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Chen Y, Jiang Y, Zhang Z, Li Z, Zhu C. Transcranial magnetic stimulation mapping of the motor cortex: comparison of five estimation algorithms. Front Neurosci 2023; 17:1301075. [PMID: 38130697 PMCID: PMC10733534 DOI: 10.3389/fnins.2023.1301075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Accepted: 11/21/2023] [Indexed: 12/23/2023] Open
Abstract
Background There are currently five different kinds of transcranial magnetic stimulation (TMS) motor mapping algorithms available, from ordinary point-based algorithms to advanced field-based algorithms. However, there have been only a limited number of comparison studies conducted, and they have not yet examined all of the currently available algorithms. This deficiency impedes the judicious selection of algorithms for application in both clinical and basic neuroscience, and hinders the potential promotion of a potential superior algorithm. Considering the influence of algorithm complexity, further investigation is needed to examine the differences between fMRI peaks and TMS cortical hotspots that were identified previously. Methods Twelve healthy participants underwent TMS motor mapping and a finger-tapping task during fMRI. The motor cortex TMS mapping results were estimated by five algorithms, and fMRI activation results were obtained. For each algorithm, the prediction error was defined as the distance between the measured scalp hotspot and optimized coil position, which was determined by the maximum electric field strength in the estimated motor cortex. Additionally, the study identified the minimum number of stimuli required for stable mapping. Finally, the location difference between the TMS mapping cortical hotspot and the fMRI activation peak was analyzed. Results The projection yielded the lowest prediction error (5.27 ± 4.24 mm) among the point-based algorithms and the association algorithm yielded the lowest (6.66 ± 3.48 mm) among field-based estimation algorithms. The projection algorithm required fewer stimuli, possibly resulting from its suitability for the grid-based mapping data collection method. The TMS cortical hotspots from all algorithms consistently deviated from the fMRI activation peak (20.52 ± 8.46 mm for five algorithms). Conclusion The association algorithm might be a superior choice for clinical applications and basic neuroscience research, due to its lower prediction error and higher estimation sensitivity in the deep cortical structure, especially for the sulcus. It also has potential applicability in various other TMS domains, including language area mapping and more. Otherwise, our results provide further evidence that TMS motor mapping intrinsically differs from fMRI motor mapping.
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Affiliation(s)
- Yuanyuan Chen
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Yihan Jiang
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
- Center for the Cognitive Science of Language, Beijing Language and Culture University, Beijing, China
| | - Zong Zhang
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Zheng Li
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
- Center for Cognition and Neuroergonomics, State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University Zhuhai, Zhuhai, China
| | - Chaozhe Zhu
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
- IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China
- Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China
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Iannotti GR, Nadin I, Ivanova V, Tourdot Q, Lascano AM, Momjian S, Schaller KL, Lovblad KO, Grouiller F. Specificity of Quantitative Functional Brain Mapping with Arterial Spin-Labeling for Preoperative Assessment. AJNR Am J Neuroradiol 2023; 44:1302-1308. [PMID: 37857448 PMCID: PMC10631521 DOI: 10.3174/ajnr.a8006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 08/28/2023] [Indexed: 10/21/2023]
Abstract
BACKGROUND AND PURPOSE Arterial spin-labeling is a noninvasive MR imaging technique allowing direct and quantitative measurement of brain perfusion. Arterial spin-labeling is well-established in clinics for investigating the overall cerebral perfusion, but it is still occasionally employed during tasks. The typical contrast for functional MR imaging is blood oxygen level-dependent (BOLD) imaging, whose specificity could be biased in neurologic patients due to altered neurovascular coupling. This work aimed to validate the use of functional ASL as a noninvasive tool for presurgical functional brain mapping. This is achieved by comparing the spatial accuracy of functional ASL with transcranial magnetic stimulation as the criterion standard. MATERIALS AND METHODS Twenty-eight healthy participants executed a motor task and received a somatosensory stimulation, while BOLD imaging and arterial spin-labeling were acquired simultaneously. Transcranial magnetic stimulation was subsequently used to define hand somatotopy. RESULTS Functional ASL was found more adjacent to transcranial magnetic stimulation than BOLD imaging, with a significant shift along the inferior-to-superior direction. With respect to BOLD imaging, functional ASL was localized significantly more laterally, anteriorly, and inferiorly during motor tasks and pneumatic stimulation. CONCLUSIONS Our results confirm the specificity of functional ASL in targeting the regional neuronal excitability. Functional ASL could be considered as a valid supplementary technique to BOLD imaging for presurgical mapping when spatial accuracy is crucial for delineating eloquent cortex.
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Affiliation(s)
- Giannina R Iannotti
- From the Division of Neuroradiology, Diagnostic Department (G.R.I., K.O.L.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
- Department of Neurosurgery (G.R.I., I.N., V.I., S.M., K.L.S.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Isaure Nadin
- Department of Neurosurgery (G.R.I., I.N., V.I., S.M., K.L.S.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Vladimira Ivanova
- Department of Neurosurgery (G.R.I., I.N., V.I., S.M., K.L.S.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Quentin Tourdot
- Faculty of Pharmacy (Q.T.), University of Montpellier, Montpellier, France
| | - Agustina M Lascano
- Division of Neurology (A.M.L.), Department of Clinical Neuroscience, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Shahan Momjian
- Department of Neurosurgery (G.R.I., I.N., V.I., S.M., K.L.S.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Karl L Schaller
- Department of Neurosurgery (G.R.I., I.N., V.I., S.M., K.L.S.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Karl O Lovblad
- From the Division of Neuroradiology, Diagnostic Department (G.R.I., K.O.L.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Frederic Grouiller
- Swiss Centre for Affective Sciences (F.G.), University of Geneva, Geneva, Switzerland
- Center for Biomedical Imaging (F.G.), MRI University of Geneva Cognitive and Affective Neuroimaging Section, Geneva, Switzerland
- Laboratory of Neurology and Imaging of Cognition (F.G.), Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland
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Jing Y, Numssen O, Weise K, Kalloch B, Buchberger L, Haueisen J, Hartwigsen G, Knösche TR. Modeling the effects of transcranial magnetic stimulation on spatial attention. Phys Med Biol 2023; 68:214001. [PMID: 37783213 DOI: 10.1088/1361-6560/acff34] [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: 01/12/2023] [Accepted: 10/02/2023] [Indexed: 10/04/2023]
Abstract
Objectives. Transcranial magnetic stimulation (TMS) has been widely used to modulate brain activity in healthy and diseased brains, but the underlying mechanisms are not fully understood. Previous research leveraged biophysical modeling of the induced electric field (E-field) to map causal structure-function relationships in the primary motor cortex. This study aims at transferring this localization approach to spatial attention, which helps to understand the TMS effects on cognitive functions, and may ultimately optimize stimulation schemes.Approach. Thirty right-handed healthy participants underwent a functional magnetic imaging (fMRI) experiment, and seventeen of them participated in a TMS experiment. The individual fMRI activation peak within the right inferior parietal lobule (rIPL) during a Posner-like attention task defined the center target for TMS. Thereafter, participants underwent 500 Posner task trials. During each trial, a 5-pulse burst of 10 Hz repetitive TMS (rTMS) was given over the rIPL to modulate attentional processing. The TMS-induced E-fields for every cortical target were correlated with the behavioral modulation to identify relevant cortical regions for attentional orientation and reorientation.Main results. We did not observe a robust correlation between E-field strength and behavioral outcomes, highlighting the challenges of transferring the localization method to cognitive functions with high neural response variability and complex network interactions. Nevertheless, TMS selectively inhibited attentional reorienting in five out of seventeen subjects, resulting in task-specific behavioral impairments. The BOLD-measured neuronal activity and TMS-evoked neuronal effects showed different patterns, which emphasizes the principal distinction between the neural activity being correlated with (or maybe even caused by) particular paradigms, and the activity of neural populations exerting a causal influence on the behavioral outcome.Significance. This study is the first to explore the mechanisms of TMS-induced attentional modulation through electrical field modeling. Our findings highlight the complexity of cognitive functions and provide a basis for optimizing attentional stimulation protocols.
