Paralysis of Sleep

Generality

Sleep paralysis, also called hypnagogic paralysis, is a sleep disorder in which - at the time of awakening or just before falling asleep - a real temporary inability to move and speak arises. This state of paralysis is due to an excessive prolongation of the REM sleep phase, or to its early start.

Figure: sleep paralysis: one is awake, so that the eyes are open, but one is unable to move and speak. From the site: sleepingresources.com

The most susceptible people are usually those who sleep little and badly; however, it is not excluded that at the origin there is a serious pathology, such as narcolepsy.

Therapy is established based on the severity and number of episodes of paralysis reported by an individual. Almost always, it is sufficient to increase the number of hours devoted to sleep and improve the quality of the night's rest.

Sleep and its phases

Before describing hypnagogic paralysis, it is appropriate to make a brief reference to the main characteristics of sleep . When one falls asleep, a transient loss of consciousness occurs, some biological functions are reduced and others are strengthened. For example, while the production of corticoid hormones is reduced, that of growth factors increases.

Sleep is characterized by two main phases, which follow one another several times (4-5 cycles):

NON-REM phase, or orthodox sleep
REM phase, or paradoxical sleep

Only the correct alternation between these two phases guarantees a restful rest.

THE NON-REM PHASE

It is characterized by 4 stages, during which sleep gradually becomes deeper. The first two stages are, respectively, sleep and light sleep. At the third stage, the deep sleep phase begins, reaching its climax in the fourth stage. It is in this last moment that the organism regenerates itself.

With each new cycle, the NON-REM phase lasts less and less, leaving more space for the REM phase.

THE REM PHASE

During this phase, the sleeping person makes sharp eye movements. The term REM, in fact, is the English acronym of Rapid Eye Movement, that is its own "rapid eye movement".

The REM phase is an "agitated" phase, in which the heart rate and respiratory rate increase, and one dreams. However, it is a phase also characterized by a state, induced by hormones, paralysis and muscle relaxation (in Greek paralysis derives from παράλυσις = parálysis, which means "relaxation, relaxation"); probably this state of muscular atony has the function of preventing unconscious movements caused by the dream.

What is sleep paralysis?

We speak of sleep paralysis when an individual, at the time of awakening or just before falling asleep, is temporarily unable to move and / or speak. In other words, the subject who suffers from sleep paralysis is conscious, but fails to perform the typical gestures of an awake person.

These episodes have a variable duration, from a few seconds to a few minutes; once finished, the individual is completely restored: he speaks and moves, as if nothing had happened. However, the feeling creates an impression and sometimes a state of anxiety.

IS IT A SERIOUS PHENOMENON?

In addition to not having repercussions on the individual, sleep paralysis is a rare episode, which occurs a few times in the course of life.

However, for some subjects, it can become a recurrent phenomenon, so as to require further assessments relating to the general state of health or daily and nocturnal habits.

As you will see later, in fact, sleep paralysis can be linked to narcolepsy, a disease that creates sudden attacks of sleepiness, or sleep poorly and badly .

Epidemiology

It is difficult to quantify how many people accuse (or have accused in the past) sleep paralysis. According to some statistical data, in industrialized countries, about 6% of the population suffers. A good part of these people is the protagonist of sporadic episodes, sometimes unique in the course of life.

The most affected individuals are adolescents and young adults, aged between 25 and 44 (the latter are 36% of the sufferers).

Women and men are, in equal measure, all possible targets.

Finally, the last statistical datum that deserves to be mentioned concerns the link with narcolepsy: about 30-50% of narcoleptic people also suffer from sleep paralysis.

Causes

Speaking of causes, two questions need to be clarified:

What is the mechanism that causes sleep paralysis?
What circumstances or situations increase the likelihood of manifesting an episode of this kind?

ANSWER TO THE FIRST QUESTION

The cause of sleep paralysis is the abnormal release - prolonged beyond waking up or anticipated before falling asleep - of those hormones that determine muscle paralysis and relaxation, typical of the REM phase. In other words, the hormonal mechanisms that characterize the REM phase, instead of being interrupted at the moment of awakening, continue for a few moments, so much so that the suffering individual is alert but immobilized. Since sleep paralysis can occur even before falling asleep, in these situations the hormonal processes of the sleep phases are established with a slight advance, although the person is still awake.

ANSWER TO THE SECOND QUESTION

The incorrect synchrony of the times in which the hormonal release occurs occurs above all in certain circumstances, which could be defined as favoring elements (or risk factors). These are:

Age between adolescence and around 40 years.
Sleep less than necessary . It is probable that those who sleep little, in the course of life, manifest phenomena of paralysis.
Irregular sleep, understood as going to bed and waking up at different times. This is the case, for example, of those who work night shifts.
Narcolepsy . Often, narcoleptic individuals experience sleep paralysis and various other disorders during sleep and during the day.
Family history . It seems that those with a family member suffering from sleep paralysis are more likely to experience similar phenomena. However, scientific research in this field is still in its infancy and deserves further study.

