Parasomnias: an overview.

Parasomnias are abnormal experiences or behaviours that occur during sleep and can be subdivided into disorders of arousal, disorders of rapid eye movement (REM) sleep or other parasomnias. Diagnosis rests on a thorough clinical evaluation with supporting data from a full polysomnography with time synchronized video. While the prognosis for arousal disorders is generally excellent, the diagnosis of REM behaviour disorder (RBD) is more ominous and associated with neurodegenerative disorders, and as such, requires routine neurological surveillance. The cornerstone of treatment for all parasomnias is adequate patient and bed partner education. Data supporting pharmacologic therapy are limited but clonazapam for RBD has been reported to be effective in up to 89 per cent of patients.