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Affiliation(s)
- Ying Jing
- Methods and Development Group Brain Networks, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, D-04103, Leipzig, Germany
- Lise Meitner Research Group Cognition and Plasticity, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, D-04103, Leipzig, Germany
| | - Ole Numssen
- Methods and Development Group Brain Networks, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, D-04103, Leipzig, Germany
- Lise Meitner Research Group Cognition and Plasticity, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, D-04103, Leipzig, Germany
| | - Konstantin Weise
- Methods and Development Group Brain Networks, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, D-04103, Leipzig, Germany
- Advanced Electromagnetics Group, Technische Universität Ilmenau, Helmholtzplatz 2, D-98693, Ilmenau, Germany
| | - Benjamin Kalloch
- Methods and Development Group Brain Networks, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, D-04103, Leipzig, Germany
- Institute of Biomedical Engineering and Informatics, Technische Universität Ilmenau, Gustav-Kirchhoff-Straße 2, D-98693, Ilmenau, Germany
| | - Lena Buchberger
- Lise Meitner Research Group Cognition and Plasticity, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, D-04103, Leipzig, Germany
| | - Jens Haueisen
- Institute of Biomedical Engineering and Informatics, Technische Universität Ilmenau, Gustav-Kirchhoff-Straße 2, D-98693, Ilmenau, Germany
| | - Gesa Hartwigsen
- Lise Meitner Research Group Cognition and Plasticity, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, D-04103, Leipzig, Germany
- Wilhelm Wundt Institute for Psychology, Leipzig University, Neumarkt 9-19, D-04109, Leipzig, Germany
| | - Thomas R Knösche
- Methods and Development Group Brain Networks, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, D-04103, Leipzig, Germany
- Institute of Biomedical Engineering and Informatics, Technische Universität Ilmenau, Gustav-Kirchhoff-Straße 2, D-98693, Ilmenau, Germany
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Selective Stimulus Intensity during Hotspot Search Ensures Faster and More Accurate Preoperative Motor Mapping with nTMS. Brain Sci 2023; 13:brainsci13020285. [PMID: 36831828 PMCID: PMC9954713 DOI: 10.3390/brainsci13020285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 02/02/2023] [Accepted: 02/06/2023] [Indexed: 02/10/2023] Open
Abstract
INTRODUCTION Navigated transcranial magnetic stimulation (nTMS) has emerged as one of the most innovative techniques in neurosurgical practice. However, nTMS motor mapping involves rigorous steps, and the importance of an accurate execution method has not been emphasized enough. In particular, despite strict adherence to procedural protocols, we have observed high variability in map activation according to the choice of stimulation intensity (SI) right from the early stage of hotspot localization. We present a retrospective analysis of motor mappings performed between March 2020 and July 2022, where the SI was only chosen with rigorous care in the most recent ones, under the guide of an expert neurophysiologist. MATERIALS AND METHODS In order to test the ability to reduce inaccurate responses and time expenditure using selective SI, data were collected from 16 patients who underwent mapping with the random method (group A) and 15 patients who underwent mapping with the proposed method (group B). The parameters considered were resting motor threshold (%), number of stimuli, number of valid motor evoked potentials (MEPs), number of valid MEPs considered true positives (TPs), number of valid MEPs considered false positives (FPs), ratio of true-positive MEPs to total stimuli, ratio of true-positive MEPs to valid MEPs, minimum amplitude, maximum amplitude and mapping time for each patient. RESULTS The analysis showed statistically significant reductions in total stimulus demand, procedural time and number of false-positive MEPs. Significant increases were observed in the number of true-positive MEPs, the ratio of true-positive MEPs to total stimuli and the ratio of true-positive MEPs to valid MEPs. In the subgroups analyzed, there were similar trends, in particular, an increase in true positives and a decrease in false-positive responses. CONCLUSIONS The precise selection of SI during hotspot search in nTMS motor mapping could provide reliable cortical maps in short time and with low employment of resources. This method seems to ensure that a MEP really represents a functionally eloquent cortical point, making mapping more intuitive even in less experienced centers.
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Hernandez‐Garcia L, Aramendía‐Vidaurreta V, Bolar DS, Dai W, Fernández‐Seara MA, Guo J, Madhuranthakam AJ, Mutsaerts H, Petr J, Qin Q, Schollenberger J, Suzuki Y, Taso M, Thomas DL, van Osch MJP, Woods J, Zhao MY, Yan L, Wang Z, Zhao L, Okell TW. Recent Technical Developments in ASL: A Review of the State of the Art. Magn Reson Med 2022; 88:2021-2042. [PMID: 35983963 PMCID: PMC9420802 DOI: 10.1002/mrm.29381] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 05/31/2022] [Accepted: 06/18/2022] [Indexed: 12/11/2022]
Abstract
This review article provides an overview of a range of recent technical developments in advanced arterial spin labeling (ASL) methods that have been developed or adopted by the community since the publication of a previous ASL consensus paper by Alsop et al. It is part of a series of review/recommendation papers from the International Society for Magnetic Resonance in Medicine Perfusion Study Group. Here, we focus on advancements in readouts and trajectories, image reconstruction, noise reduction, partial volume correction, quantification of nonperfusion parameters, fMRI, fingerprinting, vessel selective ASL, angiography, deep learning, and ultrahigh field ASL. We aim to provide a high level of understanding of these new approaches and some guidance for their implementation, with the goal of facilitating the adoption of such advances by research groups and by MRI vendors. Topics outside the scope of this article that are reviewed at length in separate articles include velocity selective ASL, multiple-timepoint ASL, body ASL, and clinical ASL recommendations.
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Affiliation(s)
| | | | - Divya S. Bolar
- Center for Functional Magnetic Resonance Imaging, Department of RadiologyUniversity of California at San DiegoSan DiegoCaliforniaUSA
| | - Weiying Dai
- Department of Computer ScienceState University of New York at BinghamtonBinghamtonNYUSA
| | | | - Jia Guo
- Department of BioengineeringUniversity of California RiversideRiversideCaliforniaUSA
| | | | - Henk Mutsaerts
- Department of Radiology & Nuclear MedicineAmsterdam University Medical Center, Amsterdam NeuroscienceAmsterdamThe Netherlands
| | - Jan Petr
- Helmholtz‐Zentrum Dresden‐RossendorfInstitute of Radiopharmaceutical Cancer ResearchDresdenGermany
| | - Qin Qin
- The Russell H. Morgan Department of Radiology and Radiological ScienceJohns Hopkins UniversityBaltimoreMarylandUSA
| | | | - Yuriko Suzuki
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
| | - Manuel Taso
- Division of MRI research, RadiologyBeth Israel Deaconess Medical Center and Harvard Medical SchoolBostonMassachusettsUSA
| | - David L. Thomas
- Department of Brain Repair and RehabilitationUCL Queen Square Institute of NeurologyLondonUnited Kingdom
| | - Matthias J. P. van Osch
- C.J. Gorter Center for high field MRI, Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Joseph Woods
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
- Department of RadiologyUniversity of CaliforniaLa JollaCaliforniaUSA
| | - Moss Y. Zhao
- Department of RadiologyStanford UniversityStanfordCaliforniaUSA
| | - Lirong Yan
- Department of Radiology, Feinberg School of MedicineNorthwestern UniversityChicagoIllinoisUSA
| | - Ze Wang
- Department of Diagnostic Radiology and Nuclear MedicineUniversity of Maryland School of MedicineBaltimoreMarylandUSA
| | - Li Zhao
- Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering & Instrument ScienceZhejiang UniversityZhejiangPeople's Republic of China
| | - Thomas W. Okell
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
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Qin Q, Alsop DC, Bolar DS, Hernandez‐Garcia L, Meakin J, Liu D, Nayak KS, Schmid S, van Osch MJP, Wong EC, Woods JG, Zaharchuk G, Zhao MY, Zun Z, Guo J. Velocity-selective arterial spin labeling perfusion MRI: A review of the state of the art and recommendations for clinical implementation. Magn Reson Med 2022; 88:1528-1547. [PMID: 35819184 PMCID: PMC9543181 DOI: 10.1002/mrm.29371] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 05/16/2022] [Accepted: 06/08/2022] [Indexed: 12/11/2022]
Abstract
This review article provides an overview of the current status of velocity-selective arterial spin labeling (VSASL) perfusion MRI and is part of a wider effort arising from the International Society for Magnetic Resonance in Medicine (ISMRM) Perfusion Study Group. Since publication of the 2015 consensus paper on arterial spin labeling (ASL) for cerebral perfusion imaging, important advancements have been made in the field. The ASL community has, therefore, decided to provide an extended perspective on various aspects of technical development and application. Because VSASL has the potential to become a principal ASL method because of its unique advantages over traditional approaches, an in-depth discussion was warranted. VSASL labels blood based on its velocity and creates a magnetic bolus immediately proximal to the microvasculature within the imaging volume. VSASL is, therefore, insensitive to transit delay effects, in contrast to spatially selective pulsed and (pseudo-) continuous ASL approaches. Recent technical developments have improved the robustness and the labeling efficiency of VSASL, making it a potentially more favorable ASL approach in a wide range of applications where transit delay effects are of concern. In this review article, we (1) describe the concepts and theoretical basis of VSASL; (2) describe different variants of VSASL and their implementation; (3) provide recommended parameters and practices for clinical adoption; (4) describe challenges in developing and implementing VSASL; and (5) describe its current applications. As VSASL continues to undergo rapid development, the focus of this review is to summarize the fundamental concepts of VSASL, describe existing VSASL techniques and applications, and provide recommendations to help the clinical community adopt VSASL.
