Insomnia is a condition where a person is able to sleep normally, but cannot. He can not fall asleep for a long time, toss from side to side, all sorts of thoughts come that prevent him from falling asleep, so-called ruminations – obsessive thoughts. And then he falls asleep, can wake up again in the middle of the night and again not be able to sleep, again he spends a long time in bed in wakefulness. He can wake up early in the morning, when he does not need to get up yet, and also lie awake. That is, the manifestations of insomnia can be very different, but they all relate to the difficulties of either initiating the onset of sleep or maintaining sleep.
And even if a person seems to have slept for a sufficient amount of time, but in the morning he gets up unresponsive, sleepy, then this is also a manifestation of insomnia, these are complaints of non-restoring sleep. Scientifically, insomnia is called insomnia ( in – ‘inside’; somnus – ‘sleep’), that is, these are the problems that arise inside a dream. And now we have really learned a lot about this condition. As previously imagined, why does insomnia syndrome develop? The most common was the idea that insomnia is just such a whim that a person behaves incorrectly, his behavior is disturbed, that before going to sleep he jumps, jumps, gets excited, worries and cannot sleep. Indeed, it happens, more often in children there are such problems in adolescents who play around on the computer.
But why an adult, serious, responsibly related to his health, falls and can not sleep? Before going to sleep, he does not do anything wrong. The domestic theory of insomnia did not answer this question. Another theory of insomnia was the other extreme, which considered a sleep disorder as a manifestation of mental illness, that if a person does not sleep, then it means that he does not have something with the psyche: he has either depression or anxiety disorders, and all this will manifest in soon. And therefore, most often, indeed, the doctors tried to refer people with insomnia, who came to them to complain, to be checked just in case by a psychiatrist. This is why, therefore, complaints of insomnia have ceased, and people prefer not to talk about the fact that they have sleep disorders, because they believe that then it will be regarded either as improper behavior, irresponsible attitude to their sleep, or as a sign of some kind of then mental illness.
It turns out, on the one hand, that if we interview people in the general population, that is, ask everyone who they meet, whether he has sleep disorders or not, then at least every tenth person will say that he has sleep disorders that prevent him from living, he has this insomnia. On the other hand, people with insomnia do not come to the doctors and do not complain, do not know who to come to, do not know which doctor can help. And gradually this problem began to rise at a higher, special level. Neurologists, psychiatrists began to gather, to discuss whose illness is insomnia, who should treat it. Some understanding has now been reached that insomnia is still a problem of the central nervous system, a problem that occurs in the brain that is associated with behavioral disorders, a problem that often coexists with mental illness, but not always mental illness causes insomnia.
What are modern ideas, where does insomnia, insomnia come from? In order to understand this, one must return to the theory of sleep. Why at some point in time we can fall asleep, at some point in time we can not sleep? It depends on the constant interaction of the two main brain systems. One system activates, it always maintains a sufficient level of wakefulness, there are several centers in the brain that constantly slow down other neurons of the brain, make them work in full force, if it is day, if you need to constantly solve some tasks during the day. That is, such a tonic activation of the central nervous system by activating centers. On the other hand, there are sleep centers that are also not averse to taking control of the brain, and all the time they are ready to take control of the brain, but they are not allowed to do this by waking centers, because daytime wakeful centers are stronger because they are also helped by internal clocks receiving information from the retina. There is such a nervous twig that goes straight into the internal clock into the hypothalamus suprachiasis nuclei and gives every millisecond information about whether the day is now or night, whether there is enough light or not.
Internal clock helps wakeful systems to maintain a sufficient level of activation during the daytime, at least in humans. There are still nocturnal animals, and they have all the opposite. The struggle takes place constantly between the activating and inhibiting centers of the nervous system. When a person goes to bed and if it becomes darker outside at this time, the activity of the internal clock decreases, their assistance to brain activation centers also decreases, and sleep centers at some point take control of the brain. This is ideal.
