Assoc. Dr. Kiril Terziyski, MD, is a pathophysiologist, neurologist and specialist in sleep medicine at the Sleep Research Laboratory at the University Hospital "St. Georgi - Base 1" in Plovdiv. Dr. Terziyski is a senior assistant in the Department of "Pathophysiology" at the Medical University - Plovdiv.
He has a European certificate as an expert somnologist from ESRS after successfully passing an exam in 2014. He has undergone numerous short- and medium-term trainings abroad: Innsbruck, Austria, Georgia, Padua, Italy, Center for Sleep Disorders, University of Parma, Edinburgh, UK, Hanover, Germany.
He also completed ESRS training in sleep research and sleep medicine (Marie Curie Project) - Bertinoro, Italy; Zurich, Switzerland; Kloster-Seeon, Germany, in 2010, as well as an ERS training course, Grenoble, France.
Participant in a number of European and world congresses on sleep medicine. Author of publications on the subject of sleep medicine.
Winner of the World Organization of Sleep Medicine Award for Outstanding Activity for Sleep Day 2015
Prof. Terziyski, every year we celebrate World Sleep Day in the month of March. Why is sleep so important for humans? Reveal to us some of the secrets of sleep
- Although sleep remains largely an enigma to modern medical science, its great importance for the functioning of the body is certain. He alth is impossible without a lack of adequate sleep, just as it is impossible without a he althy diet, for example. Sleep has many proven effects on the human body.
During sleep, neurons are restored so they can be ready to function during the day. Sleep affects the levels of almost all hormones in the human body, and therefore also the vital functions, contributing to the restorative processes.
For example, lack of adequate quality and quantity of sleep leads to slower healing of wounds, decline in immunity and, therefore, increased susceptibility to infectious and malignant diseases. Sleep has an extremely important role in memory consolidation.
If we want to remember something, be it a fact or an action (how to ride a bike), we need sleep. Emotional recovery and processing of emotions also occurs during sleep.
Of course, it is not possible to reveal the secrets of sleep to you in a few sentences, but I can tell you that what happens during sleep is not just a lack of wakefulness and a passive state of disconnected consciousness, but a completely new state of functioning of the organism, which is inextricably linked and affects wakefulness.
Why do people dream? Some remember their dreams, some don't. What caused this? Why do we have nightmares?
- The role of dreams is even more mysterious than the role of sleep. The huge difficulty in their study is the highly pronounced subjective moment in dreams, which makes it almost impossible to unify them by characteristics common to different people and statistical analysis.
However, studies in this direction are increasingly relevant. Despite the opinion that some people do not dream, the truth is just the opposite - we all dream, and several times a night. The question is when we remember these dreams. It is generally accepted that classic dreams occur during REM sleep (rapid eye movement sleep, also called paradoxical), although it has been shown that they can also occur in the second phase of sleep.
If we wake up during REM sleep, the probability of reporting a dream is very high, which has been proven experimentally. But why, if we don't wake up, do we have no memory of our dream?
This is due to retrograde amnesia associated with sleep. How many times have you read a book to fall asleep (which as a somnologist I should advise you not to do) and the next day you have to go back a few pages?
And how many times have you woken up with a clear memory of the dream, only to find out in the morning that after falling asleep again, you remember almost nothing. Now it sounds logical that when we don't wake up from our dreams, we have no memory of them, right?
Probably the fact that some people's dreams are "more colorful", at least partially, is explained by the fact that the temperaments, the emotional profile, the imagination are different for each of us. A rather interesting phenomenon is the so-called lucid dreaming.
For anyone who watched "Genesis" (Inception), this term should be familiar. This is a condition in which a person is dreaming but is aware that they are dreaming and not in reality, sometimes to the point of controlling the content and course of their dream.
The meaning of dreams still eludes science, but of course, there are various hypotheses. Dreams are believed to be important for emotional processing of what happens in our daily lives, but also for safely "simulating" reality (like scientists do simulations of how a given hurricane will develop based on some initial information, say).
In this sense, the content of dreams changes in some sleep and mental disorders.
Nightmares can be an example of exactly this, although the concept of nightmares in the commonly used sense hides various phenomena.
For example, it may be dreams with altered content relating to an experienced traumatic moment, but normal features as in post-traumatic stress disorder.
Or there may be changes in content (manifestation of aggression by humans/animals towards the dreamer) unrelated to actual events, as in REM-related conduct disorder.