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Affiliation(s)
- Qin Qin
- The Russell H. Morgan Department of Radiology and Radiological ScienceJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - David C. Alsop
- Department of RadiologyBeth Israel Deaconess Medical Center and Harvard Medical SchoolBostonMassachusettsUSA
| | - Divya S. Bolar
- Center for Functional Magnetic Resonance Imaging, Department of RadiologyUniversity of CaliforniaSan Diego La JollaCaliforniaUSA
| | | | - James Meakin
- Department of Radiology, Nuclear Medicine and AnatomyRadboud University Medical CenterNijmegenThe Netherlands
| | - Dapeng Liu
- The Russell H. Morgan Department of Radiology and Radiological ScienceJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Krishna S. Nayak
- Magnetic Resonance Engineering Laboratory, Ming Hsieh Department of Electrical EngineeringUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
| | - Sophie Schmid
- C.J. Gorter Center for high field MRI, Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Matthias J. P. van Osch
- C.J. Gorter Center for high field MRI, Department of RadiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Eric C. Wong
- Center for Functional Magnetic Resonance Imaging, Department of RadiologyUniversity of CaliforniaSan Diego La JollaCaliforniaUSA
| | - Joseph G. Woods
- Center for Functional Magnetic Resonance Imaging, Department of RadiologyUniversity of CaliforniaSan Diego La JollaCaliforniaUSA
| | - Greg Zaharchuk
- Department of RadiologyStanford UniversityStanfordCaliforniaUSA
| | - Moss Y. Zhao
- Department of RadiologyStanford UniversityStanfordCaliforniaUSA
| | - Zungho Zun
- Department of RadiologyWeill Cornell MedicineNew YorkNew YorkUSA
| | - Jia Guo
- Department of BioengineeringUniversity of California RiversideRiversideCaliforniaUSA
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Wang J, Deng X, Hu Y, Yue J, Ge Q, Li X, Feng Z. Low-frequency rTMS targeting individual self-initiated finger-tapping task activation modulates the amplitude of local neural activity in the putamen. Hum Brain Mapp 2022; 44:203-217. [PMID: 36562546 PMCID: PMC9783468 DOI: 10.1002/hbm.26045] [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: 01/27/2022] [Revised: 06/11/2022] [Accepted: 07/25/2022] [Indexed: 02/05/2023] Open
Abstract
Repetitive transcranial magnetic stimulation (rTMS) has been used in the clinical treatment of Parkinson's disease (PD). Most of rTMS studies on PD used high-frequency stimulation; however, excessive nonvoluntary movement may represent abnormally cortical excitability, which is likely to be suppressed by low-frequency rTMS. Decreased neural activity in the basal ganglia on functional magnetic resonance imaging (fMRI) is a characteristic of PD. In the present study, we found that low-frequency (1 Hz) rTMS targeting individual finger-tapping activation elevated the amplitude of local neural activity (percentage amplitude fluctuation, PerAF) in the putamen as well as the functional connectivity (FC) of the stimulation target and basal ganglia in healthy participants. These results provide evidence for our hypothesis that low-frequency rTMS over the individual task activation site can modulate deep brain functions, and that FC might serve as a bridge transmitting the impact of rTMS to the deep brain regions. It suggested that a precisely localized individual task activation site can act as a target for low-frequency rTMS when it is used as a therapeutic tool for PD.
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Affiliation(s)
- Jue Wang
- Institute of Sports Medicine and HealthChengdu Sport UniversityChengduPeople's Republic of China
| | - Xin‐Ping Deng
- Institutes of Psychological SciencesHangzhou Normal UniversityHangzhouPeople's Republic of China,Zhejiang Key Laboratory for Research in Assessment of Cognitive ImpairmentsHangzhouPeople's Republic of China,Center for Cognition and Brain DisordersThe Affiliated Hospital of Hangzhou Normal UniversityHangzhouPeople's Republic of China
| | - Yun‐Song Hu
- Institutes of Psychological SciencesHangzhou Normal UniversityHangzhouPeople's Republic of China,Zhejiang Key Laboratory for Research in Assessment of Cognitive ImpairmentsHangzhouPeople's Republic of China,Center for Cognition and Brain DisordersThe Affiliated Hospital of Hangzhou Normal UniversityHangzhouPeople's Republic of China
| | - Juan Yue
- Institutes of Psychological SciencesHangzhou Normal UniversityHangzhouPeople's Republic of China,Zhejiang Key Laboratory for Research in Assessment of Cognitive ImpairmentsHangzhouPeople's Republic of China,Center for Cognition and Brain DisordersThe Affiliated Hospital of Hangzhou Normal UniversityHangzhouPeople's Republic of China
| | - Qiu Ge
- Institutes of Psychological SciencesHangzhou Normal UniversityHangzhouPeople's Republic of China,Zhejiang Key Laboratory for Research in Assessment of Cognitive ImpairmentsHangzhouPeople's Republic of China,Center for Cognition and Brain DisordersThe Affiliated Hospital of Hangzhou Normal UniversityHangzhouPeople's Republic of China
| | - Xiao‐Long Li
- Institutes of Psychological SciencesHangzhou Normal UniversityHangzhouPeople's Republic of China,Zhejiang Key Laboratory for Research in Assessment of Cognitive ImpairmentsHangzhouPeople's Republic of China,Center for Cognition and Brain DisordersThe Affiliated Hospital of Hangzhou Normal UniversityHangzhouPeople's Republic of China
| | - Zi‐Jian Feng
- Institutes of Psychological SciencesHangzhou Normal UniversityHangzhouPeople's Republic of China,Zhejiang Key Laboratory for Research in Assessment of Cognitive ImpairmentsHangzhouPeople's Republic of China,Center for Cognition and Brain DisordersThe Affiliated Hospital of Hangzhou Normal UniversityHangzhouPeople's Republic of China
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Siebner HR, Funke K, Aberra AS, Antal A, Bestmann S, Chen R, Classen J, Davare M, Di Lazzaro V, Fox PT, Hallett M, Karabanov AN, Kesselheim J, Beck MM, Koch G, Liebetanz D, Meunier S, Miniussi C, Paulus W, Peterchev AV, Popa T, Ridding MC, Thielscher A, Ziemann U, Rothwell JC, Ugawa Y. Transcranial magnetic stimulation of the brain: What is stimulated? - A consensus and critical position paper. Clin Neurophysiol 2022; 140:59-97. [PMID: 35738037 PMCID: PMC9753778 DOI: 10.1016/j.clinph.2022.04.022] [Citation(s) in RCA: 119] [Impact Index Per Article: 59.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 03/14/2022] [Accepted: 04/15/2022] [Indexed: 12/11/2022]
Abstract
Transcranial (electro)magnetic stimulation (TMS) is currently the method of choice to non-invasively induce neural activity in the human brain. A single transcranial stimulus induces a time-varying electric field in the brain that may evoke action potentials in cortical neurons. The spatial relationship between the locally induced electric field and the stimulated neurons determines axonal depolarization. The induced electric field is influenced by the conductive properties of the tissue compartments and is strongest in the superficial parts of the targeted cortical gyri and underlying white matter. TMS likely targets axons of both excitatory and inhibitory neurons. The propensity of individual axons to fire an action potential in response to TMS depends on their geometry, myelination and spatial relation to the imposed electric field and the physiological state of the neuron. The latter is determined by its transsynaptic dendritic and somatic inputs, intrinsic membrane potential and firing rate. Modeling work suggests that the primary target of TMS is axonal terminals in the crown top and lip regions of cortical gyri. The induced electric field may additionally excite bends of myelinated axons in the juxtacortical white matter below the gyral crown. Neuronal excitation spreads ortho- and antidromically along the stimulated axons and causes secondary excitation of connected neuronal populations within local intracortical microcircuits in the target area. Axonal and transsynaptic spread of excitation also occurs along cortico-cortical and cortico-subcortical connections, impacting on neuronal activity in the targeted network. Both local and remote neural excitation depend critically on the functional state of the stimulated target area and network. TMS also causes substantial direct co-stimulation of the peripheral nervous system. Peripheral co-excitation propagates centrally in auditory and somatosensory networks, but also produces brain responses in other networks subserving multisensory integration, orienting or arousal. The complexity of the response to TMS warrants cautious interpretation of its physiological and behavioural consequences, and a deeper understanding of the mechanistic underpinnings of TMS will be critical for advancing it as a scientific and therapeutic tool.
