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Vassiliadis P, Stiennon E, Windel F, Wessel MJ, Beanato E, Hummel FC. Safety, tolerability and blinding efficiency of non-invasive deep transcranial temporal interference stimulation: first experience from more than 250 sessions. J Neural Eng 2024; 21:024001. [PMID: 38408385 DOI: 10.1088/1741-2552/ad2d32] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 02/26/2024] [Indexed: 02/28/2024]
Abstract
Objective. Selective neuromodulation of deep brain regions has for a long time only been possible through invasive approaches, because of the steep depth-focality trade-off of conventional non-invasive brain stimulation (NIBS) techniques.Approach. An approach that has recently emerged for deep NIBS in humans is transcranial Temporal Interference Stimulation (tTIS). However, a crucial aspect for its potential wide use is to ensure that it is tolerable, compatible with efficient blinding and safe.Main results. Here, we show the favorable tolerability and safety profiles and the robust blinding efficiency of deep tTIS targeting the striatum or hippocampus by leveraging a large dataset (119 participants, 257 sessions), including young and older adults and patients with traumatic brain injury. tTIS-evoked sensations were generally rated as 'mild', were equivalent in active and placebo tTIS conditions and did not enable participants to discern stimulation type.Significance. Overall, tTIS emerges as a promising tool for deep NIBS for robust double-blind, placebo-controlled designs.
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Affiliation(s)
- Pierre Vassiliadis
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute (INX), École Polytechnique Fédérale de Lausanne (EPFL), 1202 Geneva, Switzerland
- Defitech Chair of Clinical Neuroengineering, INX, EPFL Valais, Clinique Romande de Réadaptation, 1951 Sion, Switzerland
| | - Emma Stiennon
- Louvain School of Engineering, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Fabienne Windel
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute (INX), École Polytechnique Fédérale de Lausanne (EPFL), 1202 Geneva, Switzerland
- Defitech Chair of Clinical Neuroengineering, INX, EPFL Valais, Clinique Romande de Réadaptation, 1951 Sion, Switzerland
| | | | - Elena Beanato
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute (INX), École Polytechnique Fédérale de Lausanne (EPFL), 1202 Geneva, Switzerland
- Defitech Chair of Clinical Neuroengineering, INX, EPFL Valais, Clinique Romande de Réadaptation, 1951 Sion, Switzerland
| | - Friedhelm C Hummel
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute (INX), École Polytechnique Fédérale de Lausanne (EPFL), 1202 Geneva, Switzerland
- Defitech Chair of Clinical Neuroengineering, INX, EPFL Valais, Clinique Romande de Réadaptation, 1951 Sion, Switzerland
- Clinical Neuroscience, University of Geneva Medical School, 1202 Geneva, Switzerland
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2
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Pathak H, Sreeraj VS, Venkatasubramanian G. Transcranial Alternating Current Stimulation (tACS) and Its Role in Schizophrenia: A Scoping Review. CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE : THE OFFICIAL SCIENTIFIC JOURNAL OF THE KOREAN COLLEGE OF NEUROPSYCHOPHARMACOLOGY 2023; 21:634-649. [PMID: 37859437 PMCID: PMC10591171 DOI: 10.9758/cpn.22.1042] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 01/16/2023] [Accepted: 02/06/2023] [Indexed: 10/21/2023]
Abstract
Transcranial alternating current stimulation (tACS) may modulate neuronal oscillations by applying sinusoidal alternating current, thereby alleviating associated symptoms in schizophrenia. Considering its possible utility in schizophrenia, we reviewed the literature for tACS protocols administered in schizophrenia and their findings. A scoping review was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guideline in databases and clinical trial registers. The search resulted in 59 publications. After excluding review articles unrelated to tACS, trials without published results or not involving patients with schizophrenia, 14 studies were included. Among the included studies/case reports only 5 were randomized controlled therapeutic trials. The studies investigated the utility of tACS for clinical and neurobiological outcomes. All studies reported good tolerability with only transient mild side effects. It was administered mostly during the working memory task (such as computerized n-back task, dual back task, and computerized digit symbol substitution task) for schizophrenia patients with cognitive deficits and during resting state while targeting positive symptoms. A possible reduction in hallucinations and delusions using alpha tACS, and improvement in negative and cognitive deficits with theta and gamma tACS were reported. Nevertheless, one of the randomized controlled trials targeting hallucinations was negative and rigorous large-sample studies are lacking for other domains. The current evidence for tACS in schizophrenia is preliminary though promising. In future, more sham controlled randomized trials assessing the effect of tACS on various domains are needed to substantiate these early findings.
