Resting State Executive Control Network Adaptations in Amnestic Mild Cognitive Impairment

Article type: Research Article

Authors: Wu, Liyong^{a; b; c} | Soder, Ricardo Bernardi^{a; b; d} | Schoemaker, Dorothée^{a; b} | Carbonnell, Felix^d | Sziklas, Viviane^e | Rowley, Jared^{a; b} | Mohades, Sara^{a; b} | Fonov, Vladmir^d | Bellec, Pierre^d | Dagher, Alain^d | Shmuel, Amir^d | Jia, Jianping^c | Gauthier, Serge^b | Rosa-Neto, Pedro^{a; b; d; *}

Affiliations: [a] Translational Neuroimaging Laboratory, Douglas Hospital, McGill University, Montreal, QC, Canada | [b] McGill Centre for Studies in Aging (MCSA), McGill University, Montreal, QC, Canada | [c] Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China | [d] McConnell Brain Imaging Centre, Montreal Neurological Institute, Montreal, QC, Canada | [e] Department of Psychology, Neuropsychology Unit, McGill University, Montreal, QC, Canada

Correspondence: [*] Correspondence to: Pedro Rosa-Neto, MD, PhD, Translational Neuroimaging Laboratory, Douglas Hospital, McGill University, Montreal, QC, Canada; 6875 La Salle Blv, FBC Room 3149, Montreal, QC, H4H 1R3, Canada. Tel.: +1 514 761 6131/Ext. 3407; E-mail: [email protected].

Abstract: Executive dysfunction is frequently associated with episodic memory decline in amnestic mild cognitive impairment (aMCI) patients. Resting state executive control network (RS-ECN) represents a novel approach to interrogate the integrity of brain areas underlying executive dysfunction. The present study aims to investigate RS-ECN in aMCI and examine a possible link between changes in brain functional connectivity and declines in executive function. aMCI individuals (n = 13) and healthy subjects (n = 16) underwent cognitive assessment including executive function and high field functional magnetic resonance imaging. Individual RS-ECN maps were estimated using a seed-based cross-correlation method. Between groups RS-ECN functional connectivity comparison was assessed using voxel-wise statistic parametric mapping. aMCI individuals had reduced RS-ECN connectivity in the anterior cingulate cortex (ACC) and dorsal lateral prefrontal cortex (DLPFC), bilaterally. In contrast, aMCI showed increased connectivity in ventral lateral and anterior prefrontal cortex, bilaterally. Connectivity strength was associated with executive function in the ACC (r = 0.6213, p = 0.023) and right DLPFC (r = 0.6454, p = 0.017). Coexistence between connectivity declines and recruitment of brain regions outside the RS-ECN as reported here fits a brain reserve conceptual framework in which brain networks undergo remodeling in aMCI individuals.

Keywords: Executive control network, executive function, functional MRI, mild cognitive impairment, neural plasticity

DOI: 10.3233/JAD-131574

Journal: Journal of Alzheimer's Disease, vol. 40, no. 4, pp. 993-1004, 2014