Abstract

REM Sleep Behavior Disorder (RBD), often known as injurious dream enacting behaviors secondary to loss of atonia in REM sleep, was first described in 1986. While in the younger population, RBD can be associated with narcolepsy, posttraumatic stress disorder (PTSD) and antidepressant use, in middle-aged and older adults, RBD is almost always associated with a neurodegenerative disorder of synuclein––primarily Parkinson’s disease and dementia with Lewy bodies. For this reason, so-called isolated, or idiopathic RBD (iRBD), is in the great majority of cases a prodromal manifestation of neurodegeneration. Diagnosis of RBD requires video polysomnography to rule out common mimics. Specific diagnostic procedures and thresholds of electromyography (EMG) activity for the diagnosis of RBD have been developed and show high accuracy. Epidemiological studies have placed the overall prevalence of RBD around 2% across all age groups. Sleep-related injurious behaviors are common in RBD, especially in men, explaining the higher proportion of males diagnosed with RBD. In the management of RBD, safety is therefore paramount. Prognostic counselling is often warranted in iRBD, given the high rate of conversion to overt synucleinopathy. Offending agents, such as serotonergic medications, should be reduced or discontinued as possible as they exacerbate RBD behaviors. Pharmacological management involves primarily melatonin and/or clonazepam, while transdermal rivastigmine and, in select cases, sodium oxybate may be considered in treatment-resistant cases.