in this article:
The average man spends a third of his life sleeping. But sleeping does not mean completely cutting the bridges with reality: during sleep a complex series of phenomena is determined, first of all the dream. it is only in the last few decades that we have tried to deepen and understand the mechanisms of this complex and important phenomenon, which for a long time, and in part still remains similar to the dark side of the moon.
Sleep and sleep disorders
All biological activities have periodic circadian variations. Sleep and wakefulness are a typical example of these variations, but we must not forget that other important biological functions, such as body temperature, blood pressure, heart rate, hormonal increases, etc., are subject to rhythmic changes during the course. 24 hours. These periodic fluctuations depend on different nerve structures, ie the so-called internal oscillators, which are routinely synchronized on rhythms of 24. Among the environmental factors that influence the internal oscillators are the social contact and the light-dark cycle that play a determining role.
The conditions of complete isolation are able to eliminate the action of the environmental synchronizers, in these situations the internal oscillators tend to take different rhythms from that of 24 hours (the free-running man tends to synchronize in a preferential way on the rhythm of 25 hours) and can desynchronize with each other.
Sleep-wake rhythm disorders include clinical syndromes caused by external factors, such as the rapid change in time zone following trans-Egyptian flights and rotating night shift shifts, and other syndromes that appear to have an endogenous component, such as the period of delayed sleep and that of rhythm sleep-wake not 24 hours.
In all these syndromes, regardless of the causes that determine them, a shift in the sleep-wake rhythm is made with respect to the usual environmental synchronizers, with the consequent appearance of a pathology that regards the moment in which the sleep and the wake appear. The patient can not sleep when he or she wishes, when he or she needs or expects to do so. It should also be noted that long-term insomnia or hypersomnia can lead to profound changes in the sleep-wake rhythm, which are important factors for aggravating and maintaining symptoms. According to the classification of the American ASDC, the sleep-wake rhythm disorders are divided into: Transient disturbances and Persistent disorders.
This syndrome, commonly called jet-lag syndrome, can be achieved when, following a rapid change of several time zones, one tries to continue the sleep-wake pattern according to the time of the arrival area. It is characterized by drowsiness, fatigue and reduced mental efficiency during the day, and by insomnia, with difficulty in falling asleep and frequent waking up during the night. In general, the disorders are greatly reduced after a couple of days, but in some people they can last longer. Flights to the east result in longer lasting disturbances. The restoration of the sleep-wake pattern, once returned to the place of origin, is generally faster.
Change of work shift syndrome
This syndrome can occur when a traditional sleep-wake pattern changes to a night shift, which forces you to stay awake at night and sleep during the day. The symptoms consist of drowsiness and decreased mental and motor performance during the new period of work-wake, that is the night, as well as from sleep, during the day, reduced and fragmented by numerous awakenings. This symptomatology appears more severe in elderly subjects. In jet-lag syndrome, the subject must resynchronize his internal rhythm on a new schedule in accordance with the environment.
Here, however, the subject must desynchronize his rhythm from that suggested by the environment. Symptoms may improve during the second or third week of work, but often persist, at least partially, until the conventional sleep-wake pattern is restored. During the weekends and holidays the natural sleep-wake pattern is generally recovered with a rapid decrease in symptoms.
Syndrome from frequent changes in the sleep-wake pattern
The clinical picture is characterized by brief and fragmented periods of sleep during the day, from drowsiness and decreased performance during the wake, from difficulty to re-establish a regular rhythm sleep-wake even when circumstances would allow it. This syndrome can typically occur due to rotating work shifts and continuous changes in time zones. The rotations of work shifts for short periods (2 – 4 days) seem better supported than those for long periods, since the body does not have time to consolidate the adaptation to the new time and is therefore not forced to change repeatedly biological rhythms already acquired. Gastroduodenal ulcer can be a complication of this syndrome. Abuse of hypnotics, psychostimulants and alcohol is common.
This disorder depends on an altered internal regulation of the sleep-wake cycle, and is characterized by a beginning of sleep and a delayed awakening with respect to the patient’s desired or required by his / her duties. The beginning of sleep and awakening are stable, and there is an absolute inability to anticipate sleep, which, once started, presents no difficulty in maintaining. The patient can simply report a difficulty in starting the sleep at a conventional hour, so it may be mistakenly considered a sleepless one.
If the patient, who falls asleep very late in the night, insists on getting up at a conventional hour in the morning, he or she goes through a chronic sleep deprivation and subsequent symptoms during the day. If you go to bed at a conventional hour without being able to fall asleep, sometimes recourse to hypnotics, which can get some results, but worsen the disturbances during the day. A daily diary of the sleep-Waking cycle, written up for a few weeks, is essential to get to the diagnosis. The choice of an occupation whose schedules do not interfere with the sleep periods, is undoubtedly the optimal solution for these patients.
