Sleep disorders can give early warning of Parkinson’s disease
Dysfunctional neurons implicated in narcolepsy and other sleep disorders may also be involved in neurological conditions such as Parkinson’s and Lewy body dementia, writes Andrew Masterson.
Some types of sleep disorders may be precursors for serious neurological conditions such as Parkinson’s disease, according to research presented at a conference in Canada this week.
John Peever of the University of Toronto told the 2017 Canadian Neuroscience Meeting, the annual gathering of the Canadian Association for Neuroscience, that factors that interfere with dream-sleep could signal the breakdown of circuits within the brain stem.
Dreaming is associated with rapid eye movement, or REM, sleep, which is characterised by vivid mental imagery, muscle paralysis and intense activity in the brain’s cortical region.
However, the processes by which REM sleep is produced remain poorly understood, and work proceeds on identifying the key neurons and synaptic relationships involved.
Peever, however, has identified certain cells, which he dubs REM-active neurons, that seem critical to the process. Using rats, he and his team established that they are responsible for initiating dream sleep.
“When we switch on these cells, it causes a rapid transition into REM sleep,” he said before the meeting.
His research has also established that dysfunctional REM-active neurons may be implicated in at least two serious sleep disorders: narcolepsy, and REM sleep behaviour disorder – a condition that causes people to act out their dreams, sometimes violently.
More than 80% of people with these sleep issues go on to develop neurological conditions such as Parkinson’s or Lewy body dementia, he said. The sleep problems, thus, might be useful as early indicators of neurological vulnerability and provide opportunities for preventative treatment.
“Our research suggests sleep disorders may be an early warning sign for diseases that may appear some 15 years later in life,” he said.
"Much like we see in people prone to cancer, diagnosing REM disorders may allow us to provide individuals with preventative actions to keep them healthy long before they develop these more serious neurological conditions."