الفهرس 
ParasomniasOnly 14 pages are availabe for public view
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Abstract
Parasomnias are defined by the ICSD-2 as undesirable physical events or experiences that occur during entry into sleep, within sleep, or during arousals from sleep. They are classified into disorders of arousal from NREM sleep, parasomnias usually associated with REM sleep, and other parasomnias.
Parasomnias are reported in approximately 4% of the adult population. Violent behavior during sleep has been reported in 2% of a large adolescent and adult population with a higher rate in the male sex. Many of parasomnias run in families, and genetic factors have been long suggested to be involved in their occurrence. The level and type of evidence for genetic effects varies much from parasomnia to parasomnia. The genetic factors are best established in enuresis, with several linkages to chromosomal loci, but their functions are not so far known. Environmental causes and gene-environment interactions are most probably of great importance in the origin of complex traits or disorders such as parasomnias.
The pathophysiology of parasomnias is based on overlap of the three states of being: NREM sleep, REM sleep, and wakefulness. Because the states are not completely discrete, wake can intrude into either sleep state resulting in purposeful or semi-purposeful activity. This manifests as disorders of arousal during NREM sleep; REM sleep behavior disorder, recurrent isolated sleep paralysis, or nightmare disorder during REM sleep; or other parasomnias. In addition, the projection of the loco-motor center to central pattern generators in the
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absence of higher cortical control may result in the complex motor behaviors seen in parasomnias.
Although these behaviors may appear purposeful or goal directed, the patient is not consciously aware of their actions. Therefore, parasomnia behaviors are not influenced by judgment and are potentially harmful.
In addition to the above, legal repercussions and parasomnia as a harbinger of neurodegenerative disease (in RBD) make the diagnosis of these disorders of vital importance. Signs that necessitate further evaluation of parasomnias are the presence of injurious or potentially injurious behavior, extreme disruption to other family members, presence of excessive daytime sleepiness, and association with medical, psychiatric, or neurological signs or symptoms.
Parasomnias and epileptic seizures can co-exist in the same subject making the differential diagnosis of these conditions particularly challenging. The difficulties in distinguishing nocturnal epileptic seizures from parasomnias reflect just one aspect of the intriguing issue of the pathophysiological relationships between all types of paroxysmal motor behaviors during sleep. In childhood, a frequent association between epilepsy and NREM arousal parasomnias or enuresis has been documented. As far as REM parasomnias are concerned, REM sleep behavior disorder, unrecognized or misdiagnosed, has been found to co-occur in 12% of elderly epilepsy patients.
A particular pattern of association has been found between nocturnal frontal lobe epilepsy and NREM arousal parasomnias, the latter being found in the personal or family history of up to one third of NFLE patients. Even though many aspects of parasomnias and NFLE have been clarified in
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the last two decades, the problem of differential diagnosis remains a challenge for clinicians. NFLE is characterized by seizures with complex, often bizarre, violent behavior arising only or mainly during sleep. These unusual seizures and their occurrence during sleep are often accompanied by normal EEG tracings and neuroradiological findings, making it difficult to distinguish NFLE seizures from parasomnias. NFLE was described for the first time in 1981, but, as its epileptic origin was controversial, the condition was called nocturnal paroxysmal dystonia.
Sleep hygiene measures in epilepsy need to be more comprehensive, taking into account the various pathologies that may underlie disordered sleep in epilepsy patients.
RBD is characterized by vigorous movements associated with unpleasant dreams and increased electromyographic activity during REM sleep (loss of normal REM sleep atonia). Polysomnography with audiovisual recording is needed to confirm the diagnosis of RBD and to exclude other sleep disorders that can mimic its symptoms including obstructive sleep apnea, nocturnal hallucinations and confusional awakenings.
RBD may be idiopathic or related to neurodegenerative diseases, particularly multiple system atrophy, Parkinson’s disease and dementia with Lewy bodies. RBD may be the first manifestation of these disorders, antedating the onset of Parkinsonism, cerebellar syndrome, dysautonomia, and dementia by several years. RBD should thus be considered an integral part of the disease process.
When effective, neuroprotective strategies should be considered in subjects with idiopathic RBD. Patients with other neurodegenerative diseases, though, such as spinocerebellar ataxias, may also present with RBD.
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REM sleep behavior disorder is the only parasomnia requiring polysomnogram for diagnosis. However, polysomnogram may be necessary to rule out another sleep pathology causing the parasomnia, such as sleep-disordered breathing or periodic limb movements of sleep.
When clinically required, clonazepam at bedtime is effective in decreasing the intensity of dream-enacting behaviors and unpleasant dreams in both the idiopathic and secondary forms.
The overall treatment strategy for parasomnias is to treat any underlying sleep disorder, minimize other exacerbating factors, optimize sleep duration and quality, and initiate pharmacologic therapy if behaviors continue to be problematic despite conservative measures.
Therefore, therapy of all parasomnias should include education regarding patient and bed partner safety as well as the avoidance of known precipitating factors, reassurance in some cases, various forms of CBT, and pharmacologic agents.
Cognitive restructuring, imagery rehearsal, relaxation, hypnosis, desensitization, and anticipatory awakenings are some of the common CBT and non-pharmacologic interventions.
Medications that are used belong to a wide variety of pharmacologic classes, such as α-blockers, tricyclic antidepressants, selective serotonin reuptake inhibitors, benzodiazepines, anticonvulsants, desmopressin acetate, and anticholinergic agents.
In short, parasomnias encompass a fascinating catalog of peculiar, distressing, or dangerous nocturnal experiences and behaviors. They are scientifically explainable, usually
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treatable, and can carry forensic implications. An experienced sleep disorders center is a valuable resource for the evaluation and treatment of problematic parasomnias.