La paralysie du sommeil s'accompagne d'hallucinations visuelles, auditives ou sensorielles dans 75 % des cas. © Sam Moghdadam Khamsey, Unsplash

What are the mechanisms of sleep paralysis?

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Like 7.6% of the population, you may have already suffered from sleep paralysis, without necessarily knowing how to put a word on it. This sleep disorder is manifested by an inability to move or cry out, and occurs when waking up or falling asleep. The good news is that sleep paralysis is completely benign.

The feeling of being bedridden, paralyzed, stuck between sleeping and waking, unable to call for help and sometimes with a threatening presence. The sleep paralysisnot to be confused with terrors nocturnalcan be anxiety-provoking for those who experience it.

What is called “sleep paralysis” is actually muscle atony, and is, when you are asleep, completely normal. During sleep, the brain function
Located in the cranial box, the brain is the seat of higher (cognitive functions, senses, nervous responses) and vegetative functions. It is therefore an essential organ that regulates all…” data-image=”https://cdn.futura-sciences.com/buildsv6/images/midioriginal/5/c/b/5cb474dd85_121782_cerveau-3d .jpg” data-url=”https://news.google.com/health/definitions/biology-brain-3125/” data-more=”Read more”>brain and the rest of the body go through different phases. The one that interests us here is the one during which dreams happen : the Place of REM sleep in the sleep cycle
During a night’s sleep, alternate phases of slow-wave sleep (in particular sleep…” data-image=”https://cdn.futura-sciences.com/buildsv6/images/midioriginal/9/2/ 1/9211ccf126_74250_dormir-rouge.jpg” data-url=”https://news.google.com/health/definitions/sleep-paradoxical-sleep-14879/” data-more=”Read more”>paradoxical sleep.

It is also called REM sleep in English for ” rapid eye movement “. the paradoxical sleep is characterized and differs from other phases of sleep in particular by intense brain activity, and an absence of muscle tone, called atony. This sluggishness is explained by the fact that the brain prevents the dreamer from literally living his dream, otherwise he would get up and put himself or his entourage in danger. The body is paralyzed, without the sleeper being aware of it. Complete atony only affects voluntary muscles, also known as skeletal muscles, those related to motor skills. The smooth muscleor involuntary, such as those of breathing or digestion – in other words, those that operate independently of our will – only see their tone reduced.

75% of sleep paralysis cases are accompanied by hallucinations

It sometimes happens that during the passage between the state of wakefulness and that of sleep, the subject is conscious while the body is still – or already – in the state of atony which characterizes paradoxical sleep: this is the sleep paralysis. This can occur upon waking up, in which case we speak of hypnopompic sleep paralysis, or during falling asleepThis is called hypnagogic sleep paralysis.

In 75% of cases, sleep paralysis can be accompanied by vivid auditory hallucinations, visual or sensory. The testimonies of subjects who have experienced them make it possible to categorize three types of visual, auditory and olfactory Hallucinations
Hallucinations can simulate external perceptions: visual (visions), auditory (the…” data-image=”https://cdn.futura-sciences.com/buildsv6/images/midioriginal/2/7/f/ 27ffcc21c5_80791_tue-mouche.jpg” data-url=”https://news.google.com/health/definitions/medicine-hallucination-15234/” data-more=”Read more”>hallucinations recurrent in sleep paralysis. In the first case, the paralyzed person sees or feels an intrusive, even hostile presence in the room. In the second case, the paralyzed person describes a feeling of oppression on his thorax. These first two types of hallucinations are often linked. The third type corresponds to vestibulo-motor hallucinations and a feeling of floating, flying or leaving one’s body.

What factors are believed to promote episodes of sleep paralysis?

The current medical literature therefore suggests that sleep paralysis is explained by an alternating state of consciousness between the sleep and awakening. It is currently unclear why muscle atony and brain imaging of REM sleep persist during wakefulness.

However, certain factors seem to favor episodes of sleep paralysis. Studies have shown some degree of association between sleep paralysis and the consumption of
Primary alcohols: carbon carries two…” data-image=”https://cdn.futura-sciences.com/buildsv6/images/midioriginal/a/f/e/afe9d01940_121145_alcool-definition.jpg” data-url= “https://news.google.com/sciences/definitions/chemistry-alcohol-640/” data-more=”Read more”>alcohol, anxietyexposure to traumatic events, sleeping on the The purpose may be to affect an online service or a company’s network by…” data-image=”https://cdn.futura -sciences.com/buildsv6/images/midioriginal/e/f/f/eff315adf5_103383_deni-service-dos-ddos.jpg” data-url=”https://news.google.com/tech/definitions/internet-deni- service-2433/” data-more=”Read more”>backgreat fatigue, or even a rhythm Such biological rhythms exist in all living beings, including bacteria, and are manifested by cyclical variations of a large number of physiological parameters…” data-url=”https:/ /news.google.com/sante/definitions/biology-circadian-2148/” data-more=”Read more”>circadian not aligned with the local day-night cycle (in night workers or people suffering from jet lag, for example).

Sleep paralysis is also prevalent among insomniacs, narcoleptics, people with psychiatric disorders or even students. As no causal link could be proven for the moment, it is for the time being difficult to determine the nature of the correlation between these factors and sleep paralysis.

Is sleep paralysis safe for health?

One possible explanation for the hallucinations that accompany episodes of sleep paralysis is that breathing becomes irregular during REM sleep. This is due to the reduction in tone of the respiratory muscles: the volume alveolar can then be up to 40% lower than during wakefulness. Associated with a state of hypervigilance which originates in the midbrain and which can lead to the fear which accompanies these episodes, this can partly explain the hallucinations during which the subject has the impression of being oppressed at the level of the chest .

Despite the feeling of fear and panic they can cause, episodes of sleep paralysis are mild, can occur in healthy people and are not indicative of underlying psychiatric disorders. Understanding the mechanism can help to live them better. However, if they are too frequent, they can be a source of anxiety to the point of sometimes affecting the lifestyle of those who suffer from them. It is therefore necessary to improve your sleep pattern, or even to consult a doctor, if these episodes take precedence over life.

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