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Schoisswohl S, Kanig C, Osnabruegge M, Agboada D, Langguth B, Rethwilm R, Hebel T, Abdelnaim MA, Mack W, Seiberl W, Kuder M, Schecklmann M. Monitoring Changes in TMS-Evoked EEG and EMG Activity During 1 Hz rTMS of the Healthy Motor Cortex. eNeuro 2024; 11:ENEURO.0309-23.2024. [PMID: 38565296 PMCID: PMC11015949 DOI: 10.1523/eneuro.0309-23.2024] [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: 08/18/2023] [Revised: 12/13/2023] [Accepted: 01/08/2024] [Indexed: 04/04/2024] Open
Abstract
Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique capable of inducing neuroplasticity as measured by changes in peripheral muscle electromyography (EMG) or electroencephalography (EEG) from pre-to-post stimulation. However, temporal courses of neuromodulation during ongoing rTMS are unclear. Monitoring cortical dynamics via TMS-evoked responses using EMG (motor-evoked potentials; MEPs) and EEG (transcranial-evoked potentials; TEPs) during rTMS might provide further essential insights into its mode of action - temporal course of potential modulations. The objective of this study was to first evaluate the validity of online rTMS-EEG and rTMS-EMG analyses, and second to scrutinize the temporal changes of TEPs and MEPs during rTMS. As rTMS is subject to high inter-individual effect variability, we aimed for single-subject analyses of EEG changes during rTMS. Ten healthy human participants were stimulated with 1,000 pulses of 1 Hz rTMS over the motor cortex, while EEG and EMG were recorded continuously. Validity of MEPs and TEPs measured during rTMS was assessed in sensor and source space. Electrophysiological changes during rTMS were evaluated with model fitting approaches on a group- and single-subject level. TEPs and MEPs appearance during rTMS was consistent with past findings of single pulse experiments. Heterogeneous temporal progressions, fluctuations or saturation effects of brain activity were observed during rTMS depending on the TEP component. Overall, global brain activity increased over the course of stimulation. Single-subject analysis revealed inter-individual temporal courses of global brain activity. The present findings are in favor of dose-response considerations and attempts in personalization of rTMS protocols.
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Affiliation(s)
- Stefan Schoisswohl
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany
- Department of Human Sciences, Institute of Psychology, Universität der Bundeswehr München, 85579 Neubiberg, Germany
| | - Carolina Kanig
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany
- Department of Human Sciences, Institute of Psychology, Universität der Bundeswehr München, 85579 Neubiberg, Germany
| | - Mirja Osnabruegge
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany
- Department of Human Sciences, Institute of Psychology, Universität der Bundeswehr München, 85579 Neubiberg, Germany
| | - Desmond Agboada
- Department of Human Sciences, Institute of Psychology, Universität der Bundeswehr München, 85579 Neubiberg, Germany
| | - Berthold Langguth
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany
| | - Roman Rethwilm
- Department of Human Sciences, Institute of Sport Science, Universität der Bundeswehr München, 85579 Neubiberg, Germany
| | - Tobias Hebel
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany
| | - Mohamed A Abdelnaim
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany
| | - Wolfgang Mack
- Department of Human Sciences, Institute of Psychology, Universität der Bundeswehr München, 85579 Neubiberg, Germany
| | - Wolfgang Seiberl
- Department of Human Sciences, Institute of Sport Science, Universität der Bundeswehr München, 85579 Neubiberg, Germany
| | - Manuel Kuder
- Department of Electrical Engineering, Universität der Bundeswehr München, 85579 Neubiberg, Germany
| | - Martin Schecklmann
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany
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Matsuda RH, Souza VH, Marchetti TC, Soto AM, Kahilakoski OP, Zhdanov A, Malheiro VHE, Laine M, Nyrhinen M, Sinisalo H, Kicic D, Lioumis P, Ilmoniemi RJ, Baffa O. Robotic-electronic platform for autonomous and accurate transcranial magnetic stimulation targeting. Brain Stimul 2024; 17:469-472. [PMID: 38582491 DOI: 10.1016/j.brs.2024.03.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/15/2024] [Accepted: 03/31/2024] [Indexed: 04/08/2024] Open
Affiliation(s)
- Renan H Matsuda
- Department of Physics, Faculty of Philosophy Sciences and Letters of Ribeirão Preto, University of São Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirão Preto, SP, Brazil; Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Rakentajanaukio 2, 02150, Espoo, Finland.
| | - Victor H Souza
- Department of Physics, Faculty of Philosophy Sciences and Letters of Ribeirão Preto, University of São Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirão Preto, SP, Brazil; Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Rakentajanaukio 2, 02150, Espoo, Finland; School of Physiotherapy, Federal University of Juiz de Fora, Juiz de Fora, MG, Brazil
| | - Thais C Marchetti
- Department of Physics, Faculty of Philosophy Sciences and Letters of Ribeirão Preto, University of São Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirão Preto, SP, Brazil
| | - Ana M Soto
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Rakentajanaukio 2, 02150, Espoo, Finland
| | - Olli-Pekka Kahilakoski
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Rakentajanaukio 2, 02150, Espoo, Finland
| | - Andrey Zhdanov
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Rakentajanaukio 2, 02150, Espoo, Finland
| | - Victor H E Malheiro
- Department of Physics, Faculty of Philosophy Sciences and Letters of Ribeirão Preto, University of São Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirão Preto, SP, Brazil
| | - Mikael Laine
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Rakentajanaukio 2, 02150, Espoo, Finland
| | - Mikko Nyrhinen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Rakentajanaukio 2, 02150, Espoo, Finland
| | - Heikki Sinisalo
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Rakentajanaukio 2, 02150, Espoo, Finland
| | - Dubravko Kicic
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Rakentajanaukio 2, 02150, Espoo, Finland
| | - Pantelis Lioumis
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Rakentajanaukio 2, 02150, Espoo, Finland
| | - Risto J Ilmoniemi
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Rakentajanaukio 2, 02150, Espoo, Finland
| | - Oswaldo Baffa
- Department of Physics, Faculty of Philosophy Sciences and Letters of Ribeirão Preto, University of São Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirão Preto, SP, Brazil
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Tao Q, Chao H, Fang D, Dou D. Progress in neurorehabilitation research and the support by the National Natural Science Foundation of China from 2010 to 2022. Neural Regen Res 2024; 19:226-232. [PMID: 37488871 PMCID: PMC10479845 DOI: 10.4103/1673-5374.375342] [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: 02/03/2023] [Revised: 03/27/2023] [Accepted: 04/14/2023] [Indexed: 07/26/2023] Open
Abstract
The National Natural Science Foundation of China is one of the major funding agencies for neurorehabilitation research in China. This study reviews the frontier directions and achievements in the field of neurorehabilitation in China and worldwide. We used data from the Web of Science Core Collection (WoSCC) database to analyze the publications and data provided by the National Natural Science Foundation of China to analyze funding information. In addition, the prospects for neurorehabilitation research in China are discussed. From 2010 to 2022, a total of 74,220 publications in neurorehabilitation were identified, with there being an overall upward tendency. During this period, the National Natural Science Foundation of China has funded 476 research projects with a total funding of 192.38 million RMB to support neurorehabilitation research in China. With the support of the National Natural Science Foundation of China, China has made some achievements in neurorehabilitation research. Research related to neurorehabilitation is believed to be making steady and significant progress in China.
