Sleep disturbance: diagnosis

Diagnosis of sleep disorders

The approach to diagnosis and treatment of sleep disorders, presented in this chapter, is geared toward physicians who conduct outpatient admission. The modern situation is such that a general practitioner, to whom a large queue sits behind the door, can spend only a very limited time on the patient's admission. Nevertheless, it is recommended to ask the patient a few questions about the quality of sleep, the availability of daytime sleepiness and health status. If the patient, when answering these questions, reports on a particular violation, it should be subjected to a comprehensive and in-depth examination.

[1], [2], [3], [4]

Initial examination

It has already been noted that not all patients suffering from sleep disorders mention it during their visit to the doctor. Even more rarely patients specifically address a doctor about this. Nevertheless, sleep disorders are very common and have an adverse effect on well-being, performance, quality of life, general health and emotional well-being. In view of these circumstances, a brief, but capacious ("screening") assessment of the state of sleep and wakefulness should become an indispensable part of an ordinary outpatient examination of the patient.

An initial assessment of the quality of sleep should include several aspects associated with frequent sleep disorders. The most common sleep disorder is insomnia, but this is not a nosological or even a syndromic diagnosis, but rather a statement that the quality of sleep is unsatisfactory. Insomnia can manifest itself with one or more of the following symptoms:

1. disturbances of falling asleep;
2. frequent awakenings during the night (sleep disturbances);
3. premature morning awakening;
4. no feeling of rest or freshness after awakening (dissatisfaction with the quality of sleep).

When assessing the state of sleep, it is recommended to start with open questions about the overall satisfaction of the patient with sleep, and then you can additionally ask several clarifying questions regarding individual symptoms.

The second most important manifestation of sleep disorders is increased daytime sleepiness. It can be the leading symptom of a number of primary sleep disorders, including obstructive sleep apnea, PDNC, narcolepsy. In severe cases, during a doctor's examination, patients are so sleepy that they hardly support the conversation. More often, however, there are more mild cases of daytime sleepiness, when patients report only increased fatigue and loss of strength. As in the case of insomnia, in order to detect daytime sleepiness, the patient needs to ask a few clarifying questions.

Sleep disorders can also manifest themselves as somatic or behavioral changes. For example, pronounced snoring, irregular breathing, sensation of choking during sleep are characteristic for obstructive sleep apnea, frequent repetitive jerking or kicking is a sign of PDKS. Collecting information about the patient's behavior during sleep helps to identify parasomnias, such as somnambulism or night terrors.

A separate category of sleep disorders are violations of the sleep and wake cycle. In some patients, due to endogenous factors, a temporary shift of the sleep and wake cycle occurs with respect to the usual rhythm. For example, people with a premature phase of sleep syndrome fall asleep early in the evening, but also wake up early in the morning. At the same time, in the syndrome of the delayed phase of sleep, a person falls asleep only late at night and wakes up during the day. In both cases, the structure and quality of the sleep itself does not suffer. Other variants of sleep and wakefulness cycle disorders (i.e., circadian rhythm) are associated with occupational or behavioral factors. Frequent examples of such disorders are sleep disorders associated with the change of time zones (for example, for long flights) or shift work.

Thus, in conducting the initial examination, the doctor must ask several specific questions about the quality of sleep and manifestations of sleep disorders. It is also important to ask whether a person feels cheerful or sleepy during the day. Then it should be determined whether somatic or behavioral changes are noted during sleep (for example, snoring, pronounced leg movements or stimulation). Finally, one or two questions should be asked about when a person usually falls asleep and awakens, in order to exclude disorders associated with a circadian rhythm disorder. Thus, this initial survey includes a limited number of directly asked questions and can be performed fairly quickly. If you identify any symptoms, you need a comprehensive examination to diagnose a possible sleep disorder.

In-depth examination

If one or more symptoms indicating a sleep disturbance are detected, a deeper comprehensive examination is needed in order to establish a diagnosis, if possible to identify etiological factors and adequately plan treatment. This approach is similar to the usual actions of a doctor who deals with a somatic symptom (for example, fever or chest pain), which can be caused by a variety of diseases and requires special treatment in each of them. In the case of disorders, it is important to remember that insomnia is a symptom, not a diagnosis. In clinical practice, an incorrect stereotype has developed: the detection of insomnia entails the appointment of a sleeping pill - instead of stimulating a thorough search for its cause. Below is a more detailed description of the recommended approach to sleep disorders, namely, on the example of insomnia.

