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Wang B, Peterchev AV, Gaugain G, Ilmoniemi RJ, Grill WM, Bikson M, Nikolayev D. Quasistatic approximation in neuromodulation. J Neural Eng 2024; 21:10.1088/1741-2552/ad625e. [PMID: 38994790 PMCID: PMC11370654 DOI: 10.1088/1741-2552/ad625e] [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: 01/31/2024] [Accepted: 06/28/2024] [Indexed: 07/13/2024]
Abstract
We define and explain the quasistatic approximation (QSA) as applied to field modeling for electrical and magnetic stimulation. Neuromodulation analysis pipelines include discrete stages, and QSA is applied specifically when calculating the electric and magnetic fields generated in tissues by a given stimulation dose. QSA simplifies the modeling equations to support tractable analysis, enhanced understanding, and computational efficiency. The application of QSA in neuromodulation is based on four underlying assumptions: (A1) no wave propagation or self-induction in tissue, (A2) linear tissue properties, (A3) purely resistive tissue, and (A4) non-dispersive tissue. As a consequence of these assumptions, each tissue is assigned a fixed conductivity, and the simplified equations (e.g. Laplace's equation) are solved for the spatial distribution of the field, which is separated from the field's temporal waveform. Recognizing that electrical tissue properties may be more complex, we explain how QSA can be embedded in parallel or iterative pipelines to model frequency dependence or nonlinearity of conductivity. We survey the history and validity of QSA across specific applications, such as microstimulation, deep brain stimulation, spinal cord stimulation, transcranial electrical stimulation, and transcranial magnetic stimulation. The precise definition and explanation of QSA in neuromodulation are essential for rigor when using QSA models or testing their limits.
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Affiliation(s)
- Boshuo Wang
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC 27710, United States of America
| | - Angel V Peterchev
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC 27710, United States of America
- Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, United States of America
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, United States of America
- Department of Neurosurgery, Duke University, Durham, NC 27710, United States of America
| | - Gabriel Gaugain
- Institut d’Électronique et des Technologies du numéRique (IETR UMR 6164), CNRS / University of Rennes, 35000 Rennes, France
| | - Risto J Ilmoniemi
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
| | - Warren M Grill
- Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, United States of America
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, United States of America
- Department of Neurosurgery, Duke University, Durham, NC 27710, United States of America
- Department of Neurobiology, Duke University, Durham, NC 27710, United States of America
| | - Marom Bikson
- The City College of New York, New York, NY 11238, United States of America
| | - Denys Nikolayev
- Institut d’Électronique et des Technologies du numéRique (IETR UMR 6164), CNRS / University of Rennes, 35000 Rennes, France
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Delicado-Miralles M, Flix-Diez L, Gurdiel-Álvarez F, Velasco E, Galán-Calle M, Lerma Lara S. Temporal Dynamics of Adverse Effects across Five Sessions of Transcranial Direct Current Stimulation. Brain Sci 2024; 14:457. [PMID: 38790436 PMCID: PMC11118034 DOI: 10.3390/brainsci14050457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 04/26/2024] [Accepted: 04/29/2024] [Indexed: 05/26/2024] Open
Abstract
(1) Background: Transcranial direct current stimulation (tDCS) is a safe intervention, only producing mild and transient adverse effects (AEs). However, there is no detailed analysis of the pattern of adverse effects in an application transferable to the clinic. Therefore, our objective is to describe the AEs produced by tDCS and its temporal evolution. (2) Methods: A total of 33 young volunteers were randomized into a tDCS or sham group. Participants performed a hand dexterity task while receiving the tDCS or sham intervention (20 min and 1 mA), for five consecutive days. AEs were assessed daily after each intervention and classified as somatosensory, pain, or other effects. (3) Results: The number of AEs was generally increased by tDCS intervention. Specifically, tDCS led to more frequent somatosensory discomfort, characterized by sensations like itching and tingling, alongside painful sensations such as burning, compared to the sham intervention. Additionally, certain adverse events, including neck and arm pain, as well as dizziness and blurry vision, were exclusive to the tDCS group. Interestingly, tDCS produced similar AEs across the days; meanwhile, the somatosensory AEs in the sham group showed a trend to decrease. (4) Conclusions: tDCS produces mild and temporary somatosensory and pain AEs during and across sessions. The different evolution of the AEs between the tDCS and sham protocol could unmask the blinding protocol most used in tDCS studies. Potential solutions for improving blinding protocols for future studies are discussed.
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Affiliation(s)
- Miguel Delicado-Miralles
- Department of Pathology and Surgery, Center for Translational Research in Physiotherapy, Miguel Hernández University, Sant Joan d’Alacant, 03550 Alicante, Spain;
| | - Laura Flix-Diez
- Physiotherapy Faculty, Universidad de Valencia (UV), 46010 Valencia, Spain;
| | - Francisco Gurdiel-Álvarez
- Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine University of Rey Juan Carlos, 28922 Alcorcón, Spain;
| | - Enrique Velasco
- Laboratory of Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB-KU Leuven Center for Brain & Disease Research, 3001 Leuven, Belgium;
| | - María Galán-Calle
- Health Sciences Faculty, Centro Superior de Estudios Universitarios La Salle, Universidad Autónoma de Madrid, 28023 Madrid, Spain;
| | - Sergio Lerma Lara
- Health Sciences Faculty, Centro Superior de Estudios Universitarios La Salle, Universidad Autónoma de Madrid, 28023 Madrid, Spain;
- Motion in Brains Research Group, Centro Superior de Estudios Universitarios La Salle, Universidad Autónoma de Madrid, 28023 Madrid, Spain
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3
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Li S, Tang Y, Zhou Y, Ni Y. Effects of Transcranial Direct Current Stimulation on Cognitive Function in Older Adults with and without Mild Cognitive Impairment: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Gerontology 2024; 70:544-560. [PMID: 38452749 DOI: 10.1159/000537848] [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: 06/27/2023] [Accepted: 02/12/2024] [Indexed: 03/09/2024] Open
Abstract
INTRODUCTION Noninvasive brain stimulation (NIBS) has shown benefits for cognitive function in older adults. However, the effects of transcranial direct current stimulation (tDCS) on cognitive function in older adults are inconsistent across studies, and the evidence for tDCS has limitations. We aim to explore whether tDCS can improve cognitive function and different cognitive domains (i.e., learning and memory and executive function) in adults aged 65 years and older with and without mild cognitive impairment and to further analyze the influencing factors of tDCS. METHODS Five English databases (PubMed, Cochrane Library, EMBASE, Web of Science, the cumulative Index to Nursing and Allied Health Literature [CINAHL]) and four Chinese databases were searched from inception to October 14, 2023. Literature screening, data extraction, and quality assessment were completed independently by two reviewers. All statistical analyses were conducted using RevMan software (version 5.3). Standardized mean difference (SMD) along with a 95% confidence interval (CI) was used to express the effect size of the outcomes, and a random-effect model was also used. RESULTS A total of 10 RCTs and 1,761 participants were included in the meta-analysis, and the risk of bias in those studies was relatively low. A significant effect favoring tDCS on immediate postintervention cognitive function (SMD = 0.16, Z = 2.36, p = 0.02) was found. However, the effects on immediate postintervention learning and memory (SMD = 0.20, Z = 2.00, p = 0.05) and executive function (SMD = 0.10, Z = 1.22, p = 0.22), and 1-month postintervention cognitive function (SMD = 0.12, Z = 1.50, p = 0.13), learning and memory (SMD = 0.17, Z = 1.39, p = 0.16), and executive function (SMD = 0.08, Z = 0.67, p = 0.51) were not statistically significant. CONCLUSION tDCS can significantly improve the immediate postintervention cognitive function of healthy older adults and MCI elderly individuals. Additional longitudinal extensive sample studies are required to clarify the specific effects of tDCS on different cognitive domains, and the optimal tDCS parameters need to be explored to guide clinical practice.
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Affiliation(s)
- Sijia Li
- Department of Cardiology, West China Hospital, Sichuan University/West China School of Nursing, Sichuan University, Chengdu, China,
- School of Nursing, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China,
| | - Ying Tang
- Department of Cardiology, West China Hospital, Sichuan University/West China School of Nursing, Sichuan University, Chengdu, China
| | - You Zhou
- School of Nursing, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yunxia Ni
- Department of Cardiology, West China Hospital, Sichuan University/West China School of Nursing, Sichuan University, Chengdu, China
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Charvet L, George A, Charlson E, Lustberg M, Vogel-Eyny A, Eilam-Stock T, Cho H, Best P, Fernandez L, Datta A, Bikson M, Nazim K, Pilloni G. Home-administered transcranial direct current stimulation is a feasible intervention for depression: an observational cohort study. Front Psychiatry 2023; 14:1199773. [PMID: 37674552 PMCID: PMC10477781 DOI: 10.3389/fpsyt.2023.1199773] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 07/25/2023] [Indexed: 09/08/2023] Open
Abstract
Transcranial direct current stimulation (tDCS) is an emerging treatment for major depression. We recruited participants with moderate-to-severe major depressive episodes for an observational clinical trial using Soterix Medical's tDCS telehealth platform as a standard of care. The acute intervention consisted of 28 sessions (5 sessions/week, 6 weeks) of the left anodal dorsolateral prefrontal cortex (DLPFC) tDCS (2.0 mA × 30 min) followed by a tapering phase of weekly sessions for 4 weeks (weeks 7-10). The n = 16 completing participants had a significant reduction in depressive symptoms by week 2 of treatment [Montgomery-Åsberg Depression Rating Scale (MADRS), Baseline: 28.00 ± 4.35 vs. Week 2: 17.12 ± 5.32, p < 0.001] with continual improvement across each biweekly timepoint. Acute intervention responder and remission rates were 75 and 63% and 88 and 81% following the taper period (week 10).