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Affiliation(s)
- Qian Tao
- School of Medicine, Jinan University, Guangzhou, Guangdong Province, China
- School of Health and Life Science, University of Health and Rehabilitation Sciences, Qingdao, Shandong Province, China
- Department of Health Sciences, National Natural Science Foundation of China, Beijing, China
| | - Honglu Chao
- Department of Health Sciences, National Natural Science Foundation of China, Beijing, China
- Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Dong Fang
- Department of Health Sciences, National Natural Science Foundation of China, Beijing, China
| | - Dou Dou
- Department of Health Sciences, National Natural Science Foundation of China, Beijing, China
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Prei K, Kanig C, Osnabruegge M, Langguth B, Mack W, Abdelnaim M, Schecklmann M, Schoisswohl S. Limited evidence for reliability of low and high frequency rTMS over the motor cortex. Brain Res 2023; 1820:148534. [PMID: 37586677 DOI: 10.1016/j.brainres.2023.148534] [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: 06/01/2023] [Revised: 08/07/2023] [Accepted: 08/12/2023] [Indexed: 08/18/2023]
Abstract
OBJECTIVE The aim of this study was to investigate the reliability of low-frequency and high-frequency repetitive transcranial magnetic stimulation (rTMS) on healthy individuals over the motor cortex. A secondary outcome was the assessment if low-frequency rTMS results in inhibition and high-frequency rTMS results in facilitation. METHODS In this experiment, 30 healthy participants received on four consecutive days one session each with application of 1 Hz or 20 Hz rTMS over the left motor cortex. 1 Hz and 20 Hz were applied in alternating order, whereby the starting frequency was randomized. Motor evoked potentials (MEPs) were measured before and after each session. Reliability measures were intraclass and Pearson's correlation coefficient (ICC and r). RESULTS ICCs and r values were low to moderate. Notably, within subgroups of less confounded measures, we found good r values for 20 Hz rTMS. The group-level analysis did not demonstrate a clear low-frequency inhibition and high-frequency facilitation pattern. At the single-subject level, only one participant exhibited significant changes consistent with the expected pattern, with concurrent decreases in MEPs following 1 Hz sessions and increases following 20 Hz sessions. CONCLUSION The investigated neuromodulatory protocols show low to moderate reliability. Results are questioning the low-frequency inhibition and high-frequency facilitation pattern. SIGNIFICANCE Methodological improvements for the usage of rTMS are necessary to increase validity and reliability of non-invasive brain stimulation.
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Affiliation(s)
- Kilian Prei
- Department of Psychiatry and Psychotherapy, University of Regensburg, Universitätsstraße 84, 93053 Regensburg, Germany
| | - Carolina Kanig
- Department of Psychiatry and Psychotherapy, University of Regensburg, Universitätsstraße 84, 93053 Regensburg, Germany; Department of Human Sciences, University of the Bundeswehr Munich, Werner-Heisenberg-Weg 39, 85577 Neubiberg, Germany.
| | - Mirja Osnabruegge
- Department of Psychiatry and Psychotherapy, University of Regensburg, Universitätsstraße 84, 93053 Regensburg, Germany; Department of Human Sciences, University of the Bundeswehr Munich, Werner-Heisenberg-Weg 39, 85577 Neubiberg, Germany
| | - Berthold Langguth
- Department of Psychiatry and Psychotherapy, University of Regensburg, Universitätsstraße 84, 93053 Regensburg, Germany
| | - Wolfgang Mack
- Department of Human Sciences, University of the Bundeswehr Munich, Werner-Heisenberg-Weg 39, 85577 Neubiberg, Germany
| | - Mohamed Abdelnaim
- Department of Psychiatry and Psychotherapy, University of Regensburg, Universitätsstraße 84, 93053 Regensburg, Germany
| | - Martin Schecklmann
- Department of Psychiatry and Psychotherapy, University of Regensburg, Universitätsstraße 84, 93053 Regensburg, Germany
| | - Stefan Schoisswohl
- Department of Psychiatry and Psychotherapy, University of Regensburg, Universitätsstraße 84, 93053 Regensburg, Germany; Department of Human Sciences, University of the Bundeswehr Munich, Werner-Heisenberg-Weg 39, 85577 Neubiberg, Germany
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Shin H, Jeong H, Ryu W, Lee G, Lee J, Kim D, Song IU, Chung YA, Lee S. Robotic transcranial magnetic stimulation in the treatment of depression: a pilot study. Sci Rep 2023; 13:14074. [PMID: 37640754 PMCID: PMC10462606 DOI: 10.1038/s41598-023-41044-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 08/21/2023] [Indexed: 08/31/2023] Open
Abstract
There has been an increasing demand for robotic coil positioning during repetitive transcranial magnetic stimulation (rTMS) treatment. Accurate coil positioning is crucial because rTMS generally targets specific brain regions for both research and clinical application with other reasons such as safety, consistency and reliability and individual variablity. Some previous studies have employed industrial robots or co-robots and showed they can more precisely stimulate the target cortical regions than traditional manual methods. In this study, we not only developed a custom-TMS robot for better TMS coil placement but also analyzed the therapeutic effects on depression. Treatment effects were evaluated by measuring regional cerebral blood flow (rCBF) using single-photon emission computed tomography and depression severity before and after rTMS for the two positioning methods. The rTMS preparation time with our robotic coil placement was reduced by 53% compared with that of the manual method. The position and orientation errors were also significantly reduced from 11.17 mm and 4.06° to 0.94 mm and 0.11°, respectively, confirming the superiority of robotic positioning. The results from clinical and neuroimaging assessments indicated comparable improvements in depression severity and rCBF in the left dorsolateral prefrontal cortex between the robotic and manual rTMS groups. A questionnaire was used to determine the patients' feelings about the robotic system, including the safety and preparation time. A high safety score indicated good acceptability of robotic rTMS at the clinical site.
