Cavallari M, et al. – This investigation intended to examine the effect of postoperative delirium on longitudinal brain microstructural changes, as measured by diffusion tensor imaging. The authors proposed the possibility that delirium had an effect on the development of brain microstructural abnormalities, which could show brain changes underlying cognitive trajectories. To clarify whether delirium was the driving factor of the observed changes or rather a correlate of a vulnerable brain that was at high risk for neurodegenerative processes, future studies were warranted.

• The authors examined a subset of the larger Successful Aging after Elective Surgery (SAGES) study cohort of older adults (≥70 years) without dementia undergoing elective surgery: 113 participants who had diffusion tensor imaging before and 1 year after surgery.
• Using the Confusion Assessment Method and a validated chart review method, postoperative delirium severity and occurrence were evaluated during the hospital stay.
• For this study, they examined the relationship of delirium severity and occurrence with longitudinal diffusion changes across 1 year, adjusting for age, sex, vascular comorbidity, and baseline cognitive performance.
• Also, they evaluated the relationship between changes in diffusion and cognitive performance across the 1-year follow-up period, adjusting for age, sex, education, and baseline cognitive performance.

• The authors observed postoperative delirium in 25 participants (22%).
• In the periventricular, frontal, and temporal white matter, delirium severity and occurrence were correlated with longitudinal diffusion changes.
• Also, diffusion changes were correlated with changes in cognitive performance across 1 year, although the cognitive changes did not reveal significant association with delirium severity or occurrence.