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Affiliation(s)
- Leigh Charvet
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | - Allan George
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | - Erik Charlson
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | - Matthew Lustberg
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | - Amy Vogel-Eyny
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | - Tehila Eilam-Stock
- The Arthur S. Abramson Department of Rehabilitation Medicine, Albert Einstein College of Medicine, New York, NY, United States
| | - Hyein Cho
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | - Pamela Best
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | - Luis Fernandez
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | - Abhishek Datta
- Research and Development, Soterix Medical, Inc., Woodbridge Township, NJ, United States
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States
| | - Kamran Nazim
- Research and Development, Soterix Medical, Inc., Woodbridge Township, NJ, United States
| | - Giuseppina Pilloni
- Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
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Unal G, Poon C, FallahRad M, Thahsin M, Argyelan M, Bikson M. Quasi-static pipeline in electroconvulsive therapy computational modeling. Brain Stimul 2023; 16:607-618. [PMID: 36933652 PMCID: PMC10988926 DOI: 10.1016/j.brs.2023.03.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 03/09/2023] [Accepted: 03/14/2023] [Indexed: 03/18/2023] Open
Abstract
BACKGROUND Computational models of current flow during Electroconvulsive Therapy (ECT) rely on the quasi-static assumption, yet tissue impedance during ECT may be frequency specific and change adaptively to local electric field intensity. OBJECTIVES We systematically consider the application of the quasi-static pipeline to ECT under conditions where 1) static impedance is measured before ECT and 2) during ECT when dynamic impedance is measured. We propose an update to ECT modeling accounting for frequency-dependent impedance. METHODS The frequency content on an ECT device output is analyzed. The ECT electrode-body impedance under low-current conditions is measured with an impedance analyzer. A framework for ECT modeling under quasi-static conditions based on a single device-specific frequency (e.g., 1 kHz) is proposed. RESULTS Impedance using ECT electrodes under low-current is frequency dependent and subject specific, and can be approximated at >100 Hz with a subject-specific lumped parameter circuit model but at <100 Hz increased non-linearly. The ECT device uses a 2 μA 800 Hz test signal and reports a static impedance that approximate 1 kHz impedance. Combined with prior evidence suggesting that conductivity does not vary significantly across ECT output frequencies at high-currents (800-900 mA), we update the adaptive pipeline for ECT modeling centered at 1 kHz frequency. Based on individual MRI and adaptive skin properties, models match static impedance (at 2 μA) and dynamic impedance (at 900 mA) of four ECT subjects. CONCLUSIONS By considering ECT modeling at a single representative frequency, ECT adaptive and non-adaptive modeling can be rationalized under a quasi-static pipeline.
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Affiliation(s)
- Gozde Unal
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, USA.
| | - Cynthia Poon
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, USA
| | - Mohamad FallahRad
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, USA
| | - Myesha Thahsin
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, USA
| | - Miklos Argyelan
- Center for Neurosciences, The Feinstein Institute for Medical Research, North Shore- Long Island Jewish Health System, Manhasset, NY, 11030, USA
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, USA.
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Ko MH, Yoon JY, Jo YJ, Son MN, Kim DS, Kim GW, Won YH, Park SH, Seo JH, Kim YH. Home-Based Transcranial Direct Current Stimulation to Enhance Cognition in Stroke: Randomized Controlled Trial. Stroke 2022; 53:2992-3001. [PMID: 35975663 DOI: 10.1161/strokeaha.121.037629] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Transcranial direct current stimulation (tDCS) is a promising tool for improving post-stroke cognitive function. Home-based rehabilitation is increasingly required for patients with stroke, and additional benefits are expected if supplemented with remotely supervised tDCS (RS-tDCS). We evaluated the cognitive improvement effect and feasibility of RS-tDCS in patients with chronic stroke. METHODS Twenty-six patients with chronic stroke and cognitive impairment (Korean version of the Montreal Cognitive Assessment [K-MoCA] score <26) were randomized into real and sham RS-tDCS groups and underwent concurrent computerized cognitive training and RS-tDCS. Patients and caregivers underwent training to ensure correct tDCS self-application, were monitored, and treated 5 d/wk for 4 weeks. We investigated several cognition tests including K-MoCA, Korean version of the Dementia Rating Scale-2, Korean-Boston Naming Test, Trail Making Test, Go/No Go, and Controlled Oral Word Association Test at the end of the training sessions and one month later. Repeated-measures ANOVA was used for comparison between the groups and within each group. The adherence rate of the appropriate RS-tDCS session was also investigated. RESULTS In within-group comparison, unlike the sham group, the real group showed significant improvement in K-MoCA (Preal=0.004 versus Psham=0.132), particularly in patients with lower baseline K-MoCA (K-MoCA10-17; Preal=0.001 versus Psham=0.835, K-MoCA18-25; Preal=0.060 versus Psham=0.064) or with left hemispheric lesions (left; Preal=0.010 versus Psham=0.454, right; Preal=0.106 versus Psham=0.128). In between-group comparison, a significant difference was observed in K-MoCA in the lower baseline K-MoCA subgroup (K-MoCA10-17; Ptime×group=0.048), but no significant difference was found in other cognitive tests. The adherence rate of successful application of the RS-tDCS was 98.4%, and no serious adverse effects were detected. CONCLUSIONS RS-tDCS is a safe and feasible rehabilitation modality for post-stroke cognitive dysfunction. Specifically, RS-tDCS is effective in patients with moderate cognitive decline. Additionally, these data demonstrate the potential to enhance home-based cognitive training, although significant differences were not consistently found in between-group comparisons; therefore, further larger studies are needed. REGISTRATION URL: https://cris.nih.go.kr; Unique identifier: KCT0003427.
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Affiliation(s)
- Myoung-Hwan Ko
- Department of Physical Medicine and Rehabilitation, Jeonbuk National University Medical School, Jeonju, Republic of Korea (M.-H.K., J.-Y.Y., D.-S.K., G.-W.K., Y.H.W., S.-H.P., J.-H.S.).,Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Republic of Korea (M.-H.K., Y.-J.J., D.-S.K., G.-W.K., Y.H.W., S.-H.P., J.-H.S.).,Translational Research & Clinical Trials Center for Medical Devices, Jeonbuk National University Hospital, Jeonju, Republic of Korea (M.-H.K., Y.-J.J., G.-W.K.)
| | - Ju-Yul Yoon
- Department of Physical Medicine and Rehabilitation, Jeonbuk National University Medical School, Jeonju, Republic of Korea (M.-H.K., J.-Y.Y., D.-S.K., G.-W.K., Y.H.W., S.-H.P., J.-H.S.).,Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Republic of Korea (M.-H.K., Y.-J.J., D.-S.K., G.-W.K., Y.H.W., S.-H.P., J.-H.S.)
| | - Yun-Ju Jo
- Translational Research & Clinical Trials Center for Medical Devices, Jeonbuk National University Hospital, Jeonju, Republic of Korea (M.-H.K., Y.-J.J., G.-W.K.)
| | - Mi-Nam Son
- Department of Physical and Rehabilitation Medicine, Center for Prevention and Rehabilitation, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea (M.-N.S., Y.-H.K.)
| | - Da-Sol Kim
- Department of Physical Medicine and Rehabilitation, Jeonbuk National University Medical School, Jeonju, Republic of Korea (M.-H.K., J.-Y.Y., D.-S.K., G.-W.K., Y.H.W., S.-H.P., J.-H.S.).,Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Republic of Korea (M.-H.K., Y.-J.J., D.-S.K., G.-W.K., Y.H.W., S.-H.P., J.-H.S.)
| | - Gi-Wook Kim
- Department of Physical Medicine and Rehabilitation, Jeonbuk National University Medical School, Jeonju, Republic of Korea (M.-H.K., J.-Y.Y., D.-S.K., G.-W.K., Y.H.W., S.-H.P., J.-H.S.).,Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Republic of Korea (M.-H.K., Y.-J.J., D.-S.K., G.-W.K., Y.H.W., S.-H.P., J.-H.S.).,Translational Research & Clinical Trials Center for Medical Devices, Jeonbuk National University Hospital, Jeonju, Republic of Korea (M.-H.K., Y.-J.J., G.-W.K.)
| | - Yu Hui Won
- Department of Physical Medicine and Rehabilitation, Jeonbuk National University Medical School, Jeonju, Republic of Korea (M.-H.K., J.-Y.Y., D.-S.K., G.-W.K., Y.H.W., S.-H.P., J.-H.S.).,Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Republic of Korea (M.-H.K., Y.-J.J., D.-S.K., G.-W.K., Y.H.W., S.-H.P., J.-H.S.)
| | - Sung-Hee Park
- Department of Physical Medicine and Rehabilitation, Jeonbuk National University Medical School, Jeonju, Republic of Korea (M.-H.K., J.-Y.Y., D.-S.K., G.-W.K., Y.H.W., S.-H.P., J.-H.S.).,Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Republic of Korea (M.-H.K., Y.-J.J., D.-S.K., G.-W.K., Y.H.W., S.-H.P., J.-H.S.)
| | - Jeong-Hwan Seo
- Department of Physical Medicine and Rehabilitation, Jeonbuk National University Medical School, Jeonju, Republic of Korea (M.-H.K., J.-Y.Y., D.-S.K., G.-W.K., Y.H.W., S.-H.P., J.-H.S.).,Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Republic of Korea (M.-H.K., Y.-J.J., D.-S.K., G.-W.K., Y.H.W., S.-H.P., J.-H.S.)
| | - Yun-Hee Kim
- Department of Physical and Rehabilitation Medicine, Center for Prevention and Rehabilitation, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea (M.-N.S., Y.-H.K.).,Department of Health Science and Technology, Department of Medical Device Management and Research, Department of Digital Healthcare, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea (Y.-H.K.)
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Deblieck C, Smeijers S, Morlion B, Datta A, Thomas C, Theys T. Case Report: Initial Evidence of Safety and Efficacy of High Definition-Transcranial Direct Current Stimulation in a Patient With Neuropathic Pain and Implanted Spinal Cord Stimulator. FRONTIERS IN PAIN RESEARCH 2022; 2:753464. [PMID: 35295503 PMCID: PMC8915614 DOI: 10.3389/fpain.2021.753464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 10/04/2021] [Indexed: 11/13/2022] Open
Abstract
Neuropathic pain (NP), often treatment-refractory, is one of the most debilitating conditions contributing to suffering and disability worldwide. Recently, non-invasive neuromodulation techniques, particularly repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) have emerged as potential therapeutic alternatives due to their ability to alter cortical excitability of neural circuits. However, the magnetic field induced in rTMS may be unsafe for patients with an implanted electrode in the head or neck area while tDCS poses no theoretical risk of injury to these patients. High definition (HD)-tDCS is a novel, more focal technique of tDCS and may be safer to the patient compared to the more diffuse stimulation of conventional tDCS. To our knowledge, no study has ever demonstrated the safety and/or feasibility of HD-tDCS in patients with spinal cord stimulation (SCS) devices using computational modeling of induced electrical fields. Furthermore, this study highlights the potential use of (HD-)tDCS as predictive tool for a positive response in chronic epidural motor cortex stimulation (MCS), especially in patients with an implanted device not suitable for rTMS. In a 54-year-old woman with an implanted spinal cord stimulation (SCS) system for another pain syndrome, HD-tDCS was initiated for refractory post-surgical inferior alveolar nerve neuropathy. She was submitted to 7 days of anodal HD-tDCS over the left motor cortex at 1.5 mA for 30 min. A notable decrease in pain perception was observed, lasting for approximately 5-6 h (Numeric Rating Score decreased from 8 to 4.34). No adverse events were reported. The stimulation parameters and clinical efficacy of the SCS system remained unchanged. Additionally, computational analysis indicated no meaningful alteration of current flow when considering a model with a SCS implant with respect to a model without implant. Regarding the positive therapeutic effect of HD-tDCS, the patient was selected for an epidural MCS trial and subsequent implantation, which showed short-term pain relief of 50-75%. Although one case does not demonstrate efficacy, tolerability, or safety to the novel intervention, it paves the way for better diagnosis and treatment for patients who are otherwise excluded from other non-invasive neuromodulation techniques, such as rTMS. A positive tDCS effect could be a potential biomarker for positive epidural MCS response in patients with an implanted stimulation device non-compatible with rTMS.
