title: Executive attention networks show altered relationship with default mode network in PD.
abstract: Attention dysfunction is a common but often undiagnosed cognitive impairment in Parkinson's disease that significantly reduces quality of life. We sought to increase understanding of the mechanisms underlying attention dysfunction using functional neuroimaging. Functional MRI was acquired at two repeated sessions in the resting state and during the Attention Network Test, for 25 non-demented subjects with Parkinson's disease and 21 healthy controls. Behavioral and MRI contrasts were calculated for alerting, orienting, and executive control components of attention. Brain regions showing group differences in attention processing were used as seeds in a functional connectivity analysis of a separate resting state run. Parkinson's disease subjects showed more activation during increased executive challenge in four regions of the dorsal attention and frontoparietal networks, namely right frontal eye field, left and right intraparietal sulcus, and precuneus. In three regions we saw reduced resting state connectivity to the default mode network. Further, whereas higher task activation in the right intraparietal sulcus correlated with reduced resting state connectivity between right intraparietal sulcus and the precuneus in healthy controls, this relationship was absent in Parkinson's disease subjects. Our results suggest that a weakened interaction between the default mode and task positive networks might alter the way in which the executive response is processed in PD.
authors.affiliation: Department of Radiology, University of Washington, United States.
authors.forename: Peter
authors.initials: P
authors.lastname: Boord
authors.affiliation: Department of Radiology, University of Washington, United States.
authors.forename: Tara M
authors.initials: TM
authors.lastname: Madhyastha
authors.affiliation: Department of Radiology, University of Washington, United States.
authors.forename: Mary K
authors.initials: MK
authors.lastname: Askren
authors.affiliation: Department of Radiology, University of Washington, United States; Department of Neurology, University of Washington, United States.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Grabowski
mesh_terms: D000368:Aged; D001288:Attention / Q000502:physiology*; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology*; D060825:Cognitive Dysfunction / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D056344:Executive Function / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000000981:diagnostic imaging / Q000503:physiopathology*; D010300:Parkinson Disease / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*
keywords: ANT, attention network test; Attention network test; DAN, dorsal attention network; DMN, default mode network; Default mode network; Executive attention; FC, functional connectivity; FPN, frontoparietal task control network; Functional connectivity; HC, healthy controls; PD, Parkinson's disease; Parkinson's disease; RSN, resting state networks; TPN, task positive network; VAN, ventral attention network; lIPS, left intraparietal sulcus; rFEF, right frontal eye field; rIPS, right intraparietal sulcus; rSPL, right superior parietal lobule