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Affiliation(s)
- Harsh Pathak
- InSTAR Program and WISER Neuromodulation Program, Schizophrenia Clinic, Department of Psychiatry, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, India
| | - Vanteemar S Sreeraj
- InSTAR Program and WISER Neuromodulation Program, Schizophrenia Clinic, Department of Psychiatry, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, India
| | - Ganesan Venkatasubramanian
- InSTAR Program and WISER Neuromodulation Program, Schizophrenia Clinic, Department of Psychiatry, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, India
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3
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Wessel MJ, Beanato E, Popa T, Windel F, Vassiliadis P, Menoud P, Beliaeva V, Violante IR, Abderrahmane H, Dzialecka P, Park CH, Maceira-Elvira P, Morishita T, Cassara AM, Steiner M, Grossman N, Neufeld E, Hummel FC. Noninvasive theta-burst stimulation of the human striatum enhances striatal activity and motor skill learning. Nat Neurosci 2023; 26:2005-2016. [PMID: 37857774 PMCID: PMC10620076 DOI: 10.1038/s41593-023-01457-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 09/07/2023] [Indexed: 10/21/2023]
Abstract
The stimulation of deep brain structures has thus far only been possible with invasive methods. Transcranial electrical temporal interference stimulation (tTIS) is a novel, noninvasive technology that might overcome this limitation. The initial proof-of-concept was obtained through modeling, physics experiments and rodent models. Here we show successful noninvasive neuromodulation of the striatum via tTIS in humans using computational modeling, functional magnetic resonance imaging studies and behavioral evaluations. Theta-burst patterned striatal tTIS increased activity in the striatum and associated motor network. Furthermore, striatal tTIS enhanced motor performance, especially in healthy older participants as they have lower natural learning skills than younger subjects. These findings place tTIS as an exciting new method to target deep brain structures in humans noninvasively, thus enhancing our understanding of their functional role. Moreover, our results lay the groundwork for innovative, noninvasive treatment strategies for brain disorders in which deep striatal structures play key pathophysiological roles.
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Affiliation(s)
- Maximilian J Wessel
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind Institute, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind Institute, Clinique Romande de Réadaptation, École Polytechnique Fédérale de Lausanne, Sion, Switzerland
- Department of Neurology, University Hospital Würzburg, Würzburg, Germany
| | - Elena Beanato
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind Institute, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind Institute, Clinique Romande de Réadaptation, École Polytechnique Fédérale de Lausanne, Sion, Switzerland
| | - Traian Popa
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind Institute, Clinique Romande de Réadaptation, École Polytechnique Fédérale de Lausanne, Sion, Switzerland
| | - Fabienne Windel
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind Institute, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind Institute, Clinique Romande de Réadaptation, École Polytechnique Fédérale de Lausanne, Sion, Switzerland
| | - Pierre Vassiliadis
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind Institute, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind Institute, Clinique Romande de Réadaptation, École Polytechnique Fédérale de Lausanne, Sion, Switzerland
- Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium
| | - Pauline Menoud
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind Institute, Clinique Romande de Réadaptation, École Polytechnique Fédérale de Lausanne, Sion, Switzerland
| | - Valeriia Beliaeva
- Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, Zurich, Switzerland
| | - Ines R Violante
- School of Psychology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | | | - Patrycja Dzialecka
- Department of Brain Sciences, Imperial College London, London, UK
- United Kingdom Dementia Research Institute, Imperial College London, London, UK
| | - Chang-Hyun Park
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind Institute, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind Institute, Clinique Romande de Réadaptation, École Polytechnique Fédérale de Lausanne, Sion, Switzerland
| | - Pablo Maceira-Elvira
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind Institute, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind Institute, Clinique Romande de Réadaptation, École Polytechnique Fédérale de Lausanne, Sion, Switzerland
| | - Takuya Morishita
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind Institute, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind Institute, Clinique Romande de Réadaptation, École Polytechnique Fédérale de Lausanne, Sion, Switzerland
| | - Antonino M Cassara
- Foundation for Research on Information Technologies in Society, Zurich, Switzerland
| | - Melanie Steiner
- Foundation for Research on Information Technologies in Society, Zurich, Switzerland
| | - Nir Grossman
- Department of Brain Sciences, Imperial College London, London, UK
- United Kingdom Dementia Research Institute, Imperial College London, London, UK
| | - Esra Neufeld
- Foundation for Research on Information Technologies in Society, Zurich, Switzerland
| | - Friedhelm C Hummel
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind Institute, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland.
- Defitech Chair of Clinical Neuroengineering, Neuro-X Institute and Brain Mind Institute, Clinique Romande de Réadaptation, École Polytechnique Fédérale de Lausanne, Sion, Switzerland.
- Clinical Neuroscience, University of Geneva Medical School, Geneva, Switzerland.