Analyzing complaints of the patient for sleep disorders, it is necessary to obtain additional anamnestic information in order to build them into a certain system. It is necessary to detail the nature of the main complaints, to ask about other groups of symptoms that are possible with sleep disorders, the lifestyle of the patient and external factors that can contribute to sleep disturbance. Important additional information can be provided by the spouse or partner of the patient - only he can find out whether the patient snores, whether he makes dreams in the dream, whether he is breathing evenly.

Insomnia can occur against the background or due to a number of diseases, which leads to an additional series of questions. Of great importance is information on the persistence of sleep disorders, which is necessary to establish a diagnosis and choose adequate therapy. Insomnia is classified as follows:

1. Transient, lasting several days;
2. Short-term - up to 3 weeks and
3. chronic - lasting more than 3 weeks.

Many factors can cause sleep disturbances. It is well known that stress is one of the most important external factors that have an adverse effect on the quality of sleep. According to a 1995 Gallup poll, 46% of respondents said that their sleep disorders were associated with stress or anxiety. Approximately one-quarter of respondents among those who have sleep disorders believe that it is impossible to achieve career success unless they sacrifice sleep. In this regard, it is necessary to identify newly emerged or long-term stressors that can adversely affect sleep. Discussion with the patient of these factors, an analysis of their importance will help him to understand the causes of sleep disorders and make efforts to change the circumstances of his life. In some cases, the patient should be referred to a psychologist or psychotherapist to help him deal more effectively with stress.

A significant influence on sleep is often provided by the home environment, the regime of the day, habits. To denote a wide range of these aspects, the term "sleep hygiene" is used. Discussing the problems of sleep hygiene, it is useful to find out the habits of the patient, the way he usually goes to bed or gets up. A common cause of a sleep disorder is a non-observance of a certain daily schedule. Important is the situation in the bedroom. Sleep can be disturbed due to the fact that the room is too noisy, too cold or hot, too light. The quality of sleep can be affected by late supper dinner, eating at night of spicy food, exercise before bed. In this regard, it is useful to ask the patient to keep a diary for several weeks, making notes about the time and quality of a night's sleep, daytime nap, wakefulness during the day, habits or activities related to sleep. Analysis of diary entries often reveals factors that contribute to sleep disturbance.

Sleep can disrupt a variety of substances and medications. Although aware of the adverse effects of caffeine on sleep, many do not follow the amount of coffee drunk or drink it too late. In addition, often do not take into account that tea, cola, chocolate contain a very significant amount of caffeine. Often, sleep disorders are associated with drinking alcohol. Although alcohol causes a sedative effect and can reduce the latent period of falling asleep, against the background of its action, the sleep becomes fragmented and restless. Many patients with insomnia, especially associated with anxiety or depression, independently start using alcohol as a sleeping pill. However, in the long run this method is ineffective due to the ability of alcohol to cause fragmentation of sleep. In addition, if a person is accustomed to falling asleep with alcohol, attempts to stop taking him will provoke a ricochet insomnia, which in the long term may lead to alcohol dependence.

A number of drugs prescribed for somatic, neurological or psychiatric disorders have a significant effect on sleep. Some drugs (for example, antidepressant amitriptyline, various antihistamines) cause a pronounced sedative effect and can cause daytime sleepiness.

Sleep disorders in somatic and neurological diseases

Sleep disorders can be caused by a variety of somatic and neurological diseases. Therefore, when examining a patient with complaints of sleep disturbances, attention should be paid to possible signs of thyroid dysfunction (hypothyroidism or thyrotoxicosis), lung diseases (bronchial asthma, chronic obstructive diseases), gastrointestinal disorders (eg, esophageal reflux), neurological diseases , Parkinson's disease), which are capable of disturbing sleep. Any condition accompanied by a marked pain syndrome can lead to a sleep disorder. An example is fibromyalgia. In this disease, characterized by muscle pain and the presence of multiple specific painful points, insomnia is often observed, and during polysomnography, inclusions of alpha rhythm (the so-called "alpha delta sleep") are detected during slow sleep.

Diseases that cause sleep disturbances can be detected by physical examination and laboratory examination. If possible, you should always try to find and treat the underlying cause of sleep disturbance, rather than insomnia itself.

Mental and sleep disorders

Many mental illnesses are associated with sleep disorders, especially insomnia. Therefore, the examination of a patient with a sleep disorder should necessarily include an assessment of mental status. Sleep disorders are common in patients with schizophrenia, Alzheimer's disease, but especially important is the identification of anxiety and affective disorders, as these patients primarily seek general practitioners and often with complaints of sleep disorders. Approximately 70% of patients with depression express complaints about insomnia, especially complaints of intermittent restless sleep or premature morning awakenings. In one study, 90% of hospitalized patients with depression had EEG-confirmed sleep disorders. Numerous polysomnographic studies revealed characteristic changes in the architectonics of sleep in patients with depression: sleep fragmentation, sleep changes with BDG (eg, shortening of the latent period of sleep with BDG), reduction of slow sleep.

