New York : Scientists in the US have found a co-relation between violent sleep, an extreme sleep disorder and dementia.
Patients with the disorder called violent rapid eye movement sleep behaviour disorder (RBD) act out dramatic or violent dreams during rapid eye movement (REM) stage sleep.
Many of them also shout and grunt in their sleep. The disorder is usually seen in men above the age of 60, but also occurs in younger people and in women.
Researchers led by Bradley Boeve, a Mayo Clinic neurologist, studied patients with the disorders over many years and saw many of them develop symptoms of dementia.
The findings of the study, which appeared in the current issue of the journal Brain, said people with this disorder have a high probability of developing Lewy body dementia later.
Such patients are also likely to develop Parkinson's disease, which affects nerve cells or neurons in a part of the brain that controls muscle movement. They may also suffer from multiple system atrophy, similar to Parkinson's, because all these conditions appear to stem from a similar neuro-degenerative origin.
"This association may provide one of the earliest indicators thus far of eventual dementia or Parkinsonism," says Boeve.
"While some patients don't exhibit symptoms of dementia, all patients we have seen with RBD do develop the pathology."
This is both good news and bad news. While Lewy body dementia – the second most frequent form of dementia and Parkinson's disease have no cure, they can be treated, reported science portal Science daily.
Unlike Alzheimer's disease, medications can restore cognitive function for many with Lewy body dementia.