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Affiliation(s)
- Hyunsoo Shin
- Department of Electrical and Electronic Engineering, Hanyang University, Ansan, 15588, Republic of Korea
| | - Hyeonseok Jeong
- Department of Radiology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, 21431, Republic of Korea
- Department of Neurology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, 21431, Republic of Korea
| | - Wooseok Ryu
- Tesollo Inc., Gwangmyeong, 14353, Republic of Korea
| | - Geunhu Lee
- Department of Electrical and Electronic Engineering, Hanyang University, Ansan, 15588, Republic of Korea
| | - Jaeho Lee
- Department of Electrical and Electronic Engineering, Hanyang University, Ansan, 15588, Republic of Korea
| | - Doyu Kim
- Department of Nuclear Medicine, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, 21431, Republic of Korea
| | - In-Uk Song
- Department of Neurology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, 21431, Republic of Korea
| | - Yong-An Chung
- Department of Nuclear Medicine, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, 21431, Republic of Korea.
| | - Sungon Lee
- Department of Electrical and Electronic Engineering, Hanyang University, Ansan, 15588, Republic of Korea.
- Department of Robotics, Hanyang University, Ansan, 15588, Republic of Korea.
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Su B, Jia Y, Zhang L, Li D, Shen Q, Wang C, Chen Y, Gao F, Wei J, Huang G, Liu H, Wang L. Reliability of TMS measurements using conventional hand-hold method with different numbers of stimuli for tibialis anterior muscle in healthy adults. Front Neural Circuits 2022; 16:986669. [PMID: 36247728 PMCID: PMC9563236 DOI: 10.3389/fncir.2022.986669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 09/15/2022] [Indexed: 11/28/2022] Open
Abstract
Objective: The objective of this study was to determine the reliability of corticomotor excitability measurements using the conventional hand-hold transcranial magnetic stimulation (TMS) method for the tibialis anterior (TA) muscle in healthy adults and the number of stimuli required for reliable assessment. Methods: Forty healthy adults participated in three repeated sessions of corticomotor excitability assessment in terms of resting motor threshold (rMT), slope of recruitment curve (RC), peak motor evoked potential amplitude (pMEP), and MEP latency using conventional TMS method. The first two sessions were conducted with a rest interval of 1 h, and the last session was conducted 7–10 days afterward. With the exception of rMT, the other three outcomes measure elicited with the block of first 3–10 stimuli were analyzed respectively. The within-day (session 1 vs. 2) and between-day (session 1 vs. 3) reliability for all four outcome measures were assessed using intraclass correlation coefficient (ICC), standard error of measurement, and minimum detectable difference at 95% confidence interval. Results: Good to excellent within-day and between-day reliability was found for TMS-induced outcome measures examined using 10 stimuli (ICC ≥ 0.823), except in pMEP, which showed between-day reliability at moderate level (ICC = 0.730). The number of three stimuli was adequate to achieve minimum acceptable within-day reliability for all TMS-induced parameters and between-day reliability for MEP latency. With regard to between-day reliability of RC slope and pMEP, at least seven and nine stimuli were recommended respectively. Conclusion: Our findings indicated the high reliability of corticomotor excitability measurement by TMS with adequate number of stimuli for the TA muscle in healthy adults. This result should be interpreted with caveats for the specific methodological choices, equipment setting, and the characteristics of the sample in the current study. Clinical Trial Registration:http://www.chictr.org.cn, identifier ChiCTR2100045141.
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Affiliation(s)
- Bin Su
- School of Exercise and Health, Shanghai University of Sport, Shanghai, China
- Department of Rehabilitation, Wuxi Central Rehabilitation Hospital, Wuxi, China
| | - Yanbing Jia
- School of Rehabilitation Medicine, Jiangsu Vocational College of Medicine, Yancheng, China
| | - Li Zhang
- Department of Rehabilitation, Wuxi Central Rehabilitation Hospital, Wuxi, China
| | - Duo Li
- Neuro-Rehabilitation Center, JORU Rehabilitation Hospital, Yixing, China
| | - Qianqian Shen
- Department of Rehabilitation, Wuxi Central Rehabilitation Hospital, Wuxi, China
| | - Chun Wang
- Neuro-Rehabilitation Center, JORU Rehabilitation Hospital, Yixing, China
| | - Yating Chen
- Department of Rehabilitation, Wuxi Central Rehabilitation Hospital, Wuxi, China
| | - Fanglan Gao
- Department of Rehabilitation, Wuxi Central Rehabilitation Hospital, Wuxi, China
| | - Jing Wei
- Neuro-Rehabilitation Center, JORU Rehabilitation Hospital, Yixing, China
| | - Guilan Huang
- Department of Rehabilitation, Wuxi Central Rehabilitation Hospital, Wuxi, China
| | - Hao Liu
- School of Rehabilitation Medicine, Jiangsu Vocational College of Medicine, Yancheng, China
- *Correspondence: Lin Wang Hao Liu
| | - Lin Wang
- School of Exercise and Health, Shanghai University of Sport, Shanghai, China
- *Correspondence: Lin Wang Hao Liu
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Devices and Technology in Transcranial Magnetic Stimulation: A Systematic Review. Brain Sci 2022; 12:brainsci12091218. [PMID: 36138954 PMCID: PMC9496961 DOI: 10.3390/brainsci12091218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/05/2022] [Accepted: 09/07/2022] [Indexed: 01/18/2023] Open
Abstract
The technology for transcranial magnetic stimulation (TMS) has significantly changed over the years, with important improvements in the signal generators, the coils, the positioning systems, and the software for modeling, optimization, and therapy planning. In this systematic literature review (SLR), the evolution of each component of TMS technology is presented and analyzed to assess the limitations to overcome. This SLR was carried out following the PRISMA 2020 statement. Published articles of TMS were searched for in four databases (Web of Science, PubMed, Scopus, IEEE). Conference papers and other reviews were excluded. Records were filtered using terms about TMS technology with a semi-automatic software; articles that did not present new technology developments were excluded manually. After this screening, 101 records were included, with 19 articles proposing new stimulator designs (18.8%), 46 presenting or adapting coils (45.5%), 18 proposing systems for coil placement (17.8%), and 43 implementing algorithms for coil optimization (42.6%). The articles were blindly classified by the authors to reduce the risk of bias. However, our results could have been influenced by our research interests, which would affect conclusions for applications in psychiatric and neurological diseases. Our analysis indicates that more emphasis should be placed on optimizing the current technology with a special focus on the experimental validation of models. With this review, we expect to establish the base for future TMS technological developments.
