Reversal of TMS-induced motor twitch by training is associated with a reduction in excitability of the antagonist muscle
Autor: | Dylan J. Edwards, Bruce T. Volpe, Viola Giacobbe, Alvaro Pascual-Leone, Hermano Igo Krebs, Gary W. Thickbroom, Felipe Fregni |
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Přispěvatelé: | Massachusetts Institute of Technology. Department of Mechanical Engineering, Krebs, Hermano Igo |
Rok vydání: | 2011 |
Předmět: |
Adult
Male medicine.medical_specialty Movement medicine.medical_treatment Health Informatics Electromyography Wrist 050105 experimental psychology lcsh:RC321-571 Young Adult 03 medical and health sciences 0302 clinical medicine Physical medicine and rehabilitation Forearm medicine Humans Learning 0501 psychology and cognitive sciences Muscle Skeletal lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry medicine.diagnostic_test Research 05 social sciences Rehabilitation Motor Cortex Evoked Potentials Motor Transcranial Magnetic Stimulation Sagittal plane Transcranial magnetic stimulation body regions medicine.anatomical_structure Female Primary motor cortex medicine.symptom Psychology Neuroscience 030217 neurology & neurosurgery Muscle Contraction Motor cortex Muscle contraction |
Zdroj: | Dipòsit Digital de Documents de la UAB Universitat Autònoma de Barcelona BioMed Central Ltd Recercat: Dipósit de la Recerca de Catalunya Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya) Journal of NeuroEngineering and Rehabilitation Recercat. Dipósit de la Recerca de Catalunya instname Journal of NeuroEngineering and Rehabilitation, Vol 8, Iss 1, p 46 (2011) |
Popis: | Background: A single session of isolated repetitive movements of the thumb can alter the response to transcranial magnetic stimulation (TMS), such that the related muscle twitch measured post-training occurs in the trained direction. This response is attributed to transient excitability changes in primary motor cortex (M1) that form the early part of learning. We investigated; (1) whether this phenomenon might occur for movements at the wrist, and (2) how specific TMS activation patterns of opposing muscles underlie the practice-induced change in direction. Methods: We used single-pulse suprathreshold TMS over the M1 forearm area, to evoke wrist movements in 20 healthy subjects. We measured the preferential direction of the TMS-induced twitch in both the sagittal and coronal plane using an optical goniometer fixed to the dorsum of the wrist, and recorded electromyographic (EMG) activity from the flexor carpi radialis (FCR) and extensor carpi radialis (ECR) muscles. Subjects performed gentle voluntary movements, in the direction opposite to the initial twitch for 5 minutes at 0.2 Hz. We collected motor evoked potentials (MEPs) elicited by TMS at baseline and for 10 minutes after training. Results: Repetitive motor training was sufficient for TMS to evoke movements in the practiced direction opposite to the original twitch. For most subjects the effect of the newly-acquired direction was retained for at least 10 minutes before reverting to the original. Importantly, the direction change of the movement was associated with a significant decrease in MEP amplitude of the antagonist to the trained muscle, rather than an increase in MEP amplitude of the trained muscle. Conclusions: These results demonstrate for the first time that a TMS-twitch direction change following a simple practice paradigm may result from reduced corticospinal drive to muscles antagonizing the trained direction. Such findings may have implications for training paradigms in neurorehabilitation. National Institutes of Health (U.S.) (grant 1R21HD060999-01) |
Databáze: | OpenAIRE |
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