Circadian rhythm disorder are one of the variants of insomnia, in which there is a mismatch between the internal sleep—wake cycle and the external day-night cycle. The condition develops with the change of time zones (jetlag), shift and shift work schedules, neurological diseases. Disorders of circadian rhythms cause psychoemotional disorders, reduce performance, increase the risk of endocrine and cardiac problems. Diagnostics includes a detailed history collection, polysomnography, neuroimaging. Medications (melatonin, sleeping pills), non-drug correction of the rest regime are used for treatment.
ICD 10
G47.2 Sleep and wake cycle disorders
General information
Failures of physiological circadian rhythms are one of the most common problems in modern neurology, with various manifestations of which every person periodically encounters. The condition is of great relevance due to the lack of effective medical methods of correction, a pronounced negative impact on the well-being and somatic health of patients. Despite the improvement of treatment tactics, many people continue to suffer from somnological circadian disorders.
Causes
Changes in sleep cycles may have physiological prerequisites: in adolescence, there is usually a later falling asleep, which does not coincide with the prescribed norms, and in old age, on the contrary, people go to bed too early, and then wake up in the middle of the night and can no longer sleep. The pathological causes of circadian biorhythm disorders include the following:
- Features of the working schedule. People who work in shifts (day/night), by the day or by the shift method are more likely to face problems of somnological disorders. Pathology is caused by the inability of the body to adapt to different times of falling asleep and waking up, frequent episodes of rest in the daytime in bright light.
- Frequent travel. The change of time zones negatively affects the coordination of endogenous and external biorhythms. As a result, insomnia develops in the first few days. The situation is aggravated by regular business trips with a time shift of more than 2 hours.
- Neurodegenerative diseases. Since circadian rhythms are regulated by the central nervous system, with its pathology, persistent changes in sleep-wake cycles are often formed. Typical causes: Alzheimer’s disease, Parkinson’s disease, Huntington’s chorea.
- Blindness. People who are blind from birth are most often subject to somnological disorders, since they are not able to determine external circadian rhythms. In such patients, their own internal biorhythms do not agree with the generally accepted 24-hour system.
Pathogenesis
Regulation of internal circadian rhythms of a person is subject to a complex molecular mechanism, including 9 main “clock” regulatory genes. They contribute to the development of transcription factors, activation of casein kinases, cryptochrome proteins responsible for capturing the level of illumination. An important role is played by genes that stimulate the production of melatonin and contribute to the realization of the effects of the hormone.
Normally, all substances work together, maintaining the circadian cycle, which is regulated by feedback. But with a sharp change in external circadian rhythms (time zones), constant exposure to lighting at night (shift work, non-compliance with sleep hygiene), desynchronization of natural circadian rhythms occurs. In the brain, the production of melatonin decreases, functional pathologies of the central nervous system arise.
Symptoms
Circadian rhythm disorder have similar clinical signs: insomnia at night, pathological drowsiness during the day, impaired performance and concentration associated with sleep deprivation. As a rule, headaches, causeless mood swings are observed, many patients are worried about unexplained anxiety, nervousness. Sometimes there are digestive disorders, interruptions in the work of the heart.
Jet lag
The symptom complex manifests itself most vividly with jetlag (a sharp change in time zones). Violations of circadian rhythms bother a person from 2-3 days to several weeks. The greater the time difference between the starting point and the place of current stay, the more pronounced the signs are. It is harder to travel to the east with the transfer of falling asleep at an earlier time, whereas the body adapts to traveling to the west quite quickly.
Insomnia during shift work
In this case, the intensity of symptoms of biorhythm disorders depends on the number of work shifts per month, their duration, and rotation schedule. The most severe manifestations are noted with unfixed work with chaotic alternation of shifts and rotation “counterclockwise”. In addition, patients often consciously sleep less in order to spend time with their family and participate in social life.