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Goetz SM, Howell B, Wang B, Li Z, Sommer MA, Peterchev AV, Grill WM. Isolating two sources of variability of subcortical stimulation to quantify fluctuations of corticospinal tract excitability. Clin Neurophysiol 2022; 138:134-142. [PMID: 35397278 PMCID: PMC9271909 DOI: 10.1016/j.clinph.2022.02.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 01/17/2022] [Accepted: 02/01/2022] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Investigate the variability previously found with cortical stimulation and handheld transcranial magnetic stimulation (TMS) coils, criticized for its high potential of coil position fluctuations, bypassing the cortex using deep brain electrical stimulation (DBS) of the corticospinal tract with fixed electrodes where both latent variations of the coil position of TMS are eliminated and cortical excitation fluctuations should be absent. METHODS Ten input-output curves were recorded from five anesthetized cats with implanted DBS electrodes targeting the corticospinal tract. Goodness of fit of regressions with a conventional single variability source as well as a dual variability source model was quantified using a Schwarz Bayesian Information approach to avoid overfitting. RESULTS Motor evoked potentials (MEPs) through DBS of the corticospinal tract revealed short-term fluctuations in excitability of the targeted neuron pathway reflecting endogenous input-side variability at similar magnitude as TMS despite bypassing cortical networks. CONCLUSION Input-side variability, i.e., variability resulting in changing MEP amplitudes as if the stimulation strength was modulated, also emerges in electrical stimulation at a similar degree and is not primarily a result of varying stimulation, such as minor coil movements in TMS. More importantly, this variability component is present, although the cortex is bypassed. Thus, it may be of spinal origin, which can include cortical input from spinal projections. Further, the nonlinearity of the compound variability entails complex heteroscedastic non-Gaussian distributions and typically does not allow simple linear averages in statistical analysis of MEPs. As the average is dominated by outliers, it risks bias. With appropriate regression, the net effects of excitatory and inhibitory inputs to the targeted neuron pathways become noninvasively observable and quantifiable. SIGNIFICANCE The neural responses evoked by artificial stimulation in the cerebral cortex are variable. For example, MEPs in response to repeated presentations of the same stimulus can vary from no response to saturation across trials. Several sources of such variability have been suggested, and most of them may be technical in nature, but localization is missing.
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Affiliation(s)
- Stefan M Goetz
- Department of Engineering, University of Cambridge, Cambridge, CB2 1PZ, UK; Department of Psychiatry & Behavioral Sciences, Duke University, Durham, NC 27710, USA; Department of Neurosurgery, Duke University, Durham, NC 27710, USA; Department of Electrical & Computer Engineering, Duke University, Durham, NC 27708, USA; Duke Institute of Brain Sciences, Duke University, Durham, NC 27710, USA.
| | - Bryan Howell
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Boshuo Wang
- Department of Psychiatry & Behavioral Sciences, Duke University, Durham, NC 27710, USA
| | - Zhongxi Li
- Department of Electrical & Computer Engineering, Duke University, Durham, NC 27708, USA
| | - Marc A Sommer
- Duke Institute of Brain Sciences, Duke University, Durham, NC 27710, USA; Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA; Department of Neurobiology, Duke University, Durham, NC 27710, USA
| | - Angel V Peterchev
- Department of Psychiatry & Behavioral Sciences, Duke University, Durham, NC 27710, USA; Department of Neurosurgery, Duke University, Durham, NC 27710, USA; Department of Electrical & Computer Engineering, Duke University, Durham, NC 27708, USA; Duke Institute of Brain Sciences, Duke University, Durham, NC 27710, USA; Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Warren M Grill
- Department of Neurosurgery, Duke University, Durham, NC 27710, USA; Department of Electrical & Computer Engineering, Duke University, Durham, NC 27708, USA; Duke Institute of Brain Sciences, Duke University, Durham, NC 27710, USA; Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA; Department of Neurobiology, Duke University, Durham, NC 27710, USA
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9
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Kuo HC, Zewdie E, Giuffre A, Gan LS, Carlson HL, Wrightson J, Kirton A. Robotic mapping of motor cortex in children with perinatal stroke and hemiparesis. Hum Brain Mapp 2022; 43:3745-3758. [PMID: 35451540 PMCID: PMC9294290 DOI: 10.1002/hbm.25881] [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: 10/19/2021] [Revised: 03/15/2022] [Accepted: 04/05/2022] [Indexed: 11/13/2022] Open
Abstract
Brain stimulation combined with intensive therapy may improve hand function in children with perinatal stroke‐induced unilateral cerebral palsy (UCP). However, response to therapy varies and underlying neuroplasticity mechanisms remain unclear. Here, we aimed to characterize robotic motor mapping outcomes in children with UCP. Twenty‐nine children with perinatal stroke and UCP (median age 11 ± 2 years) were compared to 24 typically developing controls (TDC). Robotic, neuronavigated transcranial magnetic stimulation was employed to define bilateral motor maps including area, volume, and peak motor evoked potential (MEP). Map outcomes were compared to the primary clinical outcome of the Jebsen–Taylor Test of Hand Function (JTT). Maps were reliably obtained in the contralesional motor cortex (24/29) but challenging in the lesioned hemisphere (5/29). Within the contralesional M1 of participants with UCP, area and peak MEP amplitude of the unaffected map were larger than the affected map. When comparing bilateral maps within the contralesional M1 in children with UCP to that of TDC, only peak MEP amplitudes were different, being smaller for the affected hand as compared to TDC. We observed correlations between the unaffected map when stimulating the contralesional M1 and function of the unaffected hand. Robotic motor mapping can characterize motor cortex neurophysiology in children with perinatal stroke. Map area and peak MEP amplitude may represent discrete biomarkers of developmental plasticity in the contralesional M1. Correlations between map metrics and hand function suggest clinical relevance and utility in studies of interventional plasticity.