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Lee S, Park J, Choi DS, Lee C, Im CH. Multipair transcranial temporal interference stimulation for improved focalized stimulation of deep brain regions: A simulation study. Comput Biol Med 2022; 143:105337. [PMID: 35220075 DOI: 10.1016/j.compbiomed.2022.105337] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 02/02/2022] [Accepted: 02/11/2022] [Indexed: 11/29/2022]
Abstract
Temporal interference stimulation (TIS) has been proved to be effective in stimulating deep brain regions while avoiding the stimulation of neocortical regions in animal experiments. In the traditional TIS, two alternating currents are injected with different frequencies via two electrode pairs attached to the scalp. In the human brain, however, it is difficult to achieve a focal stimulation of deep brain structures due to the high complexity of human brain structures. In this study, we hypothesized that the use of multiple electrode pairs may contribute to the more focalized delivery of temporal interference (TI) currents to the target site in the deep area of the brain. Based on this hypothesis, we proposed a novel multipair TIS method that employs more than two electrode pairs for improved focalized stimulation of the deep brain region (in this study, the head of the right hippocampus). Three realistic finite element models were used to validate the feasibility of the proposed multipair TIS. Additional electrode pairs were sequentially added to the conventional two-electrode pairs with the aim of maximizing the delivery of TI currents to the target while minimizing TI currents in the neocortical regions. The results confirmed that the multipair TIS provides better focalized stimulation than the conventional two-pair TIS for all three head models. It is expected that the proposed multipair TIS can be used to enhance the effectiveness of noninvasive deep brain stimulation.
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Affiliation(s)
- Sangjun Lee
- Department of Biomedical Engineering, Hanyang University, Seoul, Republic of Korea; Department of Electronic Engineering, Hanyang University, Seoul, Republic of Korea
| | - Jimin Park
- Department of Electronic Engineering, Hanyang University, Seoul, Republic of Korea
| | - Da Som Choi
- Department of Electronic Engineering, Hanyang University, Seoul, Republic of Korea
| | - Chany Lee
- Department of Structure & Function of Neural Network, Korea Brain Research Institute, Daegu, Republic of Korea
| | - Chang-Hwan Im
- Department of Biomedical Engineering, Hanyang University, Seoul, Republic of Korea; Department of Electronic Engineering, Hanyang University, Seoul, Republic of Korea.
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5
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Song X, Zhao X, Li X, Liu S, Ming D. Multi-channel transcranial temporally interfering stimulation (tTIS): application to living mice brain. J Neural Eng 2020; 18. [PMID: 33307539 DOI: 10.1088/1741-2552/abd2c9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 12/11/2020] [Indexed: 01/10/2023]
Abstract
OBJECTIVE Transcranial temporally interfering stimulation (tTIS) is a noninvasive neuromodulation method, which has been reported to be able to affect the activity of small neuronal populations. To pinpoint smaller regions of the brain, multi-channel tTIS strategy is proposed with larger numbers of electrodes and multiple sets of interfering fields. APPROACH First, computational model is adopted to prove the concept of multi-channel tTIS theoretically. Besides, animal experiments are implemented to activate motor cortex neurons in living mice and different frequencies are attempted. Finally, to better understand the envelope modulation properties of the two applied fields, tissue phantom measurement is conducted. MAIN RESULTS The focality of six-channel (six electrode pairs) tTIS is increased by 46.7% and 70.2% respectively, compared with that of single-channel tTIS when maximal amplitude value drops by 3dB and 6dB in numerical computation experiment. Furthermore, the focality of multi-channel tTIS is less sensitive to the electrode position. Confirmed with myoelectricity signal, the movement frequencies of contralateral forepaw are consistent with the corresponding difference frequencies. What's more, compared single-channel (one electrode pair) tTIS with multi-channel (three electrode pairs) tTIS, the intensity of multi-channel tTIS stimulation is decreased by 28.5% on average in animal experiment. And the c-fos-positive neurons of target region are significantly higher than that of the non-target region. Results of the modulated envelope distribute around the whole regions and its amplitude reaches a maximum at the interfering region. SIGNIFICANCE Both computational modeling and animal experiment validate the feasibility of the proposed multi-channel tTIS strategy and confirm that it can enhance focality and reduce scalp sensation.