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Affiliation(s)
- Choi Deblieck
- Academic Center for Electroconvulsive Therapy (ECT) and Neuromodulation, University Psychiatric Center, KU Leuven, Leuven, Belgium
| | - Steven Smeijers
- Department of Neurosurgery, University Hospitals Leuven, Leuven, Belgium
| | - Bart Morlion
- Department of Cardiovascular Sciences, Section Anaesthesiology & Algology, KU Leuven-University of Leuven, Leuven, Belgium
| | - Abhishek Datta
- Research and Development, Soterix Medical Inc., Woodbridge, NJ, United States.,Department of Neurosurgery, UZ Leuven, Leuven, Belgium.,Biomedical Engineering, City College of New York, New York, NY, United States
| | - Chris Thomas
- Research and Development, Soterix Medical Inc., Woodbridge, NJ, United States
| | - Tom Theys
- Department of Neurosurgery, University Hospitals Leuven, Leuven, Belgium
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8
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Flix-Díez L, Delicado-Miralles M, Gurdiel-Álvarez F, Velasco E, Galán-Calle M, Lerma Lara S. Reversed Polarity bi-tDCS over M1 during a Five Days Motor Task Training Did Not Influence Motor Learning. A Triple-Blind Clinical Trial. Brain Sci 2021; 11:brainsci11060691. [PMID: 34070256 PMCID: PMC8225177 DOI: 10.3390/brainsci11060691] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/18/2021] [Accepted: 05/22/2021] [Indexed: 12/04/2022] Open
Abstract
Transcranial direct current stimulation (tDCS) has been investigated as a way of improving motor learning. Our purpose was to explore the reversal bilateral tDCS effects on manual dexterity training, during five days, with the retention component measured after 5 days to determine whether somatosensory effects were produced. In this randomized, triple-blind clinical trial, 28 healthy subjects (14 women) were recruited and randomized into tDCS and placebo groups, although only 23 participants (13 women) finished the complete protocol. Participants received the real or placebo treatment during five consecutive days, while performing a motor dexterity training program of 20 min. The motor dexterity and the sensitivity of the hand were assessed pre- and post-day 1, post 5 days of training, and 5 days after training concluded. Training improved motor dexterity, but tDCS only produced a tendency to improve retention. The intervention did not produce changes in the somatosensory variables assessed. Thus, reversal bi-tDCS had no effects during motor learning on healthy subjects, but it could favor the retention of the motor skills acquired. These results do not support the cooperative inter-hemispheric model.
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Affiliation(s)
- Laura Flix-Díez
- Department of Physical Therapy, University of Valencia (UV), 46003 Valencia, Spain;
| | - Miguel Delicado-Miralles
- Instituto de Neurociencias de Alicante (UMH-CSIC), 03550 Sant Joant d’Alacant, Spain; (M.D.-M.); (E.V.)
| | - Francisco Gurdiel-Álvarez
- Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine University of Rey Juan Carlos, 28922 Alcorcón, Spain;
| | - Enrique Velasco
- Instituto de Neurociencias de Alicante (UMH-CSIC), 03550 Sant Joant d’Alacant, Spain; (M.D.-M.); (E.V.)
| | - María Galán-Calle
- Health Sciences Faculty, Centro Superior de Estudios Universitarios La Salle, Universidad Autónoma de Madrid, 28023 Madrid, Spain;
| | - Sergio Lerma Lara
- Health Sciences Faculty, Centro Superior de Estudios Universitarios La Salle, Universidad Autónoma de Madrid, 28023 Madrid, Spain;
- Motion in Brains Research Group, Centro Superior de Estudios Universitarios La Salle, Universidad Autónoma de Madrid, 28023 Madrid, Spain
- Correspondence: ; Tel.: +34-91-5035900 (ext. 255)
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Machado S, Travassos B, Teixeira DS, Rodrigues F, Cid L, Monteiro D. Could tDCS Be a Potential Performance-Enhancing Tool for Acute Neurocognitive Modulation in eSports? A Perspective Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18073678. [PMID: 33916018 PMCID: PMC8037790 DOI: 10.3390/ijerph18073678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/27/2021] [Accepted: 03/29/2021] [Indexed: 11/16/2022]
Abstract
Competitive sports involve physical and cognitive skills. In traditional sports, there is a greater dependence on the development and performance of both motor and cognitive skills, unlike electronic sports (eSports), which depend much more on neurocognitive skills for success. However, little is known about neurocognitive functions and effective strategies designed to develop and optimize neurocognitive performance in eSports athletes. One such strategy is transcranial direct current stimulation (tDCS), characterized as a weak electric current applied on the scalp to induce prolonged changes in cortical excitability. Therefore, our objective is to propose anodal (a)-tDCS as a performance-enhancing tool for neurocognitive functions in eSports. In this manuscript, we discussed the neurocognitive processes that underlie exceptionally skilled performances in eSports and how tDCS could be used for acute modulation of these processes in eSports. Based on the results from tDCS studies in healthy people, professional athletes, and video game players, it seems that tDCS is applied over the left dorsolateral prefrontal cortex (DLPFC) as a potential performance-enhancing tool for neurocognition in eSports.
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Affiliation(s)
- Sergio Machado
- Laboratory of Physical Activity Neuroscience, Physical Activity Sciences Postgraduate Program, Salgado de Oliveira University, Niterói 24456-570, Brazil;
- Department of Sports Science, University of Beira Interior, 6201-001 Covilhã, Portugal;
- Laboratory of Physical Activity Neuroscience, Neurodiversity Institute, Queimados 26325-020, Brazil
| | - Bruno Travassos
- Department of Sports Science, University of Beira Interior, 6201-001 Covilhã, Portugal;
- Research Center in Sport, Health and Human Development (CIDESD), 5000-558 Vila Real, Portugal;
- Portugal Football School, Portuguese Football Federation, 1495-433 Cruz Quebrada, Portugal
| | - Diogo S. Teixeira
- Faculty of Physical Education and Sport, Lusófona University, 1749-024 Lisbon, Portugal;
- Research Center in Sport, Physical Education, and Exercise and Health (CIDEFES), (CIDEFES), 1749-024 Lisbon, Portugal
| | - Filipe Rodrigues
- Sport Science School of Rio Maior, ESDRM-IPSantarém, 2040-413 Rio Maio, Portugal;
- Life Quality Research Center (CIEQV), 2040-413 Rio Maior, Portugal
| | - Luis Cid
- Research Center in Sport, Health and Human Development (CIDESD), 5000-558 Vila Real, Portugal;
- Sport Science School of Rio Maior, ESDRM-IPSantarém, 2040-413 Rio Maio, Portugal;
| | - Diogo Monteiro
- Research Center in Sport, Health and Human Development (CIDESD), 5000-558 Vila Real, Portugal;
- ESECS, Polytechnic of Leiria, 2411-901 Leiria, Portugal
- Correspondence:
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10
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Khadka N, Bikson M. Role of skin tissue layers and ultra-structure in transcutaneous electrical stimulation including tDCS. Phys Med Biol 2020; 65:225018. [PMID: 32916670 DOI: 10.1088/1361-6560/abb7c1] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND During transcranial electrical stimulation (tES), including transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS), current density concentration around the electrode edges that is predicted by simplistic skin models does not match experimental observations of erythema, heating, or other adverse events. We hypothesized that enhancing models to include skin anatomical details, would alter predicted current patterns to align with experimental observations. METHOD We develop a high-resolution multi-layer skin model (epidermis, dermis, and fat), with or without additional ultra-structures (hair follicles, sweat glands, and blood vessels). Current flow patterns across each layer and within ultra-structures were predicted using finite element methods considering a broad range of modeled tissue parameters including 78 combinations of skin layer conductivities (S m-1): epidermis (standard: 1.05 × 10-5; range: 1.05 × 10-6 to 0.465); dermis (standard: 0.23; range: 0.0023 to 23), fat (standard: 2 × 10-4; range: 0.02 to 2 × 10-5). The impact of each ultra-structures in isolation and combination was evaluated with varied basic geometries. An integrated final model is then developed. RESULTS Consistent with prior models, current flow through homogenous skin was annular (concentrated at the electrode edges). In multi-layer skin, reducing epidermis conductivity and/or increasing dermis conductivity decreased current near electrode edges, however no realistic tissue layer parameters produced non-annular current flow at both epidermis and dermis. Addition of just hair follicles, sweat glands, or blood vessels resulted in current peaks around each ultrastructure, irrespective of proximity to electrode edges. Addition of only sweat glands was the most effective approach in reducing overall current concentration near electrode edges. Representation of blood vessels resulted in a uniform current flow across the vascular network. Finally, we ran the first realistic model of current flow across the skin. CONCLUSION We confirm prior models exhibiting current concentration near hair follicles or sweat glands, but also exhibit that an overall annular pattern of current flow remains for realistic tissue parameters. We model skin blood vessels for the first time and show that this robustly distributes current across the vascular network, consistent with experimental erythema patterns. Only a state-of-the-art precise model of skin current flow predicts lack of current concentration near electrode edges across all skin layers.
