All living beings on our planet, both animals and plants, show fluctuations in the functioning of the organism over the course of twenty-four hours. Such oscillations called circadian (from about diem or "around the day"), concern not only sleep and wakefulness, but also the main functions of the body, body temperature, heartbeat, blood pressure and hormonal secretions.
The dream represents the mental activity of sleep associated with the REM (Rapid Eye Movement) phase, although numerous evidences confirm the presence of a similar "dream activity in other phases of sleep.
During sleep or in the transitions between sleep and wakefulness, it is possible that disorders characterized by physical and / or behavioral phenomena may occur: these disorders are called parasomnia. We are therefore talking about parasomnia associated with REM sleep (for example, nightmares and behavioral disturbances), parasomnia due to generalized activation of the nervous system (in English, arousal) such as, for example, sleepwalking and night terror (pavor nocturnus) and, finally, sleep-wake transition disorders and other parasomnias.
About 15-40% of the child population between the ages of 5 and 12 has at least one episode of sleepwalking while 36% undergoes multiple attacks. Usually the child stops being sleepwalker by entering the age of sexual development (puberty). Those who continue to have episodes in adulthood account for about 0.5-2.5%. Sleepwalking is hereditary: if both parents are the risk that the child is sleepwalker is around 60%. If only one parent is sleepwalker, the probability is reduced to 45%. The incidence of pavor appears to be significantly lower for all age groups and hovers around 1-2% in infant populations. Sleepwalking and pavor nocturnus can be potentially very dangerous: about 75% of sleepwalkers and those with pavor reported physical injury during episodes. One study showed that more than 50% of sleepwalkers left the house at least once during the attack. Some sleepwalkers also become violent when suddenly awakened. Other studies have found that approximately 28-41% of sleepwalkers and 55% of those with pavor exhibit violent behavior during episodes.
In modern life, unfortunately, the hours of sleep are increasingly sacrificed to work needs and the desire for leisure; in fact, if we consider people who consciously limit the hours of sleep and individuals who suffer from insomnia, we can identify a large number of people who cannot sleep well, suffering negative consequences for the body and mind. A real disease that is increasing, which involves high social costs and inconveniences, and too often is not dealt with in the right way.
Sleeping deeply and for a sufficient number of hours is of considerable benefit to the health, well-being and aesthetics of the body; in fact, it is during sleep that the rearrangement of metabolic functions and the body's defense system (immune system) occurs.
Sleep, therefore, which regulates the quality of life, mood, efficiency during the day, is a fascinating and still partly unexplored phenomenon, without which it would be impossible to live. Sleeping badly causes various ailments and ailments and insomnia can be a sign of other diseases.Symptoms
Sleepwalking is a particular sleep disorder, or parasony, of a "benign nature" that occurs in the first phase of sleep, the one defined not REM. Those who suffer from it carry out movements or behaviors that are sometimes even complex without being aware of it, continuing to sleep and not remembering anything of what they did the following morning when they wake up: they can talk, walk, turn on the TV, get dressed, leave the house. The attacks of sleepwalking can last from a few seconds to a few minutes with an average of about 6 minutes per episode, although episodes lasting more than one "hour have been reported. The phenomenon, which remains one of the most mysterious of all, in some hereditary cases, it can affect anyone, both adults and children. There are also several causes, which vary according to age; in the first years of life, in fact, it is often favored by the onset of respiratory problems during sleep.
The confusional awakenings, which prevail in children under the age of five, often manifest themselves with movement and vocalization (usually screams) and a state of marked agitation, so much so that they very often attract the attention of parents. The baby is in the throes of uncontrolled crying, says nonsense and does not have the ability to respond adequately to stimuli.
Specifically, pavor nocturnus (or night terror) is a disorder caused by the generalized activation of the nervous system (arousal) that occurs during the first three hours of the night, when stages three and four of non-REM sleep predominate. Generally, it has I start with a high-pitched cry and the person, in apparent anxiety, has tachycardia (heart beating very fast), tachypnea (rapid breathing), increased blood pressure and sweating. The attempt to awaken the person in full crisis should be avoided since the resulting state of disorientation and agitation can last for about half an hour. The episodes are more frequent in people characterized by deep sleep (deep dormitories) and in males. in this case the person does not keep any memory of what happened (very differently from what happens with terrifying dreams in the REM phase). After an episode of pavor the subject tends to calm down quickly and go back to sleep.
Although sleepwalking and pavor may appear to be different entities, the typical disorders of the two forms often occur within the same episode. In a study it was shown that 55% of adult sleepwalkers also have episodes of night terror (pavor nocturnus ), and 72% of individuals with pavor have sleepwalking. Some researchers argue that these parasomnia are manifestations of a single disorder caused by generalized activation of the nervous system (arousal) that differ only in the severity of symptoms (disorders): the somnambulism is the lightest form, confusional awakenings the intermediate one and pavor the most severe.Causes
As previously noted, both sleepwalking and night terror (pavor nocturnus) are disorders caused by the generalized activation of the nervous system (arousal) of stages three and four of non-REM sleep; both forms are characterized by partial awakenings during which there is an activation of movements. At the basis of this phenomenon it is assumed that there may be an involvement of the physiological mechanisms responsible for awakening from the phase of deep sleep. This involvement occurs more frequently in the period of development and could explain why this type of parasomnias are so frequent in the still "immature" nervous system of children and because their frequency decreases significantly with age.