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Affiliation(s)
- Xizi Song
- Academy of Medical Engineering and Translation Medicine, Tianjin University, Tianjin, Tianjin, CHINA
| | - Xue Zhao
- , Tianjin University, Academy of Medical Engineering and Translational Medicine, Tianjin, Tianjin, 300072, CHINA
| | - Xiaohong Li
- Academy of Medical Engineering and Translation Medicine, Tianjin University, Academy of Medical Engineering and Translational Medicine, Tianjin, 300072, CHINA
| | - Shuang Liu
- Tianjin University, Tianjin, 300072, CHINA
| | - Dong Ming
- Dept. of Biomedical Engineering, Tianjin University, School of Precision Instrument and Opto-Electronics Engineering, Tianjin 300072, Tianjin, 300072, CHINA
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6
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Individually customized transcranial temporal interference stimulation for focused modulation of deep brain structures: a simulation study with different head models. Sci Rep 2020; 10:11730. [PMID: 32678264 PMCID: PMC7366675 DOI: 10.1038/s41598-020-68660-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 06/22/2020] [Indexed: 01/25/2023] Open
Abstract
Temporal interference (TI) stimulation was recently proposed that allows for the stimulation of deep brain structures with neocortical regions being minimally stimulated. For human brain modulation, TI current patterns are known to be considerably affected by the complex structures of the human head, and thus, it is hard to deliver TI current to a specific deep brain region. In this study, we optimized scalp electrode configurations and injection currents that can deliver maximum TI stimulation currents to a specific deep brain region, the head of the right hippocampus in this study, considering the real anatomical head structures of each individual. Three realistic finite element (FE) head models were employed for the optimization of TI stimulation. To generate TI current patterns, two pairs of scalp electrodes were selected, which carry two sinusoidally alternating currents with a small frequency difference. For every possible combination of electrode pairs, optimal injection currents delivering the maximal TI currents to the head of the right hippocampus were determined. The distribution of the optimized TI currents was then compared with that of the unoptimized TI currents and the conventional single frequency alternating current stimulation. Optimization of TI stimulation parameters allows for the delivery of the desired amount of TI current to the target region while effectively reducing the TI currents delivered to cortical regions compared to the other stimulation approaches. Inconsistency of the optimal stimulation conditions suggest that customized stimulation, considering the individual anatomical differences, is necessary for more effective transcranial TI stimulation. Customized transcranial TI stimulation based on the numerical field analysis is expected to enhance the overall effectiveness of noninvasive stimulation of the human deep brain structures.
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7
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Howell B, McIntyre CC. Feasibility of Interferential and Pulsed Transcranial Electrical Stimulation for Neuromodulation at the Human Scale. Neuromodulation 2020; 24:843-853. [PMID: 32147953 DOI: 10.1111/ner.13137] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 02/06/2020] [Accepted: 02/13/2020] [Indexed: 12/19/2022]
Abstract
OBJECTIVES Transcranial electrical stimulation (tES) is a promising tool for modulating neural activity, but tES has poor penetrability and spatiotemporal resolution compared to invasive techniques like deep brain stimulation (DBS). Interferential strategies for alternating-current stimulation (IF-tACS) and pulsed/intersectional strategies for transcranial direct-current stimulation (IS-tDCS) address some of the limitations of tES, but the comparative advantages and disadvantages of these new techniques is not well understood. This study's objective was to evaluate the suprathreshold and subthreshold membrane dynamics of neurons in response to IF-tACS and IS-tDCS. MATERIALS AND METHODS We analyzed the biophysics of IF-tACS and IS-tDCS using a bioelectric field model of tES. Neural responses were quantified for suprathreshold generation of action potentials in axons and for subthreshold modulation of membrane dynamics in spiking pyramidal neurons. RESULTS IF-tACS and IS-tDCS could not directly activate axons at or below 10 mA, but within this current range, these fields were able to modulate, albeit indirectly, spiking activity in the neuron model. IF-tACS facilitated phase synchronization similar to tACS, and IS-tDCS enhanced and suppressed spiking activity similar to tDCS; however, in either case, the modulatory effects of these fields were less potent than their standard counterparts at a matched field intensity. Moreover, neither IF-tACS nor IS-tDCS improved the spatial selectivity of their parent strategies. CONCLUSIONS Enhancing the spatiotemporal precision and penetrability of tES with interferential and intersectional strategies is possible at the human scale. However, IF-tACS or IS-tDCS will likely require spatial multiplexing with multiple simultaneous sources to counteract their reduced potency, compared to standard techniques, to maintain stimulation currents at tolerable levels.