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Affiliation(s)
- Hartwig R Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark; Institute for Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.
| | - Klaus Funke
- Department of Neurophysiology, Medical Faculty, Ruhr-University Bochum, Bochum, Germany
| | - Aman S Aberra
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Andrea Antal
- Department of Clinical Neurophysiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Sven Bestmann
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom; Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Robert Chen
- Krembil Brain Institute, University Health Network and Division of Neurology, University of Toronto, Toronto, Ontario, Canada
| | - Joseph Classen
- Department of Neurology, University of Leipzig, Leipzig, Germany
| | - Marco Davare
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom; Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Vincenzo Di Lazzaro
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, Università Campus Bio-Medico di Roma, via Álvaro del Portillo 21, 00128 Rome, Italy
| | - Peter T Fox
- Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Mark Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Anke N Karabanov
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Nutrition and Exercise, University of Copenhagen, Copenhagen, Denmark
| | - Janine Kesselheim
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Mikkel M Beck
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Giacomo Koch
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy; Non-invasive Brain Stimulation Unit, Laboratorio di NeurologiaClinica e Comportamentale, Fondazione Santa Lucia IRCCS, Rome, Italy
| | - David Liebetanz
- Department of Clinical Neurophysiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Sabine Meunier
- Sorbonne Université, Faculté de Médecine, INSERM U 1127, CNRS 4 UMR 7225, Institut du Cerveau, F-75013, Paris, France
| | - Carlo Miniussi
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Italy; Cognitive Neuroscience Section, IRCCS Centro San Giovanni di DioFatebenefratelli, Brescia, Italy
| | - Walter Paulus
- Department of Clinical Neurophysiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Angel V Peterchev
- Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Psychiatry & Behavioral Sciences, School of Medicine, Duke University, Durham, NC, USA; Department of Electrical & Computer Engineering, Duke University, Durham, NC, USA; Department of Neurosurgery, School of Medicine, Duke University, Durham, NC, USA
| | - Traian Popa
- Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland; Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), Swiss Federal Institute of Technology (EPFL Valais), Clinique Romande de Réadaptation, Sion, Switzerland
| | - Michael C Ridding
- University of South Australia, IIMPACT in Health, Adelaide, Australia
| | - Axel Thielscher
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Health Technology, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Ulf Ziemann
- Department of Neurology & Stroke, University Tübingen, Tübingen, Germany; Hertie Institute for Clinical Brain Research, University Tübingen, Tübingen, Germany
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Yoshikazu Ugawa
- Department of Neurology, Fukushima Medical University, Fukushima, Japan; Fukushima Global Medical Science Centre, Advanced Clinical Research Centre, Fukushima Medical University, Fukushima, Japan
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9
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Mills-Finnerty C, Frangos E, Allen K, Komisaruk B, Wise N. Functional Magnetic Resonance Imaging Studies in Sexual Medicine: A Primer. J Sex Med 2022; 19:1073-1089. [DOI: 10.1016/j.jsxm.2022.03.217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 01/27/2022] [Accepted: 03/04/2022] [Indexed: 11/17/2022]
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10
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Mehta S, Downar J, Mulsant BH, Voineskos D, Daskalakis ZJ, Weissman CR, Vila-Rodriguez F, Blumberger DM. Effect of high frequency versus theta-burst repetitive transcranial magnetic stimulation on suicidality in patients with treatment-resistant depression. Acta Psychiatr Scand 2022; 145:529-538. [PMID: 35188677 PMCID: PMC9007836 DOI: 10.1111/acps.13412] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 01/08/2022] [Accepted: 02/01/2022] [Indexed: 12/17/2022]
Abstract
OBJECTIVE To investigate the effect of 10 Hz repetitive transcranial magnetic stimulation (rTMS) and intermittent theta-burst stimulation (iTBS) on suicidality in patients with treatment-resistant depression (TRD). METHODS We used data from a three-site randomized clinical trial comparing 10 Hz rTMS and iTBS applied to the left dorsolateral prefrontal cortex (DLPFC) in patients with TRD. We compared the effect of 10Hz rTMS and iTBS on suicidality as measured by the suicide item of the Hamilton Depression Rating Scale 17-item (HDRS-17). RESULTS Suicidality remitted in 71 (43.7%) participants randomized to 10Hz stimulation and 91 (49.1%) participants randomized to iTBS, without a significant difference between the proportions in the two groups (Χ2 = 0.674, df = 1, p = 0.4117). There was a significant correlation between change in suicidality and change in depression severity for both modalities (10 Hz, Pearson's r = 0.564; iTBS, Pearson's r = 0.502), with a significantly larger decrease in depression severity for those in whom suicidality remitted compared to those in whom it did not (t = 10.912, df = 276.8, p < 0.001). CONCLUSIONS Both 10 Hz and iTBS rTMS were effective in reducing suicidality in TRD. Future trials of iTBS for depression should include discrete measures of suicidality.
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Affiliation(s)
- Shobha Mehta
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, M5J 1H4, Canada,Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8, Canada
| | - Jonathan Downar
- Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8, Canada,Centre for Mental Health and Krembil Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Benoit H. Mulsant
- Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8, Canada,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8, Canada
| | - Daphne Voineskos
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, M5J 1H4, Canada,Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8, Canada,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8, Canada
| | - Zafiris J. Daskalakis
- Department of Psychiatry, University of California San Diego, La Jolla, California, 92093-0021, United States
| | - Cory R. Weissman
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, M5J 1H4, Canada,Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8, Canada
| | - Fidel Vila-Rodriguez
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada,Non-Invasive Neurostimulation Therapies (NINET) Laboratory, Vancouver, British Columbia, V6T 2A1, Canada
| | - Daniel M. Blumberger
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, M5J 1H4, Canada,Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8, Canada,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8, Canada
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11
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Hensel L, Lange F, Tscherpel C, Viswanathan S, Freytag J, Volz LJ, Eickhoff SB, Fink GR, Grefkes C. Recovered grasping performance after stroke depends on interhemispheric frontoparietal connectivity. Brain 2022; 146:1006-1020. [PMID: 35485480 PMCID: PMC9976969 DOI: 10.1093/brain/awac157] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 03/19/2022] [Accepted: 04/14/2022] [Indexed: 01/11/2023] Open
Abstract
Activity changes in the ipsi- and contralesional parietal cortex and abnormal interhemispheric connectivity between these regions are commonly observed after stroke, however, their significance for motor recovery remains poorly understood. We here assessed the contribution of ipsilesional and contralesional anterior intraparietal cortex (aIPS) for hand motor function in 18 recovered chronic stroke patients and 18 healthy control subjects using a multimodal assessment consisting of resting-state functional MRI, motor task functional MRI, online-repetitive transcranial magnetic stimulation (rTMS) interference, and 3D movement kinematics. Effects were compared against two control stimulation sites, i.e. contralesional M1 and a sham stimulation condition. We found that patients with good motor outcome compared to patients with more substantial residual deficits featured increased resting-state connectivity between ipsilesional aIPS and contralesional aIPS as well as between ipsilesional aIPS and dorsal premotor cortex. Moreover, interhemispheric connectivity between ipsilesional M1 and contralesional M1 as well as ipsilesional aIPS and contralesional M1 correlated with better motor performance across tasks. TMS interference at individual aIPS and M1 coordinates led to differential effects depending on the motor task that was tested, i.e. index finger-tapping, rapid pointing movements, or a reach-grasp-lift task. Interfering with contralesional aIPS deteriorated the accuracy of grasping, especially in patients featuring higher connectivity between ipsi- and contralesional aIPS. In contrast, interference with the contralesional M1 led to impaired grasping speed in patients featuring higher connectivity between bilateral M1. These findings suggest differential roles of contralesional M1 and aIPS for distinct aspects of recovered hand motor function, depending on the reorganization of interhemispheric connectivity.