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Affiliation(s)
- Hsing-Ching Kuo
- Calgary Pediatric Stroke Program, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute (ACHRI), Calgary, Alberta, Canada.,Hotchkiss Brain Institute (HBI), Calgary, Alberta, Canada.,Department of Pediatrics and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physical Medicine & Rehabilitation, University of California Davis, Sacramento, California, USA
| | - Ephrem Zewdie
- Calgary Pediatric Stroke Program, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute (ACHRI), Calgary, Alberta, Canada.,Hotchkiss Brain Institute (HBI), Calgary, Alberta, Canada.,Department of Pediatrics and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Adrianna Giuffre
- Calgary Pediatric Stroke Program, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute (ACHRI), Calgary, Alberta, Canada.,Hotchkiss Brain Institute (HBI), Calgary, Alberta, Canada.,Department of Pediatrics and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Liu Shi Gan
- Hotchkiss Brain Institute (HBI), Calgary, Alberta, Canada
| | - Helen L Carlson
- Calgary Pediatric Stroke Program, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute (ACHRI), Calgary, Alberta, Canada.,Hotchkiss Brain Institute (HBI), Calgary, Alberta, Canada.,Department of Pediatrics and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - James Wrightson
- Calgary Pediatric Stroke Program, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute (ACHRI), Calgary, Alberta, Canada.,Hotchkiss Brain Institute (HBI), Calgary, Alberta, Canada.,Department of Pediatrics and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Adam Kirton
- Calgary Pediatric Stroke Program, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute (ACHRI), Calgary, Alberta, Canada.,Hotchkiss Brain Institute (HBI), Calgary, Alberta, Canada.,Department of Pediatrics and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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10
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Dannhauer M, Huang Z, Beynel L, Wood E, Bukhari-Parlakturk N, Peterchev AV. TAP: targeting and analysis pipeline for optimization and verification of coil placement in transcranial magnetic stimulation. J Neural Eng 2022; 19:10.1088/1741-2552/ac63a4. [PMID: 35377345 PMCID: PMC9131512 DOI: 10.1088/1741-2552/ac63a4] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 04/01/2022] [Indexed: 11/12/2022]
Abstract
Objective.Transcranial magnetic stimulation (TMS) can modulate brain function via an electric field (E-field) induced in a brain region of interest (ROI). The ROI E-field can be computationally maximized and set to match a specific reference using individualized head models to find the optimal coil placement and stimulus intensity. However, the available software lacks many practical features for prospective planning of TMS interventions and retrospective evaluation of the experimental targeting accuracy.Approach.The TMS targeting and analysis pipeline (TAP) software uses an MRI/fMRI-derived brain target to optimize coil placement considering experimental parameters such as the subject's hair thickness and coil placement restrictions. The coil placement optimization is implemented in SimNIBS 3.2, for which an additional graphical user interface (TargetingNavigator) is provided to visualize/adjust procedural parameters. The coil optimization process also computes the E-field at the target, allowing the selection of the TMS device intensity setting to achieve specific E-field strengths. The optimized coil placement information is prepared for neuronavigation software, which supports targeting during the TMS procedure. The neuronavigation system can record the coil placement during the experiment, and these data can be processed in TAP to quantify the accuracy of the experimental TMS coil placement and induced E-field.Main results.TAP was demonstrated in a study consisting of three repetitive TMS sessions in five subjects. TMS was delivered by an experienced operator under neuronavigation with the computationally optimized coil placement. Analysis of the experimental accuracy from the recorded neuronavigation data indicated coil location and orientation deviations up to about 2 mm and 2°, respectively, resulting in an 8% median decrease in the target E-field magnitude compared to the optimal placement.Significance.TAP supports navigated TMS with a variety of features for rigorous and reproducible stimulation delivery, including planning and evaluation of coil placement and intensity selection for E-field-based dosing.
