REM sleep behaviour disorder in the elderly.

REM sleep behaviour disorder is a recently described parasomnia characterized by a history of excessive motor activities during sleep and is associated with pathological absence of muscle atonia during REM sleep. There is very limited literature on the condition. Two out of 349 elderly patients referred to a psychogeriatric unit were identified to have REM sleep behaviour disorder. These two patients are presented to illustrate the clinical features of the condition. Both of them showed a good response to clonazepam treatment.