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Affiliation(s)
- Lukas Hensel
- Faculty of Medicine and University Hospital Cologne, Department of Neurology, University of Cologne, Cologne, Germany
| | - Fabian Lange
- Faculty of Medicine and University Hospital Cologne, Department of Neurology, University of Cologne, Cologne, Germany
| | - Caroline Tscherpel
- Faculty of Medicine and University Hospital Cologne, Department of Neurology, University of Cologne, Cologne, Germany,Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, Jülich, Germany
| | - Shivakumar Viswanathan
- Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, Jülich, Germany
| | - Jana Freytag
- Faculty of Medicine and University Hospital Cologne, Department of Neurology, University of Cologne, Cologne, Germany
| | - Lukas J Volz
- Faculty of Medicine and University Hospital Cologne, Department of Neurology, University of Cologne, Cologne, Germany
| | - Simon B Eickhoff
- Institute of Systems Neuroscience, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany,Institute of Neuroscience and Medicine, Brain & Behaviour (INM-7), Research Centre Jülich, Jülich, Germany
| | - Gereon R Fink
- Faculty of Medicine and University Hospital Cologne, Department of Neurology, University of Cologne, Cologne, Germany,Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, Jülich, Germany
| | - Christian Grefkes
- Correspondence to: Christian Grefkes Institute of Neuroscience and Medicine - Cognitive Neuroscience (INM-3) Research Centre Juelich, Juelich, Germany E-mail:
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12
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Batschelett M, Gibbs S, Holder CM, Holcombe B, Wheless JW, Narayana S. Plasticity in the developing brain: neurophysiological basis for lesion-induced motor reorganization. Brain Commun 2021; 4:fcab300. [PMID: 35174326 PMCID: PMC8842689 DOI: 10.1093/braincomms/fcab300] [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: 05/19/2021] [Revised: 11/10/2021] [Accepted: 12/17/2021] [Indexed: 11/13/2022] Open
Abstract
The plasticity of the developing brain can be observed following injury to the
motor cortex and/or corticospinal tracts, the most commonly injured brain area
in the pre- or peri-natal period. Factors such as the timing of injury, lesion
size and lesion location may affect a single hemisphere’s ability to
acquire bilateral motor representation. Bilateral motor representation of single
hemisphere origin is most likely to occur if brain injury occurs before the age
of 2 years; however, the link between injury aetiology, reorganization type and
functional outcome is largely understudied. We performed a retrospective review
to examine reorganized cortical motor maps identified through transcranial
magnetic stimulation in a cohort of 52 patients. Subsequent clinical,
anthropometric and demographic information was recorded for each patient. Each
patient’s primary hand motor cortex centre of gravity, along with the
Euclidian distance between reorganized and normally located motor cortices, was
also calculated. The patients were classified into broad groups including
reorganization type (inter- and intrahemispheric motor reorganization), age at
the time of injury (before 2 years and after 2 years) and injury aetiology
(developmental disorders and acquired injuries). All measures were analysed to
find commonalities between motor reorganization type and injury aetiology,
function and centre of gravity distance. There was a significant effect of
injury aetiology on type of motor reorganization
(P < 0.01), with 60.7% of patients
with acquired injuries and 15.8% of patients with developmental disorders
demonstrating interhemispheric motor reorganization. Within the interhemispheric
motor reorganization group, ipsilaterally and contralaterally projecting hand
motor cortex centres of gravity overlapped, indicating shared cortical motor
representation. Furthermore, the data suggest significantly higher prevalence of
bilateral motor representation from a single hemisphere in cases of acquired
injuries compared to those of developmental origin. Functional outcome was found
to be negatively affected by acquired injuries and interhemispheric motor
reorganization relative to their respective counterparts with developmental
lesions and intrahemispheric motor reorganization. These results provide novel
information regarding motor reorganization in the developing brain via an
unprecedented cohort sample size and transcranial magnetic stimulation.
Transcranial magnetic stimulation is uniquely suited for use in understanding
the principles of motor reorganization, thereby aiding in the development of
more efficacious therapeutic techniques to improve functional recovery following
motor cortex injury.
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Affiliation(s)
- Mitchell Batschelett
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN, USA
- Rhodes College, Memphis, TN, USA
| | - Savannah Gibbs
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN, USA
| | - Christen M. Holder
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN, USA
- Department of Pediatrics, Division of Pediatric Neurology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Billy Holcombe
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN, USA
- Department of Pediatrics, Division of Pediatric Neurology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - James W. Wheless
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN, USA
- Department of Pediatrics, Division of Pediatric Neurology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Shalini Narayana
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN, USA
- Department of Pediatrics, Division of Pediatric Neurology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Anatomy and Neurobiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
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13
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Numssen O, Zier AL, Thielscher A, Hartwigsen G, Knösche TR, Weise K. Efficient high-resolution TMS mapping of the human motor cortex by nonlinear regression. Neuroimage 2021; 245:118654. [PMID: 34653612 DOI: 10.1016/j.neuroimage.2021.118654] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 09/22/2021] [Accepted: 10/11/2021] [Indexed: 11/29/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) is a powerful tool to investigate causal structure-function relationships in the human brain. However, a precise delineation of the effectively stimulated neuronal populations is notoriously impeded by the widespread and complex distribution of the induced electric field. Here, we propose a method that allows rapid and feasible cortical localization at the individual subject level. The functional relationship between electric field and behavioral effect is quantified by combining experimental data with numerically modeled fields to identify the cortical origin of the modulated effect. Motor evoked potentials (MEPs) from three finger muscles were recorded for a set of random stimulations around the primary motor area. All induced electric fields were nonlinearly regressed against the elicited MEPs to identify their cortical origin. We could distinguish cortical muscle representation with high spatial resolution and localized them primarily on the crowns and rims of the precentral gyrus. A post-hoc analysis revealed exponential convergence of the method with the number of stimulations, yielding a minimum of about 180 random stimulations to obtain stable results. Establishing a functional link between the modulated effect and the underlying mode of action, the induced electric field, is a fundamental step to fully exploit the potential of TMS. In contrast to previous approaches, the presented protocol is particularly easy to implement, fast to apply, and very robust due to the random coil positioning and therefore is suitable for practical and clinical applications.
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Affiliation(s)
- Ole Numssen
- Lise Meitner Research Group Cognition and Plasticity, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, 04103 Leipzig, Germany.