Early sleep syndrome
It is characterized by a beginning of sleep and an awakening that are earlier than desired by the patient or required by his social commitments. As in the Late sleep Syndrome syndrome, there is no difficulty in continuing sleep once it has begun; the sleep period is stable, but absolutely not modifiable. This syndrome does not generally interfere with school or work. It is less frequent than the previous one and only rarely leads to a chronic sleep deprivation with the appearance of drowsiness and reduced efficiency during the day. What the patient complains about most is the inability to stay awake in the evening.
Non-24-hour sleep-wake rhythm syndrome
This syndrome is characterized by a progressive delay of the beginning of the sleep and the awakening in the following days, due to a sleep-wake rhythm greater than 24 hours (typically about 25 hours). Because of these alternate periods in which the internal rhythm is not in phase with the socio-environmental ‘synchronizers’ and the patient complains of difficulty in initiating sleep and sleepiness during the day, and periods in which the internal rhythm is synchronized with the environment and the patient has no disturbance. A diary of the sleep-wake cycle is necessary for diagnosis. Periodic difficulties of the patient to fulfill their commitments can be exacerbated by the abuse of hypnotics and psychostimulants.
Irregular sleep-wake rhythm syndrome
This syndrome is characterized by the lack of a clearly organized sleep-Wake rhythm. During the day, it involves short periods of irregular sleep and an excessive stay in bed: sometimes the patients can not even keep their meal times fixed. Night sleep is abbreviated and sometimes fragmented. Thus, a polyrhythmic sleep-wake cycle is realized with a clinical picture that can mistakenly be considered insomnia.
The patient can, in fact, complain of difficulty falling asleep at conventional hours and continuing the sleep for a suitable time; it can also report drowsiness and reduced efficiency during waking periods. Patients often do not realize that daytime naps and nocturnal insomnia are closely related, and therefore sometimes they abuse hypnotics and psychostimulants. Not only the sleep-wake cycle, but also other biological functions, such as temperature and hormonal increments, lose their usual circadian rhythm.
In fact, despite the huge amount of studies, the problems to be solved, the questions to be answered, there are still many. If highlighting the two phases of sleep (REM and non-REM) has constituted a first fundamental step for an objective study of sleep, it is true that little we know not only about the cyclical mechanisms that trigger the sleep and its phases, but also on what happens overall in the human organism during sleep. The importance of sleep can also be seen on the evolutionary level: absent in fish and amphibians, it begins to appear in reptiles, while the REM and non-REM phases make a timid appearance in birds, to definitively structure themselves in mammals. But apart from the importance of the neurophysiological study of Sleep, the problem of the pathology of sleep is also open: that is, insomnia, parasomnias, hypersomnia. It is estimated that currently about a quarter of the population over the age of 40 suffers from insomnia. Taking into account this high incidence and the fact that chronic insomnia is not only a sleep disorder but of the whole personality, one can understand the importance of the study of sleep, not only on the theoretical level, but also on the clinical
REM sleep may have the specialized function for information processing by the right hemisphere. In favor of this hypothesis is the fact that pre-sleep manipulations that activate the right hemisphere reduce the need for REM sleep and thus some transcendental meditation practices. This hypothesis also gives the REM sleep a function to reset the information recording system. This function would have the task of erasing the irrelevant information accumulated during the vigil and preparing the brain for the arrival of new information. Perhaps this function integrates with the one discussed above so as to allow REM sleep a comparison between current information and those retrieved from long-term memory.
This integration process would be able to give meaning to new information and condition its reorganization. To these essentially neurobiological hypotheses of the functions of REM and NREM sleep should be added the hypotheses of psychological and psychodynamic nature related to those mental states that are organized precisely in the ‘biological frames’ created by the different phases of sleep. It is central, in fact, in the discourse on the functional meaning of sleep, the fact that the sleep NREM has its own mental activity that can also be considered preparatory to the activity that emerges in REM sleep. In this last phase, the mental functions are represented by dream processes that therefore pose the problem of the functions of the dream.
We can therefore state that sleep as a biological moment is also a function of the dream as a mental process. Psychoanalysis has discovered the importance of this process in human life and studies it to know the unconscious mechanisms that condition its feelings, emotions, thoughts and conscious behavior.
Thus, we can distinguish four theories on the meaning of sleep:
Sleep disorders: cataplexy
Cataplexy is a sudden and transient loss of muscle tone, caused by a strong emotion from a crisis. The subject suddenly collapses to the ground without losing consciousness.
Cataplexy is a rare neurological disorder, but common in individuals with narcolepsy (occurs in about 70% of cases). It can be partial or generalized: difficulty in articulating words, weakness in the knees, until complete atony. During a cataplexic attack, the subject loses voluntary control of the muscles and may fall to the ground, but remains conscious and alert. The episodes can last for a few minutes and are often triggered by an emotional stimulus like laughter, fear, anger, surprise or excitement. Treatment involves the use of anticaplectic drugs (sodium oxybate or antidepressants).
