Insomnia (insomnia)

Insomnia is "recurrent disturbances in the initiation, duration, consolidation, or quality of sleep that occur despite adequate time and conditions for sleep and that are characterized by disturbances in daytime activities of various kinds."

In this definition, it is necessary to highlight the main features, namely:

• persistent nature of sleep disturbances (they occur over several nights);
• the possibility of developing various types of sleep disorders;
• the availability of sufficient time to ensure sleep in a person (for example, lack of sleep in intensively working members of an industrial society cannot be considered insomnia);
• the occurrence of disturbances in daytime functioning in the form of decreased attention, mood, daytime sleepiness, vegetative symptoms, etc.

Epidemiology of insomnia

Insomnia is the most common sleep disorder, its frequency in the general population is 12-22%. The frequency of sleep-wake cycle disorders in general and insomnia in particular is very high among neurological patients, although they often fade into the background against the background of massive neurological disorders.

Frequency of insomnia in some neurological diseases. Read also: Sleep and other diseases

Diseases	Frequency of sleep disorders, %
	Subjective	Objective
Stroke (acute period)	45-75	100
Parkinsonism	60-90	Up to 90
Epilepsy	15-30	Up to 90
Headaches	30-60	Up to 90
Dementia	15-25	100
Neuromuscular diseases	Up to 50	?

Undoubtedly, insomnia develops more often in older people, which is due to both physiological age-related changes in the sleep-wake cycle and the high prevalence of somatic and neurological diseases that can cause sleep disorders (arterial hypertension, chronic pain, etc.).

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Causes of insomnia

The causes of insomnia are varied: stress, neuroses; mental disorders; somatic and endocrine-metabolic diseases; use of psychotropic drugs, alcohol; toxic factors; organic brain damage; syndromes that occur during sleep (sleep apnea syndrome, movement disorders during sleep); pain syndromes; adverse external conditions (noise, etc.); shift work; time zone changes; sleep hygiene disorders, etc.

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Symptoms of insomnia

The clinical phenomenology of insomnia includes presomnic, intrasomnic and postsomnic disorders.

• Presomnic disorders - difficulties in initiating sleep. The most common complaint is difficulty falling asleep; with a long course, pathological rituals of going to bed may develop, as well as "bed anxiety" and fear of "not sleeping". The desire to sleep disappears as soon as the patients find themselves in bed: distressing thoughts and memories appear, motor activity increases in an effort to find a comfortable position. The onset of drowsiness is interrupted by the slightest sound, physiological myoclonus. If a healthy person falls asleep within a few minutes (3-10 minutes), then in patients it sometimes drags on for 2 hours or more. Polysomnographic studies note a significant increase in the time it takes to fall asleep, frequent transitions from the 1st and 2nd stages of the first sleep cycle to wakefulness.
• Intrasomnic disorders include frequent nocturnal awakenings, after which the patient cannot fall asleep for a long time, and sensations of superficial sleep. Awakenings are caused by both external (primarily noise) and internal factors (frightening dreams, fears and nightmares, pain and vegetative shifts in the form of respiratory failure, tachycardia, increased motor activity, urge to urinate, etc.). All these factors can awaken healthy people, but in patients, the threshold of awakening is sharply reduced and the process of falling asleep is difficult. The decrease in the threshold of awakening is largely due to insufficient depth of sleep. Polysomnographic correlates of these sensations are an increased representation of superficial sleep (stages I and II of FMS), frequent awakenings, long periods of wakefulness within sleep, reduction of deep sleep (δ-sleep), and increased motor activity.
• Postsomnic disorders (occurring in the immediate period after awakening) - early morning awakening, decreased performance, feeling of being “broken”, dissatisfaction with sleep.

Forms of insomnia

In everyday life, the most common cause of sleep disorders is adaptive insomnia - a sleep disorder that occurs against the background of acute stress, conflict or changes in the environment. As a result of these factors, the general activity of the nervous system increases, making it difficult to fall asleep when falling asleep in the evening or waking up at night. With this form of sleep disorder, the cause can be determined with great certainty. The duration of adaptive insomnia does not exceed 3 months.

If sleep disorders persist for a longer period, psychological disorders join them (most often, the formation of "fear of sleep"). In this case, the activation of the nervous system increases in the evening hours, when the patient tries to "force" himself to fall asleep faster, which leads to worsening sleep disorders and increased anxiety the following evening. This form of sleep disorders is called psychophysiological insomnia.