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Affiliation(s)
- Niranjan Khadka
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY 10031, United States of America
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11
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Solomons CD, Shanmugasundaram V. Transcranial direct current stimulation: A review of electrode characteristics and materials. Med Eng Phys 2020; 85:63-74. [PMID: 33081965 DOI: 10.1016/j.medengphy.2020.09.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 09/10/2020] [Accepted: 09/25/2020] [Indexed: 12/15/2022]
Abstract
Electrode characteristics are crucial in transcranial direct current stimulation (tDCS) since electrode design and placement determine the cortical area being modulated, current density and spatial resolution of stimulation. Early research on tDCS sought to determine optimal parameters for stimulation by specifying maximum current, duration and sizes of electrodes. Further research focused on determining efficient ways to deliver stimulation to targeted regions on the cortex with minimal discomfort to the user by altering electrode size, placement, shape and material. This review aims to give an insight on the main characteristics of electrodes used in tDCS and on the variability found in electrode parameters and placements from tDCS to high definition tDCS (HD-tDCS) applications and beyond.
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Affiliation(s)
- Cassandra D Solomons
- School of Electrical Engineering, Vellore Institute of Technology, Vellore 632014, India
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12
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Wu YJ, Chien ME, Huang CH, Chiang CC, Lin CC, Huang CW, Durand DM, Hsu KS. Transcranial direct current stimulation alleviates seizure severity in kainic acid-induced status epilepticus rats. Exp Neurol 2020; 328:113264. [DOI: 10.1016/j.expneurol.2020.113264] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 02/28/2020] [Indexed: 12/20/2022]
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13
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Chhabra H, Bose A, Shivakumar V, Agarwal SM, Sreeraj VS, Shenoy S, Hazari N, Dinakaran D, Parlikar R, Koparde V, Ramesh V, Biswal J, Murugaraja V, Gowda SM, Chand PK, Sivakumar PT, Kalmady SV, Narayanaswamy JC, Murthy P, Girimaji SC, Venkatasubramanian G. Tolerance of transcranial direct current stimulation in psychiatric disorders: An analysis of 2000+ sessions. Psychiatry Res 2020; 284:112744. [PMID: 31955053 DOI: 10.1016/j.psychres.2020.112744] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 12/05/2019] [Accepted: 01/01/2020] [Indexed: 12/29/2022]
Abstract
Transcranial direct current stimulation (tDCS), a non-invasive, neuromodulatory technique, is being increasingly applied to several psychiatric disorders. In this study, we describe the side-effect profile of repeated tDCS sessions (N = 2005) that were administered to 171 patients (156 adults and 15 adolescents) with different psychiatric disorders [schizophrenia [N = 109], obsessive-compulsive disorder [N = 28], alcohol dependence syndrome [N = 13], mild cognitive impairment [N = 10], depression [N = 6], dementia [N = 2] and other disorders [N = 3]]. tDCS was administered at a constant current strength of 2 mA with additional ramp-up and ramp-down phase of 20 s each at the beginning and end of the session, respectively. Other tDCS protocol parameters were: schizophrenia and obsessive-compulsive disorder: 5-days of twice-daily 20-min sessions with an inter-session interval of 3-h; Mild cognitive impairment/dementia and alcohol dependence syndrome: at least 5-days of once-daily 20-min session; Depression: 10-days of once-daily 30 min session. At the end of each tDCS session, any adverse event observed by the administrator and/or reported by the patient was systematically assessed using a comprehensive questionnaire. The commonly reported adverse events during tDCS included burning sensations (16.2%), skin redness (12.3%), scalp pain (10.1%), itching (6.7%), and tingling (6.3%). Most of the adverse events were noted to be mild, transient and well-tolerated. In summary, our observations suggest that tDCS is a safe mode for therapeutic non-invasive neuromodulation in psychiatric disorders in adults as well as the adolescent population.
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Affiliation(s)
- Harleen Chhabra
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Anushree Bose
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Venkataram Shivakumar
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Sri Mahavir Agarwal
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Vanteemar S Sreeraj
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Sonia Shenoy
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Nandita Hazari
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Damodharan Dinakaran
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Rujuta Parlikar
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Vinayak Koparde
- Department of Child and Adolescent Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Vinutha Ramesh
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Jitendriya Biswal
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Venkatachalam Murugaraja
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Shayanth Manche Gowda
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Prabhat K Chand
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India; Centre for Addiction Medicine, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Palanimuthu T Sivakumar
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Sunil V Kalmady
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Janardhanan C Narayanaswamy
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Pratima Murthy
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India; Centre for Addiction Medicine, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Satish C Girimaji
- Department of Child and Adolescent Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - Ganesan Venkatasubramanian
- WISER Neuromodulation Program, Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore 560029, India.
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Zhu Z, Zhou J, Manor B, Wang X, Fu W, Liu Y. Commentary: "Brain-Doping," Is It a Real Threat? Front Physiol 2019; 10:1489. [PMID: 31866878 PMCID: PMC6906138 DOI: 10.3389/fphys.2019.01489] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 11/21/2019] [Indexed: 11/13/2022] Open
Affiliation(s)
- Zhiqiang Zhu
- School of Kinesiology, Shanghai University of Sport, Shanghai, China.,School of Physical Education, East China Jiao Tong University, Nanchang, China
| | - Junhong Zhou
- Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA, United States.,Harvard Medical School, Boston, MA, United States
| | - Brad Manor
- Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA, United States.,Harvard Medical School, Boston, MA, United States
| | - Xi Wang
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Weijie Fu
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Yu Liu
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
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15
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Bland NS, Sale MV. Current challenges: the ups and downs of tACS. Exp Brain Res 2019; 237:3071-3088. [DOI: 10.1007/s00221-019-05666-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 10/09/2019] [Indexed: 02/08/2023]
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16
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Chen L, Zou X, Tang R, Ke A, He J. Effect of electrode-electrolyte spatial mismatch on transcranial direct current stimulation: a finite element modeling study. J Neural Eng 2019; 16:056012. [DOI: 10.1088/1741-2552/ab29c5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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17
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Khadka N, Borges H, Paneri B, Kaufman T, Nassis E, Zannou AL, Shin Y, Choi H, Kim S, Lee K, Bikson M. Adaptive current tDCS up to 4 mA. Brain Stimul 2019; 13:69-79. [PMID: 31427272 DOI: 10.1016/j.brs.2019.07.027] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 07/16/2019] [Accepted: 07/29/2019] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Higher tDCS current may putatively enhance efficacy, with tolerability the perceived limiting factor. OBJECTIVE We designed and validated electrodes and an adaptive controller to provide tDCS up to 4 mA, while managing tolerability. The adaptive 4 mA controller included incremental ramp up, impedance-based current limits, and a Relax-mode where current is transiently decreased. Relax-mode was automatically activated by self-report VAS-pain score >5 and in some conditions by a Relax-button available to participants. METHODS In a parallel-group participant-blind design with 50 healthy subjects, we used specialized electrodes to administer 3 daily session of tDCS for 11 min, with a lexical decision task as a distractor, in 5 study conditions: adaptive 4 mA, adaptive 4 mA with Relax-button, adaptive 4 mA with historical-Relax-button, 2 mA, and sham. A tablet-based stimulator with a participant interface regularly queried VAS pain score and also limited current based on impedance and tolerability. An Abort-button provided in all conditions stopped stimulation. In the adaptive 4 mA with Relax-button and adaptive 4 mA with historical-Relax-button conditions, participants could trigger a Relax-mode ad libitum, in the latter case with incrementally longer current reductions. Primary outcome was the average current delivered during each session, VAS pain score, and adverse event questionnaires. Current delivered was analyzed either excluding or including dropouts who activated Abort (scored as 0 current). RESULTS There were two dropouts each in the adaptive 4 mA and sham conditions. Resistance based current attenuation was rarely activated, with few automatic VAS pain score triggered relax-modes. In conditions with Relax-button option, there were significant activations often irrespective of VAS pain score. Including dropouts, current across conditions were significantly different from each other with maximum current delivered during adaptive 4 mA with Relax-button. Excluding dropouts, maximum current was delivered with adaptive 4 mA. VAS pain score and adverse events for the sham was only significantly lower than the adaptive 4 mA with Relax-button and adaptive 4 mA with historical-Relax-button. There was no difference in VAS pain score or adverse events between 2 mA and adaptive 4 mA. CONCLUSIONS Provided specific electrodes and controllers, adaptive 4 mA tDCS is tolerated and effectively blinded, with acceptability likely higher in a clinical population and absence of regular querying. Indeed, presenting participants with overt controls increases rumination on sensation.
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Affiliation(s)
- Niranjan Khadka
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, 10031, USA
| | - Helen Borges
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, 10031, USA
| | - Bhaskar Paneri
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, 10031, USA
| | - Trynia Kaufman
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, 10031, USA
| | - Electra Nassis
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, 10031, USA
| | - Adantchede L Zannou
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, 10031, USA
| | | | | | | | - Kiwon Lee
- Ybrain Inc., Seongnam-si, Republic of Korea
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, 10031, 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: 73] [Impact Index Per Article: 14.6] [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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19
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Meiron O, Gale R, Namestnic J, Bennet-Back O, Gebodh N, Esmaeilpour Z, Mandzhiyev V, Bikson M. Antiepileptic Effects of a Novel Non-invasive Neuromodulation Treatment in a Subject With Early-Onset Epileptic Encephalopathy: Case Report With 20 Sessions of HD-tDCS Intervention. Front Neurosci 2019; 13:547. [PMID: 31191235 PMCID: PMC6548848 DOI: 10.3389/fnins.2019.00547] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 05/13/2019] [Indexed: 01/30/2023] Open
Abstract
The current clinical investigation examined high-definition transcranial direct current stimulation (HD-tDCS) as a focal, non-invasive, anti-epileptic treatment in a child with early-onset epileptic encephalopathy. We investigated the clinical impact of repetitive (20 daily sessions) cathode-centered 4 × 1 HD-tDCS (1 mA, 20 min, 4 mm ring radius) over the dominant seizure-generating cortical zone in a 40-month-old child suffering from a severe neonatal epileptic syndrome known as Ohtahara syndrome (OS). Seizures and epileptiform activity were monitored and quantified using video-EEG over multiple days of baseline, intervention, and post-intervention periods. Primary outcome measures were changes in seizure frequency and duration on the last day of intervention versus the last baseline day, preceding the intervention. In particular, we examined changes in tonic spasms, tonic-myoclonic seizures (TM-S), and myoclonic seizures from baseline to post-intervention. A trend in TM-S frequency was observed indicating a reduction of 73% in TM-S frequency, which was non-significant [t(4) = 2.05, p = 0.1], and denoted a clinically significant change. Myoclonic seizure (M-S) frequency was significantly reduced [t(4) = 3.83, p = 0.019] by 68.42%, compared to baseline, and indicated a significant clinical change as well. A 73% decrease in interictal epileptic discharges (IEDs) frequency was also observed immediately after the intervention period, compared to IED frequency at 3 days prior to intervention. Post-intervention seizure-related peak delta desynchronization was reduced by 57%. Our findings represent a case-specific significant clinical response, reduction in IED, and change in seizure-related delta activity following the application of HD-tDCS. The clinical outcomes, as noted in the current study, encourage the further investigation of this focal, non-invasive neuromodulation procedure in other severe electroclinical syndromes (e.g., West syndrome) and in larger pediatric populations diagnosed with early-onset epileptic encephalopathy. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT02960347, protocol ID: Meiron 2013-4.