The exact cause of cataplexy is unknown, but the condition is strongly associated with emotional stimuli. The emotions that can trigger a cataplettic event include: laughter, fear, anger, frustration, irritation, nervousness, embarrassment and sadness. As soon as stimulation is reduced, the person regains normal muscle control. Emotions can also be modest, while other times an attack takes place spontaneously, in the absence of an apparent cause.
The loss of muscle tone, which occurs in cataplexy, resembles the interruption of muscle activity that occurs naturally during REM sleep: the sudden weakness of the body’s muscles could be caused by a massive inhibition of the motor neurons in the spinal cord , caused by a dysfunction of the sleep-wake cycle. Using an animal model, scientists have learned that this same group of neurons is inactive during cataplexy attacks.
Role of hypocretin
Cataplexy is associated with significantly reduced levels of hypocretin, a neuropeptide produced in the hypothalamus, of primary importance in the regulation of sleep, as well as of states of excitation. According to some researchers, an autoimmune mechanism would exist at the base of this depletion. Cataplexy may also occur as a side effect of SSRI suspension syndrome (the ‘selective serotonin reuptake inhibitors’ belong to the pharmaceutical class of non-tricyclic antidepressants).
Narcolepsy and Cataplexy
Cataplexy is often found in association with narcolepsy, a chronic neurological disorder characterized by excessive daytime sleepiness (hypersomnia) and a sudden sleep crisis. When patients experience both conditions, it is called Gélineau’s syndrome.
Cataplexy attacks make the diagnosis of narcolepsy more certain, especially when there are signs such as excessive daytime sleepiness (EDS), hallucinations and other unwanted manifestations accompanying REM sleep. However, it is important to remember that not all narcoleptic patients manifest episodes of cataplexy.
Cataplexy may be associated with other pathological conditions. In particular, it is considered secondary when it is caused by specific brain lesions, located mainly in the lateral hypothalamus (responsible for a depletion of the hypocretin). The lesions of the brain stem can determine, instead, isolated cases of cataplexy; these include: encephalic tumors (for example: astrocytoma, glioblastoma, glioma and subependimoma) and arterio-venous malformations. Other conditions in which cataplexy can be found include: ischemic events, multiple sclerosis, cranial traumas, paraneoplastic syndromes and infections such as encephalitis. Cataplexy can also occur transiently or permanently due to hypothalamic lesions caused by surgical interventions, especially in the case of particularly complex tumor resections.
Cataplexy is extremely unpredictable, both in terms of gravity and frequency. Loss of muscle tone varies from a barely perceptible weakening of the facial muscles, to sagging of the upper or lower limbs, to complete muscular atony. These sudden manifestations can cause postural collapse and patient fall. During the cataplexy attacks, both mild and severe, the person remains fully conscious, so he or she is aware of everything that happens around (hence the hypothesis of sleep-wake dysfunction: the atony of the musculature occurs as during the phase REM, but the subject is vigilant). Cataplexy manifests itself more frequently in times of emotional stress and in cases of lack of sleep. Cataplexy is an easily overlooked and often undiagnosed disorder that can affect the most basic activities of everyday life.
Cataplexy should not be confused with an epileptic seizure:
Cataplexic attack: occurs rapidly, during periods of emotional stimulation; the subject maintains his state of consciousness unchanged and recovers almost immediately; Epileptic crisis: needed during periods of quiet and stimulation; the person recovers more slowly and may not remember what happened.
In most cases, the attacks are transient and suddenly stop after a few seconds or a few minutes. A cataplexy episode is considered ‘typical’ when it is short-lived (
Cataplexy is rarely found during an outpatient visit and the diagnosis can be made by a specialist who is familiar with the condition. Measurement of hypocretin levels in cerebrospinal fluid can confirm the diagnosis.
- Cataplexy is treated pharmacologically. The first product approved by the FDA for the treatment of cataplexy, related to narcolepsy is Xyrem (sodium oxybate). Symptoms can be repressed with the help of tricyclic antidepressants and serotonin reuptake inhibitors. Despite its relationship with narcolepsy, in most cases, cataplexy must be treated separately.
- Selective serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs). SSRIs and SNRIs can be used to help relieve the symptoms of cataplexy and other manifestations associated with REM sleep, such as hypnagogic hallucinations (they consist of hallucinations, especially visual, present at the beginning or end of sleep) and sleep paralysis ( a disorder characterized by the temporary inability to move or speak, before falling asleep or upon waking up). They include fluoxetine and venlafaxine. Serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs) have minor side effects compared to tricyclics.
