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dc.contributor.authorBajaj, Sahil
dc.contributor.authorHousley, Stephen N.
dc.contributor.authorWu, David
dc.contributor.authorDhamala, Mukesh
dc.contributor.authorJames, G. A.
dc.contributor.authorButler, Andrew J.
dc.date.accessioned2017-03-03T21:52:22Z
dc.date.available2017-03-03T21:52:22Z
dc.date.issued2016-12-27
dc.identifier.citationDominance of the Unaffected Hemisphere Motor Network and Its Role in the Behavior of Chronic Stroke Survivors 2016, 10 Frontiers in Human Neuroscienceen
dc.identifier.issn1662-5161
dc.identifier.doi10.3389/fnhum.2016.00650
dc.identifier.urihttp://hdl.handle.net/10150/622772
dc.description.abstractBalance of motor network activity between the two brain hemispheres after stroke is crucial for functional recovery. Several studies have extensively studied the role of the affected brain hemisphere to better understand changes in motor network activity following stroke. Very few studies have examined the role of the unaffected brain hemisphere and confirmed the testretest reliability of connectivity measures on unaffected hemisphere. We recorded blood oxygenation level dependent functional magnetic resonance imaging (fMRI) signals from nine stroke survivors with hemiparesis of the left or right hand. Participants performed a motor execution task with affected hand, unaffected hand, and both hands simultaneously. Participants returned for a repeat fMRI scan 1 week later. Using dynamic causal modeling (DCM), we evaluated effective connectivity among three motor areas: the primary motor area (M1), the premotor cortex (PMC) and the supplementary motor area for the affected and unaffected hemispheres separately. Five participants manual motor ability was assessed by Fugl-Meyer Motor Assessment scores and root-mean square error of participants tracking ability during a robot-assisted game. We found (i) that the task performance with the affected hand resulted in strengthening of the connectivity pattern for unaffected hemisphere, (ii) an identical network of the unaffected hemisphere when participants performed the task with their unaffected hand, and (iii) the pattern of directional connectivity observed in the affected hemisphere was identical for tasks using the affected hand only or both hands. Furthermore, paired t-test comparison found no significant differences in connectivity strength for any path when compared with one-week follow-up. Brain-behavior linear correlation analysis showed that the connectivity patterns in the unaffected hemisphere more accurately reflected the behavioral conditions than the connectivity patterns in the affected hemisphere. Above findings enrich our knowledge of unaffected brain hemisphere following stroke, which further strengthens our neurobiological understanding of stroke-affected brain and can help to effectively identify and apply stroke-treatments.
dc.description.sponsorshipU.S. Department of Veterans Affairs, Rehabilitation Research & Development Service [5I21RX000561 (B7676-P)]en
dc.language.isoenen
dc.publisherFRONTIERS MEDIA SAen
dc.relation.urlhttp://journal.frontiersin.org/article/10.3389/fnhum.2016.00650/fullen
dc.rights© 2016 Bajaj, Housley, Wu, Dhamala, James and Butler. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).en
dc.subjectfunctional magnetic resonance imaging(fMRI)en
dc.subjecteffective connectivityen
dc.subjectdynamic causal modeling (DCM)en
dc.subjectmotor tasken
dc.subjectstrokeen
dc.subjectaffected hemisphereen
dc.subjectunaffected hemisphereen
dc.titleDominance of the Unaffected Hemisphere Motor Network and Its Role in the Behavior of Chronic Stroke Survivorsen
dc.typeArticleen
dc.contributor.departmentUniv Arizona, Coll Med, Dept Psychiaten
dc.identifier.journalFrontiers in Human Neuroscienceen
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.en
dc.eprint.versionFinal published versionen
refterms.dateFOA2018-06-24T22:13:27Z
html.description.abstractBalance of motor network activity between the two brain hemispheres after stroke is crucial for functional recovery. Several studies have extensively studied the role of the affected brain hemisphere to better understand changes in motor network activity following stroke. Very few studies have examined the role of the unaffected brain hemisphere and confirmed the testretest reliability of connectivity measures on unaffected hemisphere. We recorded blood oxygenation level dependent functional magnetic resonance imaging (fMRI) signals from nine stroke survivors with hemiparesis of the left or right hand. Participants performed a motor execution task with affected hand, unaffected hand, and both hands simultaneously. Participants returned for a repeat fMRI scan 1 week later. Using dynamic causal modeling (DCM), we evaluated effective connectivity among three motor areas: the primary motor area (M1), the premotor cortex (PMC) and the supplementary motor area for the affected and unaffected hemispheres separately. Five participants manual motor ability was assessed by Fugl-Meyer Motor Assessment scores and root-mean square error of participants tracking ability during a robot-assisted game. We found (i) that the task performance with the affected hand resulted in strengthening of the connectivity pattern for unaffected hemisphere, (ii) an identical network of the unaffected hemisphere when participants performed the task with their unaffected hand, and (iii) the pattern of directional connectivity observed in the affected hemisphere was identical for tasks using the affected hand only or both hands. Furthermore, paired t-test comparison found no significant differences in connectivity strength for any path when compared with one-week follow-up. Brain-behavior linear correlation analysis showed that the connectivity patterns in the unaffected hemisphere more accurately reflected the behavioral conditions than the connectivity patterns in the affected hemisphere. Above findings enrich our knowledge of unaffected brain hemisphere following stroke, which further strengthens our neurobiological understanding of stroke-affected brain and can help to effectively identify and apply stroke-treatments.


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