Very early symptoms of Parkinson's disease can be revealed in dream or Rapid Eye Movement (REM) sleep, say Danish researchers.
Parkinson's disease is a brain disease best known for the trembling it causes. It is an incurable, chronic disease and gradually affects the muscles and mental capacity, seriously afflicting the lives if the patient and his or her immediate relatives.
"In the study we saw that eight years before diagnosis, Parkinson's sufferers exhibited work and health indications that something was wrong," said Poul Jennum, professor of clinical neurophysiology at the Center for Healthy Ageing, University of Copenhagen, and the Sleep Centre at Glostrup Hospital.
Among the very early symptoms is the sleep disorder RBD, or REM sleep behaviour disorder. REM is a particular stage of sleep in which we dream, and our eyes flicker rapidly behind our eyelids, hence the term REM, or Rapid Eye Movement. To prevent us from actually acting out our dreams the body usually shuts down our muscle movement during REM sleep, but in RBD it is still active, and REM sleepers with RBD display a range of behaviours from simple arm and leg spasms to kicking, shouting, seizing or jumping out of bed.
"In some cases their behaviour may be violent and result in injuries to the patients or their partners," explained Jennum.
"Our hypothesis is that the very earliest stages of Parkinson's disease show up as various other diseases such as RBD," added Jennum.