Single Pulse Stimulation of the Human Subthalamic Nucleus Facilitates the Motor Cortex at Short Intervals

2004 ◽  
Vol 92 (3) ◽  
pp. 1937-1943 ◽  
Author(s):  
Ritsuko Hanajima ◽  
Peter Ashby ◽  
Andres M. Lozano ◽  
Anthony E. Lang ◽  
Robert Chen
Keyword(s):  
Motor Cortex ◽  
Subthalamic Nucleus ◽  
Motor Evoked Potential ◽  
Single Pulse ◽  
Internal Globus Pallidus ◽  
Motor Cortex Excitability ◽  
Motor Cortical ◽  
Stn Dbs ◽  
Pulse Stimulation ◽  
Anterior Posterior

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for Parkinson's disease (PD). The mechanism is poorly understood. High-frequency STN DBS has been reported to affect motor cortex excitability in a complex way, but the timing between STN stimuli and changes in motor cortical (M1) excitability has not been investigated. We examined the time course of changes in motor cortical excitability following single pulse STN DBS. We studied 14 PD patients with implanted DBS electrodes in the STN, 2 patients with electrodes in internal globus pallidus (GPi), and 1 patient with an electrode in the sensory thalamus. Transcranial magnetic stimulation (TMS) was delivered to the M1 ipsilateral to the DBS with induced currents either in the anterior-posterior direction in the brain to evoke indirect (I) waves or in the lateral-medial direction to activate corticospinal axons directly. Single pulse stimulation through the DBS contacts preceded the TMS by 0–10 ms. Surface EMG was recorded from the contralateral first dorsal interosseous muscle. Three milliseconds after STN stimulation, the motor evoked potential (MEP) amplitudes produced by anterior-posterior current were significantly larger than control responses, while the responses to lateral-medial currents were unchanged. Similar facilitation also occurred after GPi stimulation, but not with thalamic stimulation. Single pulse STN stimulation facilitates the M1 at short latencies. The possible mechanisms include antidromic excitation of the cortico-STN fibers or transmission through the basal ganglia-thalamocortical pathway.

scholarly journals Systematic examination of low-intensity ultrasound parameters on human motor cortex excitability and behavior

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Anton Fomenko ◽  
Kai-Hsiang Stanley Chen ◽  
Jean-François Nankoo ◽  
James Saravanamuttu ◽  
Yanqiu Wang ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Short Interval ◽  
Motor Evoked Potential ◽  
Cortical Inhibition ◽  
Transcranial Ultrasound ◽  
Human Motor Cortex ◽  
Low Intensity ◽  
Visuomotor Task ◽  
Motor Cortex Excitability ◽  
And Behavior

Low-intensity transcranial ultrasound (TUS) can non-invasively modulate human neural activity. We investigated how different fundamental sonication parameters influence the effects of TUS on the motor cortex (M1) of 16 healthy subjects by probing cortico-cortical excitability and behavior. A low-intensity 500 kHz TUS transducer was coupled to a transcranial magnetic stimulation (TMS) coil. TMS was delivered 10 ms before the end of TUS to the left M1 hotspot of the first dorsal interosseous muscle. Varying acoustic parameters (pulse repetition frequency, duty cycle, and sonication duration) on motor-evoked potential amplitude were examined. Paired-pulse measures of cortical inhibition and facilitation, and performance on a visuomotor task was also assessed. TUS safely suppressed TMS-elicited motor cortical activity, with longer sonication durations and shorter duty cycles when delivered in a blocked paradigm. TUS increased GABAA-mediated short-interval intracortical inhibition and decreased reaction time on visuomotor task but not when controlled with TUS at near-somatosensory threshold intensity.

scholarly journals Chronic low-frequency rTMS of primary motor cortex diminishes exercise training-induced gains in maximal voluntary force in humans

2009 ◽  
Vol 106 (2) ◽  
pp. 403-411 ◽  
Author(s):  
Tibor Hortobágyi ◽  
Sarah Pirio Richardson ◽  
Mikhael Lomarev ◽  
Ejaz Shamim ◽  
Sabine Meunier ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Low Frequency ◽  
Motor Evoked Potential ◽  
Single Pulse ◽  
Compound Action Potential ◽  
Voluntary Contraction ◽  
Maximal Voluntary Force ◽  
Resting Motor Threshold