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Affiliation(s)
- Oded Meiron
- The Clinical Research Center for Brain Sciences, Herzog Medical Center, Jerusalem, Israel
| | - Rena Gale
- Children Respiratory Unit, Herzog Medical Center, Jerusalem, Israel
| | - Julia Namestnic
- Children Respiratory Unit, Herzog Medical Center, Jerusalem, Israel
| | - Odeya Bennet-Back
- Pediatric Neurology Department, Shaare Zedek Medical Center, Jerusalem, Israel
| | - Nigel Gebodh
- Department of Biomedical Engineering, The City College of the City University of New York, New York, NY, United States
| | - Zeinab Esmaeilpour
- Department of Biomedical Engineering, The City College of the City University of New York, New York, NY, United States
| | - Vladislav Mandzhiyev
- Department of Biomedical Engineering, The City College of the City University of New York, New York, NY, United States
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of the City University of New York, New York, NY, United States
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Gebodh N, Esmaeilpour Z, Adair D, Chelette K, Dmochowski J, Woods AJ, Kappenman ES, Parra LC, Bikson M. Inherent physiological artifacts in EEG during tDCS. Neuroimage 2018; 185:408-424. [PMID: 30321643 DOI: 10.1016/j.neuroimage.2018.10.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 09/10/2018] [Accepted: 10/08/2018] [Indexed: 12/30/2022] Open
Abstract
Online imaging and neuromodulation is invalid if stimulation distorts measurements beyond the point of accurate measurement. In theory, combining transcranial Direct Current Stimulation (tDCS) with electroencephalography (EEG) is compelling, as both use non-invasive electrodes and image-guided dose can be informed by the reciprocity principle. To distinguish real changes in EEG from stimulation artifacts, prior studies applied conventional signal processing techniques (e.g. high-pass filtering, ICA). Here, we address the assumptions underlying the suitability of these approaches. We distinguish physiological artifacts - defined as artifacts resulting from interactions between the stimulation induced voltage and the body and so inherent regardless of tDCS or EEG hardware performance - from methodology-related artifacts - arising from non-ideal experimental conditions or non-ideal stimulation and recording equipment performance. Critically, we identify inherent physiological artifacts which are present in all online EEG-tDCS: 1) cardiac distortion and 2) ocular motor distortion. In conjunction, non-inherent physiological artifacts which can be minimized in most experimental conditions include: 1) motion and 2) myogenic distortion. Artifact dynamics were analyzed for varying stimulation parameters (montage, polarity, current) and stimulation hardware. Together with concurrent physiological monitoring (ECG, respiration, ocular, EMG, head motion), and current flow modeling, each physiological artifact was explained by biological source-specific body impedance changes, leading to incremental changes in scalp DC voltage that are significantly larger than real neural signals. Because these artifacts modulate the DC voltage and scale with applied current, they are dose specific such that their contamination cannot be accounted for by conventional experimental controls (e.g. differing stimulation montage or current as a control). Moreover, because the EEG artifacts introduced by physiologic processes during tDCS are high dimensional (as indicated by Generalized Singular Value Decomposition- GSVD), non-stationary, and overlap highly with neurogenic frequencies, these artifacts cannot be easily removed with conventional signal processing techniques. Spatial filtering techniques (GSVD) suggest that the removal of physiological artifacts would significantly degrade signal integrity. Physiological artifacts, as defined here, would emerge only during tDCS, thus processing techniques typically applied to EEG in the absence of tDCS would not be suitable for artifact removal during tDCS. All concurrent EEG-tDCS must account for physiological artifacts that are a) present regardless of equipment used, and b) broadband and confound a broad range of experiments (e.g. oscillatory activity and event related potentials). Removal of these artifacts requires the recognition of their non-stationary, physiology-specific dynamics, and individualized nature. We present a broad taxonomy of artifacts (non/stimulation related), and suggest possible approaches and challenges to denoising online EEG-tDCS stimulation artifacts.
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Affiliation(s)
- Nigel Gebodh
- Neural Engineering Laboratory, Department of Biomedical Engineering, The City College of New York of the City University of New York, New York, NY, USA.
| | - Zeinab Esmaeilpour
- Neural Engineering Laboratory, Department of Biomedical Engineering, The City College of New York of the City University of New York, New York, NY, USA.
| | - Devin Adair
- Department of Psychology, The Graduate Center at City University of New York, New York, NY, USA.
| | | | - Jacek Dmochowski
- Neural Engineering Laboratory, Department of Biomedical Engineering, The City College of New York of the City University of New York, New York, NY, USA.
| | - Adam J Woods
- Center for Cognitive Aging and Memory, McKnight Brain Institute, Department of Clinical and Health Psychology, Department of Neuroscience, University of Florida, Gainesville, FL, USA.
| | | | - Lucas C Parra
- Neural Engineering Laboratory, Department of Biomedical Engineering, The City College of New York of the City University of New York, New York, NY, USA.
| | - Marom Bikson
- Neural Engineering Laboratory, Department of Biomedical Engineering, The City College of New York of the City University of New York, New York, NY, USA; Department of Psychology, The Graduate Center at City University of New York, New York, NY, USA.
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Welch ES, Weigand A, Hooker JE, Philip NS, Tyrka AR, Press DZ, Carpenter LL. Feasibility of Computerized Cognitive‐Behavioral Therapy Combined With Bifrontal Transcranial Direct Current Stimulation for Treatment of Major Depression. Neuromodulation 2018; 22:898-903. [DOI: 10.1111/ner.12807] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/20/2018] [Accepted: 06/04/2018] [Indexed: 12/22/2022]
Affiliation(s)
- Emma S. Welch
- Mood Disorders Research ProgramButler Hospital Providence RI USA
| | - Anne Weigand
- Department of Neurology, Berenson‐Allen Center for Noninvasive Brain StimulationHarvard Medical School and Beth Israel Deaconess Medical Center Boston MA USA
| | - Julia E. Hooker
- Department of Neurology, Berenson‐Allen Center for Noninvasive Brain StimulationHarvard Medical School and Beth Israel Deaconess Medical Center Boston MA USA
| | - Noah S. Philip
- Center for Neurorestoration and NeurotechnologyProvidence VA Medical CenterProvidenceRIUSA
- Department of Psychiatry and Human BehaviorAlpert Medical School of Brown University Providence RI USA
| | - Audrey R. Tyrka
- Mood Disorders Research ProgramButler Hospital Providence RI USA
- Department of Psychiatry and Human BehaviorAlpert Medical School of Brown University Providence RI USA
| | - Daniel Z. Press
- Department of Neurology, Berenson‐Allen Center for Noninvasive Brain StimulationHarvard Medical School and Beth Israel Deaconess Medical Center Boston MA USA
| | - Linda L. Carpenter
- Mood Disorders Research ProgramButler Hospital Providence RI USA
- Department of Psychiatry and Human BehaviorAlpert Medical School of Brown University Providence RI USA
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Chhatbar PY, Kautz SA, Takacs I, Rowland NC, Revuelta GJ, George MS, Bikson M, Feng W. Evidence of transcranial direct current stimulation-generated electric fields at subthalamic level in human brain in vivo. Brain Stimul 2018; 11:727-733. [PMID: 29576498 PMCID: PMC6019625 DOI: 10.1016/j.brs.2018.03.006] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 02/28/2018] [Accepted: 03/08/2018] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Transcranial direct current stimulation (tDCS) is a promising brain modulation technique for several disease conditions. With this technique, some portion of the current penetrates through the scalp to the cortex and modulates cortical excitability, but a recent human cadaver study questions the amount. This insufficient intracerebral penetration of currents may partially explain the inconsistent and mixed results in tDCS studies to date. Experimental validation of a transcranial alternating current stimulation-generated electric field (EF) in vivo has been performed on the cortical (using electrocorticography, ECoG, electrodes), subcortical (using stereo electroencephalography, SEEG, electrodes) and deeper thalamic/subthalamic levels (using DBS electrodes). However, tDCS-generated EF measurements have never been attempted. OBJECTIVE We aimed to demonstrate that tDCS generates biologically relevant EF as deep as the subthalamic level in vivo. METHODS Patients with movement disorders who have implanted deep brain stimulation (DBS) electrodes serve as a natural experimental model for thalamic/subthalamic recordings of tDCS-generated EF. We measured voltage changes from DBS electrodes and body resistance from tDCS electrodes in three subjects while applying direct current to the scalp at 2 mA and 4 mA over two tDCS montages. RESULTS Voltage changes at the level of deep nuclei changed proportionally with the level of applied current and varied with different tDCS montages. CONCLUSIONS Our findings suggest that scalp-applied tDCS generates biologically relevant EF. Incorporation of these experimental results may improve finite element analysis (FEA)-based models.
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Affiliation(s)
- Pratik Y Chhatbar
- Department of Neurology, College of Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Steven A Kautz
- Department of Health Science & Research, College of Health Professions, Medical University of South Carolina, Charleston, SC, USA; Ralph H. Johnson VA Medical Center, Charleston, SC, USA
| | - Istvan Takacs
- Department of Neurosurgery, College of Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Nathan C Rowland
- Department of Neurosurgery, College of Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Gonzalo J Revuelta
- Department of Neurology, College of Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Mark S George
- Ralph H. Johnson VA Medical Center, Charleston, SC, USA; Brain Stimulation Laboratory, Department of Psychiatry and Behavioral Science, College of Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of The City University of New York, New York, NY, USA
| | - Wuwei Feng
- Department of Neurology, College of Medicine, Medical University of South Carolina, Charleston, SC, USA; Department of Health Science & Research, College of Health Professions, Medical University of South Carolina, Charleston, SC, USA.
