Parasomnia

Category of sleep disorders
the disorder

Parasomnias are a category of sleep disorders that involve abnormal movements, behaviors, emotions, perceptions, and dreams that occur while falling asleep, sleeping, between sleep stages, or during arousal from sleep. Parasomnias are dissociated sleep states which are partial arousals during the transitions between wakefulness, NREM sleep, and REM sleep, and their combinations.

The newest version of the International Classification of Sleep Disorders (ICSD, 3rd. Ed.) uses State Dissociation as the paradigm for parasomnias. Although the previous definition is technically correct, it contains flaws. The consideration of the State Dissociation paradigm facilitates the understanding of the sleep disorder and provides a classification of 10 core categories.

NREM parasomnias are arousal disorders that occur during stage 3 (or 4 by the R&K standardization) of NREM sleep—also known as slow wave sleep (SWS). They are caused by a physiological activation in which the patient's brain exits from SWS and is caught in between a sleeping and waking state. In particular, these disorders involve activation of the autonomic nervous system, motor system, or cognitive processes during sleep or sleep wake transitions. Some NREM parasomnias (sleep walking, night terrors, and confusional arousal) are common during childhood but decrease in frequency with increasing age. They can be triggered in certain individuals, by alcohol, sleep deprivation, physical activity, emotional stress, depression, medications, or a fevered illness. These disorders of arousal can range from confusional arousals, somnambulism, to night terrors. Other specific disorders include sleepeating, sleep sex, teeth grinding, rhythmic movement disorder, restless legs syndrome, and somniloquy. === Differential diagnosis for NREM related parasomnias Confusional arousal is more common in children than in adults. It has a lifetime prevalence of 18.5% in children and a lifetime prevalence of 2.9–4.2% in adults. Infants and toddlers usually experience confusional arousals beginning with large amounts of movement and moaning, which can later progress to occasional thrashings or inconsolable crying. In rare cases, confusional arousals can cause injuries and drowsy driving accidents, thus it can also be considered dangerous. Another sleeping disorder may be present triggering these incomplete arousals.

A form of parasomnia where a person will speak during their dreams.

Sleep related abnormal sexual behavior, Sleep sex, or sexsomnia, is a form of confusional arousal that may overlap with somnambulism. These behaviors are unconscious, occur frequently without dreaming, and bring along clinical, social, and legal implications. It has a lifetime prevalence of 7.1% and an annual prevalence of 2.7%. Normal sleep cycles include states varying from drowsiness all the way to deep sleep. Every time an individual sleeps, he or she goes through various sequences of non REM and REM sleep. Anxiety and fatigue are often connected with sleepwalking. For adults, alcohol, sedatives, medications, medical conditions and mental disorders are all associated with sleepwalking. Sleep walking may involve sitting up and looking awake when the individual is actually asleep, and getting up and walking around, moving items or undressing themselves. They will also be confused when waking up or opening their eyes during sleep. Sleep walking can be associated with sleeptalking.

Sleep terror is the most disruptive arousal disorder since it may involve loud screams and panic; in extreme cases, it may result in bodily harm or property damage by running about or hitting walls. All attempts to console the individual are futile and may prolong or intensify their confused state. Usually they experience amnesia after the event but it may not be complete amnesia. Up to 3% of adults have sleep terrors and exhibited behavior of this parasomnia can range from mild to extremely violent. This is very prevalent in those who have violent post traumatic stress disorder (PTSD).

Nightmares are like dreams primarily associated with REM sleep. Nightmare disorder is defined as recurrent nightmares associated with awakening dysphoria that impairs sleep or daytime functioning. It consists of breath holding and expiratory groaning during sleep, is distinct from both somniloquy and obstructive sleep apnea. The sound is produced during exhalation as opposed to snoring which occurs during inhalation. It is usually not noticed by the person producing the sound but can be extremely disturbing to sleep partners, although once aware of it, they tend to be woken up by their own groaning as well. Bed partners generally report hearing the person take a deep breath, hold it, then slowly exhale; often with a high pitched squeak or groaning sound.

The painful penile erections will appear only during sleep. There is no lesion or physical damage, but hypertonia of the pelvic floor could be one cause. Several pharmacologic treatments such as propranolol, clozapine, clonazepam, baclofen and various antidepressants are considered effective.

Sleep drunkenness, also known as confusional arousal, is the feeling of confusion or sudden action upon waking up from deep sleep. Severe sleep inertia, one cause of oversleeping, is considered to develop sleep drunkenness.

According to ICSD 3 it is not defined a disorder in particular. It is rather an isolated symptom or normal variant and ranges from isolated speech to full conversations without recall. In potentially harmful or disturbing cases a specialist in sleep disorders should be approached. Eventually, using actigraphy for parasomnias in general is disputed.

Parasomnias can be considered as potentially harmful to oneself as well as to bed partners, and are associated with other disorders. Behavioral treatments, i. e., relaxation therapy, biofeedback, hypnosis, and stress reduction, may also be helpful, but are not considered as universally effective. Adults with NREM related parasomnias, however, are faced with a stronger persistence of the symptoms, therefore, full remission is quite unlikely and is also associated with violent complications, including homicide. The variant sleep related eating disorders is chronic, without remission, but treatable. REM sleep behavior disorder (RBD) can mostly be handled well with the use of melatonin or clonazepam. However, there is high comorbidity with neurodegenerative disorders, that is in up to 93% of cases. The underlying psychopathology of nightmare disorder complicates a clear prognosis. The prognosis for other parasomnias seems promising. While exploding head syndrome usually resolves spontaneously, the symptoms for sleep related hallucinations tend to diminish over time.