Although there is consensus that the central nervous system mediates the increases in maximal voluntary force (maximal voluntary contraction, MVC) produced by resistance exercise, the involvement of the primary motor cortex (M1) in these processes remains controversial. We hypothesized that 1-Hz repetitive transcranial magnetic stimulation (rTMS) of M1 during resistance training would diminish strength gains. Forty subjects were divided equally into five groups. Subjects voluntarily (Vol) abducted the first dorsal interosseus (FDI) (5 bouts × 10 repetitions, 10 sessions, 4 wk) at 70–80% MVC. Another group also exercised but in the 1-min-long interbout rest intervals they received rTMS [Vol+rTMS, 1 Hz, FDI motor area, 300 pulses/session, 120% of the resting motor threshold (rMT)]. The third group also exercised and received sham rTMS (Vol+Sham). The fourth group received only rTMS (rTMS_only). The 37.5% and 33.3% gains in MVC in Vol and Vol+Sham groups, respectively, were greater ( P = 0.001) than the 18.9% gain in Vol+rTMS, 1.9% in rTMS_only, and 2.6% in unexercised control subjects who received no stimulation. Acutely, within sessions 5 and 10, single-pulse TMS revealed that motor-evoked potential size and recruitment curve slopes were reduced in Vol+rTMS and rTMS_only groups and accumulated to chronic reductions by session 10. There were no changes in rMT, maximum compound action potential amplitude (Mmax), and peripherally evoked twitch forces in the trained FDI and the untrained abductor digiti minimi. Although contributions from spinal sources cannot be excluded, the data suggest that M1 may play a role in mediating neural adaptations to strength training.

scholarly journals Primary Motor Cortex Excitability Is Modulated During the Mental Simulation of Hand Movement

2017 ◽  
Vol 23 (2) ◽  
pp. 185-193 ◽  
Author(s):  
Christian Hyde ◽  
Ian Fuelscher ◽  
Jarrad A.G. Lum ◽  
Jacqueline Williams ◽  
Jason He ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Motor Evoked Potentials ◽  
Hand Movement ◽  
Single Pulse ◽  
Stimulus Presentation ◽  
Mental Simulation ◽  
Right Hand ◽  
Hand Laterality ◽  
Motor Cortex Excitability

AbstractObjectives:It is unclear whether the primary motor cortex (PMC) is involved in the mental simulation of movement [i.e., motor imagery (MI)]. The present study aimed to clarify PMC involvement using a highly novel adaptation of the hand laterality task (HLT).Methods:Participants were administered single-pulse transcranial magnetic stimulation (TMS) to the hand area of the left PMC (hPMC) at either 50 ms, 400 ms, or 650 ms post stimulus presentation. Motor-evoked potentials (MEPs) were recorded from the right first dorsal interosseous via electromyography. To avoid the confound of gross motor response, participant response (indicating left or right hand) was recorded via eye tracking. Participants were 22 healthy adults (18 to 36 years), 16 whose behavioral profile on the HLT was consistent with the use of a MI strategy (MI users).Results:hPMC excitability increased significantly during HLT performance for MI users, evidenced by significantly larger right hand MEPs following single-pulse TMS 50 ms, 400 ms, and 650 ms post stimulus presentation relative to baseline. Subsequent analysis showed that hPMC excitability was greater for more complex simulated hand movements, where hand MEPs at 50 ms were larger for biomechanically awkward movements (i.e., hands requiring lateral rotation) compared to simpler movements (i.e., hands requiring medial rotation).Conclusions:These findings provide support for the modulation of PMC excitability during the HLT attributable to MI, and may indicate a role for the PMC during MI. (JINS, 2017,23, 185–193)

Paired-pulse measures

2012 ◽  
Author(s):  
Ritsuko Hanajima ◽  
Yoshikazu Ugawa
Keyword(s):  
Motor Cortex ◽  
Cortical Excitability ◽  
Motor Evoked Potential ◽  
Paired Pulse ◽  
Motor Cortical Excitability ◽  
Interhemispheric Connectivity ◽  
Conditioned Motor ◽  
Human Motor ◽  
Motor Cortical ◽  
Insight Into

