Transcranial Electrical and Magnetic Stimulation

Author(s):  
Alexander Rotenberg ◽  
Alvaro Pascual-Leone ◽  
Alan D. Legatt

Noninvasive magnetic and electrical stimulation of cerebral cortex is an evolving field. The most widely used variant, transcranial electrical stimulation (TES), is routinely used for intraoperative monitoring. Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are emerging as clinical and experimental tools. TMS has gained wide acceptance in extraoperative functional cortical mapping. TES and TMS rely on pulsatile stimulation with electrical current intensities sufficient to trigger action potentials within the stimulated cortical volume. tDCS, in contrast, is based on neuromodulatory effects of very-low-amplitude direct current conducted through the scalp. tDCS and TMS, particularly when applied in repetitive trains, can modulate cortical excitability for prolonged periods and thus are either in active clinical use or in advanced stages of clinical trials for common neurological and psychiatric disorders such as major depression and epilepsy. This chapter summarizes physiologic principles of transcranial stimulation and clinical applications of these techniques.

2009 ◽  
Vol 110 (6) ◽  
pp. 1300-1303 ◽  
Author(s):  
Mario F. Dulay ◽  
Dona K. Murphey ◽  
Ping Sun ◽  
Yadin B. David ◽  
John H. R. Maunsell ◽  
...  

Cortical mapping with electrical stimulation (ES) in neurosurgical patients typically involves the manually controlled delivery of suprathreshold electrical current to a discrete area of the brain. Limited numbers of trials and imprecise current delivery methods increase the variability of the behavioral response and make it difficult to collect quantitative mapping data, which is especially important in research studies of human cortical function. To overcome these limitations, the authors developed a method for computer-controlled delivery of defined electrical current to implanted intracranial electrodes. They demonstrate that stimulation can be time locked to a behavioral task to rapidly and systematically measure the detection threshold for ES in human visual cortex over many trials. Computer-controlled ES is well suited for the systematic and quantitative study of the function of virtually any region of cerebral cortex. It may be especially useful for studying human cortical regions that are not well characterized and for verifying the presence of stimulation-evoked percepts that are difficult to objectively confirm.


Author(s):  
Jacky Au ◽  
Martin Buschkuehl ◽  
Susanne M. Jaeggi

The aim of this chapter is to contribute to the discussion of the cognitive neuroscience of brain stimulation. In doing so, the authors emphasize work from their own laboratory that focuses both on working memory training and transcranial direct current stimulation. Transcranial direct current stimulation is one of the most commonly used and extensively researched methods of transcranial electrical stimulation. The chapter focuses on implementation of transcranial direct current stimulation to enhance and inform research on working memory training, and not on the underlying mechanisms of transcranial direct current stimulation. Thus, while respecting the intricacies and unknowns of the inner workings of electrical stimulation on the brain, the chapter relies on the premise that transcranial direct current stimulation is able to directly affect the electrophysiological profile of the brain and provides evidence that this in turn can influence behavior given the right parameters.


1989 ◽  
Vol 100 (4) ◽  
pp. 345-347 ◽  
Author(s):  
Ian M. Windmill ◽  
Serge A. Martinez ◽  
Christopher B. Shields ◽  
Markku Paloheimo

Facial nerve stimulation by electrical current is painful and tends to discourage serial studies. Transcutaneous magnetic stimulation of the facial nerve is painless, easily reproducible, and elicits facial muscle responses identical to electrical stimulation.


2020 ◽  
Vol 123 (6) ◽  
pp. 2504-2514
Author(s):  
Kevin T. Jones ◽  
Elizabeth L. Johnson ◽  
Zoe S. Tauxe ◽  
Donald C. Rojas

Gamma frequency-tuned transcranial alternating current stimulation (tACS) adjusts the magnitude and timing of auditory gamma responses, as compared with both sham stimulation and transcranial direct current stimulation (tDCS). However, both tACS and tDCS strengthen the gamma phase connectome, which is disrupted in numerous neurological and psychiatric disorders. These findings reveal dissociable neurophysiological changes following two noninvasive neurostimulation techniques commonly applied in clinical and research settings.


2012 ◽  
Vol 107 (7) ◽  
pp. 1881-1889 ◽  
Author(s):  
Anatoli Y. Kabakov ◽  
Paul A. Muller ◽  
Alvaro Pascual-Leone ◽  
Frances E. Jensen ◽  
Alexander Rotenberg

Transcranial direct current stimulation (tDCS) is a method for modulating cortical excitability by weak constant electrical current that is applied through scalp electrodes. Although often described in terms of anodal or cathodal stimulation, depending on which scalp electrode pole is proximal to the cortical region of interest, it is the orientation of neuronal structures relative to the direct current (DC) vector that determines the effect of tDCS. To investigate the contribution of neural pathway orientation, we studied DCS-mediated neuromodulation in an in vitro rat hippocampal slice preparation. We examined the contribution of dendritic orientation to the direct current stimulation (DCS) neuromodulatory effect by recording field excitatory postsynaptic potentials (fEPSPs) in apical and basal dendrites of CA1 neurons within a constant DC field. In addition, we assessed the contribution of axonal orientation by recording CA1 and CA3 apical fEPSPs generated by stimulation of oppositely oriented Schaffer collateral and mossy fiber axons, respectively, during DCS. Finally, nonsynaptic excitatory signal propagation was measured along antidromically stimulated CA1 axons at different DCS amplitudes and polarity. We find that modulation of both the fEPSP and population spike depends on axonal orientation relative to the electric field vector. Axonal orientation determines whether the DC field is excitatory or inhibitory and dendritic orientation affects the magnitude, but not the overall direction, of the DC effect. These data suggest that tDCS may oppositely affect neurons in a stimulated cortical volume if these neurons are excited by oppositely orientated axons in a constant electrical field.