A special form of insomnia is pseudoinsomnia (previously called distorted sleep perception, or sleep agnosia), in which the patient claims that he does not sleep at all, but an objective study confirms that he has had a sufficiently long sleep (6 hours or more). Pseudoinsomnia is caused by a disturbance in the perception of one's own sleep, associated primarily with the peculiarities of the sense of time at night (periods of wakefulness at night are well remembered, while periods of sleep, on the contrary, are amnesic), and a fixation on problems of one's own health associated with sleep disorders.

Insomnia can also develop against the background of inadequate sleep hygiene, i.e. the characteristics of a person's life that lead to increased activation of the nervous system (drinking coffee, smoking, physical and mental stress in the evening), or conditions that prevent the onset of sleep (going to bed at different times of the day, using bright light in the bedroom, an uncomfortable environment for sleep). Similar to this form of sleep disorder is behavioral insomnia of childhood, caused by the formation of incorrect associations in children related to sleep (for example, the need to fall asleep only when rocked), and when trying to eliminate or correct them, the child actively resists, leading to a reduction in sleep time.

Of the so-called secondary (associated with other diseases) sleep disorders, insomnia is most often observed in mental disorders (in the old way - in diseases of the neurotic circle). 70% of patients with neuroses have disorders of sleep initiation and maintenance. Sleep disorders are often the main symptom-forming factor, due to which, in the patient's opinion, numerous vegetative complaints develop (headache, fatigue, deterioration of vision, etc.) and social activity is limited (for example, they believe that they cannot work because they do not get enough sleep). Anxiety and depression play a particularly large role in the development of insomnia. Thus, in various depressive disorders, the frequency of night sleep disorders reaches 100% of cases. Polysomnographic correlates of depression are considered to be a shortening of the latent period of REM sleep (<40 min - strict, <65 min - "democratic" criterion), a decrease in the duration of δ-sleep in the first sleep cycle, and α-δ-sleep. Increased anxiety most often manifests itself in presomnic disorders, and as the disease progresses - in intrasomnic and postsomnic complaints. Polysomnographic manifestations in high anxiety are nonspecific and are determined by prolonged falling asleep, an increase in superficial stages, motor activity, wakefulness time, a decrease in the duration of sleep and deep stages of slow sleep.

Complaints about sleep disorders are also quite common among patients with somatic diseases such as hypertension, diabetes, etc.

A special form of insomnia is sleep disorders associated with a disorder of the body's biological rhythms. In this case, the "internal clock" that signals the onset of sleep prepares for the onset of sleep either too late (for example, at 3-4 a.m.) or too early. Accordingly, either falling asleep is disrupted, when a person unsuccessfully tries to fall asleep at a socially acceptable time, or morning awakening occurs too early according to standard time (but at the "correct" time according to the internal clock). A common case of sleep disorders associated with a disorder of biological rhythms is "jet lag syndrome" - insomnia that develops with rapid movement through several time zones in one direction or another.

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The course of insomnia

According to the course, acute (<3 weeks) and chronic (>3 weeks) insomnia are distinguished. Insomnia lasting less than 1 week is called transient. The chronicity of insomnia is facilitated by the persistence of stress, depression, anxiety, hypochondriacal attitude, alexithymia (difficulty differentiating and describing one's own emotions and sensations), and irrational use of sleeping pills.

Consequences of insomnia

There are social and medical consequences of insomnia. The former have a great public resonance, first of all, in connection with the problem of daytime sleepiness. This concerns, in particular, the problem of driving vehicles. It has been shown that in terms of the effect on concentration and reaction speed, 24-hour sleep deprivation is equivalent to a blood alcohol concentration of 0.1% (the state of intoxication is confirmed at an ethanol concentration of 0.08%). The medical consequences of insomnia are currently being actively studied. It has been shown that insomnia is associated with psychosomatic diseases - arterial hypertension, chronic gastritis, atopic dermatitis, bronchial asthma, etc. The effect of lack of sleep is especially pronounced in the child population: first of all, in the form of deterioration in the ability to learn and behavior in a group.