This article reviews the physiology and application of the currently available paired-pulse protocols. Paired-pulse transcranial magnetic stimulation (TMS) techniques study the modulation of human motor cortical excitability. Paired-pulse experiments are designed to give insight into the nature of the cortical circuitry activated by TMS. Changes in motor cortical excitability produced by the conditioning pulse are estimated by changes in the size of the conditioned motor-evoked potential (MEP). It is possible to identify specific abnormalities in the balance between inhibitory and facilitatory processes, even if the pathology lies in abnormal afferent signalling to the motor cortex rather than in the motor cortex itself. The conclusion that emerges from the studies on interhemispheric interactions is that it is now possible by means of TMS protocols to chart long-range functional interhemispheric connectivity of remote areas of the human brain.

scholarly journals Facial Motor Neuron Excitability in Hemifacial Spasm: A Facial MEP Study

2014 ◽  
Vol 41 (2) ◽  
pp. 239-245 ◽  
Author(s):  
Marshall F. Wilkinson ◽  
Anthony M. Kaufmann
Keyword(s):  
Motor Neuron ◽  
Skull Base ◽  
Hemifacial Spasm ◽  
Motor Evoked Potential ◽  
Single Pulse ◽  
Skull Base Tumor ◽  
Tumor Patients ◽  
Central Hypothesis ◽  
Motor Neuron Excitability ◽  
Pulse Stimulation

Introduction:Hemifacial spasm (HFS) may be due to peripheral axon ephapsis or central motor neuron hyperexcitability. Low facial motor evoked potential (MEP) thresholds or MEP responses to single pulse stimulation (normally multipulse stimulation is needed) may support the central hypothesis.Methods:We retrospectively compared response thresholds for facial MEPs in 65 patients undergoing surgical microvascular decompression (MVD) for HFS and 29 patients undergoing surgery for skull base tumors.Results:Single pulse stimulation elicited facial Mep in up to 87% of HFS patients whereas only 10% of tumor patients responded to single pulse stimulation. When comparing facial MEP thresholds using multi-pulse stimulus trains the voltage required in the HFS group were significantly lower then in skull base tumor patients (p < 0.001). the MEP latencies and amplitudes at threshold stimulation were similar between the two groups.Conclusions:these results suggest the facial corticobulbar pathway demonstrates enhanced excitability in HFS.

Transcranial direct current stimulation effects on I-wave activity in humans

2011 ◽  
Vol 105 (6) ◽  
pp. 2802-2810 ◽  
Author(s):  
Nicolas Lang ◽  
Michael A. Nitsche ◽  
Michele Dileone ◽  
Paolo Mazzone ◽  
Javier De Andrés-Arés ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Cortical Neurons ◽  
Primary Motor Cortex ◽  
Motor Evoked Potential ◽  
Anodal Tdcs ◽  
Direct Current Stimulation ◽  
Cathodal Tdcs ◽  
Motor Cortex Excitability

Transcranial direct current stimulation (tDCS) of the human cerebral cortex modulates cortical excitability noninvasively in a polarity-specific manner: anodal tDCS leads to lasting facilitation and cathodal tDCS to inhibition of motor cortex excitability. To further elucidate the underlying physiological mechanisms, we recorded corticospinal volleys evoked by single-pulse transcranial magnetic stimulation of the primary motor cortex before and after a 5-min period of anodal or cathodal tDCS in eight conscious patients who had electrodes implanted in the cervical epidural space for the control of pain. The effects of anodal tDCS were evaluated in six subjects and the effects of cathodal tDCS in five subjects. Three subjects were studied with both polarities. Anodal tDCS increased the excitability of cortical circuits generating I waves in the corticospinal system, including the earliest wave (I1 wave), whereas cathodal tDCS suppressed later I waves. The motor evoked potential (MEP) amplitude changes immediately following tDCS periods were in agreement with the effects produced on intracortical circuitry. The results deliver additional evidence that tDCS changes the excitability of cortical neurons.

Effects of subthalamic nucleus stimulation on motor cortex excitability in Parkinson's disease

Neurology ◽  
2002 ◽  
Vol 58 (11) ◽  
pp. 1665-1672 ◽  
Author(s):  
D. Cunic ◽  
L. Roshan ◽  
F. I. Khan ◽  
A. M. Lozano ◽  
A. E. Lang ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Motor Cortex ◽  
Subthalamic Nucleus ◽  
Subthalamic Nucleus Stimulation ◽  
Motor Cortex Excitability

scholarly journals Response inhibition activates distinct motor cortical inhibitory processes

