P2–186: Resting state executive control network adaptations in amnestic mild cognitive impairment

Abstract

Although episodic memory decline is the most prominent deficit in amnestic mild cognitive impairment (aMCI), most aMCI individuals also exhibit impairments of executive function. Resting state executive control network (RS-ECN) constitutes a novel approach to investigate the integrity of brain areas underlying executive dysfunction in aMCI patients. The present study aims to investigate changes in RS-ECN in aMCI and examine a possible link between changes in brain functional connectivity and declines in executive function. Thirteen aMCI individuals and sixteen healthy subjects underwent cognitive assessment including executive function and high field functional magnetic resonance imaging (fMRI). Individual RS-ECN maps were estimated by cross-correlation method using a seed-based approach. Neuropsychological scores and functional connectivity of RS-ECN were compared between groups. Correlation analysis between RS-ECN and composite executive score was conducted specifically on brain regions where group differences reach the highest significance based on the peak and cluster extension. aMCI individuals had reduced RS-ECN connectivity in large clusters encompassing anterior cingulate cortex(ACC) and dorsal lateral prefrontal cortex (DLPFC), bilaterally. In contrast, aMCI showed large clusters with increased connectivity in ventral lateral and anterior prefrontal cortex, bilaterally. In aMCI individuals, correlation analysis showed a positive association between composite executive score and functional connectivity strength in ACC (r=0.6213, p =0.023), as well as in right DLPFC (r=0.6454, p =0.017).