Catathrenia
Before the ICSD-3, Catathrenia was classified as a rapid-eye-movement sleep parasomnia, but is now classified as sleep-related breathing disorder. 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. Sleep-Related painful erections
Painful erections appear only during the sleep. This condition is present during the REM sleep. Sexual activity does not produce any pain. There is not any lesion or physical damage but an hypertonia of the pelvic floor could be one cause. It affects men of all ages but especially from the middle-age. Some pharmacologic treatment as propranolol, clozapine, clonazepam, baclofen and various antidepressants, seems to be effective. Other parasomnias
Exploding head syndrome
Sleep-related hallucinations
Sleep-related hallucinations are brief episodes of dream-like imagery that can be of any sensory modality, i.e., auditory, visual, or tactile. They are differentiated between hypnagogic hallucination, that occur at sleep onset, and hypnapompic hallucinations, which occur at the transition of sleep to awakening. Although normal individuals have reported nocturnal hallucinations, they are more frequent in comorbidity with other sleep disorders, e.g. narcolepsy.
Treatment
Parasomnias can be considered as potentially harmful to oneself as well as to bed partners, and are associated with other disorders. Children with parasomnias do not undergo medical intervention, because they tend to recover the NREM-related disorder with the process of growth. In those cases, the parents receive education on sleep hygiene to reduce and eventually eliminate precipitating factors.In adults psychoeducation about a proper sleep hygiene can reduce the risk to develop parasomnia. Case studies have shown that pharmacological interventions can improve symptoms of parasomnia, however mostly they are accompanied by side-effects. Behavioral treatments, i.e., relaxation therapy, biofeedback, hypnosis, and stress reduction, may also be helpful, but are not considered as universally effective. Prognosis
NREM-related parasomnias which are common in childhood show a good prognosis, since severity decreases with age, the symptoms tend to resolve during puberty. 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. See also
Dyssomnia
Insomnia
Rhythmic movement disorder
Sleep medicine
Sleep paralysis
Alien abduction, which some investigators claim is caused by parasomnia.