From the Research
Polysomnographic findings in REM sleep behavior disorder (RBD) are generally similar regardless of whether the cause is trauma, antidepressants, or neurodegenerative diseases, with the primary finding being increased muscle tone during REM sleep (REM sleep without atonia), which is detected as elevated chin EMG activity. However, some differences exist between medication/trauma-induced RBD and neurodegenerative RBD. In antidepressant-induced and trauma-related RBD, the polysomnographic abnormalities are often less severe and more focal, with phasic muscle activity predominating over tonic activity. These cases may show more variable and intermittent loss of muscle atonia. In contrast, RBD associated with neurodegenerative diseases like Parkinson's disease or multiple system atrophy typically displays more widespread and consistent REM without atonia, with both prominent tonic and phasic EMG activity, as noted in a review of the literature 1.
Some key points to consider in the polysomnographic findings of RBD include:
- The presence of REM sleep without atonia, which is a hallmark of RBD
- The severity and consistency of REM sleep without atonia, which can vary between medication/trauma-induced RBD and neurodegenerative RBD
- The presence of other sleep architecture abnormalities, such as reduced sleep efficiency and increased sleep fragmentation, which are more common in neurodegenerative RBD
- The use of melatonin as a potential treatment for RBD, particularly in cases with low melatonin secretion, as reported in a study on melatonin therapy for RBD 2
The most recent and highest quality study on this topic is from 2021, which provides an update on the current concepts and controversies in the management of REM sleep behavior disorder 3. This study highlights the importance of symptomatic treatment of RBD to prevent injurious complications, with usual choices being melatonin or clonazepam. Additionally, the study notes that there is an increasing appreciation regarding isolated or idiopathic RBD (iRBD) and the need for further research on the pathophysiology of RBD and the definition of biomarkers of neurodegeneration.
In terms of the management of RBD, the use of melatonin or clonazepam is recommended as a first-line treatment, with the choice of treatment depending on the individual patient's needs and circumstances, as noted in a review of the literature on RBD diagnosis and treatment 4. Overall, the management of RBD requires a comprehensive approach that takes into account the underlying cause of the disorder, as well as the individual patient's needs and circumstances.