The parasomnias

By Dr. Stefano Casali

Under the term parasomnias a heterogeneous group of disorders is collected that have in common the characteristic of not depending directly on a dysfunction of the structures that regulate sleep and waking, but rather on the activation, in connection with the Sleep, of structures to them correlated with consequent involvement of the neuromuscular and / or neurovegetative system. Some parasomnias are characterized by activities that, like walking and painting, although normal during wakefulness, create problems when they are performed during Sleep.

Some parasomnias appear exclusively or almost during certain stages of sleep: for example, sleepwalking generally occurs during slow deep sleep, and painful nocturnal erections arise with great prevalence during REM sleep. Others, such as bruxism, may appear during various stages of sleep, while others, such as the family sleep paralysis, are preferably realized during the transition period between sleep and waking (Lungaresi E., 2005; G. Coccagna., 2000 ). The parasomnias that arise during slow deep sleep come from many authors considered as an expression of the confusional state determined by partial awakening. In fact, it is known that sudden awakening from slow deep sleep or delta sleep can lead to a brief state of confusion during which it is possible to perform automatic activities, such as going to the bathroom, closing a window, etc. In predisposed individuals, awakening from slow deep sleep can lead to a more prolonged and more pronounced confusional state than usual, with consequent appearance of sleepwalking, pavor nocturnus or enuresis. These parasomnias appear more frequently in children because they have a richer sleep than delta stages; they occur predominantly in the initial period of sleep, which is richer in delta stages (Ferri R. et Al., 1999; Jouvet M, 2000; Sudhansu Chokroverty., 2000). The anomalous episodes connected to them are not usually remembered by patients because they generally do not wake up completely. Following the classification of the American ASDC (Classification Committee., 1979) to the parasomnias belong: