The effect of transcranial random noise stimulation on corticospinal excitability and motor performance

doi:10.1016/j.neulet.2019.04.049

Neuroscience Letters

Volume 705, 13 July 2019, Pages 138-142

https://doi.org/10.1016/j.neulet.2019.04.049 Get rights and content

Highlights

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We examined the effect of tRNS on the corticospinal excitability and motor performance.
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Corticospinal excitability was increased immediately after tRNS intervention.
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Visuomotor performance improved 10 min after tRNS intervention.
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Subjects with lower motor performance may be more likely to benefit from tRNS.
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We revealed that tRNS is effective not only for cortical excitability but also for motor performance.

Abstract

Although transcranial random noise stimulation (tRNS) over the primary motor cortex (M1) region can be used to enhance cortical excitability, it remains unclear whether tRNS over the M1 region improves motor performance. The present study aims to clarify the effect of tRNS on both corticospinal excitability and motor performance. We applied tRNS at the frequency range of 0.1–640 Hz over the left M1 for 10 min to 16 healthy adults. All subjects were tested in the following two interventions: (1) tRNS condition and (2) sham condition. Motor evoked potential (MEP) amplitudes were recorded from the right first dorsal interosseous muscle by transcranial magnetic stimulation. The motor performance was evaluated using a visuomotor tracking task by isometric abduction motion of the right index finger. MEP amplitudes and motor performance were measured before intervention, immediately after and 10 min after the intervention. The two interventions (tRNS and sham) were randomly performed separated by a break of at least 1 week. In the tRNS condition, MEP amplitudes were significantly increased immediately and 10 min after the intervention, while the motor performance was significantly improved 10 min after the intervention. The present study revealed that tRNS over the M1 region is effective for cortical excitability as well as for motor performance.

Introduction

Transcranial electric stimulation (tES) is a noninvasive brain stimulation (NIBS) technique that can alter the excitability of the cerebral cortex [16] and is applied as a rehabilitation tool for patients with stroke. Numerous studies have been conducted using transcranial direct current stimulation (tDCS), a typical tES method. Anodal tDCS for 10 min was reported to increase the primary motor cortex (M1) excitability [9] and to improve the motor performance [2,8]. However, a recent study suggests that the effect of tDCS varies and a stable effect is difficult to obtain [15]. A new tES method, transcranial random noise stimulation (tRNS), is highly effective for increasing cortical excitability. tRNS employs an alternating current stimulation ranging between 0.1 Hz and 640 Hz or 100 and 640 Hz. Terney et al. (2008) reported that the corticospinal excitability increase are lasting 60 min after tRNS stimulation over the M1 region at 1.0 mA for 10 min [13]. Inukai et al. (2016) demonstrated that tRNS increases the corticospinal excitability in a more stable way than anodal tDCS [6]. In addition, Prichard et al. (2014) reported that motor performance was improved after applying tRNS during motor tasks [10]. tRNS might improve motor performance as tRNS increases cortical excitability like tDCS but this remains to be clarified. The aim of the present study is to evaluate the influence of tRNS independent intervention on the M1 region with respect to corticospinal excitability and motor performance.

Section snippets

Subjects

The study included 16 right-handed adults (12 males, 4 females; average ± standard deviation = 21.0 ± 0.35 years old) without neurological disease. All subject, after being fully informed on the study goals and assessments, provided a written consent to participate in this study. This study was conducted in accordance with the principles of the Declaration of Helsinki and was approved by the ethics committee of Niigata University of Health and Welfare.

Transcranial random noise stimulation (tRNS)

tRNS was delivered using a DC-STIMULATOR

MEP amplitude

Two-way repeated-measures ANOVA revealed a significant stimulus condition × time interaction (F_{(3, 29)} = 8.41, p < 0.01 partial η2 = 0.359) and the main effect of the stimulus condition factor (F_{(1, 15)} = 15.04, p < 0.01, partial η2 = 0.403). No significant difference was found the main effect of time factor (F_{(2, 30)} = 3.27, p = 0.73, partial η2 = 0.247). In the tRNS condition, post hoc analyses showed that the MEP amplitudes at post-0 min (p < 0.05) and post-10 min (p < 0.05) were

Discussion

This study investigated whether tRNS over the M1 region does affect corticospinal excitability and motor performance. We demonstrated that the corticospinal excitability is increased starting immediately after tRNS intervention, and the motor performance is improved at 10 min after tRNS intervention. Therefore, tRNS over the M1 region shows efficacy in increasing corticospinal excitability and improving motor performance.

tRNS at 1.0 mA for 10 min increased the MEP amplitude immediately after

Conclusions

This study demonstrated that the tRNS over the M1 region in healthy subject increases the corticospinal excitability and contributes to the improvement of motor performance.

Funding sources

This work was supported by a Grant-in-Aid for Young Scientists (B) 17K13073 from the Japan Society for the Promotion of Science.

Conflicts of interest

All authors report no conflict of interest.

Acknowledgement

The authors would like to thank Enago (www.enago.jp) for the English language review.

References (16)

A. Bastani et al.
a-tDCS differential modulation of corticospinal excitability: the effects of electrode size
Brain Stimul.
(2013)
P.S. Boggio et al.
Enhancement of non-dominant hand motor function by anodal transcranial direct current stimulation
Neurosci. Lett.
(2006)
G. Prichard et al.
Effects of different electrical brain stimulation protocols on subcomponents of motor skill learning
Brain Stimul.
(2014)
S. Wiethoff et al.
Variability in response to transcranial direct current stimulation of the motor cortex
Brain Stimul.
(2014)
A.J. Woods et al.
A technical guide to tDCS, and related non-invasive brain stimulation tools
Clin. Neurophysiol.
(2016)
L. Chaieb et al.
Transcranial random noise stimulation-induced plasticity is NMDA-receptor independent but sodium-channel blocker and benzodiazepines sensitive
Front. Neurosci.
(2015)
J.M. Galea et al.
Brain polarization enhances the formation and retention of motor memories
J. Neurophysiol.
(2009)
J.M. Galea et al.
Dissociating the roles of the cerebellum and motor cortex during adaptive learning: the motor cortex retains what the cerebellum learns
Cereb. Cortex
(2011)

There are more references available in the full text version of this article.

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The dorsolateral prefrontal cortex (DLPFC) plays a key role in tactile perceptual discrimination performance. Both transcranial random noise stimulation (tRNS) and anodal transcranial pulsed current stimulation (tPCS) have been shown to modulate neural activity in cortical regions. In this study, we aimed to determine whether tRNS and anodal tPCS over the left DLPFC would improve tactile perceptual discrimination performance of the right index finger in healthy neurological individuals. Subjects underwent a grating orientation task before, immediately after, and 30 min after applying tRNS in Experiment 1 or anodal tPCS in Experiment 2. tRNS application on the left DLPFC tended to enhance tactile perceptual discrimination performance. In contrast, the application of anodal tPCS over the left DLPFC did not affect tactile perceptual discrimination performance. These findings indicate that transcranial electrical stimulation to the left DLPFC may improve tactile perceptual discrimination performance, with effects that depend on stimulus modality.
The effects of transcranial random noise stimulation on motor function: A comprehensive review of the literature
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The present review considers all papers published on the topic up to the end of the year 2022. Transcranial random noise stimulation (tRNS) is a non-invasive neuromodulation technique introduced about 15 years ago whose use is becoming increasingly widespread in neuroscience. It consists of the application over the scalp of a weak, white noise-like current, through electrodes having a surface of several square centimetres, for a duration ranging from seconds to minutes. Despite its relatively low spatial and temporal resolution, tRNS has well defined effects on central motor excitability, which critically depend on stimulation parameters. These effects seem to be chiefly based on an effect on neuronal membrane sodium channels and can last much longer than the stimulation itself. While the effects at the cellular level in the motor cortex are becoming progressively clear, much more studies are needed to understand the effects of tRNS on motor behaviour and performance, where initial research results are nevertheless promising, in both basic and applied research.
Effect of Transcranial Electrical Stimulation over the Posterior Parietal Cortex on Tactile Spatial Discrimination Performance
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The intraparietal sulcus region, which is part of the posterior parietal cortex (PPC), has been shown to play an important role in discriminating object shapes using the fingers. Transcranial random noise stimulation (tRNS) and anodal transcranial pulsed current stimulation (tPCS) are noninvasive strategies widely used to modulate neural activity in cortical regions. Therefore, we investigated the effects of tRNS and anodal tPCS applied to left or right PPC on the tactile discrimination performance of the right index finger in 20 neurologically healthy subjects. A grating orientation task (GOT) was performed before and immediately after delivering tRNS (stimulus frequency 0.1–640 Hz) in Experiment 1 or anodal tPCS (pulse width 50 ms and inter-pulse interval 5 ms) in Experiment 2. Performing tRNS over the right PPC significantly improved discrimination performance on the GOT. Subjects were classified into low and high baseline performance groups. Conducting tRNS over the left PPC significantly reduced the GOT discrimination performance in the high-performance group. By contrast, anodal tPCS delivered to the PPC of the left and right hemispheres had no significant effect on the tactile GOT discrimination performance of the right hand. We show that transcranial electric stimulation over the PPC may improve tactile perception but the effect depends on stimulus modality, parameters, and on the stimulated hemisphere.
Transcranial direct current stimulation and transcranial random noise stimulation over the cerebellum differentially affect the cerebellum and primary motor cortex pathway
2022, Journal of Clinical Neuroscience
Transcranial direct current stimulation (tDCS) and transcranial random noise stimulation (tRNS) are two methods of noninvasively modulating cortical excitability below the placed electrode. Anodal tDCS over the cerebellum has been shown to modulate cerebellar brain inhibition (CBI), which is an indication of cerebellar excitability, but does not alter contralateral M1 excitability. However, the effect of tRNS over the cerebellum has not been investigated. The purpose of this study was thus to compare the effects of tDCS and tRNS over the cerebellum on CBI and the contralateral motor evoked potentials (MEPs), as well as on the relationship between CBI and contralateral MEPs. A total of 15 healthy subjects completed four-condition transcranial electrical stimulation (tES) interventions (anodal tDCS_1 mA, anodal tDCS_2 mA, tRNS, and Sham) on separate days. CBI and MEPs were measured using transcranial magnetic stimulation (TMS) before and after the 20 min tES intervention. For all conditions, there were no significant differences before and after tES in CBI or contralateral MEPs. In contrast, following tRNS, changes in CBI and MEPs were significantly correlated. No significant correlations were found in the other three conditions, indicating that cerebellar tDCS and tRNS have distinct effects on the relationship between CBI and contralateral MEPs. Taken together, these findings suggest that cerebellar tRNS may modulate the cerebellar to contralateral M1 pathway.
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Citation Excerpt :
The peak-to-peak amplitudes (mV) of the MEPs were measured offline. The mean of 10 MEP amplitudes was calculated after excluding the largest and smallest values of each MEP assessment [23–25]. Before the statistical analysis, all data sets were checked for normal distributions using the Shapiro–Wilk test.
Repetitive peripheral magnetic stimulation (rPMS) induces proprioceptive afferents and facilitates corticospinal excitability. Short-term sessions of rPMS combined with motor imagery (MI) enhance corticospinal excitability more than rPMS alone. However, it is not clear how long the intervention of rPMS combined with MI would be needed to facilitate corticospinal excitability. Therefore, we investigated the time course change in corticospinal excitability during the combination of rPMS and MI. Thirteen healthy volunteers participated in a 20-min intervention under the following three experimental conditions on different days: rPMS, MI, and rPMS combined with MI (rPMS + MI). In the rPMS and rPMS + MI, the participants were delivered rPMS, which was 25 Hz, 2 s/train at 1.5 × of the train intensity induced muscle contractions, through the wrist extensor muscles. In the MI and rPMS + MI, the participants repeatedly imagined wrist movements for 2 s. Motor evoked potentials (MEPs) were recorded from the extensor carpi radialis (ECR) and flexor carpi radialis (FCR) muscles every 5 min for each condition. The MEP amplitudes of the ECR after > 10 min of intermittent rPMS combined with MI were greater than baseline. The MEP amplitude of the ECR in rPMS + MI was greater than that in rPMS condition after 20 min of intervention. The present results suggest that over 10 min of intermittent rPMS combined with MI facilitates corticospinal excitability, and that the effect of rPMS combined with MI on corticospinal excitability might be greater than that of rPMS alone.
Effects of transcranial random noise stimulation timing on corticospinal excitability and motor function
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Citation Excerpt :
However, regarding the dissociation between changes in motor function and MEP amplitude observed in this study, previous studies have reported that the wider the frequency bands used for tRNS, the greater the increase in corticospinal excitability [42]. Furthermore, several previous studies investigating the effects of tRNS on corticospinal excitability reported that all-frequency band tRNS increase corticospinal excitability more than that in the sham condition [17,19,20]. These reports suggest that all-frequency band tRNS may be most effective in increasing corticospinal excitability and that the optimal frequency bands for tRNS vary for improving corticospinal excitability and motor function.
Although transcranial random noise stimulation (tRNS) to the primary motor cortex (M1) increases corticospinal excitability and improves motor function, the effects of tRNS timing have not been clarified when combined with motor training. The purpose of this study was to clarify the effects of different tRNS timing on corticospinal excitability and motor function. We applied tRNS to the left M1 using a frequency of 0.1–640 Hz for 10 min to 15 healthy subjects. Subjects performed visuomotor tracking tasks with right hand for 10 min and participated in the following four conditions based on the timing of tRNS: (1) “before” condition, tRNS was performed before motor training; (2) “during” condition, tRNS was performed during motor training; (3) “after” condition, tRNS was performed after motor training; and (4) sham condition, the control group. Motor evoked potential (MEP) amplitudes were recorded from the right first dorsal interosseous muscle using transcranial magnetic stimulation. MEP amplitudes were assessed by baseline followed by three sessions at 10 min intervals. The motor function was assessed before and after tRNS and motor training. The MEP amplitude increased after tRNS in the before and during conditions but not in the after condition. Motor function after motor training improved in all conditions, but there were no significant differences between these conditions. The present study revealed that the timing of tRNS affects corticospinal excitability but not motor learning.

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Research articleThe effect of transcranial random noise stimulation on corticospinal excitability and motor performance

Highlights

Abstract

Introduction

Section snippets

Subjects

Transcranial random noise stimulation (tRNS)

MEP amplitude

Discussion

Conclusions

Funding sources

Conflicts of interest

Acknowledgement

Brain Stimul.

Neurosci. Lett.

Brain Stimul.

Brain Stimul.

Clin. Neurophysiol.

Transcranial random noise stimulation-induced plasticity is NMDA-receptor independent but sodium-channel blocker and benzodiazepines sensitive

Front. Neurosci.

Brain polarization enhances the formation and retention of motor memories

J. Neurophysiol.

Dissociating the roles of the cerebellum and motor cortex during adaptive learning: the motor cortex retains what the cerebellum learns

Cereb. Cortex

Research article
The effect of transcranial random noise stimulation on corticospinal excitability and motor performance