scholarly journals Modulation of Interhemispheric Inhibition between Primary Motor Cortices Induced by Manual Motor Imitation: A Transcranial Magnetic Stimulation Study

2021 ◽  
Vol 11 (2) ◽  
pp. 266
Author(s):  
Dongting Tian ◽  
Shin-ichi Izumi ◽  
Eizaburo Suzuki
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Motor Development ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Right Hemisphere ◽  
Mirror Neuron System ◽  
Action Observation ◽  
Silent Period ◽  
Interhemispheric Inhibition ◽  
Time Point

Imitation has been proven effective in motor development and neurorehabilitation. However, the relationship between imitation and interhemispheric inhibition (IHI) remains unclear. Transcranial magnetic stimulation (TMS) can be used to investigate IHI. In this study, the modification effects of IHI resulting from mirror neuron system (MNS) activation during different imitations are addressed. We measured IHI between homologous primary motor cortex (M1) by analyzing the ipsilateral silent period (iSP) evoked by single-pulse focal TMS during imitation and analyzed the respective IHI modulation during and after different patterns of imitation. Our main results showed that throughout anatomical imitation, significant time-course changes of iSP duration through the experiment were observed in both directions. iSP duration declined from the pre-imitation time point to the post-imitation time point and did not return to baseline after 30 min rest. We also observed significant iSP reduction from the right hemisphere to the left hemisphere during anatomical and specular imitation, compared with non-imitative movement. Our findings indicate that using anatomical imitation in action observation and execution therapy promotes functional recovery in neurorehabilitation by regulating IHI.

scholarly journals Neuroplasticity Changes on Human Motor Cortex Induced by Acupuncture Therapy: A Preliminary Study

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Yi Yang ◽  
Ines Eisner ◽  
Siqi Chen ◽  
Shaosong Wang ◽  
Fan Zhang ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Acupuncture Therapy ◽  
Motor Cortex ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Motor Evoked Potential ◽  
Interhemispheric Inhibition ◽  
Human Motor Cortex ◽  
Interhemispheric Competition ◽  
Resting Motor Threshold

While neuroplasticity changes measured by transcranial magnetic stimulation have been proved to be highly correlated to motor recovery and have been tested in various forms of interventions, it has not been applied to investigate the neurophysiologic mechanism of acupuncture therapy. The aim of this study is to investigate neuroplasticity changes induced by a single session of acupuncture therapy in healthy adults, regarding the excitability change on bilateral primary motor cortex and interhemispheric inhibition. Ten subjects took a 30-minute acupuncture therapy and the same length relaxing phase in separate days. Transcranial magnetic stimulation measures, including resting motor threshold, amplitudes of motor-evoked potential, and interhemispheric inhibition, were assessed before and 10 minutes after intervention. Acupuncture treatment showed significant changes on potential amplitude from both ipsilateral and contralateral hemispheres to acupuncture compared to baseline. Also, interhemispheric inhibition from the contralateral motor cortex to the opposite showed a significant decline. The results indicated that corticomotoneuronal excitability and interhemispheric competition could be modulated by acupuncture therapy on healthy subjects. The following question about whether these changes will be observed in the same way on stroke patients and whether they correlate with the therapeutic effect on movement need to be answered by following studies. This trial is registered with ISRCTN13074245.

scholarly journals Ultrasound stimulation of the motor cortex during tonic muscle contraction

2021 ◽  
Author(s):  
Ian Szwast Heimbuch ◽  
Tiffany Fan ◽  
Allan Wu ◽  
Guido C Faas ◽  
Andrew C Charles ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Muscle Contraction ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Silent Period ◽  
Transcranial Ultrasound ◽  
Emg Activity ◽  
Ultrasound Stimulation ◽  
Tonic Muscle

