REM sleep disorder may mark early cognitive decline and raise risk of diseases such as Parkinson’s, a long-term study suggests.
Researchers studied people with long-term isolated REM sleep behaviour disorder (iRBD), a condition where sleepers act out dreams, often screaming, laughing or making violent movements.
The term “isolated” means no other neurological disease.
They found patients tended to show marked loss of cognitive functions, potentially leading to neurodegenerative diseases such as dementia or Parkinson’s disease.
The study at Seoul National University Bundang Hospital in South Korea tracked 162 iRBD patients, whose mean age at diagnosis was 65.6 years, for an average of 7.7 years.
A total of 318 neuropsychological assessments were analysed, showing statistically significant linear declines in attention, working memory and broader memory functions.
The largest drop appeared in the digit symbol test, which measures processing speed, sustained attention and working memory. This test is sensitive to brain damage, dementia, age and depression.
The researchers also found consistent deterioration in verbal and visual memory. These declines may seem subtle at first but build to clinically meaningful levels over time.
All patients with iRBD for more than 10 years experienced cognitive deterioration, even after adjusting for age and other factors.
Male patients had broader and deeper losses, with significant declines in attention, working memory and memory. Women showed a narrower pattern of decline.
The researchers concluded: “Gradual cognitive decline in attention/working memory and memory may represent a natural course of neurodegeneration in men with iRBD, without necessarily indicating imminent phenoconversion. Women with iRBD appeared to show greater resilience to cognitive decline compared to men.”
Phenoconversion is when a condition progresses to a full neurodegenerative disease.
Yoon In-young, professor of neuropsychiatry at the hospital and a member of the research team, suggested gender-tailoured approaches to monitor and manage symptoms.
Thirty-three subjects did not develop neurodegenerative diseases during the study period, yet they showed cognitive decline similar to those who did.
The team said the findings indicate that even among patients who manage iRBD for long periods without progressing to dementia or Parkinson’s, gradual cognitive loss may still be underway.
They advised regular checkups and treatment for people with iRBD, even if no severe conditions have yet appeared.
This news item came from: https://nrtimes.co.uk/sleep-disorder-could-be-early-sign-of-parkinsons-study-suggests/
