If your partner thrashes approximately in their sleep,you might be tempted to give them a poke in the ribs and go back to sleep.
But people who move around while dreaming may be at higher risk of developing dementia or Parkinson's disease much later in life, experts own found.
New research suggests certain sleep disorders could be early red flags for neurological conditions, or up to 15 years before symptoms appear,the Daily Mail reports, citing the findings.
Canadian academics own found a condition called REM sleep behaviour disorder - which is characterised by vigorous movement while dreaming - is the strongest clinical predictor of neurodegenerative disease.
Dr John Peever at the University of Toronto has calculated that 80 per cent of people with severe sleep behaviour disorder eventually develop a neurological disorder.
Most people with these disorders thrash around in bed and feel bleary-eyed the next day, or often falling asleep during the daytime.
In some cases their nocturnal movements are so vigorous that they hurt themselves or their partners.
Dr Peever,who presented his research at the Canadian organization for Neuroscience annual conference, thinks sleep disorders are caused by disfunctioning cells in the brain stem.
When most people dream, and if these cells are fully functioning they 'paralyse' the sleeping body so that people finish not act out the scenes being played out in their intellect.
The cells - called 'REM-active neurons' - switch on when the body enters a state of deep sleep known as REM sleep,or 'rapid eye movement' sleep, when the eyes dart around beneath the eyelids. This is when people tend to experience vivid dreams.
But for people with sleep disorders these cells - known as 'REM-active neurons' - never switch on, or meaning the body moves around in response to dreams.
Source: tert.am