At the same time, a significant proportion of patients with depression (approximately 20%) do not suffer from typical insomnia, but, on the contrary, daytime drowsiness, which can be manifested by periodic hibernation or fast fatigue. Such cases are sometimes called atypical depression. Hypersomnia is also often observed in patients in the depressive phase of bipolar disorder, as well as in seasonal affective disorder.

The relationship between depression and sleep disorders is quite complex. Sometimes it is difficult to decide whether a sleep disorder is a symptom of depression or a factor that provokes the development of a depressive episode. Some depressed patients claim that their "depression goes away" if they manage to sleep normally for several nights. However, to date, there are practically no systematic studies that would determine to what extent, when treating insomnia directly, one can influence the manifestations of depression. However, it should be noted that in many cases, doctors do not recognize depression and do not prescribe adequate therapy, since they focus exclusively on symptoms of insomnia and other somatic complaints. It is generally accepted that the appointment of patients with depression only with sleeping pills can not be considered adequate therapy. This situation is especially dangerous due to the serious threat of suicide.

Factors contributing to chronic insomnia

When examining a patient with insomnia, one should try to identify not only factors that provoked insomnia, but also factors contributing to its chronicization. In particular, many patients with severe severe insomnia have expressed anxious doubts about whether it will be possible to fall asleep or not. Often, the patient embraces anxiety as soon as he crosses the threshold of the bedroom. Constant concern about the prospect of another sleepless night is reinforced by concerns about possible disability or serious health problems that may occur due to sleep disturbances. The situation is often complicated by inadequate actions of the patients themselves, with the help of which they try to normalize the sleep (for example, they can doze during the day and drink alcohol at night). This variant of sleep disorder is referred to as psychophysiological insomnia. If psychophysiological insomnia is diagnosed, then in addition to eliminating the primary factors that provoked sleep disturbance, correction of the secondary psychological problems supporting it is necessary.

[5], [6], [7]

Examination of a patient with increased daytime drowsiness

Increased daytime drowsiness is a condition that is closely related to sleep disorders and is often found in general practice. Like insomnia, daytime sleepiness is an occasion for a comprehensive in-depth examination of the patient. When you identify symptoms of increased daytime sleepiness, its cause has to be found in a fairly wide range of diseases.

First of all, a careful evaluation of the symptoms and their severity is necessary. It is necessary to find out the circumstances of the manifestation of symptoms, the factors that contribute to their amplification or weakening, the state of night sleep. Survey on systems and organs, physical examination, comprehensive laboratory testing will eliminate the somatic or neurological disease, which may be the cause of increased daytime sleepiness. It is very important to clarify which medications the patient takes, as they also often cause drowsiness.

[8], [9]

Conditions that cause increased daytime sleepiness

• Lack of sleep (for various reasons)
• Some somatic diseases (eg, hypothyroidism)
• Side effects of medicines (antihistamines, antidepressants, adreno-bactrators)
• Depressive disorders (especially bipolar affective disorder and atypical depression)
• Idiopathic hypersomnia
• Periodic movements of limbs in a dream
• Obstructive sleep apnea
• Narcolepsy

Primary sleep disorders, usually causing daytime drowsiness, include narcolepsy and obstructive sleep apnea. In connection with this, the patient needs to ask a number of questions concerning these conditions. Narcolepsy, in addition to increased daytime sleepiness, is characterized by cataplexy (transient muscle weakness, usually provoked by an intense emotional reaction), sleep paralysis (a transitory condition of immobility after awakening, which is probably associated with a short-term prolongation of muscle atony inherent in sleep with BDG), hypnagogic hallucinations in the moment of falling asleep and awakening. Obstructive sleep apnea is often seen in individuals with overweight, a short massive neck, or other features contributing to obstruction of the upper respiratory tract. Usually, these patients are characterized by pronounced snoring, fragmented, restless, unrefreshed sleep, headache and confusion in the morning, a feeling of suffocation at night. To confirm the diagnosis of narcolepsy and obstructive sleep apnea, PSG is needed.

[10]

The use of polysomnography in the diagnosis of sleep disorders

To confirm the diagnosis of primary sleep disorders (including obstructive sleep apnea, narcolepsy, PDNC, sleep disorder with BDG), and sometimes to find out the cause of insomnia, a laboratory study of night sleep is required. Due to technical complexity and high cost, a polysomnographic study must be carried out strictly according to indications. In this regard, doctors should have a clear idea of when a patient should be referred to a somnological laboratory.