Transcranial ultrasound stimulation (tUS) shows potential as a noninvasive brain stimulation (NIBS) technique, offering increased spatial precision compared to other NIBS techniques. However, its reported effects on primary motor cortex (M1) are limited. We aimed to better understand tUS effects in human M1 by performing tUS of the hand area of M1 (M1hand) during tonic muscle contraction of the index finger. Stimulation during muscle contraction was chosen because of the transcranial magnetic stimulation-induced phenomenon known as cortical silent period (cSP), in which transcranial magnetic stimulation (TMS) of M1hand involuntarily suppresses voluntary motor activity. Since cSP is widely considered an inhibitory phenomenon, it presents an ideal parallel for tUS, which has often been proposed to preferentially influence inhibitory interneurons. Recording electromyography (EMG) of the first dorsal interosseous (FDI) muscle, we investigated effects on muscle activity both during and after tUS. We found no change in FDI EMG activity concurrent with tUS stimulation. Using single-pulse TMS, we found no difference in M1 excitability before versus after sparsely repetitive tUS exposure. Using acoustic simulations in models made from structural MRI of the participants that matched the experimental setups, we estimated in-brain pressures and generated an estimate of cumulative tUS exposure experienced by M1hand for each subject. We were unable to find any correlation between cumulative M1hand exposure and M1 excitability change. We also present data that suggest a TMS-induced MEP always preceded a near-threshold cSP.

Transcallosal inhibition in patients with callosal infarction

2013 ◽  
Vol 109 (3) ◽  
pp. 659-665 ◽  
Author(s):  
Jie-Yuan Li ◽  
Ping-Hong Lai ◽  
Robert Chen
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Corpus Callosum ◽  
Healthy Subjects ◽  
Magnetic Stimulation ◽  
Silent Period ◽  
Normal Subjects ◽  
Interhemispheric Inhibition ◽  
Transcallosal Inhibition ◽  
Long Latency ◽  
Pass Through

Recent studies in normal subjects suggested that callosal motor fibers pass through the posterior body of the corpus callosum (CC), but this has not been tested in patients with callosal infarction. The objective of this study is to define the pathways involved in transcallosal inhibition by examining patients with infarctions in different subregions of the CC. We hypothesized that patients with lesions in the posterior one-half of the CC would have greater reduction in transcallosal inhibition between the motor cortices. Twenty-six patients with callosal infarction and 14 healthy subjects were studied. The callosal lesions were localized on sagittal MRI and were attributed to one of five segments of the CC. Transcranial magnetic stimulation was used to assess ipsilateral silent period (iSP) and short- and long-latency interhemispheric inhibition (SIHI and LIHI, respectively) originating from both motor cortices. The results showed that the iSP areas and durations were markedly reduced bilaterally in patients with callosal infarction compared with normal subjects. Patients with callosal infarctions also had less IHI bidirectionally compared with normal subjects. iSP areas and durations were lower in patients with lesions than in patients without lesions in segment 3 (posterior midbody) of the CC. Lesion burden in the posterior one-half of the CC negatively correlated transcallosal inhibition measured with iSP and SIHI. Our study suggests that callosal infarction led to reduced transcallosal inhibition, as measured by iSP, SIHI, and LIHI. Fibers mediating transcallosal inhibition cross the CC mainly in the posterior one-half.

Remote effects of cortical dysgenesis on the primary motor cortex: evidence from the silent period following transcranial magnetic stimulation

2000 ◽  
Vol 111 (8) ◽  
pp. 1340-1345 ◽  
Author(s):  
Massimo Cincotta ◽  
Alessandra Borgheresi ◽  
Leonello Guidi ◽  
Marco Macucci ◽  
Mirco Cosottini ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Silent Period ◽  
Cortical Dysgenesis

Interhemispheric inhibition to the biceps brachii during arm cycling

2020 ◽  
Author(s):  
Ryan Benson ◽  
Evan James Lockyer ◽  
Chris Compton ◽  
Kevin E. Power
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Magnetic Stimulation ◽  
Biceps Brachii ◽  
Silent Period ◽  
Interhemispheric Inhibition ◽  
Emg Amplitude ◽  
Arm Cycling ◽  
Cortical Circuit