In order to understand the complexity of these parasomnic phenomena, we must not forget the existence of genetic and environmental factors and of predisposing and precipitating ones.Although the familiar nature of sleepwalking and pavor is now taken for granted, its manifestation can vary significantly from person to person: for example, in some individuals particular stressful and traumatic situations are necessary for the disorders to manifest; in others, with an evidently greater genetic load, the episodes can also occur in adulthood without any stress factors being necessary for their occurrence.
Predisposing factors are represented by sleep deprivation, by alterations in the sleep-wake rhythm, by trauma and losses, mental illnesses, migraines.
Precipitating factors include: sleep apnea, seizures, fever, gastroesophageal reflux. Potentially triggered conditions can be: turning on the light, shaking the individual, antiarrhythmic drugs, sedatives, alone or in combination.Diagnosis
For the study of sleep disorders, in general, the main source of information is the person who suffers from it and who first turns to the doctor. Sometimes, however, it is others who complain about the presence of a sleep disorder, for example the parents, if it comes to children, or the partner when the person does not remember what happened during sleep. The information that the doctor is able to obtain from other people is often essential to ascertain the disorder.
A valid tool in gathering information is the diary or sleep card. A self-completed report, lasting about two weeks, of the time spent in bed, the times of falling asleep and waking up, and other factors (any physical activity, drug or alcohol intake, menstrual cycle, work activity).
Finally, it is advisable to proceed with specific tools such as the repeated sleep latency test (MSLT), which quantifies the tendency to fall asleep during the day, and polysomnography (PSG), which is the recording of several physiological variables during an entire night of sleep.
In particular, the classic PSG includes:
- electrooculogram (EOG), to measure the horizontal and vertical movements of the eyes
- electroencephalogram (EEG), for determining the stages of sleep
- electromyography (EMG), mylohyoid muscle (neck muscles)
- electrocardiogram (ECG), for measuring heart rate
- electromyography (EMG), of the right and left anterior tibialis muscles
- electromyography (EMG), of the intercostal muscles to measure the respiratory effort
- thoracic and abdominal bands, for measuring respiratory movements
- oximeter, for measuring oxygen saturation
The continuous and simultaneous recording of these physiological variables makes it possible to establish the stage of sleep, the type of respiratory activity, the heart rate and rhythm and, in addition, also the presence of periodic movements of the legs.
Polysomnographic recording is generally performed at night but daytime recordings can also be made in those people who carry out work activities, characterized by shifts. This recording takes place for a single night; the ideal, however, would be to repeat it several times for at least three consecutive nights. In fact, although desirable, it is generally not feasible, due to the high costs. With a single night recording you might not discover some pathological conditions (usually at the limits of the norm, in English borderline), but you will not run the risk of indicating conditions or diseases that are not present (overdiagnose).Therapy
The type of treatment generally depends on how the parasomnias appear. Sleepwalking and night terror in adulthood usually respond favorably to psychotherapeutic interventions. With these treatments, a significant reduction in episodes was achieved within a few weeks.
As regards the forms of sleepwalking potentially dangerous for the safety of the person who suffers from it and his family members, the therapeutic approach is from the beginning the pharmacological one, possibly associated with psychotherapy. Consequently, the best results are obtained by associating the drug treatment behavioral therapy or hypnosis. Furthermore, treatment is not always successful in people who have a strong familiarity with sleepwalking and pavor.
As for the elderly, the appearance of episodes of sleepwalking is often a consequence of the side effect of drugs and pre-existing diseases. If the drug is essential to treat the underlying disease, the doctor must still pay attention not to aggravate a state of confusion. pre-existing.Complications
A complete lack of sleep for a prolonged period (about a month) causes both humans and animals to progressively and generally weaken the organism until death. Usually, the process begins with a collapse of thermoregulatory functions. Some people experimentally underwent sleep deprivation for up to ten days without showing significant organic alterations.
The long-term effects of a chronic, albeit not excessive, lack of sleep, such as that to which most people with persistent insomnia undergo, are not yet known. There is no doubt that the lack of hours of sleep leads to a reduction in psychophysical abilities with inevitable repercussions on social and work activities. In addition, a new study has shown that sleep deprivation mainly damages affective skills rather than cognitive and motor skills.Conclusions
The parasomnias dealt with up to now can be considered real diseases, on the rise, which involve both discomfort for the person who sleeps poorly, or little, and high social costs. Costs quantified in terms of reduced productivity, absenteeism, accidents at work, road accidents, hospitalization, to which are added the medical costs for associated diseases which, too often, are not addressed, are underestimated and ignored.Further links
Mayo Clinic. Sleep terror (night terror) (English)
NHS. Sleepwalking (English)
NHS. Sleep Apnoea (English)
National Institutes of Health (NIH). National Heart, Lung, and Blood Institute. Sleep Science and Sleep Disorders (English)