Parasomnias refer to a specific category of sleep disorders. They are characterized by a set of abnormal and undesirable behavioral or psychic events occurring during sleep or at the border between wakefulness and sleep. Although sometimes having a genetic origin, parasomnias are influenced by many external factors such as stress, sleep deprivation or disease.

Definition of parasomnias

Parasomnias refer to a specific category of sleep disorders. They are characterized by a set of abnormal and undesirable behavioral or psychic events occurring during sleep or at the border between wakefulness and sleep. In the majority of cases, people prone to parasomnias are not aware of their actions.

Parasomnias can have the following consequences:

• Disruption of sleep and that of others;
• Injury to oneself and others;
• Fatigue, drowsiness, shame and anxiety.

Parasomnias become problematic when they are recurrent or continue into adulthood. They can then have a serious psychosocial impact and disrupt social life.

Types of parasomnias

Parasomnias can be classified according to their occurrence during the different phases of sleep. We then distinguish:

• Deep slow sleep parasomnias: confusing arousals, sleepwalking and night terrors;
• REM sleep parasomnias: REM sleep behavior disorder (REM sleep disorder), recurrent isolated sleep paralysis, recurrent nightmares, and catathrenia.
• Slow and REM sleep parasomnias: sleep eating disorder, sexsomnia, parasomniac recovery syndrome and sleep enuresis.

Other parasomnias can appear during the preliminary phases of sleep:

• Sleeping rhythms;
• Hallucinations hypnagogiques ;
• Somniloquies;
• Bruxism.

Causes of parasomnias

Parasomnias sometimes have a genetic component, like enuresis, but they are most often favored by external elements that disrupt the intensity, duration and articulation of the phases of sleep.

The chronic forms of behavioral disorder in REM sleep can be indicative of a neurodegenerative pathology such as Parkinson’s disease.

Diagnosis of parasomnias

The first diagnosis, carried out by an attending physician via the description of the problem experienced by the patient himself or the partner, will or will not justify the consultation of a specialized service.

Specialists in sleep disorders are as diverse as the pathologies: neurologists, pulmonologists, psychiatrists, stomatologists, endocrinologists and neuropsychologists. They measure sleep using a medical test called a polysomnography, which records physiological variables in the body during a night’s sleep. An infrared camera makes it possible to film the movements and the attitude of the sleeper. Brain activity is also recorded using an electroencephalogram (EEG). Once analyzed, the traces obtained from the recordings, the soundtracks as well as the videos constitute the basis of the diagnosis.

People affected by parasomnias

Parasomnias affect about 17% of children and 4% of adults. Confusional arousals, sleepwalking and night terrors mainly affect children. REM sleep behavior disorder is observed mainly in adults and the elderly. Sleep paralysis can start at any age, but most commonly affects adolescents and middle-aged adults.

Risk factors for parasomnias

The most common factors favoring parasomnias are:

• Stress and psychological disturbances: bereavement, relocation or conflict;
• Sport (competition);
• Sleep deprivation;
• Time differences;
• Drugs, including alcohol, and sleeping pills;
• Fever and illnesses;
• Many drugs.

Certain drugs such as those acting on dopamine – in the treatment of Parkinson’s disease or restless legs syndrome -, beta blockers, antidepressants or antiretrovirals (against HIV) contain active ingredients which can act directly on them. sleep mechanisms or change the heart rate, resulting in the onset of nightmares.

Automatic behaviors

Confusional arousals, sleepwalking and night terrors are characterized by automatic behaviors, lack of responsiveness to external stimuli and amnesia of the facts. Sleepwalking is accompanied by wandering. Night terrors are associated with heartbreaking cries of terror but do not exceed one to several tens of minutes.

Violent behavior

REM sleep behavior disorder is observed during a frightening dream that is often memorized and repetitive while the patient is unconscious of his movements. It is characterized by vocalization, rough movements, wandering and sometimes violent behavior. Patients can bump into furniture or even fall out of bed.

Paralysis

Sleep paralysis can occur when you are asleep or awake. For a few seconds to a few minutes, the subject is unable to perform voluntary movements while his state of consciousness is preserved.

Other symptoms

• Groans, growls or other inarticulate vocalizations that can occur throughout the night (catathrenia);
• Involuntary or unconscious sexual behavior depending on the degree of amnesia that follows the facts (sexsomnias);
• Repetitive or sudden movements, in the form of startles, specific to infants (sleep onset rhythms);
• Sensory disturbances such as appearances, noises or movements, difficult to dissociate from reality (hypnagogic hallucinations);
• Articulated vocalizations (somniloquies);
• Grinding of teeth (bruxism).

The management of parasomnias can combine sleep hygiene measures, cognitive-behavioral therapies and relaxation techniques. Cases requiring the use of medication are rare.

For night terrors, hypnosis methods are effective. The idea is to make one feel the real perception of the room and the bed in order to reprogram a fall asleep by suggestion. In children, a hug from parents is enough.

REM sleep behavior disorder, which can be very violent, can be treated effectively with drugs containing melatonin and clonazepam.

The majority of parasomnias result from a lack of sleep. The first step is not to deprive yourself of sleep, or even to take naps.

Some tips will also help limit their frequency, reassure and avoid accidents:

• For sleep paralysis, with or without hallucinations: sleep on your stomach or on your side rather than your back; during the event, try to move your eyes under the eyelids or toes, the only parts of the body not subject to the muscular atony of REM sleep.
• For sleepwalking: turn on a small night light; close the shutters and the bedroom door; cool off after intense sport; and do not sleep in height (mezzanine or bunk bed).
• For REM sleep behavior disorder: avoid placing brittle objects near the bed; place a bolster in the middle of the bed, or sleep separately.