Parasomnias, as described in the recent second edition of the International Classification of Sleep Disorders, are “undesirable physical events or experiences” occurring during sleep transition, during arousal from sleep, or within the sleep period. These events encompass abnormal sleep related movements, behaviors, emotions, perceptions, dreaming, and autonomic nervous system functioning. Parasomnias are classified as: 1) disorders of arousal (from non-rapid eye movement, or NREM, sleep); 2) parasomnias usually associated with REM (rapid eye movement) sleep; and 3) other parasomnias. This sleep disorders in childhood are common, and often more frequent than in adults. Clinicians should be aware that many pediatric parasomnias have benign and self-limited nature. Most of the parasomnias may not persist into late childhood or adolescence. Parasomnias in adults often differ in type from childhood parasomnias and may portend significant psychiatric disturbances or neurodegenerative disorders. A reliable diagnosis can often be made from a detailed history from the patient and, if possible, the parents or bed partner. Detailed overnight investigations of parasomnias are usually not required. The non-REM parasomnias are more common in community although REM parasomnias are more likely to be seen in general neurological practice. Sleep related eating disorder, sleep related dissociative disorders and sleep related sexual behavior and sleep related violence are novel and rarely reported sleep disorders. REM sleep behavior disorder is common and should be sought in all neurodegenerative diseases. They are included among clinical disorders due to the resulting injuries, and adverse health and psychosocial effects, which may affect the bed partner as well as the patient. Finally, parasomnias are common disturbances of sleep that may significantly affect the patient’s quality of life and that of the bed partner. Therefore, appropriate diagnostic and therapeutic strategies are warranted.
parasomnia, NREM parasomnias, REM sleep behavior disorder, sleep related sexual behavior