scholarly journals The Number or Type of Stimuli Used for Somatosensory Stimulation Affected the Modulation of Corticospinal Excitability

2021 ◽  
Vol 11 (11) ◽  
pp. 1494
Author(s):  
Sho Kojima ◽  
Shota Miyaguchi ◽  
Hirotake Yokota ◽  
Kei Saito ◽  
Yasuto Inukai ◽  
...  
Keyword(s):  
Interstimulus Interval ◽  
Magnetic Stimulation ◽  
Tactile Stimulation ◽  
Motor Evoked Potentials ◽  
Cortical Activity ◽  
Conditioning Stimulation ◽  
Somatosensory Stimulation ◽  
Afferent Inhibition ◽  
Somatosensory Stimulus ◽  
Conditioning Stimuli

Motor evoked potentials (MEPs) evoked by transcranial magnetic stimulation (TMS) a few milliseconds after this cortical activity following electrical stimulation (ES) result in an inhibition comparable to that by TMS alone; this is called short-latency afferent inhibition (SAI). Cortical activity is observed after mechanical tactile stimulation (MS) and is affected by the number of stimuli by ES. We determined the effects of somatosensory stimulus methods and multiple conditioning stimuli on SAI in 19 participants. In experiment 1, the interstimulus intervals between the conditioning stimulation and TMS were 25, 27 and 29 ms for ES and 28, 30 and 32 ms for MS. In experiment 2, we used 1, 2, 3 and 4 conditioning stimulations of ES and MS. The interstimulus interval between the ES or MS and TMS was 27 or 30 ms, respectively. In experiment 1, MEPs were significantly decreased in both the ES and MS conditions. In experiment 2, MEPs after ES were significantly decreased in all conditions. Conversely, MEPs after MS were significantly decreased after one stimulus and increased after four stimulations, indicating the SAI according to the number of stimuli. Therefore, the somatosensory stimulus methods and multiple conditioning stimuli affected the SAI.

scholarly journals Impact of the number of conditioning pulses on motor cortex excitability: a transcranial magnetic stimulation study

2020 ◽  
Author(s):  
Petyo Nikolov ◽  
Johanna V. Zimmermann ◽  
Shady S. Hassan ◽  
Philipp Albrecht ◽  
Alfons Schnitzler ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Healthy Subjects ◽  
Magnetic Stimulation ◽  
Primary Motor Cortex ◽  
Motor Evoked Potentials ◽  
Conditioning Stimulus ◽  
Threshold Test ◽  
Motor Cortex Excitability ◽  
Conditioning Stimuli

AbstractConditioning transcranial magnetic stimulation (TMS) with subthreshold conditioning stimulus followed by supra-threshold test stimulus at inter-stimulus intervals (ISI) of 1–5 ms results in inhibition (SICI), while ISI at 10–15 ms results in facilitation (ICF). One concerning issue, applying ICF/SICI protocols on patients is the substantial protocol variability. Here, we hypothesized that increasing the number of CS could result in more robust ICF/SICI protocols. Twenty healthy subjects participated in the study. Motor-evoked potentials (MEP) were obtained from conditioning TMS with a varying number of conditioning stimuli in 3, 4, 10, and 15 ms ISI over the primary motor cortex. MEP amplitudes were then compared to examine excitability. TMS with 3, 5, and 7 conditioning stimuli but not with one conditioning stimulus induced ICF. Moreover, 10 ms ISI produced stronger ICF than 15 ms ISI. Significant SICI was only induced with one conditioning stimulus. Besides, 3 ms ISI resulted in stronger SICI than 4 ms ISI. Only a train of conditioning stimuli induced stable ICF and may be more advantageous than the classical paired pulse ICF paradigm.

scholarly journals The effects of mechanical tactile stimulation on corticospinal excitability and motor function depend on pin protrusion patterns