This is the first demonstration of interhemispheric inhibition (IHI) during a locomotor output, arm cycling. IHI was quantified by assessing the depth of the ipsilateral silent period (iSP) evoked via transcranial magnetic stimulation (TMS) of the motor cortex. There was a significant reduction in EMG amplitude of the iSP during cycling compared to the control EMG (16.8 ± 17.1%; p<0.001). Depth and area for measuring the iSP during arm cycling are discussed. NOVELTY • First study to demonstrate activation of the cortical circuit, interhemispheric inhibition, during a locomotor output.

scholarly journals Repetitive Transcranial Magnetic Stimulation of the Intraparietal Sulcuschanges the Grip Force Modulation Exerted by Manual Action-Verbs – An Exploratory Study

2019 ◽  
Author(s):  
Ronaldo Luis da Silva ◽  
Victor Frak ◽  
Johanne Higgins
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Left Hemisphere ◽  
Magnetic Stimulation ◽  
Grip Force ◽  
Primary Motor Cortex ◽  
Right Hemisphere ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Force Modulation ◽  
Left And Right ◽  
The Right

Objective: To evaluate the effects of left intraparietal sulcus (IPS) inhibition by repetitive transcranial magnetic stimulation (rTMS) on grip force modulation (GFM) for both hands during a unimanual task. Methods: GFM induced by manual action-verb listening was evaluated for each hand in a unimanual task, and the motor-evoked potentials (MEP) were recorded for both left and right hemispheres prior to and following the left IPS inhibition. Left IPS inhibition was obtained by rTMS (5 min of 1.0 Hz, 60% of maximal stimulator output) of the international 10&ndash;20 system P3 point. Seven healthy right-handed subjects were evaluated. Results: One-way repeated measures ANOVA found that MEP amplitude and duration increased following IPS inhibition in the left hemisphere and did not change in the right hemisphere. Language-induced modulation did not change in the left hemisphere, while it was significantly attenuated in the right hemisphere. Since IPS inhibition increased the left primary motor cortex (M1) excitability, the maintenance of language-induced modulation intensity suggests it was also attenuated. Conclusion: Left IPS inhibition increased left M1 excitability without changing right M1 excitability, while attenuating the language-induced GFM for both the left and right hands.

scholarly journals Cerebellar Transcranial Magnetic Stimulation Reduces the Silent Period on Hand Muscle Electromyography During Force Control

2020 ◽  
Vol 10 (2) ◽  
pp. 63 ◽  
Author(s):  
Akiyoshi Matsugi ◽  
Shinya Douchi ◽  
Kodai Suzuki ◽  
Kosuke Oku ◽  
Nobuhiko Mori ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Maximum Voluntary Contraction ◽  
Motor Evoked Potential ◽  
Silent Period ◽  
Voluntary Contraction ◽  
Resting Motor Threshold ◽  
First Dorsal Interosseous Muscle ◽  
The Right

This study aimed to investigate whether cerebellar transcranial magnetic stimulation (C-TMS) affected the cortical silent period (cSP) induced by TMS over the primary motor cortex (M1) and the effect of interstimulus interval (ISI) on cerebellar conditioning and TMS to the left M1 (M1-TMS). Fourteen healthy adult participants were instructed to control the abduction force of the right index finger to 20% of the maximum voluntary contraction. M1-TMS was delivered during this to induce cSP on electromyograph of the right first dorsal interosseous muscle. TMS over the right cerebellum (C-TMS) was conducted prior to M1-TMS. In the first experiment, M1-TMS intensity was set to 1 or 1.3 × resting motor threshold (rMT) with 20-ms ISI. In the second experiment, the intensity was set to 1 × rMT with ISI of 0, 10, 20, 30, 40, 50, 60, 70, or 80 ms, and no-C-TMS trials were inserted. In results, cSP was significantly shorter in 1 × rMT condition than in 1.3 × rMT by C-TMS, and cSP was significantly shorter for ISI of 20–40 ms than for the no-C-TMS condition. Further, motor evoked potential for ISI40-60 ms were significantly reduced than that for ISI0. Thus, C-TMS may reduce cSP induced by M1-TMS with ISI of 20–40 ms.

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