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Affiliation(s)
- Bryan Howell
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Cameron C McIntyre
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
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Bikson M, Esmaeilpour Z, Adair D, Kronberg G, Tyler WJ, Antal A, Datta A, Sabel BA, Nitsche MA, Loo C, Edwards D, Ekhtiari H, Knotkova H, Woods AJ, Hampstead BM, Badran BW, Peterchev AV. Transcranial electrical stimulation nomenclature. Brain Stimul 2019; 12:1349-1366. [PMID: 31358456 DOI: 10.1016/j.brs.2019.07.010] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 06/25/2019] [Accepted: 07/14/2019] [Indexed: 01/03/2023] Open
Abstract
Transcranial electrical stimulation (tES) aims to alter brain function non-invasively by applying current to electrodes on the scalp. Decades of research and technological advancement are associated with a growing diversity of tES methods and the associated nomenclature for describing these methods. Whether intended to produce a specific response so the brain can be studied or lead to a more enduring change in behavior (e.g. for treatment), the motivations for using tES have themselves influenced the evolution of nomenclature, leading to some scientific, clinical, and public confusion. This ambiguity arises from (i) the infinite parameter space available in designing tES methods of application and (ii) varied naming conventions based upon the intended effects and/or methods of application. Here, we compile a cohesive nomenclature for contemporary tES technologies that respects existing and historical norms, while incorporating insight and classifications based on state-of-the-art findings. We consolidate and clarify existing terminology conventions, but do not aim to create new nomenclature. The presented nomenclature aims to balance adopting broad definitions that encourage flexibility and innovation in research approaches, against classification specificity that minimizes ambiguity about protocols but can hinder progress. Constructive research around tES classification, such as transcranial direct current stimulation (tDCS), should allow some variations in protocol but also distinguish from approaches that bear so little resemblance that their safety and efficacy should not be compared directly. The proposed framework includes terms in contemporary use across peer-reviewed publications, including relatively new nomenclature introduced in the past decade, such as transcranial alternating current stimulation (tACS) and transcranial pulsed current stimulation (tPCS), as well as terms with long historical use such as electroconvulsive therapy (ECT). We also define commonly used terms-of-the-trade including electrode, lead, anode, and cathode, whose prior use, in varied contexts, can also be a source of confusion. This comprehensive clarification of nomenclature and associated preliminary proposals for standardized terminology can support the development of consensus on efficacy, safety, and regulatory standards.
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Affiliation(s)
- Marom Bikson
- Department of Biomedical Engineering, The City College of the City University of New York, New York, NY, USA.
| | - Zeinab Esmaeilpour
- Department of Biomedical Engineering, The City College of the City University of New York, New York, NY, USA.
| | - Devin Adair
- Department of Biomedical Engineering, The City College of the City University of New York, New York, NY, USA
| | - Greg Kronberg
- Department of Biomedical Engineering, The City College of the City University of New York, New York, NY, USA
| | - William J Tyler
- Arizona State University, School of Biological and Health Systems Engineering, Tempe, AZ, USA
| | - Andrea Antal
- Department of Clinical Neurophysiology, University Medical Center Goettingen, Goettingen, Germany; Institute of Medical Psychology, Medical Faculty, Otto-v.-Guericke University of Magdeburg, Magdeburg, Germany
| | | | - Bernhard A Sabel
- Institute of Medical Psychology, Medical Faculty, Otto-v.-Guericke University of Magdeburg, Magdeburg, Germany
| | - Michael A Nitsche
- Leibniz Research Centre for Working Environment ant Human Factors, Dept. Psychology and Neurosciences, Dortmund, Germany; University Medical Hospital Bergmannsheil, Dept. Neurology, Bochum, Germany
| | - Colleen Loo
- School of Psychiatry & Black Dog Institute, University of New South Wales, Sydney, Australia
| | - Dylan Edwards
- Moss Rehabilitation Research Institute, Philadelphia, PA, USA; Edith Cowan University, Joondalup, Australia
| | | | - Helena Knotkova
- MJHS Institute for Innovation in Palliative Care, New York, NY, USA; Department of Family and Social Medicine, Albert Einstein College of Medicine, The Bronx, NY, USA
| | - Adam J Woods
- Center for Cognitive Aging and Memory, McKnight Brain Institute, Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA
| | - Benjamin M Hampstead
- Mental Health Service, VA Ann Arbor Healthcare System, Ann Arbor, MI, USA; Neuropsychology Section, Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA
| | - Bashar W Badran
- Department of Psychiatry, Medical University of South Carolina, Charleston, SC, USA
| | - Angel V Peterchev
- Department of Psychiatry & Behavioral Sciences, Department of Biomedical Engineering, Department of Electrical & Computer Engineering, Department of Neurosurgery, Duke University, Durham, NC, USA
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9
