The stage of sleep characterized by rapid eye movements (REM) is associated with deep sleep, muscle relaxation and dreaming. A new study suggests people with sleep disorders that prevent REM sleep have double the risk of developing mild cognitive impairment or Parkinson’s disease.
Mayo Clinic researchers discovered the risk of developing mild cognitive impairment or Parkinson’s disease comes within four years of diagnosis of the sleep disorder.
The muscle relaxation that occurs during REM sleep leaves a person in a state of paralysis; in contrast, people with rapid eye movement sleep behavior disorder (RBD) appear to act out their dreams when they are in REM sleep.
Investigators were able to diagnose RBD by using the Mayo Sleep Questionnaire among people who were otherwise neurologically normal.
Investigators found that approximately 34 percent of people diagnosed with probable RBD developed mild cognitive impairment or Parkinson’s disease within four years of entering the study, a rate 2.2 times greater than those with normal rapid eye movement sleep.
“Understanding that certain patients are at greater risk for mild cognitive impairment or Parkinson’s disease will allow for early intervention, which is vital in the case of such disorders that destroy brain cells. Although we are still searching for effective treatments, our best chance of success is to identify and treat these disorders early, before cell death,” said co-author Brad Boeve, M.D., a Mayo Clinic neurologist.
Previous studies have shown that an estimated 45 percent of people who suffer from rapid eye movement sleep behavior disorder will develop a neurodegenerative syndrome such as mild cognitive impairment or Parkinson’s disease within five years of diagnosis.
“This study is the first to quantify the risk associated with probable RBD in average people, not clinical patients, and it shows that we can predict the onset of some neurodegenerative disorders simply by asking a few critical questions,” said lead author Brendon P. Boot, M.D., a behavioral neurologist.
- MCI is an intermediate stage between the expected cognitive decline of normal aging and the more pronounced decline of dementia. It involves problems with memory, language, thinking and judgment that are greater than typical age-related changes.
- An estimated 500,000 Americans suffer from Parkinson’s disease, which is characterized by tremor or shakiness, stiffness of the limbs and trunk, slowness of movement, and impaired balance and coordination.
The study is published in the journal Annals of Neurology.
Source: Mayo Clinic