REM sleep behaviour disorder

Rapid eye movement (REM) sleep behaviour disorder is characterised by complex motor activity and vocal dream enactment behaviour associated with loss of normal REM muscle tone (atonia). This parasomnia can result in violent and dangerous behaviour during sleep. REM sleep behaviour disorder is predominantly seen in older people and affects more males than females (ratio 9:1). In most patients, REM sleep behaviour disorder precedes or is associated with alpha synucleinopathies (eg Parkinson disease, dementia with Lewy bodies, multiple systems atrophy). REM sleep behaviour disorder is occasionally associated with other neurological disorders (eg narcolepsy, neurodegenerative diseases, neurodevelopmental disorders) or drugs (eg alcohol, antidepressants, beta blockers).

If REM sleep behaviour disorder is suspected, refer the patient to a sleep specialist or neurologist for evaluation and treatment. Differential diagnoses include nocturnal frontal lobe epilepsy, posttraumatic stress disorder and other parasomnias.

Counsel the patient about ways to make their sleep environment safer (eg remove furniture or objects near the bed that could cause injury; move the bed away from windows; avoid sleeping with other people). If REM sleep behaviour disorder is violent or poses a risk of injury, specialists sometimes use melatonin or clonazepam.