Diagnosis:

A type of parasomnia

Clinical features:

M>F, usually >50 year olds
Vivid and often frightening dreams during REM sleep, but without muscle atonia i.e. act out the dream (behaviour).
Recall of the dream is intact

Finding on Investigations:

Polysomnography: confirms the diagnosis
RSWA: rim sleep without atonia
REM sleep during the episode
EEG: absence of epileptiform activity
EMG (submental or limb): elevated tone

Treatment:

Clonazepam P.O. at night
Melatonin P.O. at night [small nonrandomised study]
Safety education:

• Removing lamps & other objects from near the bed
• Placing cushions near the bed