| | - Anna-Leah Zier
- Lise Meitner Research Group Cognition and Plasticity, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, 04103 Leipzig, Germany; Methods and Development Group "Brain Networks", Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, 04103 Leipzig, Germany
| | - Axel Thielscher
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Denmark; Technical University of Denmark, Center for Magnetic Resonance, Department of Health Technology, Kongens Lyngby, Denmark
| | - Gesa Hartwigsen
- Lise Meitner Research Group Cognition and Plasticity, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, 04103 Leipzig, Germany
| | - Thomas R Knösche
- Methods and Development Group "Brain Networks", Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, 04103 Leipzig, Germany; Technische Universität Ilmenau, Institute of Biomedical Engineering and Informatics, Gustav-Kirchhoff-Straße 2, 98693 Ilmenau, Germany
| | - Konstantin Weise
- Methods and Development Group "Brain Networks", Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, 04103 Leipzig, Germany; Technische Universität Ilmenau, Advanced Electromagnetics Group, Helmholtzplatz 2, 98693 Ilmenau, Germany
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14
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Kataja J, Soldati M, Matilainen N, Laakso I. A probabilistic transcranial magnetic stimulation localization method. J Neural Eng 2021; 18. [PMID: 34475274 DOI: 10.1088/1741-2552/ac1f2b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 08/05/2021] [Indexed: 12/15/2022]
Abstract
Objective.Transcranial magnetic stimulation (TMS) can be used to safely and noninvasively activate brain tissue. However, the characteristic parameters of the neuronal activation have been largely unclear. In this work, we propose a novel neuronal activation model and develop a method to infer its parameters from measured motor evoked potential signals.Approach.The connection between neuronal activation due to an induced electric field and a measured motor threshold is modeled. The posterior distribution of the model parameters are inferred from measurement data using Bayes' formula. The measurements are the active motor thresholds obtained with multiple stimulating coil locations, and the parameters of the model are the location, preferred direction of activation, and threshold electric field value of the activation site. The posterior distribution is sampled using a Markov chain Monte Carlo method. We quantify the plausibility of the model by calculating the marginal likelihood of the measured thresholds. The method is validated with synthetic data and applied to motor threshold measurements from the first dorsal interosseus muscle in five healthy participants.Main results.The method produces a probability distribution for the activation location, from which a minimal volume where the activation occurs with 95% probability can be derived. For eight or nine stimulating coil locations, the smallest such a volume obtained was approximately 100 mm3. The 95% probability volume intersected the pre-central gyral crown and the anterior wall of the central sulcus, and the preferred direction was perpendicular to the central sulcus, both findings being consistent with the literature. Furthermore, it was not possible to rule out if the activation occurred either in the white or grey matter. In one participant, two distinct activations sites were found while others exhibited a unique site.Significance.The method is both generic and robust, and it lays a foundation for a framework that enables accurate analysis and characterization of TMS activation mechanisms.
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Affiliation(s)
- Juhani Kataja
- Department of Electrical Engineering and Automation, Aalto University, Espoo, Finland
| | - Marco Soldati
- Department of Electrical Engineering and Automation, Aalto University, Espoo, Finland
| | - Noora Matilainen
- Department of Electrical Engineering and Automation, Aalto University, Espoo, Finland
| | - Ilkka Laakso
- Department of Electrical Engineering and Automation, Aalto University, Espoo, Finland.,Aalto Neuroimaging, Aalto University, Espoo, Finland
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15
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The Myelin Content of the Human Precentral Hand Knob Reflects Interindividual Differences in Manual Motor Control at the Physiological and Behavioral Level. J Neurosci 2021; 41:3163-3179. [PMID: 33653698 PMCID: PMC8026359 DOI: 10.1523/jneurosci.0390-20.2021] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 02/22/2021] [Accepted: 02/24/2021] [Indexed: 11/21/2022] Open
Abstract
The primary motor cortex hand area (M1HAND) and adjacent dorsal premotor cortex (PMd) form the so-called motor hand knob in the precentral gyrus. M1HAND and PMd are critical for dexterous hand use and are densely interconnected via corticocortical axons, lacking a sharp demarcating border. In 24 young right-handed volunteers, we performed multimodal mapping to delineate the relationship between structure and function in the right motor hand knob. Quantitative structural magnetic resonance imaging (MRI) at 3 tesla yielded regional R1 maps as a proxy of cortical myelin content. Participants also underwent functional MRI (fMRI). We mapped task-related activation and temporal precision, while they performed a visuomotor synchronization task requiring visually cued abduction movements with the left index or little finger. We also performed sulcus-aligned transcranial magnetic stimulation of the motor hand knob to localize the optimal site (hotspot) for evoking a motor evoked potential (MEP) in two intrinsic hand muscles. Individual motor hotspot locations varied along the rostrocaudal axis. The more rostral the motor hotspot location in the precentral crown, the longer were corticomotor MEP latencies. “Hotspot rostrality” was associated with the regional myelin content in the precentral hand knob. Cortical myelin content also correlated positively with task-related activation of the precentral crown and temporal precision during the visuomotor synchronization task. Together, our results suggest a link among cortical myelination, the spatial cortical representation, and temporal precision of finger movements. We hypothesize that the myelination of cortical axons facilitates neuronal integration in PMd and M1HAND and, hereby, promotes the precise timing of movements. SIGNIFICANCE STATEMENT Here we used magnetic resonance imaging and transcranial magnetic stimulation of the precentral motor hand knob to test for a link among cortical myelin content, functional corticomotor representations, and manual motor control. A higher myelin content of the precentral motor hand knob was associated with more rostral corticomotor presentations, with stronger task-related activation and a higher precision of movement timing during a visuomotor synchronization task. We propose that a high precentral myelin content enables fast and precise neuronal integration in M1 (primary motor cortex) and dorsal premotor cortex, resulting in higher temporal precision during dexterous hand use. Our results identify the degree of myelination as an important structural feature of the neocortex that is tightly linked to the function and behavior supported by the cortical area.
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16
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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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17
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Binder E, Leimbach M, Pool EM, Volz LJ, Eickhoff SB, Fink GR, Grefkes C. Cortical reorganization after motor stroke: A pilot study on differences between the upper and lower limbs. Hum Brain Mapp 2020; 42:1013-1033. [PMID: 33165996 PMCID: PMC7856649 DOI: 10.1002/hbm.25275] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 09/03/2020] [Accepted: 09/29/2020] [Indexed: 11/11/2022] Open
Abstract
Stroke patients suffering from hemiparesis may show substantial recovery in the first months poststroke due to neural reorganization. While reorganization driving improvement of upper hand motor function has been frequently investigated, much less is known about the changes underlying recovery of lower limb function. We, therefore, investigated neural network dynamics giving rise to movements of both the hands and feet in 12 well-recovered left-hemispheric chronic stroke patients and 12 healthy participants using a functional magnetic resonance imaging sparse sampling design and dynamic causal modeling (DCM). We found that the level of neural activity underlying movements of the affected right hand and foot positively correlated with residual motor impairment, in both ipsilesional and contralesional premotor as well as left primary motor (M1) regions. Furthermore, M1 representations of the affected limb showed significantly stronger increase in BOLD activity compared to healthy controls and compared to the respective other limb. DCM revealed reduced endogenous connectivity of M1 of both limbs in patients compared to controls. However, when testing for the specific effect of movement on interregional connectivity, interhemispheric inhibition of the contralesional M1 during movements of the affected hand was not detected in patients whereas no differences in condition-dependent connectivity were found for foot movements compared to controls. In contrast, both groups featured positive interhemispheric M1 coupling, that is, facilitation of neural activity, mediating movements of the affected foot. These exploratory findings help to explain why functional recovery of the upper and lower limbs often develops differently after stroke, supporting limb-specific rehabilitative strategies.
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Affiliation(s)
- Ellen Binder
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Institute of Neuroscience and Medicine (INM-1, INM-3), Research Centre Juelich, Juelich, Germany
| | - Martha Leimbach
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Eva-Maria Pool
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Institute of Neuroscience and Medicine (INM-1, INM-3), Research Centre Juelich, Juelich, Germany
| | - Lukas J Volz
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Department of Psychological and Brain Sciences, University of California, Santa Barbara, California, USA
| | - Simon B Eickhoff
- Institute of Neuroscience and Medicine (INM-1, INM-3), Research Centre Juelich, Juelich, Germany.,Institute for Clinical Neuroscience, Heinrich-Heine-University, Duesseldorf, Germany
| | - Gereon R Fink
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Institute of Neuroscience and Medicine (INM-1, INM-3), Research Centre Juelich, Juelich, Germany
| | - Christian Grefkes
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Institute of Neuroscience and Medicine (INM-1, INM-3), Research Centre Juelich, Juelich, Germany
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18
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Kim H, Kim J, Lee HJ, Lee J, Na Y, Chang WH, Kim YH. Optimal stimulation site for rTMS to improve motor function: Anatomical hand knob vs. hand motor hotspot. Neurosci Lett 2020; 740:135424. [PMID: 33075419 DOI: 10.1016/j.neulet.2020.135424] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 09/28/2020] [Accepted: 10/01/2020] [Indexed: 01/28/2023]
Abstract
Repetitive transcranial magnetic stimulation (rTMS) is used to modulate neuronal excitability of the human brain. Distant effects on contralateral corticomotor excitability can be exerted by interhemispheric modulation by low-frequency rTMS on ipsilateral hemisphere. To modulate corticospinal excitability, accurate determination of the stimulation site is important to maximize the effects of rTMS. In the present study, we investigated the difference in the distant effect of 1 Hz rTMS with respect to inducing functional improvement in the non-dominant hand by inhibiting the dominant hemisphere depending on cortical target areas. Ten healthy right-handed volunteers without any neurological disorders were enrolled. The anatomical hand knob (HK) identified from individual magnetic resonance imaging and the transcranial magnetic stimulation (TMS) induced hand motor hotspot (hMHS) by recording motor evoked potentials (MEPs) in the contralateral first dorsal interosseous muscle were determined. All participants underwent three conditions of 1 Hz rTMS on left hemisphere intervention; rTMS application over the HK, rTMS application over the hMHS, and sham-rTMS. Before and after each intervention, all participants undergone motor function assessments with their left hand. The cortical mapping showed that the hMHS was located anteriorly and laterally compared to the HK. Motor function tests showed the most significant improvements after the hMHS stimulation. When we compared the distant effects of target site on corticospinal excitability and motor behavior, delivering 1 Hz rTMS to the hMHS was more effective than delivering it to the HK for improving corticomotor excitability, motor skill, and dexterity. These results suggest that TMS-induced hMHS is an optimal target area to induce distant effect of low-frequency rTMS in motor function.