Author(s):  
J. S. A. Lee ◽  
S. Bestmann ◽  
C. Evans

Abstract Purpose of Review Transcranial electrical stimulation (tES) is used to non-invasively modulate brain activity in health and disease. Current flow modeling (CFM) provides estimates of where and how much electrical current is delivered to in the brain during tES. It therefore holds promise as a method to reduce commonplace variability in tES delivery and, in turn, the outcomes of stimulation. However, the adoption of CFM has not yet been widespread and its impact on tES outcome variability is unclear. Here, we discuss the potential barriers to effective, practical CFM-informed tES use. Recent Findings CFM has progressed from models based on concentric spheres to gyri-precise head models derived from individual MRI scans. Users can now estimate the intensity of electrical fields (E-fields), their spatial extent, and the direction of current flow in a target brain region during tES. Here. we consider the multi-dimensional challenge of implementing CFM to optimise stimulation dose: this requires informed decisions to prioritise E-field characteristics most likely to result in desired stimulation outcomes, though the physiological consequences of the modelled current flow are often unknown. Second, we address the issue of a disconnect between predictions of E-field characteristics provided by CFMs and predictions of the physiological consequences of stimulation which CFMs are not designed to address. Third, we discuss how ongoing development of CFM in conjunction with other modelling approaches could overcome these challenges while maintaining accessibility for widespread use. Summary The increasing complexity and sophistication of CFM is a mandatory step towards dose control and precise, individualised delivery of tES. However, it also risks counteracting the appeal of tES as a straightforward, cost-effective tool for neuromodulation, particularly in clinical settings.


2021 ◽  
Vol 15 ◽  
Author(s):  
Mujda Nooristani ◽  
Thomas Augereau ◽  
Karina Moïn-Darbari ◽  
Benoit-Antoine Bacon ◽  
François Champoux

The effects of transcranial electrical stimulation (tES) approaches have been widely studied for many decades in the motor field, and are well known to have a significant and consistent impact on the rehabilitation of people with motor deficits. Consequently, it can be asked whether tES could also be an effective tool for targeting and modulating plasticity in the sensory field for therapeutic purposes. Specifically, could potentiating sensitivity at the central level with tES help to compensate for sensory loss? The present review examines evidence of the impact of tES on cortical auditory excitability and its corresponding influence on auditory processing, and in particular on hearing rehabilitation. Overall, data strongly suggest that tES approaches can be an effective tool for modulating auditory plasticity. However, its specific impact on auditory processing requires further investigation before it can be considered for therapeutic purposes. Indeed, while it is clear that electrical stimulation has an effect on cortical excitability and overall auditory abilities, the directionality of these effects is puzzling. The knowledge gaps that will need to be filled are discussed.


Author(s):  
Nils-Frederic Wagner ◽  
Jeffrey Robinson ◽  
Christine Wiebking

Using cognitive enhancement technology is becoming increasingly popular. In another paper, the authors argued that using pharmacological cognitive enhancers is detrimental to society, through promoting competitiveness over cooperation, by usurping personal and social identifies and thus changing our narrative and moral character. In this chapter, the authors seek to expand that argument by looking at an emerging technology that is rapidly gaining popularity, that of transcranial stimulation (TS). Here the authors explore TS via two major methods, transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (TES). In this, the authors seek to demonstrate that artificial cognitive enhancement is detrimental to society. Furthermore, that the argument can be applied beyond the moral dubiousness of using pharmacological cognitive enhancement, but applied to new, emergent technologies as well. In other words, artificial cognitive enhancement regardless of the technology/medium is detrimental to society.


2021 ◽  
Vol 11 (8) ◽  
pp. 1078
Author(s):  
Pushpinder Walia ◽  
Kavya Narendra Kumar ◽  
Anirban Dutta

Surgical skill acquisition may be facilitated with a safe application of transcranial direct current stimulation (tDCS). A preliminary meta-analysis of randomized control trials showed that tDCS was associated with significantly better improvement in surgical performance than the sham control; however, meta-analysis does not address the mechanistic understanding. It is known from skill learning studies that the hierarchy of cognitive control shows a rostrocaudal axis in the frontal lobe where a shift from posterior to anterior is postulated to mediate progressively abstract, higher-order control. Therefore, optimizing the transcranial electrical stimulation to target surgical task-related brain activation at different stages of motor learning may provide the causal link to the learning behavior. This comment paper presents the computational approach for neuroimaging guided tDCS based on open-source software pipelines and an open-data of functional near-infrared spectroscopy (fNIRS) for complex motor tasks. We performed an fNIRS-based cortical activation analysis using AtlasViewer software that was used as the target for tDCS of the motor complexity-related brain regions using ROAST software. For future studies on surgical skill training, it is postulated that the higher complexity laparoscopic suturing with intracorporeal knot tying task may result in more robust activation of the motor complexity-related brain areas when compared to the lower complexity laparoscopic tasks.


Sign in / Sign up

Export Citation Format

Share Document