Effects of low frequency and low intensity repetitive paired pulse stimulation of the primary motor cortex

2004 ◽  
Vol 115 (6) ◽  
pp. 1259-1263 ◽  
Author(s):  
Eman M Khedr ◽  
Francesca Gilio ◽  
John Rothwell
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Low Frequency ◽  
Paired Pulse ◽  
Low Intensity ◽  
Pulse Stimulation ◽  
Stimulation Of

Influence of Short-Interval Intracortical Inhibition on Short-Interval Intracortical Facilitation in Human Primary Motor Cortex

2010 ◽  
Vol 104 (3) ◽  
pp. 1382-1391 ◽  
Author(s):  
Yuichiro Shirota ◽  
Masashi Hamada ◽  
Yasuo Terao ◽  
Hideyuki Matsumoto ◽  
Shinya Ohminami ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Short Interval ◽  
Conditioning Stimulus ◽  
Intracortical Inhibition ◽  
Intracortical Facilitation ◽  
Paired Pulse ◽  
Active Motor ◽  
Second Peak ◽  
Pulse Stimulation

Using the paired-pulse paradigm, transcranial magnetic stimulation (TMS) has revealed much about the human primary motor cortex (M1). A preceding subthreshold conditioning stimulus (CS) inhibits the excitability of the motor cortex, which is named short-interval intracortical inhibition (SICI). In contrast, facilitation is observed when the first pulse (S1) is followed by a second one at threshold (S2), named short-interval intracortical facilitation (SICF). SICI and SICF have been considered to be mediated by different neural circuits within M1, but more recent studies reported relations between them. In this study, we performed triple-pulse stimulation consisting of CS-S1-S2 to further explore putative interactions between these two effects. Three intensities of CS (80–120% of active motor threshold: AMT) and two intensities of S2 (120 and 140% AMT) were combined. The SICF in the paired-pulse paradigm exhibited clear facilitatory peaks at ISIs of 1.5 and 3 ms. The second peak at 3 ms was significantly suppressed by triple-pulse stimulation using 120% AMT CS, although the first peak was almost unaffected. Our present results obtained using triple-pulse stimulation suggest that each peak of SICF is differently modulated by different intensities of CS. The suppression of the second peak might be ascribed to the findings in the paired-pulse paradigm that CS mediates SICI by inhibiting later I waves such as I3 waves and that the second peak of SICF is most probably related to I3 waves. We propose that CS might inhibit the second peak of SICF at the interneurons responsible for I3 waves.

Low-Intensity Paired-Pulse rTMS given to the Primary Motor Cortex at 5Hz Attenuates Intracortical Excitability

2004 ◽  
Vol 35 (03) ◽  
Author(s):  
I Holler ◽  
TV Ilic ◽  
M Peller ◽  
M Pötter ◽  
G Deuschl ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Paired Pulse ◽  
Low Intensity ◽  
Intracortical Excitability

scholarly journals Reduced Interhemispheric Coherence in Cerebellar Kainic Acid-Induced Lateralized Dystonia

2020 ◽  
Vol 11 ◽  
Author(s):  
Elena Laura Georgescu Margarint ◽  
Ioana Antoaneta Georgescu ◽  
Carmen Denise Mihaela Zahiu ◽  
Stefan-Alexandru Tirlea ◽  
Alexandru Rǎzvan Şteopoaie ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Kainic Acid ◽  
Primary Motor Cortex ◽  
Low Frequency ◽  
Muscular Activity ◽  
Cerebellar Hemisphere ◽  
Interhemispheric Coherence ◽  
General Locomotor Activity ◽  
Complex Circuits ◽  
The Right