To learn more: Sleep paralysis - Causes and Symptoms

Symptoms

As anticipated, the main symptom of sleep paralysis is the temporary inability to move and speak, which can manifest itself upon awakening or before falling asleep.

It is a rather strange sensation and, in some respects, distressing, since those who are victims of such an episode remain conscious but cannot react or perform any movement.

The duration of the phenomenon can vary from a few seconds to a few minutes and, once exhausted, it has no repercussions on the sufferer: the latter, in fact, is well and resumes his life and his daily activities, without any problem.

THE HALLUCINATIONS

Feeling unable to move is not the only symptom of sleep paralysis. Sometimes, in fact, it can happen that the person has hallucinations and perceives presences or not real sounds.

A classic example, described by the protagonists of such phenomena, is the feeling of not being alone in the room where you are.

Hallucinations, if they occur in the passage from wake to sleep, are called hypnagogic hallucinations ; if, on the other hand, they occur on awakening, hypnopompic hallucinations are defined.

Diagnosis

The diagnosis of sleep paralysis is based almost exclusively on the medical history . By medical history, we mean the collection by the physician of the descriptions that the patient makes of the symptoms felt (when it is impossible to interrogate the patient, the relatives or those who were with him at a given time are addressed).

The HISTORY

During the anamnesis, the doctor makes a real and proper inquiry, asking the patient:

How paralysis evolves and how long they last
If you have hallucinations of some kind
If you remember when you were the victim, for the first time, of a paralysis and if there was a change in nocturnal habits prior to that episode.
If you suffer, during the day, sudden loss of control of the muscles ( cataplexy ) or automatic behavior, that is, the inexorable and relentless continuation of the activities in which you are trying.

These last two aspects, cataplexy and automatic behavior, are very important for diagnostic purposes, since, if reported by the patient, they could mean that sleep paralysis is the result of a much more serious pathology: narcolepsy.

In these cases, the situation becomes pathological and must be treated with appropriate and immediate countermeasures: think, in fact, of the danger that a narcoleptic patient runs when driving a vehicle or engaged in dangerous work.

Treatment

Since, very often, those who sleep poorly and badly complain of sleep paralysis, it may be sufficient to cure the nocturnal habits appropriate to the needs of the human body to cure the disorder.

The drug therapy of sleep paralysis is prescribed only in the most severe cases, ie when the episodes are chronic. It consists of taking antidepressant drugs .

SLEEP WELL AND SUFFICIENCY

Our body and our brain need about 6-8 hours of sleep at night to stay healthy. Therefore, the first step to do, for those suffering from sleep paralysis, is to sleep an adequate number of hours.

Moreover, it is equally essential to lie down and always wake up at the same time, in other words to have a regular sleep rhythm.

Alongside these two most important countermeasures, it is worth remembering some other small tricks:

Create a cozy night environment : dark room, not too hot, but not too cold; silence.
Comfortable bed .
Exercise regularly, but never before going to bed.
Limit caffeine consumption .
Do not eat or drink alcohol shortly before going to bed.
For smokers, do not smoke before going to bed, as nicotine is a stimulant.

PHARMACOLOGICAL TREATMENT

As anticipated, antidepressant-based drug treatment is used when sleep paralysis is chronic and creates discomfort for those who are victims of it.

The most widely used drug is usually clomipramine, a tricyclic antidepressant that must be prescribed on the instructions of the treating physician.

The reason for administering these preparations is as follows: they reduce the intensity with which night-time muscle relaxation and the depth of sleep occur, particularly in the REM phase.

The duration of treatment can vary from one month to two; in any case, it is the patient's improvements, and above all the medical consultation, that determine whether or not to stop the therapy.

Tricyclic antidepressants are not free from side effects (see table below).

Side effects of tricyclic antidepressants

Dry mouth
Constipation
Excessive sweating
Bladder problems and urination difficulties
Blurred vision
Drowsiness during daylight hours

NB: although it may seem a contradiction (given what has been said previously), sleepiness during the hours of the day is one of the typical and even more dangerous side effects of tricyclic antidepressants. Think of what could happen to an individual, who uses it, when he is driving a car and is caught by a sudden attack of sleep.

NARCOLEPSY

If the sleep paralysis is due to narcolepsy, it is advisable to consult doctors who are experts in the matter, as this is a serious pathological condition.