Evidence for cognitive compensation mechanism in the postoperative delirium: a prospective multi-modal neuroimaging cohort study.

To explore the effect of brain cognitive compensation on the pathogenesis of postoperative delirium (POD) in the frontal glioma patients. Eighty-four adult patients with unilateral frontal glioma who underwent elective craniotomy and 37 healthy controls were recruited. Primary outcomes were POD during postoperative 1-7 days, as assessed by Confusion Assessment Method. Cognition before surgery was measured by the battery of neuropsychological tests. Then we evaluated gray matter volume (GMV) and white matter integrity (i.e. fractional anisotropy (Casey et al.)) by presurgical voxel-based morphometry and diffusion tensor imaging. We investigated the association between presurgical structural index of potential compensatory brain regions with POD incidence and severity. POD occurred in 13 of 67 subjects (19.4%). Pearson correlation revealed a tendency of negative correlation between the GMV in the contralateral dorsal lateral prefrontal cortex (DLPFC) and glioma grade. After controlling for age, gender and education, partial correlation analysis suggested that the GMV in the contralateral DLPFC was significantly positive correlated with presurgical cognition, and negatively correlated with POD incidence and severity (all P < 0.05); and the FA value of the genu of the corpus callosum was significantly positively correlated with the GMV in the contralateral DLPFC and preoperative cognition, while was negative correlated with the incidence and severity of POD (all P < 0.05). Our findings showed that compensation of contralateral DLPFC could decrease the risk and severity of POD in patients with frontal glioma. Our findings provide imaging-based evidence for the presence of cognitive compensation in the development of POD.