Daijiworld Media Network – Montreal

Montreal, May 30: Unusual sleep behavior where individuals physically act out their dreams could be an early warning sign of neurodegenerative diseases like Parkinson’s disease and Lewy Body Dementia (LBD), according to a new study by researchers at Université de Montréal, Canada.

The study focused on Rapid Eye Movement Behaviour Disorder (RBD) a condition that causes people, often around age 50, to punch, kick, or shout during the dream stage of sleep, when muscles are typically paralysed.

“Normally, during REM sleep, our muscles are immobile. But in RBD, that protective paralysis fades, leading people to violently act out dreams,” explained Shady Rahayel, medical professor at Université de Montréal. He noted that RBD is different from sleepwalking, which occurs in a different sleep phase.

Published in the journal eBioMedicine, the study reveals a concerning link: around 90% of individuals with RBD may go on to develop Parkinson’s disease or Lewy Body Dementia a form of dementia second only to Alzheimer’s.

“The people with RBD who come to see us are usually healthy,” Rahayel said. “But of those who later develop disease, half are diagnosed with Parkinson’s and the other half with LBD.”

Lewy Body Dementia is marked by severe cognitive decline, hallucinations, fluctuating attention, and symptoms similar to Parkinson’s. “These patients gradually lose their ability to function in daily life,” Rahayel added.

To understand how these diseases evolve, researchers analysed MRI scans of 1,276 individuals some at risk of neurodegenerative disease, some already diagnosed, and some healthy. Using advanced machine learning, they identified two distinct patterns of brain atrophy:

• In LBD, atrophy begins in the cortex (outer brain) and spreads inward.
• In Parkinson’s, the damage starts deep inside the brain and moves outward.

The team now plans to explore factors that may influence this atrophy, including vascular damage, medications, and lifestyle choices.

“Now that we’ve identified these progression patterns, we hope to use MRI scans to detect them early and tailor care for each patient,” Rahayel said.

The findings bring new hope for early detection and targeted treatment of debilitating brain disorders through something as seemingly simple as sleep behaviour.