REM sleep behavior disorder (RBD) may be one of the first symptoms of Parkinson’s disease (PD) and Lewy body dementia (LBD). Doctors have recognized that patients may have RBD years before other symptoms of PD or LBD appear. Dr. Bradley Boeve, Mayo Clinic researcher and LBDA Scientific Advisory Council member, and his colleagues wanted to find out how long that interval between diagnosis of RBD and PD/LBD could be. Their research on this question appeared in a recent article in the journal Neurology.
In most people, the brain turns off muscle activity during our REM sleep. However, in people with REM sleep behavior disorder, the part of the brain that “paralyzes” them during REM sleep is damaged, allowing them to move about. They may act out often violent dreams in which they are attacked or pursued – punching, kicking, or flailing about. While not everyone with RBD will go on to develop PD or LBD, a significant proportion do.
Dr. Boeve and his colleagues examined the medical histories of a group of patients at the Mayo Clinic with RBD who then developed neurodegenerative diseases such as PD or LBD at least 15 years later. Among this group of patients, the median interval between the two diagnoses was 25 years, and in one patient the interval was 50 years.
The study’s authors hope that, as new treatments for PD and LBD are developed, this information will help to target therapies to individuals years before cognitive and motor degeneration begins.