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Miao Y, Koomson VJ. A CMOS-Based Bidirectional Brain Machine Interface System With Integrated fdNIRS and tDCS for Closed-Loop Brain Stimulation. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2018; 12:554-563. [PMID: 29877819 DOI: 10.1109/tbcas.2018.2798924] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A CMOS-based bidirectional brain machine interface system with on-chip frequency-domain near infrared spectroscopy (fdNIRS) and transcranial direct-current stimulation (tDCS) is designed to enable noninvasive closed-loop brain stimulation for neural disorders treatment and cognitive performance enhancement. The dual channel fdNIRS can continuously monitor absolute cerebral oxygenation during the entire tDCS process by measuring NIR light's attenuation and phase shift across brain tissue. Each fdNIRS channel provides 120 dBΩ transimpedance gain at 80 MHz with a power consumption of 30 mW while tolerating up to 8 pF input capacitance. A photocurrent between 10 and 450 nA can be detected with a phase resolution down to 0.2°. A lensless system with subnanowatt sensitivity is realized by using an avalanche photodiode. The on-chip programmable voltage-controlled resistor stimulator can support a stimulation current from 0.6 to 2.2 mA with less than 1% variation, which covers the required current range of tDCS. The chip is fabricated in a standard 130-nm CMOS process and occupies an area of 2.25 mm2.
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Meiron O, Gale R, Namestnic J, Bennet-Back O, David J, Gebodh N, Adair D, Esmaeilpour Z, Bikson M. High-Definition transcranial direct current stimulation in early onset epileptic encephalopathy: a case study. Brain Inj 2017; 32:135-143. [PMID: 29156988 DOI: 10.1080/02699052.2017.1390254] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PRIMARY OBJECTIVE Early onset epileptic encephalopathy is characterized by high daily seizure-frequency, multifocal epileptic discharges, severe psychomotor retardation, and death at infancy. Currently, there are no effective treatments to alleviate seizure frequency and high-voltage epileptic discharges in these catastrophic epilepsy cases. The current study examined the safety and feasibility of High-Definition transcranial direct current stimulation (HD-tDCS) in reducing epileptiform activity in a 30-month-old child suffering from early onset epileptic encephalopathy. DESIGN AND METHODS HD-tDCS was administered over 10 intervention days spanning two weeks including pre- and post-intervention video-EEG monitoring. RESULTS There were no serious adverse events or side effects related to the HD-tDCS intervention. Frequency of clinical seizures was not significantly reduced. However, interictal sharp wave amplitudes were significantly lower during the post-intervention period versus baseline. Vital signs and blood biochemistry remained stable throughout the entire study. CONCLUSIONS These exploratory findings support the safety and feasibility of 4 × 1 HD-tDCS in early onset epileptic encephalopathy and provide the first evidence of HD-tDCS effects on paroxysmal EEG features in electroclinical cases under the age of 36 months. Extending HD-tDCS treatment may enhance electrographic findings and clinical effects.
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Affiliation(s)
- Oded Meiron
- a Clinical Research Center for Brain Sciences , Herzog Medical Center , Jerusalem , Israel
| | - Rena Gale
- b Children Respiratory Unit , Herzog Medical Center , Jerusalem , Israel
| | - Julia Namestnic
- b Children Respiratory Unit , Herzog Medical Center , Jerusalem , Israel
| | - Odeya Bennet-Back
- c Pediatric Neurology Department , Shaare Zedek Medical Center , Jerusalem , Israel
| | - Jonathan David
- a Clinical Research Center for Brain Sciences , Herzog Medical Center , Jerusalem , Israel
| | - Nigel Gebodh
- d Department of Biomedical Engineering , The City College of the City University of New York , New York , USA
| | - Devin Adair
- d Department of Biomedical Engineering , The City College of the City University of New York , New York , USA
| | - Zeinab Esmaeilpour
- d Department of Biomedical Engineering , The City College of the City University of New York , New York , USA.,e Biomedical Engineering Department , Amirkabir University of Technology , Tehran , Iran
| | - Marom Bikson
- d Department of Biomedical Engineering , The City College of the City University of New York , New York , USA
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25
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Alonzo A, Aaronson S, Bikson M, Husain M, Lisanby S, Martin D, McClintock SM, McDonald WM, O'Reardon J, Esmailpoor Z, Loo C. Study design and methodology for a multicentre, randomised controlled trial of transcranial direct current stimulation as a treatment for unipolar and bipolar depression. Contemp Clin Trials 2016; 51:65-71. [DOI: 10.1016/j.cct.2016.10.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 10/04/2016] [Accepted: 10/10/2016] [Indexed: 01/17/2023]
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26
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Chhatbar PY, Sawers JR, Feng W. Response to the Response to "Does tDCS Actually Deliver DC Stimulation?". Brain Stimul 2016; 9:952-954. [PMID: 27613489 PMCID: PMC5299539 DOI: 10.1016/j.brs.2016.08.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 08/01/2016] [Accepted: 08/11/2016] [Indexed: 11/26/2022] Open
Affiliation(s)
- Pratik Y Chhatbar
- Department of Neurology, College of Medicine, Medical University of South Carolina, Charleston, SC, USA.
| | - James R Sawers
- Department of Psychiatry and Behavioral Sciences, College of Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Wuwei Feng
- Department of Neurology, College of Medicine, Medical University of South Carolina, Charleston, SC, USA; Department of Health Science & Research, College of Health Professions, Medical University of South Carolina, Charleston, SC, USA
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27
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Opitz A, Falchier A, Yan CG, Yeagle EM, Linn GS, Megevand P, Thielscher A, Deborah A. R, Milham MP, Mehta AD, Schroeder CE. Spatiotemporal structure of intracranial electric fields induced by transcranial electric stimulation in humans and nonhuman primates. Sci Rep 2016; 6:31236. [PMID: 27535462 PMCID: PMC4989141 DOI: 10.1038/srep31236] [Citation(s) in RCA: 198] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Accepted: 07/15/2016] [Indexed: 11/08/2022] Open
Abstract
Transcranial electric stimulation (TES) is an emerging technique, developed to non-invasively modulate brain function. However, the spatiotemporal distribution of the intracranial electric fields induced by TES remains poorly understood. In particular, it is unclear how much current actually reaches the brain, and how it distributes across the brain. Lack of this basic information precludes a firm mechanistic understanding of TES effects. In this study we directly measure the spatial and temporal characteristics of the electric field generated by TES using stereotactic EEG (s-EEG) electrode arrays implanted in cebus monkeys and surgical epilepsy patients. We found a small frequency dependent decrease (10%) in magnitudes of TES induced potentials and negligible phase shifts over space. Electric field strengths were strongest in superficial brain regions with maximum values of about 0.5 mV/mm. Our results provide crucial information of the underlying biophysics in TES applications in humans and the optimization and design of TES stimulation protocols. In addition, our findings have broad implications concerning electric field propagation in non-invasive recording techniques such as EEG/MEG.
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Affiliation(s)
- Alexander Opitz
- Nathan Kline Institute for Psychiatric Research, Orangeburg, New York, USA
- Center for the Developing Brain, Child Mind Institute, New York, USA
| | - Arnaud Falchier
- Nathan Kline Institute for Psychiatric Research, Orangeburg, New York, USA
| | - Chao-Gan Yan
- Nathan Kline Institute for Psychiatric Research, Orangeburg, New York, USA
- Key Laboratory of Behavioral Science and Magnetic Resonance Imaging Research Center, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | - Erin M. Yeagle
- Department of Neurosurgery, Hofstra Northwell School of Medicine, and Feinstein Institute for Medical Research, Manhasset, NY, USA
| | - Gary S. Linn
- Nathan Kline Institute for Psychiatric Research, Orangeburg, New York, USA
- Department of Psychiatry, NYU Langone School of Medicine, NY, USA
| | - Pierre Megevand
- Department of Neurosurgery, Hofstra Northwell School of Medicine, and Feinstein Institute for Medical Research, Manhasset, NY, USA
| | - Axel Thielscher
- Danish Research Center for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Denmark
- Max Planck Institute for Biological Cybernetics, Tübingen, Germany
- Department of Electrical Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Ross Deborah A.
- Nathan Kline Institute for Psychiatric Research, Orangeburg, New York, USA
| | - Michael P. Milham
- Nathan Kline Institute for Psychiatric Research, Orangeburg, New York, USA
- Center for the Developing Brain, Child Mind Institute, New York, USA
| | - Ashesh D. Mehta
- Department of Neurosurgery, Hofstra Northwell School of Medicine, and Feinstein Institute for Medical Research, Manhasset, NY, USA
| | - Charles E. Schroeder
- Nathan Kline Institute for Psychiatric Research, Orangeburg, New York, USA
- Departments of Neurological Surgery and Psychiatry, Columbia University College of Physicians and Surgeons, New York, USA
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28
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Zhang C, Bin Altaf MA, Yoo J. Design and Implementation of an On-Chip Patient-Specific Closed-Loop Seizure Onset and Termination Detection System. IEEE J Biomed Health Inform 2016; 20:996-1007. [DOI: 10.1109/jbhi.2016.2553368] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Horvath JC, Vogrin SJ, Carter O, Cook MJ, Forte JD. Effects of a common transcranial direct current stimulation (tDCS) protocol on motor evoked potentials found to be highly variable within individuals over 9 testing sessions. Exp Brain Res 2016; 234:2629-42. [PMID: 27150317 DOI: 10.1007/s00221-016-4667-8] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 04/27/2016] [Indexed: 11/28/2022]
Abstract
Transcranial direct current stimulation (tDCS) uses a weak electric current to modulate neuronal activity. A neurophysiologic outcome measure to demonstrate reliable tDCS modulation at the group level is transcranial magnetic stimulation engendered motor evoked potentials (MEPs). Here, we conduct a study testing the reliability of individual MEP response patterns following a common tDCS protocol. Fourteen participants (7m/7f) each underwent nine randomized sessions of 1 mA, 10 min tDCS (3 anode; 3 cathode; 3 sham) delivered using an M1/orbito-frontal electrode montage (sessions separated by an average of ~5.5 days). Fifteen MEPs were obtained prior to, immediately following and in 5 min intervals for 30 min following tDCS. TMS was delivered at 130 % resting motor threshold using neuronavigation to ensure consistent coil localization. A number of non-experimental variables were collected during each session. At the individual level, considerable variability was seen among different testing sessions. No participant demonstrated an excitatory response ≥20 % to all three anodal sessions, and no participant demonstrated an inhibitory response ≥20 % to all three cathodal sessions. Intra-class correlation revealed poor anodal and cathodal test-retest reliability [anode: ICC(2,1) = 0.062; cathode: ICC(2,1) = 0.055] and moderate sham test-retest reliability [ICC(2,1) = 0.433]. Results also revealed no significant effect of tDCS at the group level. Using this common protocol, we found the effects of tDCS on MEP amplitudes to be highly variable at the individual level. In addition, no significant effects of tDCS on MEP amplitude were found at the group level. Future studies should consider utilizing a more strict experimental protocol to potentially account for intra-individual response variations.