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Affiliation(s)
- Moritz Dannhauer
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC 27710, USA
| | - Ziping Huang
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC 27710, USA
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Lysianne Beynel
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC 27710, USA
| | - Eleanor Wood
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC 27710, USA
| | | | - Angel V. Peterchev
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC 27710, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA
- Department of Neurosurgery, Duke University, Durham, NC 27710, USA
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
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11
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Nieminen JO, Sinisalo H, Souza VH, Malmi M, Yuryev M, Tervo AE, Stenroos M, Milardovich D, Korhonen JT, Koponen LM, Ilmoniemi RJ. Multi-locus transcranial magnetic stimulation system for electronically targeted brain stimulation. Brain Stimul 2022; 15:116-124. [PMID: 34818580 PMCID: PMC8807400 DOI: 10.1016/j.brs.2021.11.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 11/17/2021] [Accepted: 11/19/2021] [Indexed: 11/02/2022] Open
Abstract
BACKGROUND Transcranial magnetic stimulation (TMS) allows non-invasive stimulation of the cortex. In multi-locus TMS (mTMS), the stimulating electric field (E-field) is controlled electronically without coil movement by adjusting currents in the coils of a transducer. OBJECTIVE To develop an mTMS system that allows adjusting the location and orientation of the E-field maximum within a cortical region. METHODS We designed and manufactured a planar 5-coil mTMS transducer to allow controlling the maximum of the induced E-field within a cortical region approximately 30 mm in diameter. We developed electronics with a design consisting of independently controlled H-bridge circuits to drive up to six TMS coils. To control the hardware, we programmed software that runs on a field-programmable gate array and a computer. To induce the desired E-field in the cortex, we developed an optimization method to calculate the currents needed in the coils. We characterized the mTMS system and conducted a proof-of-concept motor-mapping experiment on a healthy volunteer. In the motor mapping, we kept the transducer placement fixed while electronically shifting the E-field maximum on the precentral gyrus and measuring electromyography from the contralateral hand. RESULTS The transducer consists of an oval coil, two figure-of-eight coils, and two four-leaf-clover coils stacked on top of each other. The technical characterization indicated that the mTMS system performs as designed. The measured motor evoked potential amplitudes varied consistently as a function of the location of the E-field maximum. CONCLUSION The developed mTMS system enables electronically targeted brain stimulation within a cortical region.
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Affiliation(s)
- Jaakko O Nieminen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland; BioMag Laboratory, HUS Medical Imaging Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
| | - Heikki Sinisalo
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland; BioMag Laboratory, HUS Medical Imaging Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Victor H Souza
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland; BioMag Laboratory, HUS Medical Imaging Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; School of Physiotherapy, Federal University of Juiz de Fora, Juiz de Fora, MG, Brazil
| | - Mikko Malmi
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland; BioMag Laboratory, HUS Medical Imaging Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Mikhail Yuryev
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
| | - Aino E Tervo
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland; BioMag Laboratory, HUS Medical Imaging Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; AMI Centre, Aalto NeuroImaging, Aalto University School of Science, Espoo, Finland
| | - Matti Stenroos
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
| | - Diego Milardovich
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland; Institute for Microelectronics, Technische Universität Wien, Vienna, Austria
| | - Juuso T Korhonen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
| | - Lari M Koponen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
| | - Risto J Ilmoniemi
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland; BioMag Laboratory, HUS Medical Imaging Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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12
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Giuffre A, Zewdie E, Wrightson JG, Cole L, Carlson HL, Kuo HC, Babwani A, Kirton A. Effects of Transcranial Direct Current Stimulation and High-Definition Transcranial Direct Current Stimulation Enhanced Motor Learning on Robotic Transcranial Magnetic Stimulation Motor Maps in Children. Front Hum Neurosci 2021; 15:747840. [PMID: 34690726 PMCID: PMC8526891 DOI: 10.3389/fnhum.2021.747840] [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: 07/26/2021] [Accepted: 09/16/2021] [Indexed: 11/13/2022] Open
Abstract
Introduction: Conventional transcranial direct current stimulation (tDCS) and high-definition tDCS (HD-tDCS) may improve motor learning in children. Mechanisms are not understood. Neuronavigated robotic transcranial magnetic stimulation (TMS) can produce individualised maps of primary motor cortex (M1) topography. We aimed to determine the effects of tDCS- and HD-tDCS-enhanced motor learning on motor maps. Methods: Typically developing children aged 12-18 years were randomised to right M1 anodal tDCS, HD-tDCS, or Sham during training of their left-hand on the Purdue Pegboard Task (PPT) over 5 days. Bilateral motor mapping was performed at baseline (pre), day 5 (post), and 6-weeks retention time (RT). Primary muscle was the first dorsal interosseous (FDI) with secondary muscles of abductor pollicis brevis (APB) and adductor digiti minimi (ADM). Primary mapping outcomes were volume (mm2/mV) and area (mm2). Secondary outcomes were centre of gravity (COG, mm) and hotspot magnitude (mV). Linear mixed-effects modelling was employed to investigate effects of time and stimulation type (tDCS, HD-tDCS, Sham) on motor map characteristics. Results: Twenty-four right-handed participants (median age 15.5 years, 52% female) completed the study with no serious adverse events or dropouts. Quality maps could not be obtained in two participants. No effect of time or group were observed on map area or volume. LFDI COG (mm) differed in the medial-lateral plane (x-axis) between tDCS and Sham (p = 0.038) from pre-to-post mapping sessions. Shifts in map COG were also observed for secondary left-hand muscles. Map metrics did not correlate with behavioural changes. Conclusion: Robotic TMS mapping can safely assess motor cortex neurophysiology in children undergoing motor learning and neuromodulation interventions. Large effects on map area and volume were not observed while changes in COG may occur. Larger controlled studies are required to understand the role of motor maps in interventional neuroplasticity in children.
