Medical Xpress: Analysis of Brain Waves During Sleep May Indicate Dementia Risk

Researchers from the University of California, San Francisco, and Beth Israel Deaconess Medical Center in Boston have identified people at high risk of developing dementia long before obvious symptoms appear by analyzing brain waves during sleep. The findings were reported by Medical Xpress on March 22.

According to the publication, the scientists used a machine learning model to estimate “brain age” based on EEG data. When this measure exceeded a person’s actual biological age, the risk of cognitive decline increased: for every 10-year gap between “brain age” and chronological age, the likelihood of developing dementia rose by nearly 40%.

The study analyzed data from around 7,000 participants aged 40 to 94 who showed no signs of dementia at the start. They were followed for periods ranging from 3.5 to 17 years, during which approximately 1,000 individuals were diagnosed with the condition.

Traditional sleep assessment methods—such as stage duration or overall sleep efficiency—did not show a significant association with disease risk. However, analyzing the microstructural features of brain waves provided more accurate results. In particular, the model accounted for delta waves associated with deep sleep, as well as “sleep spindles,” short bursts of activity linked to memory consolidation.

The researchers also found that sudden large spikes in EEG activity (known as “bursts”) were associated with a lower risk of dementia. The link between “accelerated brain aging” and the disease remained even after adjusting for factors such as education level, smoking, body mass index, and genetic predisposition.

The study’s first author, PhD and Assistant Professor of Neurology at Beth Israel Deaconess Medical Center, Haoqi Sun, noted that the findings open up possibilities for early diagnosis using wearable devices, while also emphasizing the importance of lifestyle factors. The results suggest that improving sleep quality may influence brain aging.

“Better management of overall health—for example, reducing body mass index and increasing physical activity to lower the risk of sleep apnea—may have an impact,” he подчеркнул.