Sleep phase disorder syndrome
This type of disorders is characterized by the normal quality of night rest in combination with the discrepancy between the physiological schedule and the desired daily routine. Young people mostly have a delayed onset of the sleep phase, which is why they go to bed late at night, and then hardly wake up in the morning to study or work. The elderly, on the contrary, suffer from an advanced phase, too early awakenings.
Usually, there are no difficulties with falling asleep in “your rhythm”, which distinguishes the condition from typical insomnia. The main problem of sleep phase disorders is the need to adapt to the generally accepted routine, as a result of which patients experience a constant lack of rest, during working hours they suffer from problems with thinking, memory, concentration.
Complications
With prolonged violation of daily rhythms, the content of leptin (satiety hormone) decreases by 7-10%, the indicator of ghrelin (hunger hormone) increases. This is fraught with overeating, obesity, to which women are more susceptible due to the peculiarities of metabolism. Chronic lack of sleep reduces the immune defense of the body, increases the risk of developing diabetes, cardiovascular diseases.
Another danger of circadian disorders is that people with this problem often do not seek medical help, trying to cope with the situation on their own. Patients resort to alcohol, sleeping pills and sedatives to facilitate falling asleep, and take psychostimulants during the day to improve their performance. As a result, the pathology is aggravated by dependence on psychoactive substances.
Diagnostics
The main stage in the diagnosis of circadian rhythm disorder is a detailed inquiry of the insomnia sufferer: collection of complaints, information about professional activities, frequency of travel. Several doctors are often involved in the examination — neurologists, psychiatrists, somnologists, specialized specialists in somatic diseases. The diagnostic plan includes:
- Polysomnography. The study is used for a comprehensive study of various sleep parameters, identification of the root cause of insomnia, exclusion of dangerous diseases (obstructive apnea, sleep paralysis, narcolepsy).
- MRI of the brain. Neuroimaging is prescribed if organic lesions of the cerebral cortex or subcortical nuclei are suspected. MRI is an important method of diagnosing Alzheimer’s and Parkinson’s disease.
- Consultation of a psychiatrist. Circadian rhythm disorder can occur against the background of neuroses, depressions, psychopathies, so the patient necessarily needs a profile examination, passing special tests and questionnaires.
Treatment
Therapy of circadian rhythm disorder is a difficult task. The best way to deal with the problem is to eliminate the provoking factor, if possible (move to a position with a standard working day, limit long—distance flights). However, in most cases, radical measures are not suitable for patients, or the trigger cannot be completely excluded. In such a situation , several treatment options are used:
- Compliance with the rules of healthy sleep. This point is especially important for people who work shifts and have to sleep during the day. It is necessary to ensure maximum darkening of the room, protect yourself from harsh sounds, explain yourself in advance with family members, ask them to understand the situation.
- Advance preparation for the flight. To minimize the manifestations of jetlag, it is recommended to start shifting the time of falling asleep in advance in order to adapt the mode to the intended place of travel. For convenience, there are special sites that help to shift the sleep-wake schedule correctly, without compromising health.
- Taking melatonin. The hormonal drug has a physiological effect on endogenous rhythms, helps to fall asleep faster, improves the quality of sleep. Taking into account the type of insomnia, an individual schedule for taking medication is selected at least 1-1.5 hours before the desired moment of falling asleep.
According to indications, other medications may be prescribed (sleeping pills, psychostimulants, adaptogens). In each specific case, a personalized scheme for the use of drugs is selected in order to eliminate negative symptoms and at the same time not aggravate circadian disorders. The dosage and schedule of medications are carefully monitored by a neurologist.
Prognosis and prevention
Circadian disorders are quite difficult to treat, but with an integrated approach, a combination of drugs and non-drug methods, it is possible to synchronize biorhythms. Less favorable prognosis for patients with neurodegenerative pathologies that are not subject to correction. Prevention includes the observance of rest hygiene, proper organization of the labor process, regular occupational examinations of people engaged in shift / shift work.