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Diagnosis of insomnia

The main principles of insomnia diagnostics are the following: assessment of the individual chronobiological stereotype of a person (owl/lark, short/long sleeper), which is probably genetically determined; consideration of cultural characteristics (siesta in Spain), professional activity (night and shift work); study of the clinical picture, psychological research data, polysomnography results; assessment of concomitant diseases (somatic, neurological, mental), toxic and drug effects.

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Treatment of insomnia

Non-drug treatments for insomnia include sleep hygiene, psychotherapy, phototherapy (bright white light therapy), encephalophony (“brain music”), acupuncture, biofeedback, and physical therapy.

An important and integral component of the treatment of any form of insomnia is maintaining sleep hygiene, which involves following the following recommendations.

• Go to bed and get up at the same time.
• Avoid daytime sleep, especially in the afternoon.
• Do not drink tea or coffee at night.
• Reduce stressful situations and mental strain, especially in the evening.
• Organize physical activity in the evening, but no later than 2 hours before bedtime.
• Regularly use water procedures before bedtime. You can take a cool shower (slight cooling of the body is one of the elements of the physiology of falling asleep). In some cases, a warm shower (at a comfortable temperature) is acceptable until you feel slight muscle relaxation. The use of contrast water procedures, excessively hot or cold baths is not recommended.

Drug treatment for insomnia

Ideally, it is necessary to treat the disease that caused insomnia, which in most cases is one of the manifestations of a particular pathology. However, in most cases, identifying the etiologic factor is difficult, or the causes of insomnia in a particular patient are numerous and cannot be eliminated. In such cases, it is necessary to limit ourselves to prescribing symptomatic therapy, that is, sleeping pills. Historically, many drugs from different groups have been used as sleeping pills - bromides, opium, barbiturates, neuroleptics (mainly phenothiazine derivatives), antihistamines, etc. A significant step in the treatment of insomnia was the introduction of benzodiazepines into clinical practice - chlordiazepoxide (1960), diazepam (1963), oxazepam (1965); At the same time, drugs of this group have many negative effects (addiction, dependence, need for constant increase in daily dose, withdrawal syndrome, worsening of sleep apnea syndrome, decreased memory, attention, reaction time, etc.). In this regard, new sleeping pills have been developed. Drugs of the "three Z" group are widely used - zopiclone, zolpidem, zaleplon (agonists of various receptor subtypes of the GABA-ergic receptor postsynaptic complex). Melatonin (melaxen) and melatonin receptor agonists are of great importance in the treatment of insomnia.

The basic principles of drug treatment of insomnia are as follows.

• Preferential use of short-lived drugs such as zaleplon, zolpidem, zopiclone (listed in order of increasing half-life).
• To avoid the formation of habituation and dependence, the duration of the prescription of sleeping pills should not exceed 3 weeks (optimally 10-14 days). During this time, the doctor should determine the causes of insomnia.
• Older patients should be prescribed half the daily dose of sleeping pills (compared to middle-aged patients); it is important to consider their possible interactions with other drugs.
• If there is even minimal suspicion of sleep apnea syndrome as the cause of insomnia and its polysomnographic verification is impossible, doxylamine and melatonin can be used.
• If, with subjective dissatisfaction with sleep, the objectively recorded duration of sleep exceeds 6 hours, the prescription of sleeping pills is unjustified (psychotherapy is indicated).
• Patients who have been taking sleeping pills for a long time need to take a “drug holiday,” which allows them to reduce the dose of the drug or replace it (this primarily concerns benzodiazepines and barbiturates).
• It is advisable to use sleeping pills as needed (especially drugs from the “three Z” group).

When prescribing hypnotics to neurological patients, the following aspects should be taken into account.

• Predominantly elderly patients.
• Limited possibilities of using agonists of various receptor subtypes of the GABA-ergic receptor postsynaptic complex (in diseases caused by muscle pathology and neuromuscular transmission).
• Higher incidence of sleep apnea syndrome (2-5 times higher than in the general population).
• Higher risk of developing side effects of sleeping pills (especially benzodiazepines and barbiturates, which often cause complications such as ataxia, memory disorders, drug-induced parkinsonism, dystonic syndromes, dementia, etc.).

If insomnia is associated with depression, antidepressants are optimal for treating sleep disorders. Of particular interest are antidepressants that have a hypnotic effect without sedative effects, in particular, agonists of cerebral melatonin receptors of types 1 and 2 (agomelatine).