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Antal A, Alekseichuk I, Bikson M, Brockmöller J, Brunoni AR, Chen R, Cohen LG, Dowthwaite G, Ellrich J, Flöel A, Fregni F, George MS, Hamilton R, Haueisen J, Herrmann CS, Hummel FC, Lefaucheur JP, Liebetanz D, Loo CK, McCaig CD, Miniussi C, Miranda PC, Moliadze V, Nitsche MA, Nowak R, Padberg F, Pascual-Leone A, Poppendieck W, Priori A, Rossi S, Rossini PM, Rothwell J, Rueger MA, Ruffini G, Schellhorn K, Siebner HR, Ugawa Y, Wexler A, Ziemann U, Hallett M, Paulus W. Low intensity transcranial electric stimulation: Safety, ethical, legal regulatory and application guidelines. Clin Neurophysiol 2017; 128:1774-1809. [PMID: 28709880 PMCID: PMC5985830 DOI: 10.1016/j.clinph.2017.06.001] [Citation(s) in RCA: 646] [Impact Index Per Article: 92.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 05/29/2017] [Accepted: 06/06/2017] [Indexed: 12/11/2022]
Abstract
Low intensity transcranial electrical stimulation (TES) in humans, encompassing transcranial direct current (tDCS), transcutaneous spinal Direct Current Stimulation (tsDCS), transcranial alternating current (tACS), and transcranial random noise (tRNS) stimulation or their combinations, appears to be safe. No serious adverse events (SAEs) have been reported so far in over 18,000 sessions administered to healthy subjects, neurological and psychiatric patients, as summarized here. Moderate adverse events (AEs), as defined by the necessity to intervene, are rare, and include skin burns with tDCS due to suboptimal electrode-skin contact. Very rarely mania or hypomania was induced in patients with depression (11 documented cases), yet a causal relationship is difficult to prove because of the low incidence rate and limited numbers of subjects in controlled trials. Mild AEs (MAEs) include headache and fatigue following stimulation as well as prickling and burning sensations occurring during tDCS at peak-to-baseline intensities of 1-2mA and during tACS at higher peak-to-peak intensities above 2mA. The prevalence of published AEs is different in studies specifically assessing AEs vs. those not assessing them, being higher in the former. AEs are frequently reported by individuals receiving placebo stimulation. The profile of AEs in terms of frequency, magnitude and type is comparable in healthy and clinical populations, and this is also the case for more vulnerable populations, such as children, elderly persons, or pregnant women. Combined interventions (e.g., co-application of drugs, electrophysiological measurements, neuroimaging) were not associated with further safety issues. Safety is established for low-intensity 'conventional' TES defined as <4mA, up to 60min duration per day. Animal studies and modeling evidence indicate that brain injury could occur at predicted current densities in the brain of 6.3-13A/m2 that are over an order of magnitude above those produced by tDCS in humans. Using AC stimulation fewer AEs were reported compared to DC. In specific paradigms with amplitudes of up to 10mA, frequencies in the kHz range appear to be safe. In this paper we provide structured interviews and recommend their use in future controlled studies, in particular when trying to extend the parameters applied. We also discuss recent regulatory issues, reporting practices and ethical issues. These recommendations achieved consensus in a meeting, which took place in Göttingen, Germany, on September 6-7, 2016 and were refined thereafter by email correspondence.
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Affiliation(s)
- A Antal
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Georg August University, Göttingen, Germany.
| | - I Alekseichuk
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Georg August University, Göttingen, Germany
| | - M Bikson
- Department of Biomedical Engineering, The City College of New York, New York, USA
| | - J Brockmöller
- Department of Clinical Pharmacology, University Medical Center Goettingen, Germany
| | - A R Brunoni
- Service of Interdisciplinary Neuromodulation, Department and Institute of Psychiatry, Laboratory of Neurosciences (LIM-27) and Interdisciplinary Center for Applied Neuromodulation University Hospital, University of São Paulo, São Paulo, Brazil
| | - R Chen
- Division of Neurology, Department of Medicine, University of Toronto and Krembil Research Institute, Toronto, Ontario, Canada
| | - L G Cohen
- Human Cortical Physiology and Neurorehabilitation Section, National Institute of Neurological Disorders and Stroke NIH, Bethesda, USA
| | | | - J Ellrich
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark; Institute of Physiology and Pathophysiology, University of Erlangen-Nürnberg, Erlangen, Germany; EBS Technologies GmbH, Europarc Dreilinden, Germany
| | - A Flöel
- Universitätsmedizin Greifswald, Klinik und Poliklinik für Neurologie, Greifswald, Germany
| | - F Fregni
- Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, USA
| | - M S George
- Brain Stimulation Division, Medical University of South Carolina, and Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC, USA
| | - R Hamilton
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - J Haueisen
- Institute of Biomedical Engineering and Informatics, Technische Universität Ilmenau, Germany
| | - C S Herrmann
- Experimental Psychology Lab, Department of Psychology, European Medical School, Carl von Ossietzky Universität, Oldenburg, Germany
| | - F C Hummel
- Defitech Chair of Clinical Neuroengineering, Centre of Neuroprosthetics (CNP) and Brain Mind Institute, Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland; Defitech Chair of Clinical Neuroengineering, Clinique Romande de Réadaptation, Swiss Federal Institute of Technology (EPFL Valais), Sion, Switzerland
| | - J P Lefaucheur
