Modulation of attentional network coherence during manipulation of cognitive load in Parkinson’s freezing

Abstract

Event Abstract Back to Event Modulation of attentional network coherence during manipulation of cognitive load in Parkinson’s freezing James Shine1*, Elie Matar1, Philip Ward2, Sharon Naismith1 and Simon Lewis1 1 Brain and Mind Research Institute, Australia 2 University of Western Sydney, School of Psychiatry, Australia FOG is a poorly understood disorder of advanced Parkinson’s disease, however recent advances in functional neuroimaging have helped to improve our conception of the pathophysiological mechanisms underlying the disorder. Based on a confluence of findings from both clinical and neuroimaging studies (Nutt et al., 2012; Shine et al., 2011a), there is rising consensus that freezing behavior is due to dysfunction between frontoparietal regions and key subcortical regions, such as the striatum, and brainstem structures controlling posture and gait (Bartels and Leenders, 2008; Lewis and Barker, 2010; Nutt et al., 2012). However, evidence for this dysfunction has arisen from studies that are either removed from motor performance, such as tasks that utilize imagined walking paradigms (Snidjers et al., 2011), or from studies with low temporal resolution, such as Positron Emission Tomography (Bartels and Leenders, 2008). Furthermore, evidence from functional MRI studies has relied on mass univariate approaches, which are able to detect dysfunctional regions without speaking to the interactions among these regions (Shine et al., 2011b). In this study, we utilize a data-driven multivariate approach (independent component analysis) to explore impaired communication between distributed ‘networks’ of neural regions in 12 patients with Parkinson’s disease and freezing behavior. Using a combination of a validated virtual reality gait task and functional MRI while the patients were ‘off’ their regular medication, we show that a major frontoparietal network underlying associative and executive functions becomes dissociated from a network encompassing the anterior striatum and frontopolar cortex under periods of increased cognitive load. Furthermore, the degree of this dissociation is significantly correlated with the number of motor arrests that occurred during the virtual reality task. These results provide further evidence to support the hypothesis that freezing behavior in Parkinson’s disease is due to impaired communication between competing, yet complimentary neural networks. References Bartels A and Leenders K. Mov Disord. 23(S2): S461-467. 2008 Nutt JG, et al. Lancet Neurol. 10(8): 734-744. 2012. Shine JM, et al. J Clin Neurosci. 18: 1154-1157. 2011a. Shine JM, et al. J Clin Neurosci. 18: 807-810. 2011b. Snijders AH, et al. Brain. 134(1): 54-72. 2011. Keywords: Independent Component Analysis, Functional Neuroimaging, Parkinson Disease, virtual reality, Cogntive Load Conference: ACNS-2012 Australasian Cognitive Neuroscience Conference, Brisbane, Australia, 29 Nov - 2 Dec, 2012. Presentation Type: Oral Presentation Topic: Attention Citation: Shine J, Matar E, Ward P, Naismith S and Lewis S (2012). Modulation of attentional network coherence during manipulation of cognitive load in Parkinson’s freezing. Conference Abstract: ACNS-2012 Australasian Cognitive Neuroscience Conference. doi: 10.3389/conf.fnhum.2012.208.00084 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 25 Oct 2012; Published Online: 07 Nov 2012. * Correspondence: Dr. James Shine, Brain and Mind Research Institute, Sydney, Australia, mac.shine@sydney.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers James Shine Elie Matar Philip Ward Sharon Naismith Simon Lewis Google James Shine Elie Matar Philip Ward Sharon Naismith Simon Lewis Google Scholar James Shine Elie Matar Philip Ward Sharon Naismith Simon Lewis PubMed James Shine Elie Matar Philip Ward Sharon Naismith Simon Lewis Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.