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sho Kojima ◽  
Shota Miyaguchi ◽  
Ryoki Sasaki ◽  
Shota Tsuiki ◽  
Kei Saito ◽  
...  
Keyword(s):  
Motor Function ◽  
Tactile Stimulation ◽  
Index Finger ◽  
Motor Evoked Potentials ◽  
Corticospinal Excitability ◽  
Somatosensory Stimulation ◽  
Left And Right ◽  
The Right ◽  
Single Blind ◽  
Finger Pad

Abstract Somatosensory stimulation modulates corticospinal excitability. Mechanical tactile stimulation (MS) activates cortical activity depending on tactile stimulation patterns. In this study, we examined whether the effects of mechanical tactile stimulation on corticospinal excitability and motor function depend on different pin protrusions patterns. This single-blind study included 18 healthy subjects. Two types of MS interventions were used: repetitive global stimulus (RGS) intervention was used to stimulate the finger by using 24 pins installed on a finger pad, and sequential stepwise displacement stimulus (SSDS) intervention was used to stimulate the finger by moving a row of 6 pins between the left and right sides on the finger pad. MS interventions were applied to the right index finger for 20 min (stim on/stim off, 1 s/5 s) at a frequency of 20 Hz. After RGS intervention, motor evoked potentials (MEPs) by transcranial magnetic stimulation were observed to be significantly smaller than pre-intervention MEPs; however, motor function using the grooved pegboard task remained unchanged. After SSDS intervention, MEPs were significantly larger and motor function significantly improved compared with pre-intervention values. Our results demonstrated that MS intervention can modulate corticospinal excitability and motor function and that the effects of MS intervention depend on MS intervention patterns.

scholarly journals Reliability of diaphragmatic motor-evoked potentials induced by transcranial magnetic stimulation

2020 ◽  
Vol 129 (6) ◽  
pp. 1393-1404
Author(s):  
Joseph F. Welch ◽  
Patrick J. Argento ◽  
Gordon S. Mitchell ◽  
Emily J. Fox
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Evoked Potentials ◽  
Magnetic Stimulation ◽  
Motor Evoked Potentials ◽  
Surface Emg ◽  
Noninvasive Technique ◽  
Large Variability ◽  
Adult Men ◽  
Latency Duration ◽  
Excellent Reproducibility

Transcranial magnetic stimulation (TMS) is a noninvasive technique to assess neural impulse conduction along the cortico-diaphragmatic pathway. The reliability of diaphragm motor-evoked potentials (MEP) induced by TMS is unknown. Notwithstanding large variability in MEP amplitude, we found good-to-excellent reproducibility of all MEP characteristics (latency, duration, amplitude, and area) both within- and between-day in healthy adult men and women. Our findings support the use of TMS and surface EMG to assess diaphragm activation in humans.

scholarly journals Intracortical and Intercortical Motor Disinhibition to Transcranial Magnetic Stimulation in Newly Diagnosed Celiac Disease Patients

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1530
Author(s):  
Francesco Fisicaro ◽  
Giuseppe Lanza ◽  
Carmela Cinzia D’Agate ◽  
Raffaele Ferri ◽  
Mariagiovanna Cantone ◽  
...  
Keyword(s):  
Celiac Disease ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Rating Scale ◽  
De Novo ◽  
Motor Evoked Potentials ◽  
Silent Period ◽  
Cross Sectional ◽  
Transcallosal Inhibition ◽  
Resting Motor Threshold

Background: Celiac disease (CD) may present or be complicated by neurological and neuropsychiatric manifestations. Transcranial magnetic stimulation (TMS) probes brain excitability non-invasively, also preclinically. We previously demonstrated an intracortical motor disinhibition and hyperfacilitation in de novo CD patients, which revert back after a long-term gluten-free diet (GFD). In this cross-sectional study, we explored the interhemispheric excitability by transcallosal inhibition, which has never been investigated in CD. Methods: A total of 15 right-handed de novo, neurologically asymptomatic, CD patients and 15 age-matched healthy controls were screened for cognitive and depressive symptoms to the Montreal Cognitive Assessment (MoCA) and the 17-item Hamilton Depression Rating Scale (HDRS), respectively. TMS consisted of resting motor threshold, amplitude, latency, and duration of the motor evoked potentials, duration and latency of the contralateral silent period (cSP). Transcallosal inhibition was evaluated as duration and latency of the ipsilateral silent period (iSP). Results: MoCA and HDRS scored significantly worse in patients. The iSP and cSP were significantly shorter in duration in patients, with a positive correlation between the MoCA and iSP. Conclusions: An intracortical and interhemispheric motor disinhibition was observed in CD, suggesting the involvement of GABA-mediated cortical and callosal circuitries. Further studies correlating clinical, TMS, and neuroimaging data are needed.