Assoc. Dr. Kiril Terziyski
Or we can talk about extremely vague terrifying dreams, with no memory of specific content, but with a memory of the strongly negative emotion, which have changed characteristics, for example - a strong autonomic reaction and confusion of the dreamer.
They occur during deep sleep, most often in children and usually stop after puberty. These are night terrors that are part of the group of NREM parasomnias.
What complications can chronic insomnia lead to?
- Chronic insomnia is most often associated with mental illnesses of the anxiety-depressive spectrum. This connection is so strong that it is a matter of debate which is the chicken and which is the egg.
Depressive episodes are often preceded by worsening sleep. A number of somatic diseases also have an increased frequency in patients with insomnia, starting with cardiovascular diseases and ending with an increased risk of carcinomas.
Is the problem of “discrepancy” in the sensation of sleep common?
- “Discrepancy” in the sensation of sleep is a common phenomenon in patients with insomnia. Not infrequently, someone comes in claiming that they haven't slept a single minute in the last week
This is as likely as a person spreading their arms and flying, but it does not mean that the patient is lying to us. It's just that the subjective and objective feeling of sleep can diverge quite seriously, especially when the sleep is superficial and with more micro-awakenings.The role of the somnologist is to discover the cause of them and, if possible, to influence them.
What treatment do you administer to patients suffering from insomnia? Is it true that in the long term, 70% of insomnia cases are not cured? If yes, what are the reasons for this?
- This statement is absolutely true, unfortunately. The prospect is so for several reasons. First, there are supporting factors that have nothing to do with the original precipitating factors, and are sometimes extremely difficult to address.
For example, the so-called cognitive arousal. In other words, stimulation of brain activity at bedtime and "chewing over" problems from everyday life, which is naturally a function of alertness and prevents patients from falling asleep.
How to influence cognitive arousal?
- The answer is not with medication. The mass prescription of sleeping pills is almost equivalent to a legal drug addiction with zero effect. According to the consensus for the treatment of insomnia, benzodiazepine therapy is administered for a period of no longer than 4 weeks, mostly in the acute period.
The commentary on the subject can be endless, but the fact is that the recommendations of the European Society for Sleep Research are that the first line of therapy is cognitive-behavioral therapy.
What are you doing?
- First of all, we clarify if there is an underlying cause for the insomnia, as too often it can be due to other sleep disorders such as sleep apnea, restless legs syndrome, which are treatable.
If we are talking about primary insomnia, our arsenal of tools will soon be enriched with a "biofeedback" device, which is a high-tech method of "training" the patient's brain waves and suppressing said cognitive arousal.
This will be the scientific work of the youngest colleague from our team - Dr. Georgiev. I am convinced that apart from the scientific value, this study will give us the opportunity to help a lot of people suffering from insomnia.
As patients, we know about sleep apnea, but it turns out that sleep disorders are much more - over 50? Which ones are of interest to you?
- Yes, that's right, sleep apnea is the business card of sleep medicine, but according to the latest version of the International Classification of Sleep Disorders, there is a really wide variety of diseases.
As in any other field of human knowledge, the new, the rare, the different, the strange, are of greatest interest. In other words, what is interesting to the doctor is not at all interesting to the patient.
Tell us more about some of these sleep disorders, such as sleep paralysis, sleepwalking, and narcolepsy
- Sleep paralysis is usually just a symptom that can occur without a disease being present or being a sign of one, and would extremely rarely be classified as an independent disorder.
Represents a transient state of inability to move the muscles immediately after waking up. It is extremely frightening for the patient, but practically harmless, since in 100% of cases it passes within a minute.
Sometimes, especially combined with other characteristic complaints and pronounced daytime sleepiness, sleep paralysis leads us to the diagnosis of narcolepsy.
The latter is a disease in which there is a disturbance of nocturnal sleep combined with sleep paralysis, hallucinations of a presence in the room when falling asleep and waking up, excessive daytime sleepiness, to the point of being unable to stay awake and in classic type 1 narcolepsy - presence of cataplexy.
The latter is a very strange symptom and is characterized by a loss of muscle tone during a strong, usually positive, emotion.
For example, someone tells a joke and the patient starts laughing, then collapses on the floor fully conscious because he has "lost control" of his muscles. The condition is transient and within a few minutes the patient is back on his feet. Cataplexy can also affect only individual muscle groups, in which case there can be a simple softening of the legs, head tilting.