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Affiliation(s)
- Adrianna Giuffre
- Calgary Pediatric Stroke Program, Alberta Children's Hospital, Calgary, AB, Canada.,Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Ephrem Zewdie
- Calgary Pediatric Stroke Program, Alberta Children's Hospital, Calgary, AB, Canada.,Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - James G Wrightson
- Calgary Pediatric Stroke Program, Alberta Children's Hospital, Calgary, AB, Canada.,Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Lauran Cole
- Calgary Pediatric Stroke Program, Alberta Children's Hospital, Calgary, AB, Canada
| | - Helen L Carlson
- Calgary Pediatric Stroke Program, Alberta Children's Hospital, Calgary, AB, Canada.,Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Hsing-Ching Kuo
- Department of Physical Medicine & Rehabilitation, University of California, Davis, Sacramento, CA, United States
| | - Ali Babwani
- Calgary Pediatric Stroke Program, Alberta Children's Hospital, Calgary, AB, Canada
| | - Adam Kirton
- Calgary Pediatric Stroke Program, Alberta Children's Hospital, Calgary, AB, Canada.,Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
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13
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Giuffre A, Zewdie E, Carlson HL, Wrightson JG, Kuo HC, Cole L, Kirton A. Robotic transcranial magnetic stimulation motor maps and hand function in adolescents. Physiol Rep 2021; 9:e14801. [PMID: 33817998 PMCID: PMC8020044 DOI: 10.14814/phy2.14801] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 02/24/2021] [Indexed: 12/31/2022] Open
Abstract
Introduction Transcranial magnetic stimulation (TMS) motor mapping can characterize the neurophysiology of the motor system. Limitations including human error and the challenges of pediatric populations may be overcome by emerging robotic systems. We aimed to show that neuronavigated robotic motor mapping in adolescents could efficiently produce discrete maps of individual upper extremity muscles, the characteristics of which would correlate with motor behavior. Methods Typically developing adolescents (TDA) underwent neuronavigated robotic TMS mapping of bilateral motor cortex. Representative maps of first dorsal interosseous (FDI), abductor pollicis brevis (APB), and abductor digiti minimi (ADM) muscles in each hand were created. Map features including area (primary), volume, and center of gravity were analyzed across different excitability regions (R100%, R75%, R50%, R25%). Correlations between map metrics and validated tests of hand motor function (Purdue Pegboard Test as primary) were explored. Results Twenty‐four right‐handed participants (range 12–18 years, median 15.5 years, 52% female) completed bilateral mapping and motor assessments with no serious adverse events or dropouts. Gender and age were associated with hand function and motor map characteristics. Full motor maps (R100%) for FDI did not correlate with motor function in either hand. Smaller excitability subset regions demonstrated reduced variance and dose‐dependent correlations between primary map variables and motor function in the dominant hemisphere. Conclusions Hand function in TDA correlates with smaller subset excitability regions of robotic TMS motor map outcomes. Refined motor maps may have less variance and greater potential to quantify interventional neuroplasticity. Robotic TMS mapping is safe and feasible in adolescents.
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Affiliation(s)
- Adrianna Giuffre
- Calgary Pediatric Stroke Program, Alberta Children's Hospital, Calgary, Alberta, Canada.,Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Ephrem Zewdie
- Calgary Pediatric Stroke Program, Alberta Children's Hospital, Calgary, Alberta, Canada.,Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Helen L Carlson
- Calgary Pediatric Stroke Program, Alberta Children's Hospital, Calgary, Alberta, Canada.,Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - James G Wrightson
- Calgary Pediatric Stroke Program, Alberta Children's Hospital, Calgary, Alberta, Canada.,Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Hsing-Ching Kuo
- Department of Physical Medicine & Rehabilitation, University of California, Davis, CA, USA
| | - Lauran Cole
- Calgary Pediatric Stroke Program, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Adam Kirton
- Calgary Pediatric Stroke Program, Alberta Children's Hospital, Calgary, Alberta, Canada.,Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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14
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Abstract
The pathophysiological mechanisms that underlie the generation and maintenance of tinnitus are being unraveled progressively. Based on this knowledge, a large variety of different neuromodulatory interventions have been developed and are still being designed, adapting to the progressive mechanistic insights in the pathophysiology of tinnitus. rTMS targeting the temporal, temporoparietal, and the frontal cortex has been the mainstay of non-invasive neuromodulation. Yet, the evidence is still unclear, and therefore systematic meta-analyses are needed for drawing conclusions on the effectiveness of rTMS in chronic tinnitus. Different forms of transcranial electrical stimulation (tDCS, tACS, tRNS), applied over the frontal and temporal cortex, have been investigated in tinnitus patients, also without robust evidence for universal efficacy. Cortex and deep brain stimulation with implanted electrodes have shown benefit, yet there is insufficient data to support their routine clinical use. Recently, bimodal stimulation approaches have revealed promising results and it appears that targeting different sensory modalities in temporally combined manners may be more promising than single target approaches.While most neuromodulatory approaches seem promising, further research is required to help translating the scientific outcomes into routine clinical practice.
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15
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Gomez LJ, Dannhauer M, Peterchev AV. Fast computational optimization of TMS coil placement for individualized electric field targeting. Neuroimage 2020; 228:117696. [PMID: 33385544 PMCID: PMC7956218 DOI: 10.1016/j.neuroimage.2020.117696] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 12/04/2020] [Accepted: 12/22/2020] [Indexed: 12/21/2022] Open
Abstract
Background: During transcranial magnetic stimulation (TMS) a coil placed on the scalp is used to non-invasively modulate activity of targeted brain networks via a magnetically induced electric field (E-field). Ideally, the E-field induced during TMS is concentrated on a targeted cortical region of interest (ROI). Determination of the coil position and orientation that best achieve this objective presently requires a large computational effort. Objective: To improve the accuracy of TMS we have developed a fast computational auxiliary dipole method (ADM) for determining the optimum coil position and orientation. The optimum coil placement maximizes the E-field along a predetermined direction or, alternatively, the overall E-field magnitude in the targeted ROI. Furthermore, ADM can assess E-field uncertainty resulting from precision limitations of TMS coil placement protocols. Method: ADM leverages the electromagnetic reciprocity principle to compute rapidly the TMS induced E-field in the ROI by using the E-field generated by a virtual constant current source residing in the ROI. The framework starts by solving for the conduction currents resulting from this ROI current source. Then, it rapidly determines the average E-field induced in the ROI for each coil position by using the conduction currents and a fast-multipole method. To further speed-up the computations, the coil is approximated using auxiliary dipoles enabling it to represent all coil orientations for a given coil position with less than 600 dipoles. Results: Using ADM, the E-fields generated in an MRI-derived head model when the coil is placed at 5900 different scalp positions and 360 coil orientations per position (over 2.1 million unique configurations) can be determined in under 15 min on a standard laptop computer. This enables rapid extraction of the optimum coil position and orientation as well as the E-field variation resulting from coil positioning uncertainty. ADM is implemented in SimNIBS 3.2. Conclusion: ADM enables the rapid determination of coil placement that maximizes E-field delivery to a specific brain target. This method can find the optimum coil placement in under 15 min enabling its routine use for TMS. Furthermore, it enables the fast quantification of uncertainty in the induced E-field due to limited precision of TMS coil placement protocols, enabling minimization and statistical analysis of the E-field dose variability.