- Sodium oxybate (Xyrem). This drug is highly effective for cataplexy associated with narcolepsy. Sodium oxybate improves nighttime rest and, in high doses, can also help control daytime sleepiness. Xyrem can have serious side effects, such as nausea, enuresis and worsening of sleepwalking. Sodium oxybate intake along with other sleeping drugs, narcotic analgesics or alcohol can lead to breathing difficulties, coma and death.
- Tricyclic antidepressants. For many years, cataplexy has been treated with drugs such as imipramine, clomipramine or protriptyline. The main characteristic of tricyclic antidepressants is their ability to inhibit the re-uptake of norepinephrine and serotonin at the level of nerve endings. However, these may have unpleasant side effects (example: dry mouth and dizziness) and for this they have been replaced by new drugs, such as venlafaxine.
- Emerging therapies. Promising treatments for cataplexy include gene therapy to promote hypocretin expression and immunotherapy, but further research is needed to confirm their efficacy.
Sleep disorders: insomnia
The term insomnia comes from the Latin insomnia and literally means lack of dreams. In common language it indicates an insufficient continuity of sleep. In the definition of insomnia, therefore, the aspect of insufficient duration and continuity of sleep, objectively controllable in the laboratory, must be associated with the unsatisfactory quality of sleep, linked to the subjective evaluation of each person on the restful properties of their sleep.
Insomnia is not a disease, but a symptom of various psychological or physical pathological conditions, or of altered situational or environmental balances. It is frequently perceived by the patient as a primary disorder, because of its significant existential impact and because of the difficulty in recognizing the true primary pathology that it underlies. The polysomnographic parameters show that sleeplessness is generally increased regardless of age, while the number of awakenings does not seem to be particularly influenced by insomnia. This observation leads us to interpret the difficulty of starting sleep as the primary problem of insomnia since it is in the foreground both at the beginning of sleep and during awakening at night. The total waking time of the sleepless seems to be influenced by age, similar to that of the normal.
Insomnia finds its maximum expression during the early hours of the night, regardless of age. In sleepless patients, a general representation of the sleep stages similar to that of normal dormitories was observed, but a greater variability of the percentage of REM sleep from one night to another. The percentage of sleep spent in stage 4, ie the deeper and more restful stage of sleep, which together with the decrease of REM sleep, causes an increase in the less profound sleep stages, ie stage 1 and, even more so, the stage 2.
It can therefore be concluded that in general sleepless sleepers have more difficulty falling asleep, have more sleep intrasleep and total wake during the night, have a considerable variability in the quality and efficiency of sleep from one night to the night, they can have more awakenings and a less deep sleep. From the point of view of the objective measurement of the polygraphic parameters of sleep, it can therefore be concluded that in the general population there are those who sleep well and have no sleep problems, the so-called ‘good dorms’, and those who sleep less well or frankly badly, so-called ‘bad dorms’, which have a sleep with the characteristics reported above, which are generally attributed to chronic sleepless. The latter are mostly bad dorms.
Chronic sleepless people are therefore not a homogeneous population as regards the objective parameters of sleep and, if some of them actually sleep badly, others do not find in the sleep laboratory objective explanations for their disorder. Alongside the heterogeneity of the conditions responsible for insomnia, there is considerable polymorphism in the clinical expression of this disorder. In certain conditions, insomnia has in fact peculiar characteristics that differentiate it from insomnia that occurs under different conditions, even if there is rarely a short overlap of its clinical aspects.
We can divide the insomnia into:
- psychophysiological insomnia;
- insomnia associated with psychiatric disorders;
- insomnia associated with the use of drugs, drugs and alcohol;
- insomnia associated with sleep-induced breathing disorders;
- insomnia associated with nocturnal myoclonus and restless legs syndrome;
- insomnia associated with diseases, intoxication and unfavorable environmental conditions;
- insomnia at the onset in childhood;
- insomnia associated with unusual polysomnographic pictures;
- pseudo-insomnia: short periods of sleep;
- subjective insomnia without corresponding polysomnographic findings.
In many cases insomnia evolves parallel to the condition that triggered it and may be transient, recurrent or long-lasting. In many cases it presents itself as a chronic disorder with no apparent connections to the conditions that led to its onset or even without clear causal elements. Once established, insomnia changes the way patients live and determines, both in themselves and in others, reactions that can contribute to the maintenance of the disorder. As with any chronic condition, even insomnia is therefore incorrect to consider only the disease and attribute all the symptoms to the factors that triggered the year. When insomnia becomes chronic, a complex interaction of factors that go beyond those originally responsible for the disorder is at stake.
Sleep disorders: hypersomnia
Hypersomnias include several functional and organic disorders, whose common denominator is excessive daytime sleepiness, severely disturbing and sometimes so severe as to be uncontrollable. Depending on the hypersomnia considered, the main symptoms are from time to time represented by drowsiness during the daytime hours, reduced cognitive and motor performance, excessive tendency to sleep, uncontrollable sleep attacks, increase in sleep time in the 24 hours and difficulty in reaching a complete awakening.
