Real-time changes in corticospinal excitability during voluntary contraction with concurrent electrical stimulation.

While previous studies have assessed changes in corticospinal excitability following voluntary contraction coupled with electrical stimulation (ES), we sought to examine, for the first time in the field, real-time changes in corticospinal excitability. We monitored motor evoked potentials (MEPs) eli...

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Main Authors: Tomofumi Yamaguchi, Kenichi Sugawara, Satoshi Tanaka, Naoshin Yoshida, Kei Saito, Shigeo Tanabe, Yoshihiro Muraoka, Meigen Liu
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2012-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC3458815?pdf=render
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author Tomofumi Yamaguchi
Kenichi Sugawara
Satoshi Tanaka
Naoshin Yoshida
Kei Saito
Shigeo Tanabe
Yoshihiro Muraoka
Meigen Liu
author_facet Tomofumi Yamaguchi
Kenichi Sugawara
Satoshi Tanaka
Naoshin Yoshida
Kei Saito
Shigeo Tanabe
Yoshihiro Muraoka
Meigen Liu
author_sort Tomofumi Yamaguchi
collection DOAJ
description While previous studies have assessed changes in corticospinal excitability following voluntary contraction coupled with electrical stimulation (ES), we sought to examine, for the first time in the field, real-time changes in corticospinal excitability. We monitored motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation and recorded the MEPs using a mechanomyogram, which is less susceptible to electrical artifacts. We assessed the MEPs at each level of muscle contraction of wrist flexion (0%, 5%, or 20% of maximum voluntary contraction) during voluntary wrist flexion (flexor carpi radialis (FCR) voluntary contraction), either with or without simultaneous low-frequency (10 Hz) ES of the median nerve that innervates the FCR. The stimulus intensity corresponded to 1.2 × perception threshold. In the FCR, voluntary contraction with median nerve stimulation significantly increased corticospinal excitability compared with FCR voluntary contraction without median nerve stimulation (p<0.01). In addition, corticospinal excitability was significantly modulated by the level of FCR voluntary contraction. In contrast, in the extensor carpi radialis (ECR), FCR voluntary contraction with median nerve stimulation significantly decreased corticospinal excitability compared with FCR voluntary contraction without median nerve stimulation (p<0.05). Thus, median nerve stimulation during FCR voluntary contraction induces reciprocal changes in cortical excitability in agonist and antagonist muscles. Finally we also showed that even mental imagery of FCR voluntary contraction with median nerve stimulation induced the same reciprocal changes in cortical excitability in agonist and antagonist muscles. Our results support the use of voluntary contraction coupled with ES in neurorehabilitation therapy for patients.
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spelling doaj.art-4ee1ea471a9347658eedd999cb57149e2022-12-22T01:12:16ZengPublic Library of Science (PLoS)PLoS ONE1932-62032012-01-0179e4612210.1371/journal.pone.0046122Real-time changes in corticospinal excitability during voluntary contraction with concurrent electrical stimulation.Tomofumi YamaguchiKenichi SugawaraSatoshi TanakaNaoshin YoshidaKei SaitoShigeo TanabeYoshihiro MuraokaMeigen LiuWhile previous studies have assessed changes in corticospinal excitability following voluntary contraction coupled with electrical stimulation (ES), we sought to examine, for the first time in the field, real-time changes in corticospinal excitability. We monitored motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation and recorded the MEPs using a mechanomyogram, which is less susceptible to electrical artifacts. We assessed the MEPs at each level of muscle contraction of wrist flexion (0%, 5%, or 20% of maximum voluntary contraction) during voluntary wrist flexion (flexor carpi radialis (FCR) voluntary contraction), either with or without simultaneous low-frequency (10 Hz) ES of the median nerve that innervates the FCR. The stimulus intensity corresponded to 1.2 × perception threshold. In the FCR, voluntary contraction with median nerve stimulation significantly increased corticospinal excitability compared with FCR voluntary contraction without median nerve stimulation (p<0.01). In addition, corticospinal excitability was significantly modulated by the level of FCR voluntary contraction. In contrast, in the extensor carpi radialis (ECR), FCR voluntary contraction with median nerve stimulation significantly decreased corticospinal excitability compared with FCR voluntary contraction without median nerve stimulation (p<0.05). Thus, median nerve stimulation during FCR voluntary contraction induces reciprocal changes in cortical excitability in agonist and antagonist muscles. Finally we also showed that even mental imagery of FCR voluntary contraction with median nerve stimulation induced the same reciprocal changes in cortical excitability in agonist and antagonist muscles. Our results support the use of voluntary contraction coupled with ES in neurorehabilitation therapy for patients.http://europepmc.org/articles/PMC3458815?pdf=render
spellingShingle Tomofumi Yamaguchi
Kenichi Sugawara
Satoshi Tanaka
Naoshin Yoshida
Kei Saito
Shigeo Tanabe
Yoshihiro Muraoka
Meigen Liu
Real-time changes in corticospinal excitability during voluntary contraction with concurrent electrical stimulation.
PLoS ONE
title Real-time changes in corticospinal excitability during voluntary contraction with concurrent electrical stimulation.
title_full Real-time changes in corticospinal excitability during voluntary contraction with concurrent electrical stimulation.
title_fullStr Real-time changes in corticospinal excitability during voluntary contraction with concurrent electrical stimulation.
title_full_unstemmed Real-time changes in corticospinal excitability during voluntary contraction with concurrent electrical stimulation.
title_short Real-time changes in corticospinal excitability during voluntary contraction with concurrent electrical stimulation.
title_sort real time changes in corticospinal excitability during voluntary contraction with concurrent electrical stimulation
url http://europepmc.org/articles/PMC3458815?pdf=render
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