There are many situations where activation centers are too active. A modern idea of the possibility of developing insomnia suggests that there is a group of people who have an innate feature called hyperarousal – brain hyperactivation. They have this hyperactivity can be traced even in the daytime: not when they can not sleep at night, they complain of insomnia, and even during the day their brains are working too actively. This can be traced, for example, if you do an electroencephalogram in a group of such people, they will have more so-called fast rhythms, beta rhythms on the electroencephalogram, than people who do not have insomnia. You can make them a special research method called transcranial magnetic stimulation. A powerful magnetic field is used there, the motor areas of the brain are stimulated with this magnetic field, and they look at how well these areas produce a motor response – most often through the movement of the thumb.
It turned out that people with insomnia have constant hyperactivation of virtually all areas of the brain, including those who, like sleeping, do not have a relationship, which are related to the big toe. This proves the presence of hyperactivation. And according to other indicators, in fact, it is also proved that with insomnia everything is too active for these people, that they live initially with increased activation, which helps them during the day, in principle, because they react better to changes in external circumstances, they can concentrate more quickly, faster make the necessary response to some kind of reaction, but in the evening, when they go to bed, it begins to interfere with them, because the activating centers of the brain interfere with the sleep centers in time to take control and return the body to sleep.
And when a person is lying, trying to sleep, he fails because of this hyperactivity. Then the secondary mechanisms of insomnia maintenance are switched on, and these are already various psychological factors. For example, a person lies down and gives himself an assignment to fall asleep urgently: I have to urgently fall asleep in order to be vigorous and sleepy tomorrow morning. It seems to be nothing special, but when he gives himself such a task, he begins to subconsciously keep track of whether he fell asleep or did not fall asleep. After a while he does not manage to sleep , he begins to worry that he did not fall asleep. From this, his brain activation, which is already high, increases even more, and he may feel drowsiness even less, and to a lesser extent, and the probability of falling asleep decreases even more. A person becomes excited, begins to ask himself: “Why am I not falling asleep? I urgently need to fall asleep. ” And the more he tries to drive himself to sleep, the less likely he is to fall asleep.
Academician Wayne, one of the initiators of sleep research in Russia, was very fond of the metaphor that sleep is a bird that sat on an open palm, and the faster you try to grab it, the faster it flies away, because the more you strain to catch sleep the more activating systems are activated and prevent the development of this inhibition, necessary for sleeping and entering sleep. That is, a person drives himself into this state. And gradually it becomes fixed, and already at some point even the habit of the difficult process of falling asleep or the fear of bed is formed. When a person goes to bed in the evening, he does not think whether he will fall asleep or not fall asleep, but when he walks into the bedroom, gets into a familiar environment, then Pavlov’s conditioned reflex works: the pillow is the lack of sleep, like a dog’s bell (a bell means food – the dog had saliva). And here it turns out that he saw his pillow and his body immediately remembered the failure of the previous nights when he could not sleep. Accordingly, he automatically develops hyperactivation, which prevents him from falling asleep. This is one of the most common patterns that explains why insomnia develops.
Now they think that there are people with constant hyperactivation, and there are people without hyperactivation, their insomnia develops according to other laws, and it is most often associated with the perception of time that they spend at night in the waking state. It is interesting that any person at night, when he sleeps, actually does not sleep completely, sometimes he wakes up, and this is normal. And, as it turned out, we wake up more than once a night, not two, but 10-15 times a night, because a person needs to toss and turn to bed from time to time in order not to lie down on his side. This is completely normal. And when a person turns over in bed, he has a short awakening of 10–15 minutes on his electroencephalogram. He wakes up at this time, he may open his eyes at the same time, but he does not remember about it the next morning. But there are people who remember it all too well.