Patients may come to the doctor’s observation in an anxiety and depression situation reactive to the inefficiency of their most basic daily activities, interfered by continuous drowsiness, asthenia, lack of mental clarity and ability to concentrate. The nocturnal sleep and that of the daytime naps, which are often forced to indulge, is not restful. Other frequent complaints of these patients are the morning headache and, for men, difficulties in the sexual sphere. Sometimes they present automatic behaviors, referable to brief intrusions of sleep phases during wakefulness, the so-called microsleeps.
It is necessary to differentiate these patients from those who complain of asthenia and reduced mental efficiency and not real drowsiness: it will be more likely, in these cases, of sleepless or depressed patients. An even more important differentiation to operate is between hypersomnia and the alterations of the state of vigilance resulting from noxae pathogenic of various nature, which depress the activity of the ascending reticular substance and determine the coma.
Hypersomeric patients have a significantly lower sleep time than normal dorms. In general, the diagnosis of hypersomnia should be reserved for patients who feel sleepy but who also have a demonstrable tendency to fall asleep quickly when they are not engaged in any activity. The only exception to this rule is subjective hypersomnia without polysomnographic findings, which is the opposite form of insomnia with a similar definition and which, at least in a few cases, represents a hypochondriac symptom.
According to the classification adopted by the American ASDC the hypersomnia are divided ►
- psychophysiological hypersomnia
- hypersomnia associated with psychiatric disorders
- hypersomnia associated with the use of drugs
- hypersomnia associated with impaired sleep-induced breathing
- hypersomnia associated with nocturnal myoclonus and restless legs syndrome
- idiopathic hypersomnia
- hypersomnia associated with diseases, poisoning and unfavorable environmental conditions
- periodic hypersomnia
- hypersomnia from insufficient sleep
- intoxication of sleep
- pseudo-hypersomnia: the long dormitories
- subjective hypersomnia and without corresponding polysomnographic findings.
Under the term parasomnia a heterogeneous group of disorders is collected that have in common the characteristic of not directly depending on a dysfunction of the structures that regulate sleep and waking, but rather from the activation, in connection with sleep, of structures to them related with consequent involvement of the neuromuscular and / or neurovegetative system. Some parasomnias are characterized by activities that, like walking and mingling, while normal during waking, create problems when they are performed during sleep. nocturnalSome parasomnias appear exclusively or almost during certain stages of sleep: for example, sleepwalking generally occurs during deep slow sleep, and painful nocturnal erections arise with great prevalence during REM sleep.
Others, such as bruxism, may appear during various stages of sleep, while others, such as the family paralysis of sleep, occur preferably in the transition period between sleep and wake. Parasomnias that arise during deep slow sleep are considered by many authors as an expression of the confusional state caused by partial awakening. In fact, it is known that the sudden awakening from the slow deep sleep or the delta sleep can determine a brief state of confusion during which it is possible to perform automatic activities, such as going to the bathroom, closing a window and so on.
In predisposed individuals, the awakening from deep slow sleep can lead to a more prolonged and more marked confusional state than usual, with the consequent appearance of sleepwalking, pavor nocturnus or enuresis. These parasomnias appear more frequently in children because they have a richer sleep than delta stages; they occur predominantly in the initial sleep period, which is richer in delta stages. The abnormal episodes connected to them are not usually remembered by the patients because they generally do not wake up completely.
Following the classification of the American ASDC to the parasomials belong: ►
- the pavor nocturnus and the nightmare
- nocturnal enuresis
- anxiety attacks linked to the dream
- the morpheic epileptic seizures
- jactatio capitis
- the familial paralysis of sleep
- painful nocturnal erections
- cluster headache and onset migraine during sleep
- abnormal swallowing syndrome during sleep
- night asthma
- heart and respiratory disorders precipitated by sleep
- gastroesophageal reflux at night
- nocturnal paratossic haemoglobinuria.
For us, air travel has an unexpected effect: the well-known phenomenon of the JET LAG or a symptom of fatigue, warned by all those who move between areas with different time zones. The occurrence of jet lag depends on a profound alteration of our circadian rhythm.
We can define the circadian rhythm as an internal clock, which determines numerous bodily functions. Usually, the circadian rhythm consists of a cycle of 24 to 26 hours and is influenced by the exposure of a subject to alternating dark-light. When a person travels, it can happen that he or she or she crosses different zones with different time zones; as a consequence, the simple exposure to sunlight is clearly altered, with a subsequent change in the circadian rhythm. Since the phenomenon called upon affects many physiological processes, its change will result in symptoms – such as daytime sleepiness and a drop in energies – characteristic of the JET LAG. These variations tend to last for several days and their duration increases in proportion to the increase in the number of zones with different time zones crossed.