Increased corticospinal excitability prior to arm cycling is due to enhanced supraspinal but not spinal motoneurone excitability

2013 ◽  
Vol 38 (11) ◽  
pp. 1154-1161 ◽  
Author(s):  
Kevin E. Power ◽  
David B. Copithorne
Keyword(s):  
Magnetic Stimulation ◽  
Corticospinal Tract ◽  
Biceps Brachii ◽  
Motor Evoked Potentials ◽  
Corticospinal Excitability ◽  
Quiescent State ◽  
M Wave ◽  
Arm Cycling ◽  
Intention To Move ◽  
Stimulation Of

Human studies have not assessed supraspinal or spinal motoneurone excitability in the quiescent state prior to a rhythmic and alternating cyclical motor output. The purpose of the current study was to determine whether supraspinal and (or) spinal motoneurone excitability was modulated in humans prior to arm cycling when compared with rest with no intention to move. We hypothesized that corticospinal excitability would be enhanced prior to arm cycling due, in part, to increased spinal motoneurone excitability. Supraspinal and spinal motoneurone excitability were assessed via transcranial magnetic stimulation (TMS) of the motor cortex and transmastoid stimulation of the corticospinal tract, respectively. Surface electromyography recordings of TMS motor evoked potentials (MEPs) and cervicomedullary MEPs (CMEPs) were made from the relaxed biceps brachii muscle prior to rhythmic arm cycling and at rest with no intention to move. The amplitude of the MEPs was greater (mean increase: +9.8% of maximal M wave; p = 0.006) and their onset latencies were shorter (mean decrease: –1.5 ms; p < 0.05) prior to cycling when compared with rest. The amplitudes of the CMEPs at any of 3 stimulation intensities were not different between conditions. We conclude that premovement enhancement of corticospinal excitability is greater prior to arm cycling than at rest because of increases in supraspinal but not spinal motoneurone excitability.

scholarly journals Hand Motor Recovery after Stroke: A Transcranial Magnetic Stimulation Mapping Study of Motor Output Areas and Their Relation to Functional Status

2002 ◽  
Vol 16 (3) ◽  
pp. 275-282 ◽  
Author(s):  
Eric P. Bastings ◽  
Jason P. Greenberg ◽  
David C. Good
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Surface Area ◽  
Magnetic Stimulation ◽  
Motor Evoked Potentials ◽  
Motor Recovery ◽  
Motor Output ◽  
Motor Abilities ◽  
Cortical Motor ◽  
Motor Outcome ◽  
Large Motor

The respective contributions of the stroke and undamaged hemispheres to motor recovery after stroke remains controversial. The aim of this article is to evaluate the relationship between location and size of cortical motor areas and outcome after stroke. Twelve controls and 12 stroke patients were studied. Hand cortical motor output areas were determined using transcranial magnetic stimulation. Motor-evoked potentials were recorded simultaneously from both hands. Functional motor abilities were evaluated using well-validated measures. Surface area, weighted surface area, and center of gravity of motor output areas were calculated. Different patterns of motor output areas to the paretic hand were observed; there was no motor output from the stroke hemisphere in patients with poor outcome, contrasting to large motor output area in the stroke hemisphere in patients with good outcome, regardless of infarct size or location. A significant correlation was found between measures of motor outcome in the stroke-affected upper extremity and both the surface area and weight of the central motor output area in the stroke hemisphere. No ipsilateral motor response was obtained after stimulation of either hemisphere. These data support an association between preservation of cortical motor output area to the paretic hand in the stroke hemisphere and good motor outcome.

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