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Affiliation(s)
- Luis J Gomez
- Department of Psychiatry and Behavioral Sciences, Duke University, 40 Duke Medicine Circle, Box 3620 DUMC, Durham, NC 27710, USA.
| | - Moritz Dannhauer
- Department of Psychiatry and Behavioral Sciences, Duke University, 40 Duke Medicine Circle, Box 3620 DUMC, Durham, NC 27710, USA.
| | - Angel V Peterchev
- Department of Psychiatry and Behavioral Sciences, Duke University, 40 Duke Medicine Circle, Box 3620 DUMC, Durham, NC 27710, USA; Department of Electrical and Computer Engineering, Duke University, NC 27708, USA; Department of Neurosurgery, Duke University, NC 27710, USA; Department of Biomedical Engineering, Duke University, NC 27708, USA.
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16
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Navarro de Lara LI, Daneshzand M, Mascarenas A, Paulson D, Pratt K, Okada Y, Raij T, Makarov SN, Nummenmaa A. A 3-axis coil design for multichannel TMS arrays. Neuroimage 2020; 224:117355. [PMID: 32916290 PMCID: PMC7837414 DOI: 10.1016/j.neuroimage.2020.117355] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 08/13/2020] [Accepted: 09/04/2020] [Indexed: 01/24/2023] Open
Abstract
Purpose: Multichannel Transcranial Magnetic Stimulation (mTMS) arrays enable
multiple sites to be stimulated simultaneously or sequentially under
electronic control without moving the system’s stimulation coils.
Here, we build and characterize the performance of a novel modular 3-axis
TMS coil that can be utilized as a unit element in large-scale multichannel
TMS arrays. Methods: We determined the basic physical characteristics of the 3-axis TMS
coil x-, y- and
z-elements using a custom 2-channel programmable stimulator
prototype. We mapped the temporal rate-of-change of the induced magnetic
field (dB/dt) on a 2D plane parallel to the coil surface
(including an extended line for full spatial coverage) and compared those
values with predictions from magnetic field simulations. Temperature
measurements were carried out to assess the incorporated air-cooling method.
We measured the mutual and self-inductances of the
x/y/z-elements to assess coupling between them.
Additionally, we measured and calculated the coupling between
z-elements in the array configuration. Finally, we
performed electric field simulations to evaluate the stimulation intensity
and focality of the coil and compared the results to conventional TMS coils
as well as demonstrated suitability of the 3-axis coil for a multichannel
array configuration. Results: The experimentally obtained dB/dt values validated
the computational model of the 3-axis coil and therefore confirmed that both
the coil and stimulator system are operating as intended. The air-cooling
system was effective for brief high-frequency pulse trains and extended
single- and paired-pulse TMS protocols. The electromagnetic simulations
suggested that an array of the 3-axis coils would have comparable
stimulation intensity to conventional TMS coils, therefore enabling clearly
suprathreshold stimulation of the human brain. The recorded coil coupling
between the x/y/z-elements was < 1%
and the maximal coupling between z-elements in the array
configuration was 1.8% and 3.4% for the measured and calculated values,
respectively. Conclusion: We presented a 3-axis coil intended for multichannel TMS arrays. The
electromagnetic measurements and simulations verified that the coil
fabrication met the desired specifications and that the inductive coupling
between the elements was negligible. The air-cooled 3-axis TMS coil appears
suitable to be used as an element in multichannel TMS arrays.
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Affiliation(s)
- Lucia I Navarro de Lara
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA 02129, USA.
| | - Mohammad Daneshzand
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | | | | | - Kevin Pratt
- Tristan Technologies, San Diego, CA 92121, USA
| | | | - Tommi Raij
- Center for Brain Stimulation, Shirley Ryan AbilityLab, Chicago IL 60611 USA; Department of Physical Medicine and Rehabilitation, Department of Neurobiology, Northwestern University, Chicago IL 60611 USA
| | - Sergey N Makarov
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA 02129, USA; Department of Electrical and Computer Engineering, Worcester Polytechnic Institute, Worcester, MA 01609, USA
| | - Aapo Nummenmaa
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA 02129, USA.
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17
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Makarov SN, Wartman WA, Daneshzand M, Fujimoto K, Raij T, Nummenmaa A. A software toolkit for TMS electric-field modeling with boundary element fast multipole method: an efficient MATLAB implementation. J Neural Eng 2020; 17:046023. [PMID: 32235065 DOI: 10.1088/1741-2552/ab85b3] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Objective To present and disseminate our transcranial magnetic stimulation (TMS) modeling software toolkit, including several new algorithmic developments, and to apply this software to realistic TMS modeling scenarios given a high-resolution model of the human head including cortical geometry and an accurate coil model. Approach The recently developed charge-based boundary element fast multipole method (BEM-FMM) is employed as an alternative to the 1st order finite element method (FEM) most commonly used today. The BEM-FMM approach provides high accuracy and unconstrained numerical field resolution close to and across cortical interfaces. Here, the previously proposed BEM-FMM algorithm has been improved in several novel ways. Main results The improvements resulted in a threefold increase in computational speed while maintaining the same solution accuracy. The computational code based on the MATLAB® platform is made available to all interested researchers, along with a coil model repository and examples to create custom coils, head model repository, and supporting documentation. The presented software toolkit may be useful for post-hoc analyses of navigated TMS data using high-resolution subject-specific head models as well as accurate and fast modeling for the purposes of TMS coil/hardware development. Significance TMS is currently the only non-invasive neurostimulation modality that enables painless and safe supra-threshold stimulation by employing electromagnetic induction to efficiently penetrate the skull. Accurate, fast, and high resolution modeling of the electric fields may significantly improve individualized targeting and dosing of TMS and therefore enhance the efficiency of existing clinical protocols as well as help establish new application domains.
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Affiliation(s)
- Sergey N Makarov
- Electrical & Computer Engineering Department, Worcester Polytechnic Institute, Worcester, MA 01609 United States of America. Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115 United States of America. Author to whom any correspondence should be addressed
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