2018 ◽  
Vol 119 (3) ◽  
pp. 877-886 ◽  
Author(s):  
John Cirillo ◽  
Matthew J. Cowie ◽  
Hayley J. MacDonald ◽  
Winston D. Byblow
Keyword(s):  
Motor Cortex ◽  
Response Inhibition ◽  
Primary Motor Cortex ◽  
Motor Evoked Potentials ◽  
Short Interval ◽  
Left Hand ◽  
Motor Cortex Excitability ◽  
Motor Cortical ◽  
Inhibitory Tone ◽  
Inhibitory Networks

We routinely cancel preplanned movements that are no longer required. If stopping is forewarned, proactive processes are engaged to selectively decrease motor cortex excitability. However, without advance information there is a nonselective reduction in motor cortical excitability. In this study we examined modulation of human primary motor cortex inhibitory networks during response inhibition tasks with informative and uninformative cues using paired-pulse transcranial magnetic stimulation. Long- (LICI) and short-interval intracortical inhibition (SICI), indicative of GABAB- and GABAA-receptor mediated inhibition, respectively, were examined from motor evoked potentials obtained in task-relevant and task-irrelevant hand muscles when response inhibition was preceded by informative and uninformative cues. When the participants (10 men and 8 women) were cued to stop only a subcomponent of the bimanual response, the remaining response was delayed, and the extent of delay was greatest in the more reactive context, when cues were uninformative. For LICI, inhibition was reduced in both muscles during all types of response inhibition trials compared with the pre-task resting baseline. When cues were uninformative and left-hand responses were suddenly canceled, task-relevant LICI positively correlated with response times of the responding right hand. In trials where left-hand responding was highly probable or known (informative cues), task-relevant SICI was reduced compared with that when cued to rest, revealing a motor set indicative of responding. These novel findings indicate that the GABAB-receptor-mediated pathway may set a default inhibitory tone according to task context, whereas the GABAA-receptor-mediated pathways are recruited proactively with response certainty. NEW & NOTEWORTHY We examined how informative and uninformative cues that trigger both proactive and reactive processes modulate GABAergic inhibitory networks within human primary motor cortex. We show that GABAB inhibition was released during the task regardless of cue type, whereas GABAA inhibition was reduced when responding was highly probable or known compared with rest. GABAB-receptor-mediated inhibition may set a default inhibitory tone, whereas GABAA circuits may be modulated proactively according to response certainty.

Effects of internal globus pallidus stimulation on motor cortex excitability

Neurology ◽  
2002 ◽  
Vol 58 (4) ◽  
pp. 669-670 ◽  
Author(s):  
A. Gironell ◽  
J. Kulisevsky ◽  
B. P. Sedano ◽  
J. Molet ◽  
R. Chen ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Globus Pallidus ◽  
Internal Globus Pallidus ◽  
Motor Cortex Excitability

scholarly journals Recovery of the 20 Hz Rebound to Tactile and Proprioceptive Stimulation after Stroke

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Eeva Parkkonen ◽  
Kristina Laaksonen ◽  
Lauri Parkkonen ◽  
Nina Forss
Keyword(s):  
Motor Cortex ◽  
Cortical Excitability ◽  
Afferent Input ◽  
Motor Recovery ◽  
Somatosensory Stimulation ◽  
Tactile Stimuli ◽  
Potential Marker ◽  
Motor Cortex Excitability ◽  
Motor Cortical

Sensorimotor integration is closely linked to changes in motor-cortical excitability, observable in the modulation of the 20 Hz rhythm. After somatosensory stimulation, the rhythm transiently increases as a rebound that reflects motor-cortex inhibition. Stroke-induced alterations in afferent input likely affect motor-cortex excitability and motor recovery. To study the role of somatosensory afferents in motor-cortex excitability after stroke, we employed magnetoencephalographic recordings (MEG) at 1–7 days, one month, and 12 months in 23 patients with stroke in the middle cerebral artery territory and 22 healthy controls. The modulation of the 20 Hz motor-cortical rhythm was evaluated to two different somatosensory stimuli, tactile stimulation, and passive movement of the index fingers. The rebound strengths to both stimuli were diminished in the acute phase compared to the controls and increased significantly during the first month after stroke. However, only the rebound amplitudes to tactile stimuli fully recovered within the follow-up period. The rebound strengths in the affected hemisphere to both stimuli correlated strongly with the clinical scores across the follow-up. The results show that changes in the 20 Hz rebound to both stimuli behave similarly and occur predominantly during the first month. The 20 Hz rebound is a potential marker for predicting motor recovery after stroke.

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