- Department of Physiology, Henri Mondor Hospital, Assistance Publique - Hôpitaux de Paris, and EA 4391, Nerve Excitability and Therapeutic Team (ENT), Faculty of Medicine, Paris Est Créteil University, Créteil, France
| | - D Liebetanz
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Georg August University, Göttingen, Germany
| | - C K Loo
- School of Psychiatry & Black Dog Institute, University of New South Wales, Sydney, Australia
| | - C D McCaig
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland, UK
| | - C Miniussi
- Center for Mind/Brain Sciences CIMeC, University of Trento, Rovereto, Italy; Cognitive Neuroscience Section, IRCCS Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - P C Miranda
- Institute of Biophysics and Biomedical Engineering, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - V Moliadze
- Institute of Medical Psychology and Medical Sociology, University Hospital of Schleswig-Holstein (UKSH), Campus Kiel, Christian-Albrechts-University, Kiel, Germany
| | - M A Nitsche
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany; Department of Neurology, University Hospital Bergmannsheil, Bochum, Germany
| | - R Nowak
- Neuroelectrics, Barcelona, Spain
| | - F Padberg
- Department of Psychiatry and Psychotherapy, Munich Center for Brain Stimulation, Ludwig-Maximilian University Munich, Germany
| | - A Pascual-Leone
- Division of Cognitive Neurology, Harvard Medical Center and Berenson-Allen Center for Noninvasive Brain Stimulation at Beth Israel Deaconess Medical Center, Boston, USA
| | - W Poppendieck
- Department of Information Technology, Mannheim University of Applied Sciences, Mannheim, Germany
| | - A Priori
- Center for Neurotechnology and Experimental Brain Therapeutich, Department of Health Sciences, University of Milan Italy; Deparment of Clinical Neurology, University Hospital Asst Santi Paolo E Carlo, Milan, Italy
| | - S Rossi
- Department of Medicine, Surgery and Neuroscience, Human Physiology Section and Neurology and Clinical Neurophysiology Section, Brain Investigation & Neuromodulation Lab, University of Siena, Italy
| | - P M Rossini
- Area of Neuroscience, Institute of Neurology, University Clinic A. Gemelli, Catholic University, Rome, Italy
| | | | - M A Rueger
- Department of Neurology, University Hospital of Cologne, Germany
| | | | | | - H R Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark
| | - Y Ugawa
- Department of Neurology, Fukushima Medical University, Fukushima, Japan; Fukushima Global Medical Science Center, Advanced Clinical Research Center, Fukushima Medical University, Japan
| | - A Wexler
- Department of Science, Technology & Society, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - U Ziemann
- Department of Neurology & Stroke, and Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - M Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - W Paulus
- Department of Clinical Neurophysiology, University Medical Center Göttingen, Georg August University, Göttingen, Germany
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10
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Kleinert ML, Szymanski C, Müller V. Frequency-Unspecific Effects of θ-tACS Related to a Visuospatial Working Memory Task. Front Hum Neurosci 2017; 11:367. [PMID: 28747881 PMCID: PMC5506205 DOI: 10.3389/fnhum.2017.00367] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 06/28/2017] [Indexed: 02/02/2023] Open
Abstract
Working memory (WM) is crucial for intelligent cognitive functioning, and synchronization phenomena in the fronto-parietal network have been suggested as an underlying neural mechanism. In an attempt to provide causal evidence for this assumption, we applied transcranial alternating current stimulation (tACS) at theta frequency over fronto-parietal sites during a visuospatial match-to-sample (MtS) task. Depending on the stimulation protocol, i.e., in-phase, anti-phase or sham, we anticipated a differential impact of tACS on behavioral WM performance as well as on the EEG (electroencephalography) during resting state before and after stimulation. We hypothesized that in-phase tACS of the fronto-parietal theta network (stimulation frequency: 5 Hz; intensity: 1 mA peak-to-peak) would result in performance enhancement, whereas anti-phase tACS would cause performance impairment. Eighteen participants (nine female) received in-phase, anti-phase, and sham stimulation in balanced order. While being stimulated, subjects performed the MtS task, which varied in executive demand (two levels: low and high). EEG analysis of power peaks within the delta (0.5–4 Hz), theta (4–8 Hz), alpha (8–12 Hz), and beta (12–30 Hz) frequency bands was carried out. No significant differences were observed between in-phase and anti-phase stimulation regarding both behavioral and EEG measurements. Yet, with regard to the alpha frequency band, we observed a statistically significant drop of peak power from pre to post in the sham condition, whereas alpha power remained on a similar level in the actively stimulated conditions. Our results indicate a frequency-unspecific modulation of neuronal oscillations by tACS. However, the closer participants’ individual theta peak frequencies were to the stimulation frequency of 5 Hz after anti-phase tACS, the faster they responded in the MtS task. This effect did not reach statistical significance during in-phase tACS and was not present during sham. A lack of statistically significant behavioral results in the MtS task and frequency-unspecific effects on the electrophysiological level question the effectiveness of tACS in modulating cortical oscillations in a frequency-specific manner.