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Affiliation(s)
- Heegoo 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; Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea
| | - Jinuk 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; Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea
| | - Hwang-Jae Lee
- 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; Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea
| | - Jungsoo Lee
- 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
| | - Yoonju Na
- 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
| | - Won Hyuk Chang
- 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
| | - 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; Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea; Department of Medical Device Management & Research, Department of Digital Health, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea.
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19
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Hensel L, Tscherpel C, Freytag J, Ritter S, Rehme AK, Volz LJ, Eickhoff SB, Fink GR, Grefkes C. Connectivity-Related Roles of Contralesional Brain Regions for Motor Performance Early after Stroke. Cereb Cortex 2020; 31:993-1007. [DOI: 10.1093/cercor/bhaa270] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 08/22/2020] [Accepted: 08/25/2020] [Indexed: 02/07/2023] Open
Abstract
Abstract
Hemiparesis after stroke is associated with increased neural activity not only in the lesioned but also in the contralesional hemisphere. While most studies have focused on the role of contralesional primary motor cortex (M1) activity for motor performance, data on other areas within the unaffected hemisphere are scarce, especially early after stroke. We here combined functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) to elucidate the contribution of contralesional M1, dorsal premotor cortex (dPMC), and anterior intraparietal sulcus (aIPS) for the stroke-affected hand within the first 10 days after stroke. We used “online” TMS to interfere with neural activity at subject-specific fMRI coordinates while recording 3D movement kinematics. Interfering with aIPS activity improved tapping performance in patients, but not healthy controls, suggesting a maladaptive role of this region early poststroke. Analyzing effective connectivity parameters using a Lasso prediction model revealed that behavioral TMS effects were predicted by the coupling of the stimulated aIPS with dPMC and ipsilesional M1. In conclusion, we found a strong link between patterns of frontoparietal connectivity and TMS effects, indicating a detrimental influence of the contralesional aIPS on motor performance early after stroke.
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Affiliation(s)
- Lukas Hensel
- Faculty of Medicine and University Hospital Cologne, Department of Neurology, University of Cologne, 50931 Cologne, Germany
| | - Caroline Tscherpel
- Faculty of Medicine and University Hospital Cologne, Department of Neurology, University of Cologne, 50931 Cologne, Germany
- Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, 52428 Jülich, Germany
| | - Jana Freytag
- Faculty of Medicine and University Hospital Cologne, Department of Neurology, University of Cologne, 50931 Cologne, Germany
| | - Stella Ritter
- Faculty of Medicine and University Hospital Cologne, Department of Neurology, University of Cologne, 50931 Cologne, Germany
| | - Anne K Rehme
- Faculty of Medicine and University Hospital Cologne, Department of Neurology, University of Cologne, 50931 Cologne, Germany
| | - Lukas J Volz
- Faculty of Medicine and University Hospital Cologne, Department of Neurology, University of Cologne, 50931 Cologne, Germany
| | - Simon B Eickhoff
- Medical Faculty, Institute of Systems Neuroscience, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
- Brain and Behaviour, Institute of Neuroscience and Medicine, (INM-7), Research Centre Jülich, 52428 Jülich, Germany
| | - Gereon R Fink
- Faculty of Medicine and University Hospital Cologne, Department of Neurology, University of Cologne, 50931 Cologne, Germany
- Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, 52428 Jülich, Germany
| | - Christian Grefkes
- Faculty of Medicine and University Hospital Cologne, Department of Neurology, University of Cologne, 50931 Cologne, Germany
- Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, 52428 Jülich, Germany
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20
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Rashed EA, Gomez-Tames J, Hirata A. Deep Learning-Based Development of Personalized Human Head Model With Non-Uniform Conductivity for Brain Stimulation. IEEE TRANSACTIONS ON MEDICAL IMAGING 2020; 39:2351-2362. [PMID: 31995479 DOI: 10.1109/tmi.2020.2969682] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Electromagnetic stimulation of the human brain is a key tool for neurophysiological characterization and the diagnosis of several neurological disorders. Transcranial magnetic stimulation (TMS) is a commonly used clinical procedure. However, personalized TMS requires a pipeline for individual head model generation to provide target-specific stimulation. This process includes intensive segmentation of several head tissues based on magnetic resonance imaging (MRI), which has significant potential for segmentation error, especially for low-contrast tissues. Additionally, a uniform electrical conductivity is assigned to each tissue in the model, which is an unrealistic assumption based on conventional volume conductor modeling. This study proposes a novel approach for fast and automatic estimation of the electric conductivity in the human head for volume conductor models without anatomical segmentation. A convolutional neural network is designed to estimate personalized electrical conductivity values based on anatomical information obtained from T1- and T2-weighted MRI scans. This approach can avoid the time-consuming process of tissue segmentation and maximize the advantages of position-dependent conductivity assignment based on the water content values estimated from MRI intensity values. The computational results of the proposed approach provide similar but smoother electric field distributions of the brain than that provided by conventional approaches.
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21
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Weiss Lucas C, Nettekoven C, Neuschmelting V, Oros-Peusquens AM, Stoffels G, Viswanathan S, Rehme AK, Faymonville AM, Shah NJ, Langen KJ, Goldbrunner R, Grefkes C. Invasive versus non-invasive mapping of the motor cortex. Hum Brain Mapp 2020; 41:3970-3983. [PMID: 32588936 PMCID: PMC7469817 DOI: 10.1002/hbm.25101] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 05/05/2020] [Accepted: 06/08/2020] [Indexed: 11/26/2022] Open
Abstract
Precise and comprehensive mapping of somatotopic representations in the motor cortex is clinically essential to achieve maximum resection of brain tumours whilst preserving motor function, especially since the current gold standard, that is, intraoperative direct cortical stimulation (DCS), holds limitations linked to the intraoperative setting such as time constraints or anatomical restrictions. Non‐invasive techniques are increasingly relevant with regard to pre‐operative risk‐assessment. Here, we assessed the congruency of neuronavigated transcranial magnetic stimulation (nTMS) and functional magnetic resonance imaging (fMRI) with DCS. The motor representations of the hand, the foot and the tongue regions of 36 patients with intracranial tumours were mapped pre‐operatively using nTMS and fMRI and by intraoperative DCS. Euclidean distances (ED) between hotspots/centres of gravity and (relative) overlaps of the maps were compared. We found significantly smaller EDs (11.4 ± 8.3 vs. 16.8 ± 7.0 mm) and better spatial overlaps (64 ± 38% vs. 37 ± 37%) between DCS and nTMS compared with DCS and fMRI. In contrast to DCS, fMRI and nTMS mappings were feasible for all regions and patients without complications. In summary, nTMS seems to be the more promising non‐invasive motor cortex mapping technique to approximate the gold standard DCS results.