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Affiliation(s)
- Jared Cooney Horvath
- Melbourne School of Psychological Sciences, University of Melbourne, Redmond Barry Building, Melbourne, VIC, 3010, Australia. .,Departments of Medicine and Neurology, St. Vincent's Hospital, University of Melbourne, Melbourne, VIC, Australia. .,Melbourne Graduate School of Education, University of Melbourne, Melbourne, VIC, Australia.
| | - Simon J Vogrin
- Departments of Medicine and Neurology, St. Vincent's Hospital, University of Melbourne, Melbourne, VIC, Australia
| | - Olivia Carter
- Melbourne School of Psychological Sciences, University of Melbourne, Redmond Barry Building, Melbourne, VIC, 3010, Australia
| | - Mark J Cook
- Melbourne School of Psychological Sciences, University of Melbourne, Redmond Barry Building, Melbourne, VIC, 3010, Australia.,Departments of Medicine and Neurology, St. Vincent's Hospital, University of Melbourne, Melbourne, VIC, Australia
| | - Jason D Forte
- Melbourne School of Psychological Sciences, University of Melbourne, Redmond Barry Building, Melbourne, VIC, 3010, Australia
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Transcranial direct current stimulation and neuroplasticity genes: implications for psychiatric disorders. Acta Neuropsychiatr 2016; 28:1-10. [PMID: 25877668 DOI: 10.1017/neu.2015.20] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND AIM Transcranial direct current stimulation (tDCS) is a non-invasive and well-tolerated brain stimulation technique with promising efficacy as an add-on treatment for schizophrenia and for several other psychiatric disorders. tDCS modulates neuroplasticity; psychiatric disorders are established to be associated with neuroplasticity abnormalities. This review presents the summary of research on potential genetic basis of neuroplasticity-modulation mechanism underlying tDCS and its implications for treating various psychiatric disorders. METHOD A systematic review highlighting the genes involved in neuroplasticity and their role in psychiatric disorders was carried out. The focus was on the established genetic findings of tDCS response relationship with BDNF and COMT gene polymorphisms. RESULT Synthesis of these preliminary observations suggests the potential influence of neuroplastic genes on tDCS treatment response. These include several animal models, pharmacological studies, mentally ill and healthy human subject trials. CONCLUSION Taking into account the rapidly unfolding understanding of tDCS and the role of synaptic plasticity disturbances in neuropsychiatric disorders, in-depth evaluation of the mechanism of action pertinent to neuroplasticity modulation with tDCS needs further systematic research. Genes such as NRG1, DISC1, as well as those linked with the glutamatergic receptor in the context of their direct role in the modulation of neuronal signalling related to neuroplasticity aberrations, are leading candidates for future research in this area. Such research studies might potentially unravel observations that might have potential translational implications in psychiatry.
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Gillick B, Menk J, Mueller B, Meekins G, Krach LE, Feyma T, Rudser K. Synergistic effect of combined transcranial direct current stimulation/constraint-induced movement therapy in children and young adults with hemiparesis: study protocol. BMC Pediatr 2015; 15:178. [PMID: 26558386 PMCID: PMC4642615 DOI: 10.1186/s12887-015-0498-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 10/27/2015] [Indexed: 11/10/2022] Open
Abstract
Background Perinatal stroke occurs in more than 1 in 2,500 live births and resultant congenital hemiparesis necessitates investigation into interventions which may improve long-term function and decreased burden of care beyond current therapies (http://www.cdc.gov/ncbddd/cp/data.html). Constraint-Induced Movement Therapy (CIMT) is recognized as an effective hemiparesis rehabilitation intervention . Transcranial direct current stimulation as an adjunct treatment to CIMT may potentiate neuroplastic responses and improve motor function. The methodology of a clinical trial in children designed as a placebo-controlled, serial –session, non-invasive brain stimulation trial incorporating CIMT is described here. The primary hypotheses are 1) that no serious adverse events will occur in children receiving non-invasive brain stimulation and 2) that children in the stimulation intervention group will show significant improvements in hand motor function compared to children in the placebo stimulation control group. Methods/design A randomized, controlled, double-blinded clinical trial. Twenty children and/or young adults (ages 8–21) with congenital hemiparesis, will be enrolled. The intervention group will receive ten 2-hour sessions of transcranial direct current stimulation combined with constraint-induced movement therapy and the control group will receive sham stimulation with CIMT. The primary outcome measure is safety assessment of transcranial direct current stimulation by physician evaluation, vital sign monitoring and symptom reports. Additionally, hand function will be evaluated using the Assisting Hand Assessment, grip strength and assessment of goals using the Canadian Occupational Performance Measure. Neuroimaging will confirm diagnoses, corticospinal tract integrity and cortical activation. Motor cortical excitability will also be examined using transcranial magnetic stimulation techniques. Discussion Combining non-invasive brain stimulation and CIMT interventions has the potential to improve motor function in children with congenital hemiparesis beyond each intervention independently. Such a combined intervention has the potential to benefit an individual throughout their lifetime. Trial registration Clinicaltrials.gov, NCT02250092Registered 18 September 2014
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Affiliation(s)
- Bernadette Gillick
- University of Minnesota, 420 Delaware Street SE, MMC 388, Minneapolis, MN, 55455, USA.
| | - Jeremiah Menk
- Biostatistical Design and Analysis Center, University of Minnesota, Minneapolis, MN, 55455, USA.
| | - Bryon Mueller
- Department of Psychiatry, University of Minnesota, Minneapolis, MN, 55455, USA.
| | - Gregg Meekins
- Department of Neurology, University of Minnesota, Minneapolis, MN, USA.
| | - Linda E Krach
- Courage Kenny Rehabilitation Institute, part of Allina Health, 800 East 28th Street, Minneapolis, MN, 55407, USA.
| | - Timothy Feyma
- Department of Neurology, Gillette Children's Specialty Healthcare, 200 University Ave E, Saint Paul, MN, 55101, USA.
| | - Kyle Rudser
- Division of Biostatistics, University of Minnesota, Minneapolis, MN, USA.
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Malavera A, Vasquez A, Fregni F. Novel methods to optimize the effects of transcranial direct current stimulation: a systematic review of transcranial direct current stimulation patents. Expert Rev Med Devices 2015; 12:679-88. [PMID: 26415093 DOI: 10.1586/17434440.2015.1090308] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that has been extensively studied. While there have been initial positive results in some clinical trials, there is still variability in tDCS results. The aim of this article is to review and discuss patents assessing novel methods to optimize the use of tDCS. A systematic review was performed using Google patents database with tDCS as the main technique, with patents filling date between 2010 and 2015. Twenty-two patents met our inclusion criteria. These patents attempt to address current tDCS limitations. Only a few of them have been investigated in clinical trials (i.e., high-definition tDCS), and indeed most of them have not been tested before in human trials. Further clinical testing is required to assess which patents are more likely to optimize the effects of tDCS. We discuss the potential optimization of tDCS based on these patents and the current experience with standard tDCS.
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Affiliation(s)
- Alejandra Malavera
- a Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School , Boston, Massachusetts, USA
| | - Alejandra Vasquez
- a Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School , Boston, Massachusetts, USA
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Bikson M, Truong DQ, Mourdoukoutas AP, Aboseria M, Khadka N, Adair D, Rahman A. Modeling sequence and quasi-uniform assumption in computational neurostimulation. PROGRESS IN BRAIN RESEARCH 2015; 222:1-23. [PMID: 26541374 DOI: 10.1016/bs.pbr.2015.08.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Computational neurostimulation aims to develop mathematical constructs that link the application of neuromodulation with changes in behavior and cognition. This process is critical but daunting for technical challenges and scientific unknowns. The overarching goal of this review is to address how this complex task can be made tractable. We describe a framework of sequential modeling steps to achieve this: (1) current flow models, (2) cell polarization models, (3) network and information processing models, and (4) models of the neuroscientific correlates of behavior. Each step is explained with a specific emphasis on the assumptions underpinning underlying sequential implementation. We explain the further implementation of the quasi-uniform assumption to overcome technical limitations and unknowns. We specifically focus on examples in electrical stimulation, such as transcranial direct current stimulation. Our approach and conclusions are broadly applied to immediate and ongoing efforts to deploy computational neurostimulation.
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Affiliation(s)
- Marom Bikson
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, USA.
| | - Dennis Q Truong
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, USA
| | | | - Mohamed Aboseria
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, USA
| | - Niranjan Khadka
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, USA
| | - Devin Adair
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, USA
| | - Asif Rahman
- Department of Biomedical Engineering, The City College of New York, CUNY, New York, NY, USA
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No Effect of 2 mA Anodal tDCS Over the M1 on Performance and Practice Effect on Grooved Pegboard Test and Trail Making Test B. eNeuro 2015; 2:eN-NWR-0072-14. [PMID: 26465001 PMCID: PMC4596020 DOI: 10.1523/eneuro.0072-14.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 07/06/2015] [Accepted: 07/07/2015] [Indexed: 12/27/2022] Open
Abstract
Previous studies suggest that transcranial direct current stimulation (tDCS) can facilitate motor performance and learning. In this double-blind experiment, 60 healthy human subjects (29 females) were randomized into three groups (active tDCS, sham tDCS, and no-treatment control group) in order to investigate the effect of a 20 min session of 2 mA tDCS over the motor cortex contralateral to the dominant hand on practice effect and performance on the Grooved Pegboard Test (GPT) and Trail Making Test (TMT). Performance was operationalized as the time to complete the tests before, during, and after stimulation. The practice effect was termed as the difference in time to complete the tests from pretest to post-test. Data on body mass index (BMI), head circumference, sleep status, interelectrode impedance, and caffeine and nicotine use were sampled to control for the influence of individual differences on the effect of tDCS. Adverse effects were registered using a standardized form. The results indicated no effect of tDCS on performance and practice effects on the GPT and TMT. For all groups, BMI was a predictor for a practice effect on the TMT. In the active tDCS group, high caffeine intake and low impedance predicted a practice effect on the GPT for the dominant hand. The present results suggest that impedance levels in tDCS studies should be routinely reported in future studies, as it might not only provide valuable information on the efficacy of the blinding conditions and participant discomfort, but also correlate with individual differences that are relevant to the outcome of the stimulation.