It is shown that there is a group of people who complain of sleep disturbances, moreover, they actually have a lot of sleep. For example, now the sleep recommended by the international community is not less than seven hours to maintain a sufficient level of vigor, for a sufficient level of health. But if you conduct sleep studies of such a person who complains of sleep, we will also see that he has 6–6.5 hours of sleep, but he can tell in the morning that he has not slept at all. Why? He has changed the perception of his own sleep. He perfectly remembers those periods of sleep, or rather, those periods of wakefulness, when he didn’t sleep, when he suffered, when he looked at his watch, when he listened to what was happening on the other end of the house, how the neighbors move the cupboard once again in the middle of the night, but he absolutely does not remember when he fell into a dream. This is a feature of the perception of time at night.
There is a group of people who, precisely because of this, develop complaints of insomnia, because they do not know how to count the time correctly. They have those periods when they woke up at night, merge in their perception. They wake up in the morning, they are sure that they have not slept, although in fact this is not true. Maybe they slept a little worse than other people, but slept enough. This is the so-called pseudo-insomnia phenomenon. There is a group of people who are unhappy with their sleep – they are not happy because they do not know how to count time. This is the next cause of insomnia.
Even now, congenital features of the brain are considered as one of the causes of insomnia. When they began to carry out more complex neurophysiological studies (there is such a study – functional magnetic resonance imaging, which allows you to determine not only the structure of the brain, but also its function, how well certain sections of the brain work, for example, in insomnia and in healthy people (always compared with the control group; the control group is healthy people)), it turned out that people with insomnia have worse areas of the brain that are involved in the emotional assessment of the situation ii. These areas of the brain belong to the oldest areas, and they are called zones of the orbitofrontal cortex, that is, this part of the hemispheres of the large brain, which is adjacent to the sockets, hangs above the sockets.
It turned out that this is a very important part of the cerebral cortex, since it is just responsible for slowing down the overheated danger assessment centers, so to speak. In the temporal areas there is the so-called amygdala, which we also need to evaluate every stimulus, every impact on the subject of whether it is dangerous for us or not. This amygdala responds in order to instantly assess the sound, the emergence of a new subject, or assess the danger to us of some thought that flashed through our mind. And it turned out that in insomnia this amygdala works too hard, she is always ready to react to the danger, which is not even there, she perceives everything as a threat. Why? Because in patients with insomnia, this part of the brain, the orbitofrontal cortex, is underdeveloped.
One of the most important functions of the orbitofrontal cortex is the inhibition of this loose tonsil, so that it does not perceive everything as a danger to the body, while the orbitofrontal cortex makes it possible to slow down in time. And in some people, the orbitofrontal cortex does not have time to slow down the amygdala to the proper extent, the amygdala constantly, day and night, gives alarm signals. In the daytime, in principle, this does not interfere, since it may even help to be always alert, always reacting to a change in the situation, a traffic situation, for example. And at night it is completely unnecessary, at night it is not necessary to react, at night the brain must go about its internal affairs, change the ratio of neural weights, it does not need to react to anything. And this amygdala prevents him from reacting, and again the insomnia symptom complex develops, when a person cannot fall asleep, all the time on the alert, all the time he reacts to a small sound.
Indeed, people with such violations often say that as soon as night falls, for some reason, neighbors start drilling, knocking, moving something there, not because neighbors in other houses do not knock, do not drill, do not move, but because people with this type of response have excessive attention to all external stimuli. They even hear what healthy people do not even hear, what happens on the other end of the house. This is now the main theory of the development of insomnia – the theory that insomnia is a heterogeneous group of states, and some of these conditions are caused by innate features of the organization of the nervous system. Either these are functional features, when hyperactivation goes on permanently, or this is an underdevelopment of the orbitofrontal cortex, or this is psychology, or this is an incorrect assessment of the situation, an incorrect assessment of time.
There are several other insomnia phenotypes that scientists haven’t reached now, a point of view has not been formed. Here, for example, the development of one of the types of insomnia is associated with sleep deprivation with fast sleep dreams. It turned out that if a person sleeps improperly in a fast sleep, then he too is violated protection from the stress factor, the consequence of this is the development of a chronic sleep disorder, while for him this fast sleep does not function properly. But this is the topic of the next talk about the fast sleep function.