Yelling in sleep could be early sign of dementia, Parkinson’s

Abnormal behavior during sleep, specifically during rapid eye movement (REM) sleep, may be an early indicator of declining cognitive function, according to a recent study. Researchers focused on individuals with long-term isolated REM sleep behavior disorder (iRBD), a condition characterized by acting out dreams, sometimes with vocalizations like screaming or laughing, without the presence of other neurological diseases.

The Link Between Sleep and Cognitive Decline

The study, conducted by researchers at Seoul National University Bundang Hospital, tracked 162 patients with iRBD over an average of 7.7 years. Analysis of 318 neuropsychological assessments revealed statistically significant declines in attention, working memory, and broader memory functions among the participants.

Did You Know? The average age of iRBD patients at the time of diagnosis was 65.6 years.

Specific Cognitive Areas Affected

The most notable decline was observed in the digit symbol test, a measure of processing speed, sustained attention, and working memory. Researchers also noted consistent deterioration in both verbal and visual memory. These declines, while potentially subtle initially, can accumulate over time to become clinically significant.

Gender Differences in Cognitive Impact

The study revealed distinct patterns of cognitive decline between men and women with iRBD. Male patients experienced broader and deeper functional losses, affecting both attention/working memory and memory. Women, however, showed a more limited pattern of decline, primarily observed in the digit symbol test and tasks involving numerical processing.

Expert Insight: The observed gender differences suggest that the neurodegenerative processes underlying iRBD may manifest differently in men and women, potentially requiring tailored monitoring and management strategies.

Even patients who did not progress to neurodegenerative diseases like dementia or Parkinson’s disease during the study period still exhibited cognitive decline comparable to those who did. This suggests that cognitive loss may occur even in the absence of a formal diagnosis of a neurodegenerative condition.

What Could Happen Next

Based on these findings, a possible next step could be increased screening for cognitive function in individuals diagnosed with iRBD. Further research may focus on identifying biomarkers that can predict the rate of cognitive decline in iRBD patients. It is also likely that clinicians will consider gender-specific approaches to monitoring and managing iRBD symptoms.

Frequently Asked Questions

What is iRBD?

iRBD, or isolated REM sleep behavior disorder, is a condition in which people act out their dreams during sleep, often involving physical movements, vocalizations, and sometimes violent outbursts, without any other associated neurological diseases.

Can iRBD lead to other conditions?

The study suggests iRBD may be a potential marker for neurodegenerative disorders such as Parkinson’s disease and dementia with Lewy bodies, though not all patients with iRBD will necessarily develop these conditions.

Did the study find any differences between men and women with iRBD?

Yes, the study found that men with iRBD experienced broader and deeper cognitive losses compared to women, who showed a more limited pattern of decline.

Considering the potential link between sleep disorders and cognitive health, what steps can individuals take to prioritize both?