Nowadays, travelers can use some artifices to adapt to the jet lag phenomenon. Since changes in the circadian rhythm are caused by the change in exposure to sunlight, the traveler can engage during the flight to expose himself to a bright light. Putting at night in front of an artificial light and useful for those traveling to the west, while the morning exposure to light, is useful for those traveling east.
Also a pharmacological treatment can be useful. Recently, the treatment of the ‘jet lag’ phenomenon has greatly increased the use of melatonin (a known hormone involved in the maintenance of circadian rhythm).
Before intervening with a pharmacological treatment, you could take small measures (both before and during the trip) to try to prevent – or at least limit – the symptoms induced by jet lag. Before the trip you can look for – if possible – to bring your sleep rhythms and meal times slightly closer to those that will follow once you arrive in the destination. During the trip, however – especially if it is very long – it is advisable to try to rest as much as possible, eat light meals, drink a lot of water and avoid the consumption of alcohol or drinks such as tea or coffee.
In the event that the movements between different time zones are frequent and / or if jet lag is perceived as a very limiting disorder, then one can think of intervening with a pharmacological treatment. The latter, generally, is aimed at counteracting sleep disorders caused by the jet lag itself. The drugs that can be used to treat jet lag are short-acting benzodiazepines and benzodiazepine-like drugs. In addition, even the intake of melatonin in small doses could be useful in countering the jet lag phenomenon, especially when crossing many time zones. Finally, in some cases, phototherapy can be used to restore the correct sleep-wake rhythm.
Jet lag drugs
The following are the classes of drugs most used to combat jet lag and some examples of pharmacological specialties; It is up to the doctor to choose the active ingredient and the dosage most suitable for the patient, based on the severity of the disease, the health status of the patient and his response to treatment.
As mentioned, benzodiazepines can be used to counteract the sleep disorders that characterize jet lag. More in detail, the benzodiazepines used for this purpose are those with short or very short half-life (2-6 hours, indicatively). The active substance most commonly used against jet lag is triazolam (Halcion). This benzodiazepine has specific therapeutic indications for the occasional and short-term treatment of insomnia. The dose of medicine usually used in adult patients is 125-250 micrograms of active substance per day, to be taken orally just before bedtime.
The benzodiazepine-like drugs are active ingredients that have a mechanism of action similar to that of benzodiazepines, but have different chemical structure. The benzodiazepine-like drugs used to counter sleep disorders caused by jet lag belong to the so-called ‘Z drugs’ class. In fact, these medicines have specific therapeutic indications for the short-term treatment of insomnia.
Zolpidem (Stilnox): zolpidem is a drug belonging to the family of imidazopyridine and exerts a sedative action. It is available for oral administration in the form of tablets or oral drops. Generally, it is recommended to take 10 mg of the drug just before bedtime. The duration of the treatment must be as short as possible.
Zopiclone (Imovane): zopiclone also has sedative activity and is available for oral administration in the form of tablets. The usual dose of drug is 7.5 mg of active substance a day, to be taken before bedtime. Also in this case, the duration of the treatment must be as short as possible.
Polysomnography to diagnose sleep disorders
Polysomnography is a diagnostic test for individuals with sleep disorders. During the night, while the patient sleeps, a particular instrumentation detects and records some basic physiological parameters, such as brain activity, respiration, oxygen levels, etc. Based on how these parameters evolve during the night, a doctor specializing in sleep disorders is able to establish the disorder the individual undergoes suffers from.
Polysomnography takes place in a hospital center equipped to the procedure: the examination, in fact, must take place in a very special room, equipped with certain options. The risks of the test are minimal and the exam preparation is extremely simple, as it does not require any special precautions.
Before describing polysomnography, a brief reference should be made to the main characteristics of sleep. When you fall asleep, a transitory loss of consciousness occurs, some biological functions are reduced and others are strengthened. For example, while the production of corticoid hormones decreases, that of growth factors increases. Sleep is characterized by two main phases, which follow one another several times (4-5 cycles of about 90 minutes each):
- Non-REM phase, or orthodox sleep
- REM phase, or paradoxical sleep
Only the correct alternation between these two phases guarantees restorative rest.
It is distinguished by 4 stages, during which sleep becomes increasingly deeper. The first two stages are, respectively, the falling asleep and the light sleep. At the third stage, the deep sleep phase begins, reaching its climax at the fourth stage. It is at this last moment that the organism regenerates itself. With each new cycle, the non-REM phase lasts less and less, leaving more room for the REM phase.
During this phase, the sleeper performs abrupt movements of the eyes. The term REM, in fact, is the acronym of ‘rapid eye movement’.
