become aggressive, because they do not understand the context of the situation. They don't suppress their impulses. It is like alcoholic intoxication, in which a person's ability to rationally assess circumstances decreases. But it is important that you understand that somnambulism is not the only culprit for violent sleep. The mechanisms are different, but they are based on the activation of movements without understanding what is happening. That is, the scheme of such states is activation plus dissociation.
Many patients with somnambulism complain of nightmares, dreams with a violent or tragic plot. How does this condition affect dreams?
- Very little. This is usually a false statement. Lunatic episodes most often pass without dreams at all. Sleepwalking nightmares will be the exception, not the rule. If you have a lot of dreams about violence and cruelty, you should consider another diagnosis - REM sleep disorder, which is characterized by vivid, vivid dreams, often with violent stories, sometimes accompanied by physical activity.
What other common myths about sleepwalking do you know?
- That somnambulism is rare, that it is not dangerous, that it is not treated, that it is a psychological problem, not a neurological one. There are many such myths. Most of what people think about somnambulism is not true. People think they understand what it is, that this is a sleep problem and that this is a psychological problem. It is clear that during stress, episodes become more frequent, but this is still primarily not a psychological problem, it is a disruption of the brain. And then, not everything that we take for somnambulism is in fact it.
So the problem of misdiagnosis is common?
- Yes, this is a big problem. When there are such symptoms, one should look at what people are doing at night, record polysomnography, and not fantasize. Record brain activity using electrodes, record a video to understand what the person was doing.
How can such conditions be treated or symptoms relieved?
- We need to get enough sleep. Check what medications the patient is drinking: there are sleeping pills that may have this side effect. See if there are other sleep pathologies that need to be treated, if there is epilepsy. If this is not enough, special medications are used, but medical intervention is the second or third choice if changes in the regimen and other recommendations did not help. Some people suffer from somnambulism just because they slept poorly and were under a lot of stress. If you remove this, everything will go away by itself.
What if you see that your relative is going somewhere in the middle of the night? Is it true that he cannot be woken up?
- True. As we have already said, the patient does not understand the context, he may be frightened or react sharply, hit or shy away from you. You must carefully escort, follow the person, but not interfere, not grab his hands, for example, so as not to provoke him to an unexpected reaction.
Author: Ekaterina Mishchenko