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Safety and feasibility of transcranial direct current stimulation in pediatric hemiparesis: randomized controlled preliminary study. Phys Ther 2015; 95:337-49. [PMID: 25413621 PMCID: PMC4348714 DOI: 10.2522/ptj.20130565] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Transcranial direct current stimulation (tDCS) is a form of noninvasive brain stimulation that has shown improved adult stroke outcomes. Applying tDCS in children with congenital hemiparesis has not yet been explored. OBJECTIVE The primary objective of this study was to explore the safety and feasibility of single-session tDCS through an adverse events profile and symptom assessment within a double-blind, randomized placebo-controlled preliminary study in children with congenital hemiparesis. A secondary objective was to assess the stability of hand and cognitive function. DESIGN A double-blind, randomized placebo-controlled pretest/posttest/follow-up study was conducted. SETTING The study was conducted in a university pediatric research laboratory. PARTICIPANTS Thirteen children, ages 7 to 18 years, with congenital hemiparesis participated. MEASUREMENTS Adverse events/safety assessment and hand function were measured. INTERVENTION Participants were randomly assigned to either an intervention group or a control group, with safety and functional assessments at pretest, at posttest on the same day, and at a 1-week follow-up session. An intervention of 10 minutes of 0.7 mA tDCS was applied to bilateral primary motor cortices. The tDCS intervention was considered safe if there was no individual decline of 25% or group decline of 2 standard deviations for motor evoked potentials (MEPs) and behavioral data and no report of adverse events. RESULTS No major adverse events were found, including no seizures. Two participants did not complete the study due to lack of MEP and discomfort. For the 11 participants who completed the study, group differences in MEPs and behavioral data did not exceed 2 standard deviations in those who received the tDCS (n=5) and those in the control group (n=6). The study was completed without the need for stopping per medical monitor and biostatisticial analysis. LIMITATIONS A limitation of the study was the small sample size, with data available for 11 participants. CONCLUSIONS Based on the results of this study, tDCS appears to be safe, feasible, and well tolerated in most children with hemiparesis. Future investigations of serial sessions of tDCS in conjunction with rehabilitation in pediatric hemiparesis are indicated to explore the benefit of a synergistic approach to improving hand function.
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Gholami-Boroujeny S, Mekonnen A, Batkin I, Bolic M. Theoretical Analysis of the Effect of Temperature on Current Delivery to the Brain During tDCS. Brain Stimul 2014; 8:509-14. [PMID: 25686527 DOI: 10.1016/j.brs.2014.12.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 12/20/2014] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Transcranial direct current simulation (tDCS) is a non-invasive neuromodulation technique that has become increasingly popular as a potential therapeutic method for a variety of brain disorders. Since the treatment outcome may depend on the current density delivered to the brain cortical region, a significant challenge is to control the current dose reaching the cortical region. OBJECTIVE AND METHODS This study aims to investigate the effect of temperature on current delivery to the brain. We devised a method for modulating the amount of current delivered to the brain by changing the temperature of the scalp. We developed analytical and numerical models that describe the relationship between temperature and electrical properties of the scalp based on the following mechanisms: ion mobility and blood perfusion in scalp. RESULTS AND CONCLUSIONS The current delivery to brain was investigated by changing the temperature between two electrodes that are attached to the surface of the scalp, within a tolerable physiological range. Results show that by increasing the temperature between two electrodes, a higher portion of current is shunted via the scalp and the proportion of the current that penetrates the scalp and skull into brain is decreased. On the other hand, cooling the area between two electrodes on the scalp increases the current delivery to the cortical region of the brain. Our results show that cooling the scalp during tDCS can be considered as a possible way to effectively control the current delivery to the brain and increase the efficacy of tDCS.
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Affiliation(s)
- Shiva Gholami-Boroujeny
- School of Electrical Engineering and Computer Science, University of Ottawa, Ottawa, Canada K1N6N5.
| | - Abeye Mekonnen
- School of Electrical Engineering and Computer Science, University of Ottawa, Ottawa, Canada K1N6N5
| | - Izmail Batkin
- School of Electrical Engineering and Computer Science, University of Ottawa, Ottawa, Canada K1N6N5
| | - Miodrag Bolic
- School of Electrical Engineering and Computer Science, University of Ottawa, Ottawa, Canada K1N6N5
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Bikson M, Edwards D, Kappenman E. WITHDRAWN: The Outlook for Non-invasive Electrical Brain Stimulation. Brain Stimul 2014:S1935-861X(14)00338-6. [PMID: 25468076 DOI: 10.1016/j.brs.2014.10.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 10/19/2014] [Indexed: 11/19/2022] Open
Abstract
The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.brs.2014.10.005. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Khadka N, Rahman A, Sarantos C, Truong DQ, Bikson M. Methods for specific electrode resistance measurement during transcranial direct current stimulation. Brain Stimul 2014; 8:150-9. [PMID: 25456981 DOI: 10.1016/j.brs.2014.10.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 10/09/2014] [Accepted: 10/10/2014] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Monitoring of electrode resistance during tDCS is considered important for tolerability and safety. Conventional resistance measurement methods do not isolate individual electrode resistance and for HD-tDCS devices, cross talk across electrodes makes concurrent resistance monitoring unreliable. OBJECTIVE We propose a novel method to monitor individual electrode resistance during tDCS, using a super-position of direct current with a test-signal (low intensity and low frequency sinusoids with electrode-specific frequencies) and a sentinel electrode (not used for DC). METHODS We developed and solved lumped-parameter models of tDCS electrodes with or without a sentinel electrode to validate this methodology. Assumptions were tested and parameterized in participants using forearm stimulation combining tDCS (2 mA) and test-signals (38 and 76 μA pk-pk at 1 Hz, 10 Hz, & 100 Hz) and an in vitro test (creating electrode failure modes). DC and AC component voltages across the electrodes were compared and participants were asked to rate subjective pain. RESULTS A sentinel electrode is required to isolate electrode resistance in a two-electrode tDCS system. Cross talk aggravated with electrode proximity and resistance mismatch in multi-electrode resistance tracking could be corrected using proposed approaches. Average voltage and pain scores were not significantly different across test current intensities and frequencies. CONCLUSION Using our developed method, a test signal can predict DC electrode resistance. Since unique test frequencies can be used at each tDCS electrode, specific electrode resistance can be resolved for any number of stimulating channels - a process made still more robust by the use of a sentinel electrode.
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Affiliation(s)
- Niranjan Khadka
- Department of Biomedical Engineering, The City College of New York, CUNY, 160 Convent Ave., New York 10031, USA.
| | - Asif Rahman
- Department of Biomedical Engineering, The City College of New York, CUNY, 160 Convent Ave., New York 10031, USA
| | - Chris Sarantos
- Department of Biomedical Engineering, The City College of New York, CUNY, 160 Convent Ave., New York 10031, USA
| | - Dennis Q Truong
- Department of Biomedical Engineering, The City College of New York, CUNY, 160 Convent Ave., New York 10031, USA
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, CUNY, 160 Convent Ave., New York 10031, USA
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Palm U, Feichtner KB, Hasan A, Gauglitz G, Langguth B, Nitsche MA, Keeser D, Padberg F. The role of contact media at the skin-electrode interface during transcranial direct current stimulation (tDCS). Brain Stimul 2014; 7:762-4. [PMID: 25018056 DOI: 10.1016/j.brs.2014.06.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 06/14/2014] [Indexed: 10/25/2022] Open
Affiliation(s)
- Ulrich Palm
- Department of Psychiatry, Psychotherapy and Psychosomatics, Ludwig-Maximilian University, Munich 80336, Germany.
| | - Katrina B Feichtner
- Department of Psychiatry, Psychotherapy and Psychosomatics, Ludwig-Maximilian University, Munich, Germany; Department of Dermatology and Venerology, Ludwig-Maximilian University, Munich, Germany
| | - Alkomiet Hasan
- Department of Psychiatry, Psychotherapy and Psychosomatics, Ludwig-Maximilian University, Munich, Germany
| | - Gerd Gauglitz
- Department of Dermatology and Venerology, Ludwig-Maximilian University, Munich, Germany
| | - Berthold Langguth
- Department of Psychiatry and Psychotherapy at Bezirksklinikum, University of Regensburg, Germany
| | - Michael A Nitsche
- Department of Clinical Neurophysiology, Georg-August-University, Göttingen, Germany
| | - Daniel Keeser
- Department of Psychiatry, Psychotherapy and Psychosomatics, Ludwig-Maximilian University, Munich, Germany; Institute for Clinical Radiology, Ludwig-Maximilian University, Munich, Germany
| | - Frank Padberg
- Department of Psychiatry, Psychotherapy and Psychosomatics, Ludwig-Maximilian University, Munich, Germany
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Villamar MF, Volz MS, Bikson M, Datta A, Dasilva AF, Fregni F. Technique and considerations in the use of 4x1 ring high-definition transcranial direct current stimulation (HD-tDCS). J Vis Exp 2013:e50309. [PMID: 23893039 PMCID: PMC3735368 DOI: 10.3791/50309] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
High-definition transcranial direct current stimulation (HD-tDCS) has recently been developed as a noninvasive brain stimulation approach that increases the accuracy of current delivery to the brain by using arrays of smaller "high-definition" electrodes, instead of the larger pad-electrodes of conventional tDCS. Targeting is achieved by energizing electrodes placed in predetermined configurations. One of these is the 4x1-ring configuration. In this approach, a center ring electrode (anode or cathode) overlying the target cortical region is surrounded by four return electrodes, which help circumscribe the area of stimulation. Delivery of 4x1-ring HD-tDCS is capable of inducing significant neurophysiological and clinical effects in both healthy subjects and patients. Furthermore, its tolerability is supported by studies using intensities as high as 2.0 milliamperes for up to twenty minutes. Even though 4x1 HD-tDCS is simple to perform, correct electrode positioning is important in order to accurately stimulate target cortical regions and exert its neuromodulatory effects. The use of electrodes and hardware that have specifically been tested for HD-tDCS is critical for safety and tolerability. Given that most published studies on 4x1 HD-tDCS have targeted the primary motor cortex (M1), particularly for pain-related outcomes, the purpose of this article is to systematically describe its use for M1 stimulation, as well as the considerations to be taken for safe and effective stimulation. However, the methods outlined here can be adapted for other HD-tDCS configurations and cortical targets.
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Affiliation(s)
- Mauricio F Villamar
- Laboratory of Neuromodulation, Department of Physical Medicine & Rehabilitation, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Harvard Medical School, USA
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Paulus W, Opitz A. Ohm's law and tDCS over the centuries. Clin Neurophysiol 2012; 124:429-30. [PMID: 23022679 DOI: 10.1016/j.clinph.2012.08.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 08/27/2012] [Accepted: 08/28/2012] [Indexed: 10/27/2022]
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