Such episodes can be daily or once in a lifetime. The cause of narcolepsy is unknown, but most likely an autoimmune mechanism destroys a small group of neurons in the hypothalamus responsible for the production of the substance hypocretin or orexin.
Sleenamism or somnambulism is a type of NREM parasomnia. Unlike narcolepsy, where there is a "mixing" of wakefulness with REM sleep (eg, awareness and loss of muscle tone), in somnambulism there is an overlap of deep sleep with elements of wakefulness (such as walking). The exact pathogenesis is not known, but some provoking factors have been identified, such as lack of sleep the previous night, alcohol use, psycho-emotional stress.
We had an extremely interesting case with a patient of ours who had visited various specialists for years, mostly neurologists and psychiatrists, had taken countless medications without success, who had pronounced daytime sleepiness and very specific complaints related to vivid dreams with changed content, including ones where defending against attacks was hurting himself.
When he told us about how he saw little devils with bells when he winced, dropping the TV remote (apparently dozing off for a split second) and they disappeared after a few seconds, we were already thinking hallucinations related to narcolepsy. We confirmed the diagnosis in the established order and successfully treated the patient.
Is daytime sleepiness syndrome a disease and how dangerous is this condition?
- Daytime sleepiness is a symptom that indicates that sleep was not sufficient and adequate in quantity and/or quality. Most sleep disorders can therefore lead to daytime sleepiness to one degree or another. Pronounced daytime sleepiness, in addition to worsening the quality of life, can be extremely dangerous, for example when driving, when fatal accidents can occur.
Many people worry that when they fall asleep, their limbs twitch. What is this due to?
- Most often it concerns sleep twitches (hypnic jerks), which are absolutely benign.You've probably noticed that this happens more often in the supine position and during afternoon naps. By the way, sleep paralysis is also provoked by sleeping on your back, when you are most likely to have apneas, so - sleep on your side!
Do people often die in their sleep? Is insomnia a factor and increased risk of death?
- As somnologists, we are interested in the sleep of the living, not death while sleeping. However, it is a fact that sleep is extremely important for the functioning of the body, and various disorders in it can lead to serious complications that can be fatal.
In principle, the morning hours, immediately before waking up, are high-risk, since the so-called REM sleep, during which we dream and brain activity is even increased, compared to wakefulness at rest.
Our older readers have been complaining about not being able to sleep at night for years. Does this insomnia in old people have its own characteristics?
- The amount of sleep a person needs decreases with age, which is one of the signs of aging. Sometimes, though, it's really insomnia. Insomnia with early awakening is most characteristic. Another specificity in this age group is the frequent concomitant cataract, as well as limited physical activity and exposure to the sun.
These are all factors that predispose the elderly to insomnia. In addition, afternoon naps "out of boredom" have an extremely negative effect and should be avoided.
Many people like to "prescribe" themselves sleeping pills. What are the risks of self-medication in this case? Are there any medications that can be taken without consulting a specialist? For example, herbal potions
- The risks are lack of effect, robbing the side effects, chronification and deepening of the problem. Which products can be used without a doctor's prescription is clearly stated in the law.Whether prescription-only drugs are being followed is another matter. However, everyone is free to harm their he alth as much as they wish and have the opportunity.
Why is it enough for some people to sleep two hours and for others eight hours is not enough? Is it true that there are owls and larks? Are these chronotypes really so different that they can be distinguished?
- Red and violet are at opposite ends of the visible light spectrum and clearly distinguishable, but try distinguishing between two adjacent shades of green, say! It is the same with owls and larks - the different chronotypes are an indisputable fact and are genetically coded, but the big differences are in the "pure forms".
In the final options, we are already talking about diseases - disorder with haste/postponement of the sleep period. And those people who sleep for 2 hours and that's enough for them, are just as numerous as those who can see in the infrared spectrum.
“Don't count sheep, don't think about the dream, don't call for it to come! Falling asleep is a passive process, by forcing yourself to sleep you are actually waking up! Lead a he althy lifestyle, exercise, eat he althy, find a hobby that brings you peace and enjoyment, drink warm milk!” said the doctor.
Do women or men suffer more from insomnia?
“It is true that women suffer from insomnia much more often, but men are much more often and seriously affected by sleep apnea. Of course, women's sleep is more vulnerable, and one illustration of this is the fact that often sleep apnea in women is manifested by insomnia, not increased daytime sleepiness
Evolutionary psychology and evolutionary biology will tell you that sleep in women is earlier, because the care of the next generation, especially in the first few years, falls mainly on their shoulders," explained the specialist