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Synergistic but independent: The role of corticospinal and alternate motor fibers for residual motor output after stroke

BACKGROUND: Brain imaging has shown that not only the cortico-spinal tract (CST), but also alternate corticofugal motor fibers (aMF), such as the cortico-rubro-spinal and cortico-reticulo-spinal tract, influence residual motor output after stroke. So far, studies mainly have investigated each tract...

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Autores principales: Schulz, Robert, Park, Eunhee, Lee, Jungsoo, Chang, Won Hyuk, Lee, Ahee, Kim, Yun-Hee, Hummel, Friedhelm C.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Elsevier 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5426012/
https://www.ncbi.nlm.nih.gov/pubmed/28516034
http://dx.doi.org/10.1016/j.nicl.2017.04.016
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author Schulz, Robert
Park, Eunhee
Lee, Jungsoo
Chang, Won Hyuk
Lee, Ahee
Kim, Yun-Hee
Hummel, Friedhelm C.
author_facet Schulz, Robert
Park, Eunhee
Lee, Jungsoo
Chang, Won Hyuk
Lee, Ahee
Kim, Yun-Hee
Hummel, Friedhelm C.
author_sort Schulz, Robert
collection PubMed
description BACKGROUND: Brain imaging has shown that not only the cortico-spinal tract (CST), but also alternate corticofugal motor fibers (aMF), such as the cortico-rubro-spinal and cortico-reticulo-spinal tract, influence residual motor output after stroke. So far, studies mainly have investigated each tract separately. A combined analysis of CST and aMF with assessment of their interactive role, i.e., that structural integrity of one tract influences the functional role of the structural integrity of the other, is pending. METHODS: 39 late subacute stroke patients (aged 59.4 ± 12.0 years, 100 ± 11 days after stroke) were included. Probabilistic tractography was used to reconstruct CST and aMF. Fractional anisotropy (FA) was calculated as a measure of microstructural integrity. Multiple-linear-regression analysis was used to associate tract-related FA with residual motor output and to determine interactions between CST and aMF. RESULTS: Both CST (coefficient = 3.93, p < 0.0001) and aMF (coefficient = − 4.43, p = 0.003) of the affected hemisphere significantly contributed to residual motor output. An interaction of their impacts with a consecutive influence on motor output was not detected (p = 0.882). Thus, these data suggest that aMF and CST explain residual motor output in stroke patients in a synergistic, but mainly independent manner. CONCLUSIONS: The structural states of the CST and also – to a smaller degree – of the aMF correlate with residual motor output in late subacute stroke patients. Based on this statistical modeling with all inherent limitations, the novel finding of an absence of a significant interaction between both tracts in regard of their functional role, suggests that both corticofugal pathways act synergistically but largely independently. These findings add to the understanding of the functional role of different corticofugal motor fibers and their interactions for motor output after stroke.
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spelling pubmed-54260122017-05-17 Synergistic but independent: The role of corticospinal and alternate motor fibers for residual motor output after stroke Schulz, Robert Park, Eunhee Lee, Jungsoo Chang, Won Hyuk Lee, Ahee Kim, Yun-Hee Hummel, Friedhelm C. Neuroimage Clin Regular Article BACKGROUND: Brain imaging has shown that not only the cortico-spinal tract (CST), but also alternate corticofugal motor fibers (aMF), such as the cortico-rubro-spinal and cortico-reticulo-spinal tract, influence residual motor output after stroke. So far, studies mainly have investigated each tract separately. A combined analysis of CST and aMF with assessment of their interactive role, i.e., that structural integrity of one tract influences the functional role of the structural integrity of the other, is pending. METHODS: 39 late subacute stroke patients (aged 59.4 ± 12.0 years, 100 ± 11 days after stroke) were included. Probabilistic tractography was used to reconstruct CST and aMF. Fractional anisotropy (FA) was calculated as a measure of microstructural integrity. Multiple-linear-regression analysis was used to associate tract-related FA with residual motor output and to determine interactions between CST and aMF. RESULTS: Both CST (coefficient = 3.93, p < 0.0001) and aMF (coefficient = − 4.43, p = 0.003) of the affected hemisphere significantly contributed to residual motor output. An interaction of their impacts with a consecutive influence on motor output was not detected (p = 0.882). Thus, these data suggest that aMF and CST explain residual motor output in stroke patients in a synergistic, but mainly independent manner. CONCLUSIONS: The structural states of the CST and also – to a smaller degree – of the aMF correlate with residual motor output in late subacute stroke patients. Based on this statistical modeling with all inherent limitations, the novel finding of an absence of a significant interaction between both tracts in regard of their functional role, suggests that both corticofugal pathways act synergistically but largely independently. These findings add to the understanding of the functional role of different corticofugal motor fibers and their interactions for motor output after stroke. Elsevier 2017-04-19 /pmc/articles/PMC5426012/ /pubmed/28516034 http://dx.doi.org/10.1016/j.nicl.2017.04.016 Text en © 2017 The Authors http://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
spellingShingle Regular Article
Schulz, Robert
Park, Eunhee
Lee, Jungsoo
Chang, Won Hyuk
Lee, Ahee
Kim, Yun-Hee
Hummel, Friedhelm C.
Synergistic but independent: The role of corticospinal and alternate motor fibers for residual motor output after stroke
title Synergistic but independent: The role of corticospinal and alternate motor fibers for residual motor output after stroke
title_full Synergistic but independent: The role of corticospinal and alternate motor fibers for residual motor output after stroke
title_fullStr Synergistic but independent: The role of corticospinal and alternate motor fibers for residual motor output after stroke
title_full_unstemmed Synergistic but independent: The role of corticospinal and alternate motor fibers for residual motor output after stroke
title_short Synergistic but independent: The role of corticospinal and alternate motor fibers for residual motor output after stroke
title_sort synergistic but independent: the role of corticospinal and alternate motor fibers for residual motor output after stroke
topic Regular Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5426012/
https://www.ncbi.nlm.nih.gov/pubmed/28516034
http://dx.doi.org/10.1016/j.nicl.2017.04.016
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