Researchers find predictors of cognitive impairments over time

A four-year study on adults with Parkinson's disease (PD) revealed that cognitive function can either remain stable or decline progressively. Researchers identified early issues with visual processing and spatial reasoning as predictors of cognitive impairments. The study also found that an increase in slow brain waves associated with sleep, as measured by EEG at the study's start, predicted worsening cognitive outcomes after two and four years. The researchers noted that aggressive cognitive decline in PD is linked with increased slow-wave power density, emphasizing the need for further research with a larger patient population and more longitudinal EEG data to better assess the predictive power of short-term neurophysiological changes. The study, published in the Annals of Neurology, involved two groups of PD patients assessed alongside healthy controls. Cognitive changes varied widely, with 60% of patients maintaining stable cognition or improving, while 40% experienced a decline. Progressive decline was marked by worse performance in areas like planning, working memory, and attention. These patients also had an increased risk of mild cognitive impairment and dementia. Early changes in specific tasks and increased slow-wave power density in the brain predicted more aggressive cognitive decline. No significant differences were found in MRI scans and blood biomarkers between stable and declining patients at the study’s start. The study highlighted the importance of EEG in predicting cognitive outcomes, particularly temporal memory decline.