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Affiliation(s)
- Maria-Lisa Kleinert
- Center for Lifespan Psychology, Max Planck Institute for Human DevelopmentBerlin, Germany.,Department of Education and Psychology, Freie Universität BerlinBerlin, Germany
| | - Caroline Szymanski
- Center for Lifespan Psychology, Max Planck Institute for Human DevelopmentBerlin, Germany.,School of Mind and Brain, Humboldt-Universität zu BerlinBerlin, Germany
| | - Viktor Müller
- Center for Lifespan Psychology, Max Planck Institute for Human DevelopmentBerlin, Germany
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11
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Grossman N, Bono D, Dedic N, Kodandaramaiah SB, Rudenko A, Suk HJ, Cassara AM, Neufeld E, Kuster N, Tsai LH, Pascual-Leone A, Boyden ES. Noninvasive Deep Brain Stimulation via Temporally Interfering Electric Fields. Cell 2017; 169:1029-1041.e16. [PMID: 28575667 PMCID: PMC5520675 DOI: 10.1016/j.cell.2017.05.024] [Citation(s) in RCA: 383] [Impact Index Per Article: 54.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 02/22/2017] [Accepted: 05/12/2017] [Indexed: 12/22/2022]
Abstract
We report a noninvasive strategy for electrically stimulating neurons at depth. By delivering to the brain multiple electric fields at frequencies too high to recruit neural firing, but which differ by a frequency within the dynamic range of neural firing, we can electrically stimulate neurons throughout a region where interference between the multiple fields results in a prominent electric field envelope modulated at the difference frequency. We validated this temporal interference (TI) concept via modeling and physics experiments, and verified that neurons in the living mouse brain could follow the electric field envelope. We demonstrate the utility of TI stimulation by stimulating neurons in the hippocampus of living mice without recruiting neurons of the overlying cortex. Finally, we show that by altering the currents delivered to a set of immobile electrodes, we can steerably evoke different motor patterns in living mice.
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Affiliation(s)
- Nir Grossman
- Media Lab, MIT, Cambridge, MA 02139, USA; McGovern Institute for Brain Research, MIT, Cambridge, MA 02139, USA; Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA; Centre for Bio-Inspired Technology, Department of Electrical and Electronic Engineering, Imperial College London, SW7 0AZ London, UK
| | - David Bono
- Department of Materials Science and Engineering, MIT, Cambridge, MA 02139, USA
| | - Nina Dedic
- Picower Institute for Learning and Memory, MIT, Cambridge, MA 02139, USA
| | - Suhasa B Kodandaramaiah
- Media Lab, MIT, Cambridge, MA 02139, USA; Department of Mechanical Engineering, University of Minnesota, Twin Cities, Minneapolis, MN 55455, USA
| | - Andrii Rudenko
- Picower Institute for Learning and Memory, MIT, Cambridge, MA 02139, USA; Department of Biology, City College of the City University of York, New York, NY 10031, USA
| | - Ho-Jun Suk
- McGovern Institute for Brain Research, MIT, Cambridge, MA 02139, USA; Harvard-MIT Division of Health Sciences and Technology, MIT, Cambridge, MA 02139, USA
| | - Antonino M Cassara
- IT'IS Foundation for Research on Information Technologies in Society, 8004 Zurich, Switzerland
| | - Esra Neufeld
- IT'IS Foundation for Research on Information Technologies in Society, 8004 Zurich, Switzerland
| | - Niels Kuster
- IT'IS Foundation for Research on Information Technologies in Society, 8004 Zurich, Switzerland; Swiss Federal Institute of Technology (ETHZ), 8092 Zurich, Switzerland
| | - Li-Huei Tsai
- Picower Institute for Learning and Memory, MIT, Cambridge, MA 02139, USA; Broad Institute of Harvard University and MIT, Cambridge, MA 02142, USA
| | - Alvaro Pascual-Leone
- Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Edward S Boyden
- Media Lab, MIT, Cambridge, MA 02139, USA; McGovern Institute for Brain Research, MIT, Cambridge, MA 02139, USA; Broad Institute of Harvard University and MIT, Cambridge, MA 02142, USA; Department of Biological Engineering, MIT, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA; Center for Neurobiological Engineering, MIT, Cambridge, MA 02139, USA.
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