REM sleep behavior disorder may be the first symptom of Parkinson’s disease or dementia with Lewy bodies. It is observed in 25% to 58% of patients diagnosed with Parkinson’s, 70% to 80% of patients with dementia with Lewy bodies and 90% to 100% of those with multiple system atrophy.
In a long-term study of 1,280 patients with REM sleep behavior disorder who didn’t have parkinsonism – an umbrella term that refers to brain conditions, including Parkinson’s disease, that cause slowed movements, stiffness and tremors – or dementia, researchers followed participants to find out how many would develop these disorders. After 12 years, 73.5% of those with REM sleep behavior disorder had developed a related neurodegenerative disorder.
Some of the factors that independently increased the risk of developing a neurodegenerative disorder were the presence of irregular motor symptoms, abnormal dopamine levels, loss of sense of smell, cognitive impairment, abnormal color vision, erectile dysfunction, constipation and older age.
REM sleep behavior disorder may also be observed in other neurodegenerative disorders such as Alzheimer’s disease and Huntington’s disease, but at much lower rates. The association is also not as strong as that observed in the synucleinopathies.
For most neurodegenerative disorders, there is a phase that may last for decades in which brain changes are taking place but the patient either remains asymptomatic or develops symptoms without the full expression of the disease. RBD, in that scenario, is an early sign of those disorders. This provides an opportunity to study how the disease progresses in the brain and to develop therapies that could either slow this process or prevent it from happening.
At this time, there are no approved therapies to prevent the onset of these neurodegenerative diseases in those with REM sleep behavior disorder. There are, however, medications such as melatonin and clonazepam that may improve the symptoms. We also recommend measures to avoid injury, such as removing breakable objects from the room, protecting windows and padding floors.
Patients who are affected by REM sleep behavior disorder may choose to participate in research. Proper treatment of the disease can help prevent injury and improve quality of life.
This article is republished from The Conversation, an independent nonprofit news site dedicated to sharing ideas from academic experts. If you found it interesting, you could subscribe to our weekly newsletter.
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Anelyssa D'Abreu receives funding from ARDRAF