The REM phase is a ‘agitated’ phase, in which the heartbeat and respiratory rate increase and one dreams. However, it is a phase also characterized by a state, induced by hormones, paralysis and relaxation of the muscles (in Greek paralysis derives from παράλυσις = parálysis, which means precisely ‘relaxation, relaxation’)
Polysomnography is a diagnostic test that records the trend and the variations of some physiological parameters during the REM and non-REM phases, in subjects with suspected sleep disorders. The instrument used for recording these parameters is a computerized device, called a polysomnograph; this instrument is connected to the individual under examination, through skin sensors, located at the end of several cables. The physiological parameters recorded by the polysomnograph during nighttime sleep are: brainwaves (i.e. brain activity), oxygen levels, heartbeat, breathing, eye movements and limb movements (both upper and lower).
Polysomnography is indicated when an individual suffers from some sleep disorder.
In fact, the parameters recorded by the polysomnograph allow to establish the anomalies of the REM and non-REM phases and what alters the correct alternation.
Based on the results of the test, a specialist in sleep disorders is able to assess the nature of the nocturnal disturbance and plan the most appropriate therapy.
Sleep disorders for which polysonnography is indicated
- Polysomnography is performed when the doctor, on the basis of a preliminary objective examination, suspects that the patient suffers from:
- Sleep apnea syndrome. Also known as nocturnal obstructive apnea syndrome, it causes temporary interruptions of breathing during sleep.
- Movement disorders related to sleep. The individual suffering from these problems is the protagonist of involuntary movements, usually with the lower limbs (it is very rare that the arms or hands are moved). Two typical examples of sleep-related movement disorders are restless legs syndrome (RLS) and periodic limb movements.
- Narcolepsy. It is a neurological disease that causes repeated attacks of sleep and a continuous feeling of daytime sleepiness. Who suffers, falls asleep several times throughout the day, even when he or she is busy in engaging activities.
- Behavior disturbances during the REM phase. People who physically “live” their dreams, with gestures of legs or arms, imprecations, agitation, etc., suffer from such disturbances.
- Behavioral disturbances during the non-REM phase (or nocturnal behavioral disturbances of the non-REM phase). A series of different problems belongs to this category, such as somnambulism and confusing awakening.
- Chronic insomnia. It is the inability to give continuity to nocturnal sleep. Some people are affected in a chronic way.
Polysomnography is a painless and non-invasive test. The only problems that may arise are related to skin irritation caused by the application of polysomnograph sensors on the skin. Polysomnography requires a very simple preparation, which is easy to follow. In fact, just a few hours after the exam (so from the afternoon), it is sufficient not to take alcohol and foods or drinks containing caffeine. Since alcohol and caffeine can disturb nocturnal sleep, altering the results of polysomnography.
The polysomnography is performed, of course, at night and in a hospital center equipped with the procedure. The exam, in fact, takes place in a particular room, equipped with everything needed to follow the patient’s nocturnal activity step by step. Among other things, the environment also features a camera and an audio system for communication between patient and medical personnel.
The medical staff requires the patient to arrive at the hospital in the evening, so that there is time to prepare the instrument. To facilitate adaptation to the new environment, the individual under examination can bring with him everything he or she usually uses at home when he or she goes to sleep.
The room is similar to a hotel room and is equipped with all the comforts, so that the patient can feel more at ease. In addition, it is equipped with a camera and an audio system: the camera allows the medical staff to observe what happens inside the room during the night; the audio system, on the other hand, serves to communicate with the outside, in case the patient suffers from some illness.
As anticipated, the connection to the polysomnograph takes place through skin sensors, placed at the end of several cables. The cables are long enough to allow the patient any nocturnal movement. The sensors are applied to the scalp, temples, chest and legs, using a glue or adhesive. The sensor for measuring oxygen levels is an exception compared to the others: it is, in fact, a sort of clip to be applied in general to the index finger.
To summarize, the parameters measured or monitored during polysomnography are: brain waves (which describe brain activity), eye movements, heartbeat, respiration, blood oxygen levels and limb movements (both lower than higher). Recording begins when the patient falls asleep and ends when the patient wakes up. Generally, in the absence of a hitch, it lasts all night. If the patient experiences sudden illness, he or she / she has the possibility to communicate it to the medical staff, using the sound system of the room for the night. The medical staff is located in the immediate vicinity, just outside the room; therefore, he or she can intervene immediately
It can happen that the patient feels uncomfortable and struggled to sleep, because the examination and the environment, foreign to him, worry him. However, this does not alter the success of the test, as it is sufficient for the patient to sleep for a few hours, not necessarily for the whole night. Upon awakening, the recording is interrupted, the instrument and the sensors are disconnected and the patient can immediately return home. The results of the examination will be issued by the doctor of the hospital center, where the polysomnography took place, only a few days later. Indeed, their interpretation requires a lot of time.
