neurologic disorders
Parasomnias
Rapid eye movement (REM) sleep behavior disorder
Verbalization (sometimes profane) and often aggressive movements (eg, waving the arms, punching, kicking) occur during REM sleep. These behaviors may represent acting out dreams by patients who, for unknown reasons, do not have the atonia normally present during REM sleep. Patients are aware of having vivid dreams when they awaken after the behaviors. REM sleep behavior disorder is more common among older people, particularly those with degenerative disorders of the central nervous system (CNS)—eg, Parkinson Disease , Diagnosis of REM sleep behavior disorder may be suspected based on symptoms reported by patients or the bed partner. Polysomnography can usually confirm the diagnosis. It may detect excessive motor activity during REM; audiovisual monitoring may document abnormal body movements and vocalizations. A neurologic examination is done to rule out neurodegenerative disorders. If an abnormality is detected, CT or MRI may be done. Treatment of REM sleep behavior disorder is withclonazepam0.5 to 2 mg orally at bedtime. Most patients need to take the drug indefinitely to prevent recurrences; potential for tolerance or abuse is low. An alternative ismelatonin3 to 12 mg (but an optimal dosage is not known). Bed partners should be warned about the possibility of harm and may wish to sleep in another bed until symptoms resolve. Sharp objects should be removed from the bedside. 