Relationships between preoperative cortical thickness, postoperative electroencephalogram slowing, and postoperative delirium

It is unclear how preoperative neurodegeneration and postoperative changes in EEG delta power relate to postoperative delirium severity. We sought to understand the relative relationships between neurodegeneration and delta power as predictors of delirium severity. We undertook a prospective cohort study of high-risk surgical patients (>65 yr old) to identify predictors of peak delirium severity (Delirium Rating Scale-98) with twice-daily delirium assessments (NCT 03124303). Participants (n=86) underwent preoperative MRI; 54 had both an MRI and a postoperative EEG. Cortical thickness was calculated from the MRI and delta power from the EEG. In a linear regression model, the interaction between delirium status and preoperative mean cortical thickness (suggesting neurodegeneration) across the entire cortex was a significant predictor of delirium severity (P