Obstructive sleep apnea is the most common indication for PSG. Because this condition causes frequent complications and is accompanied by increased mortality, its accurate diagnosis is extremely important. Although obstructive sleep apnea can be suspected on the basis of clinical data, the diagnosis can be confirmed only with the help of PSG. The procedure for diagnosing obstructive sleep apnea usually requires a study for two nights. During the first night, there is confirmation of the presence of apnea, during the second one, the effectiveness of the method based on the creation of a constant positive air pressure (PVLD) in the upper respiratory tract is evaluated . In the abbreviated version of the study conducted overnight, during the first half of the study confirmed the presence of apnea, in the second half, the most effective parameters of PPHP were selected. In PSG, the number of episodes of apnea or hypopnea during the night is calculated. Each such episode is usually accompanied by an awakening, which leads to a fragmentation of sleep. In addition, a decrease in the level of oxyhemoglobin is usually detected. There are some disagreements about the threshold frequency of episodes of apnea and hypopnea, which allows to diagnose this disease. According to the most common opinion, a diagnosis can be made if the number of episodes of apnea and hypopnea is no less than 15 per hour. In many patients, the frequency of these episodes is significantly higher and sometimes exceeds 100 per hour. Fragmentation of night sleep is the direct reason that patients usually have pronounced daytime sleepiness. The termination of the air current is usually accompanied by an intensive respiratory movement, which can be judged by the activity of the muscles of the chest, diaphragm, abdomen. In the absence of such activity, central sleep apnea is diagnosed.

Narcolepsy is another primary sleep disorder, the diagnosis of which requires PSG. The main clinical manifestations of narcolepsy - increased daytime sleepiness, cataplexy, sleep paralysis and hypnagogic hallucinations - can be suspected of this disease. Laboratory studies necessary to confirm the diagnosis, includes not only the registration of a night's sleep, but also carrying out day study - test mnozhes idents sleep latency periods (MLPS). The MLPS test is especially widely used for objective quantitative assessment of daytime sleepiness. The study of a night's sleep in narcolepsy can reveal changes in the quality and architectonics of sleep. In many patients, fragmentation of night sleep and premature sleep with BDG are detected. The MLPS test is carried out the day after the study of a night's sleep. The patient is offered to lie down and try to fall asleep every 2 hours (for example, at 9, 11, 13 and 15 hours). 20 minutes after each fall asleep, they awaken him and force him to stay awake until the next attempt to fall asleep. Estimate the average time of falling asleep (for 4 attempts) and the type of sleep that has set. If the average latent period of sleep is less than 5 minutes, we can state a pathological drowsiness. Although the decrease in the latent period of sleep is typical for patients with narcolepsy, it is not pathognomonic and can be observed in other conditions - obstructive sleep apnea, idiopathic hypersomnia, disturbance or deprivation of night sleep. More specific for narcolepsy is the shortening of the latent period of sleep with BDG - this can also be identified in the MLPS test. According to the established criteria, the diagnosis of narcolepsy can be established if at least 2 out of 4 attempts at falling asleep will register a sleep with an RDB.

PSG is also important in the diagnosis of other sleep disorders. Periodic movements of limbs in a dream are characterized by stereotyped movements, repeated every 20-40 seconds. These movements also lead to fragmentation of sleep, which is expressed in complaints of restless, non-refreshing sleep and daytime sleepiness.

Behavioral disorder in a dream with BDG is characterized by actions, sometimes violent or aggressive, which, apparently, reflect the patient's reaction to dreams and correspond to their content. With the help of PSG, it is established that these actions are observed during sleep with BDG and are associated with the lack of muscle atony usually observed at this stage. If the anamnestic data allows one to suspect a behavioral disorder in a dream with a BDG, then the statement that there is no muscle atony during sleep with BDG is sufficient to confirm this diagnosis, even if no action was recorded during the night sleep recording. Since a disorder of behavior in a dream with BDG can be associated with a lesion in the middle brain or other parts of the brain stem, if the PSG confirms the presence of this brain disorder, additional research is needed, including brain neuroimaging.

Epileptic seizures are often associated with sleep and sometimes occur exclusively during sleep. It is often possible to diagnose nocturnal epileptic seizures with the help of PSG alone; But in order to register epileptic activity on the EEG, additional leads are needed.

Insomnia PSG is usually not performed, because due to the nonspecific data it does not allow in most cases to identify the cause of the sleep disorder, and its utility in this case clearly does not justify the costs. Nevertheless, in some patients with severe chronic insomnia, resistant to conventional treatment, the origin of which remains unclear, PSG is nevertheless shown. In these cases, it can help to identify a primary sleep disorder that could not be diagnosed by clinical data. Establishing the right diagnosis opens the way for more effective therapy.