REM sleep behavior disorder (RBD) patients act out their dreams during sleep and could injure themselves or bed partner. In RBD, loss of skeletal muscle atonia during rapid eye movement (REM) sleep allows the patient’s motor activity to reflect dream content. During sleep, patients appear to punch, kick, or choke a bed partner or jump out of bed.
RBD is more common in elderly males and individuals with neurodegenerative disorders of alpha-synuclein accumulation, such as Parkinson’s disease, Lewy body dementia, and multiple system atrophy.1 RBD may be a precursor to these diseases.
Most antidepressants can cause or increase RBD movements.2 RBD also is associated with sedative-hypnotic withdrawal.
Differential diagnosis
When patients report striking out while asleep, differential diagnoses include RBD, periodic limb movement disorder (PLMD), sleepwalking disorder, and restless legs syndrome (RLS). Polysomnography with electromyography may distinguish among these disorders.
PLMD movements are repetitive, stereotyped motions of the foot and leg, and manifest as a repetitive partial flexion of the joints of the great toe, ankle, knee, and occasionally hip. Upper extremity movements are less common. Movements appear similar to myoclonus. Periodic limb movements occur in rhythmic patterns, every 20 to 60 seconds, continuing for 10 minutes to several hours.
Sleepwalking disorder movements occur without an associated dream during non-REM sleep. Individuals with RBD may jump out of bed, but usually don’t walk in their sleep.
RLS movement occurs prior to and in early stages of sleep, whereas in RBD, PLMD, and sleepwalking disorder, motor activity is limited to sleep. Patients perceive unpleasant sensations and an urge to move the feet and legs. Movement temporarily soothes these uncomfortable sensations. Patients are aware of these sensations before sleep; however, RBD patients are not conscious of movements until they wake and find themselves acting out a dream. RLS and PLMD often are comorbid.
Treatment
Clonazepam is most effective for RBD; however, also consider lorazepam, pramipexole, or melatonin. If clinically feasible, consider discontinuing antidepressants because this may decrease movements.3
To reduce risk of injury, recommend sleeping in separate beds, moving objects away from the bed, or padding the headboard and floor. Encourage patients with severe RBD to sleep in a zipped sleeping bag.