The execution of voluntary muscular activity is controlled by the primary motor cortex, together with the cerebellum and basal ganglia. The synchronization of neural activity in the intracortical network is crucial for the regulation of movements. In certain motor diseases, such as dystonia, this synchrony can be altered in any node of the cerebello-cortical network. Questions remain about how the cerebellum influences the motor cortex and interhemispheric communication. This research aims to study the interhemispheric cortical communication between the motor cortices during dystonia, a neurological movement syndrome consisting of sustained or repetitive involuntary muscle contractions. We pharmacologically induced lateralized dystonia to adult male albino mice by administering low doses of kainic acid on the left cerebellar hemisphere. Using electrocorticography and electromyography, we investigated the power spectral densities, cortico-muscular, and interhemispheric coherence between the right and left motor cortices, before and during dystonia, for five consecutive days. Mice displayed lateralized abnormal motor signs, a reduced general locomotor activity, and a high score of dystonia. The results showed a progressive interhemispheric coherence decrease in low-frequency bands (delta, theta, beta) during the first 3 days. The cortico-muscular coherence of the affected side had a significant increase in gamma bands on days 3 and 4. In conclusion, lateralized cerebellar dysfunction during dystonia was associated with a loss of connectivity in the motor cortices, suggesting a possible cortical compensation to the initial disturbances induced by cerebellar left hemisphere kainate activation by blocking the propagation of abnormal oscillations to the healthy hemisphere. However, the cerebellum is part of several overly complex circuits, therefore other mechanisms can still be involved in this phenomenon.

Multifocal Noninvasive Magnetic Stimulation of the Primary Motor Cortex in Type 1 Myotonic Dystrophy –A Proof of Concept Pilot Study

2021 ◽  
pp. 1-10
Author(s):  
Ericka Greene ◽  
Jason Thonhoff ◽  
Blessy S. John ◽  
David B. Rosenfield ◽  
Santosh A. Helekar
Keyword(s):  
Motor Cortex ◽  
Myotonic Dystrophy ◽  
Muscle Function ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Compound Muscle Action Potential ◽  
Sham Stimulation ◽  
Stimulation Of

Background: Repeated neuromuscular electrical stimulation in type 1 Myotonic Dystrophy (DM1) has previously been shown to cause an increase in strength and a decrease in hyperexcitability of the tibialis anterior muscle. Objective: In this proof-of-principle study our objective was to test the hypothesis that noninvasive repetitive transcranial magnetic stimulation of the primary motor cortex (M1) with a new portable wearable multifocal stimulator causes improvement in muscle function in DM1 patients. Methods: We performed repetitive stimulation of M1, localized by magnetic resonance imaging, with a newly developed Transcranial Rotating Permanent Magnet Stimulator (TRPMS). Using a randomized within-patient placebo-controlled double-blind TRPMS protocol, we performed unilateral active stimulation along with contralateral sham stimulation every weekday for two weeks in 6 adults. Methods for evaluation of muscle function involved electromyography (EMG), hand dynamometry and clinical assessment using the Medical Research Council scale. Results: All participants tolerated the treatment well. While there were no significant changes clinically, EMG showed significant improvement in nerve stimulus-evoked compound muscle action potential amplitude of the first dorsal interosseous muscle and a similar but non-significant trend in the trapezius muscle, after a short exercise test, with active but not sham stimulation. Conclusions: We conclude that two-week repeated multifocal cortical stimulation with a new wearable transcranial magnetic stimulator can be safely conducted in DM1 patients to investigate potential improvement of muscle strength and activity. The results obtained, if confirmed and extended by future safety and efficacy trials with larger patient samples, could offer a potential supportive TRPMS treatment in DM1.

The effect of transcranial magnetic stimulation on the excitability of the motor neuron pools of the muscles of the lower extremities

2021 ◽  
Author(s):  
S.S. Ananiev ◽  
D.A. Pavlov ◽  
R.N. Yakupov ◽  
V.A. Golodnova ◽  
M.V. Balykin
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Lower Extremities ◽  
Transcutaneous Electrical Stimulation ◽  
Stimulation Of

The study was conducted on 22 healthy men aged 18-23 years. The primary motor cortex innervating the lower limb was stimulated with transcranial magnetic stimulation. Using transcutaneous electrical stimulation of the spinal cord, evoked motor responses of the muscles of the lower extremities were initiated when electrodes were applied cutaneous between the spinous processes in the Th11-Th12 projection. Research protocol: Determination of the thresholds of BMO of the muscles of the lower extremities during TESCS; determination of the BMO threshold of the TA muscle in TMS; determination of the thresholds of the BMO of the muscles of the lower extremities during TESCS against the background of 80% and 90% TMS. It was found that magnetic stimulation of the motor cortex of the brain leads to an increase in the excitability of the neural structures of the lumbar thickening of the spinal cord and an improvement in neuromuscular interactions. Key words: transcranial magnetic stimulation, transcutaneous electrical stimulation of the spinal cord, neural networks, excitability, neuromuscular interactions.

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