The results of the examination are first analyzed by a personnel technician and then by a doctor who specializes in sleep disorders. Once the analysis is complete, the outcomes with the patient will be discussed and therapy will be planned. Below is a brief description of what they mean (or may mean) certain parameters, recorded during a polysomnography.
Brain waves and eye movements. Diseases such as narcolepsy and behavioral disturbances during the REM phase interfere with brain activity and / or eye movements (N.B: REM stands for Rapid Eye Movement). Heartbeat, breathing and changes in oxygen levels. These three parameters undergo strong variations when the so-called nocturnal apnea syndrome is in progress.
Movements of the limbs, especially of the legs. Their presence may mean that the patient suffers from some sleep-related movement disorder, such as restless legs syndrome (RLS) and so-called periodic movements of the lower limbs.
Unusual movements and behaviors during sleep. Gestures and unusual ways of acting during sleep are the possible sign of a behavioral disorder during the REM or non-REM phase. The data emerging from polysomnography are used to confirm the doctor’s suspicions and allow us to establish the most appropriate therapeutic treatment.
Sleep disorders: Pavor Nocturnus
Pavor nocturnus (or nocturnal terror) consists in the partial awakening from the deep sleep, prey to a state of intense agitation. This phenomenon is part of the parasomnia (non-pathological perturbations of sleep) and is not connected to trauma or emotional or relational problems.
Pavor nocturnus is a fairly common manifestation in preschoolers. The disorder occurs with variable frequency, irregular and unpredictable.
During an episode of pavor nocturnus, the child:
- You can lift out of bed, crying and screaming excessively;
- He often has wide eyes, but does not seem to see;
- He does not answer either to the call or to the voice of the parents;
- It is inconsolable.
Often, this phenomenon fades with growth. In the meantime, it is important to know what not to do during an episode of pavor nocturnus: do not pick up the baby and do not try to wake him up; it will be sufficient to check that he or she does not get hurt moving in his sleep and reassure him, using a calm and quiet tone of voice.
Pavor nocturnus is a parasomnia, that is, a non-pathological disturbance of sleep, such as somnambulism and hypnagogic hallucinations.
The disorder occurs during deep non-REM sleep, during which there is no awareness (unlike the nightmares that occur, however, in the REM phase).
The pavor nocturnus can be very impressive in appearance: the child (not contactable, because not aware: he or she is sleeping in deep non-REM sleep) seems in the grip of terror and, at the same time, can present symptoms such as excessive sweating, muscle stiffness and tachycardia.
The episode lasts from a few minutes to half an hour; once finished, the child goes back to sleep, as if nothing had happened. In any case, pavor nocturnus does not present any underlying pathological cause (neurological, psychological, affective or relational).
The disorder is quite common in children between the ages of 2 and 12 and tends to disappear on its own during adolescence.
The causes of pavor nocturnus are still unknown, but it seems that stress and conditions that disturb sleep are involved, such as:
- Sound or light stimulations during rest;
- Bladder distention (full bladder);
- Adenoid hypertrophy;
- Night apnea;
- Alterations of hydro-saline equilibrium;
- Average otitis;
- Gastroesophageal reflux;
- Deprivation of sleep.
In any case, pavor nocturnus is not an expression of neurological, affective or relational disorders and is not a panic attack. This manifestation is the result of an activation of the limbic system (which, among other things, manages emotions) and is not realized as a consequence of lived experiences.
After the procedure
Upon awakening, the recording is interrupted, the instrument and the sensors are disconnected and the patient can immediately return home.
The results of the examination will be issued by the doctor of the hospital center, where the polysomnography took place, only a few days later. Indeed, their interpretation requires a lot of time.
Sleep disorders The results of the examination are first analyzed by a personnel technician and then by a doctor who specializes in sleep disorders. Once the analysis is complete, the outcomes with the patient will be discussed and therapy will be planned.
Interpretation of the analyzed parameters
Below is a brief description of what they mean (or may mean) certain parameters, recorded during a polysomnography.
Brain waves and eye movements. Diseases such as narcolepsy and behavioral disturbances during the REM phase interfere with brain activity and / or eye movements (N.B: REM stands for Rapid Eye Movement).
Heartbeat, breathing and changes in oxygen levels. These three parameters undergo strong variations when the so-called nocturnal apnea syndrome is in progress.
Movements of the limbs, especially of the legs. Their presence may mean that the patient suffers from some sleep-related movement disorder, such as restless legs syndrome (RLS) and so-called periodic movements of the lower limbs.
Unusual movements and behaviors during sleep. Gestures and unusual ways of acting during sleep are the possible sign of a behavioral disorder during the REM or NON-REM phase.
The data emerging from polysomnography are used to confirm the doctor’s suspicions and allow us to establish the most appropriate therapeutic treatment.