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Affiliation(s)
- Carolin Weiss Lucas
- Medical Faculty and University Hospital, Center for Neurosurgery, University of Cologne, Cologne, Germany
| | - Charlotte Nettekoven
- Medical Faculty and University Hospital, Center for Neurosurgery, University of Cologne, Cologne, Germany
| | - Volker Neuschmelting
- Medical Faculty and University Hospital, Center for Neurosurgery, University of Cologne, Cologne, Germany
| | | | - Gabriele Stoffels
- Research Centre Jülich, Institute of Neuroscience and Medicine, Jülich, Germany
| | | | - Anne K Rehme
- Research Centre Jülich, Institute of Neuroscience and Medicine, Jülich, Germany.,Medical Faculty and University Hospital, Department of Neurology, University of Cologne, Cologne, Germany
| | - Andrea Maria Faymonville
- Medical Faculty and University Hospital, Center for Neurosurgery, University of Cologne, Cologne, Germany
| | - N Jon Shah
- Research Centre Jülich, Institute of Neuroscience and Medicine, Jülich, Germany.,Department of Neurology, RWTH Aachen University, University Clinic Aachen, Aachen, Germany
| | - Karl Josef Langen
- Research Centre Jülich, Institute of Neuroscience and Medicine, Jülich, Germany
| | - Roland Goldbrunner
- Medical Faculty and University Hospital, Center for Neurosurgery, University of Cologne, Cologne, Germany
| | - Christian Grefkes
- Research Centre Jülich, Institute of Neuroscience and Medicine, Jülich, Germany.,Medical Faculty and University Hospital, Department of Neurology, University of Cologne, Cologne, Germany
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22
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Gomez–Tames J, Laakso I, Murakami T, Ugawa Y, Hirata A. TMS activation site estimation using multiscale realistic head models. J Neural Eng 2020; 17:036004. [DOI: 10.1088/1741-2552/ab8ccf] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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23
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Li WQ, Lin T, Li X, Jing YH, Wu C, Li MN, Ding Q, Lan Y, Xu GQ. TMS brain mapping of the pharyngeal cortical representation in healthy subjects. Brain Stimul 2020; 13:891-899. [PMID: 32289722 DOI: 10.1016/j.brs.2020.02.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 02/25/2020] [Accepted: 02/28/2020] [Indexed: 10/24/2022] Open
Abstract
BACKGROUND Brain mapping is fundamental to understanding brain organization and function. However, a major drawback to the traditional Brodmann parcellation technique is the reliance on the use of postmortem specimens. It has therefore historically been difficult to make any comparison regarding functional data from different regions or hemispheres within the same individual. Moreover, this method has been significant limited by subjective boundaries and classification criteria and therefore suffer from reproducibility issues. The development of transcranial magnetic stimulation (TMS) offers an alternative approach to brain mapping, specifically the motor cortical regions by eliciting quantifiable functional reactions. OBJECTIVE To precisely describe the motor cortical topographic representation of pharyngeal constrictor musculature using TMS and to further map the brain for use as a tool to study brain plasticity. METHODS 51 healthy subjects (20 male/31 female, 19-26 years old) were tested using single-pulse TMS combined with intraluminal catheter-guided high-resolution manometry and a standardized grid cap. We investigated various parameters of the motor-evoked potential (MEP) that include the motor map area, amplitude, latency, center of gravity (CoG) and asymmetry index. RESULTS Cortically evoked response latencies were similar for the left and right hemispheres at 6.79 ± 0.22 and 7.24 ± 0.27 ms, respectively. The average scalp positions (relative to the vertex) of the pharyngeal motor cortical representation were 10.40 ± 0.19 (SE) cm medio-lateral and 3.20 ± 0.20 (SE) cm antero-posterior in the left hemisphere and 9.65 ± 0.24 (SE) cm medio-lateral and 3.18 ± 0.23 (SE) cm antero-posterior in the right hemisphere. The mean motor map area of the pharynx in the left and right hemispheres were 9.22 ± 0.85(SE) cm2and 10.12 ± 1.24(SE) cm2, respectively. The amplitudes of the MEPs were 35.94 ± 1.81(SE)uV in the left hemisphere and 34.49 ± 1.95(SE)uV in the right hemisphere. By comparison, subtle but consistent differences in the degree of the bilateral hemispheric representation were also apparent both between and within individuals. CONCLUSION The swallowing musculature has a bilateral motor cortical representation across individuals, but is largely asymmetric within single subjects. These results suggest that TMS mapping using a guided intra-pharyngeal EMG catheter combined with a standardized gridded cap might be a useful tool to localize brain function/dysfunction by linking brain activation to the corresponding physical reaction.
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Affiliation(s)
- Wan-Qi Li
- Department of Rehabilitation Medicine, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Tuo Lin
- Department of Rehabilitation Medicine, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong, China.
| | - Xue Li
- Department of Rehabilitation Medicine, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, Guangdong, China.
| | - Ying-Hua Jing
- Department of Rehabilitation Medicine, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong, China
| | - Cheng Wu
- Department of Rehabilitation Medicine, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong, China
| | - Meng-Ni Li
- Department of Rehabilitation Medicine, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong, China
| | - Qian Ding
- Department of Rehabilitation Medicine, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong, China
| | - Yue Lan
- Department of Rehabilitation Medicine, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, Guangdong, China; Department of Rehabilitation Medicine, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong, China.
| | - Guang-Qing Xu
- Department of Rehabilitation Medicine, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China; China National Clinical Research Center for Neurological Diseases, Beijing, China.
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24
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Wang J, Meng HJ, Ji GJ, Jing Y, Wang HX, Deng XP, Feng ZJ, Zhao N, Zang YF, Zhang J. Finger Tapping Task Activation vs. TMS Hotspot: Different Locations and Networks. Brain Topogr 2019; 33:123-134. [PMID: 31691912 PMCID: PMC6943404 DOI: 10.1007/s10548-019-00741-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 10/22/2019] [Indexed: 12/15/2022]
Abstract
Both functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) have been used to non-invasively localize the human motor functional area. These locations can be clinically used as stimulation target of TMS treatment. However, it has been reported that the finger tapping fMRI activation and TMS hotspot were not well-overlapped. The aim of the current study was to measure the distance between the finger tapping fMRI activation and the TMS hotspot, and more importantly, to compare the network difference by using resting-state fMRI. Thirty healthy participants underwent resting-state fMRI, task fMRI, and then TMS hotspot localization. We found significant difference of locations between finger tapping fMRI activation and TMS hotspot. Specifically, the finger tapping fMRI activation was more lateral than the TMS hotspot in the premotor area. The fMRI activation peak and TMS hotspot were taken as seeds for resting-state functional connectivity analyses. Compared with TMS hotspot, finger tapping fMRI activation peak showed more intensive functional connectivity with, e.g., the bilateral premotor, insula, putamen, and right globus pallidus. The findings more intensive networks of finger tapping activation than TMS hotspot suggest that TMS treatment targeting on the fMRI activation area might result in more remote effects and would be more helpful for TMS treatment on movement disorders.
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Affiliation(s)
- Jue Wang
- School of Psychology, Shanghai University of Sport, Shanghai, 200438, China
| | - Hai-Jiang Meng
- School of Psychology, Shanghai University of Sport, Shanghai, 200438, China
| | - Gong-Jun Ji
- Department of Medical Psychology, Chaohu Clinical Medical College, Anhui Medical University, Hefei, 230032, China.,Collaborative Innovation Centre of Neuropsychiatric Disorder and Mental Health, Hefei, 230032, Anhui, China
| | - Ying Jing
- Institutes of Psychological Sciences, Hangzhou Normal University, Hangzhou, 311121, China.,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, 311121, China.,Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, 310015, China
| | - Hong-Xiao Wang
- Institutes of Psychological Sciences, Hangzhou Normal University, Hangzhou, 311121, China.,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, 311121, China.,Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, 310015, China
| | - Xin-Ping Deng
- Institutes of Psychological Sciences, Hangzhou Normal University, Hangzhou, 311121, China.,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, 311121, China.,Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, 310015, China
| | - Zi-Jian Feng
- Institutes of Psychological Sciences, Hangzhou Normal University, Hangzhou, 311121, China.,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, 311121, China.,Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, 310015, China
| | - Na Zhao
- Institutes of Psychological Sciences, Hangzhou Normal University, Hangzhou, 311121, China.,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, 311121, China.,Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, 310015, China
| | - Yu-Feng Zang
- Institutes of Psychological Sciences, Hangzhou Normal University, Hangzhou, 311121, China. .,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, 311121, China. .,Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, 310015, China.
| | - Jian Zhang
- School of Psychology, Shanghai University of Sport, Shanghai, 200438, China.
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25
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Tscherpel C, Hensel L, Lemberg K, Freytag J, Michely J, Volz LJ, Fink GR, Grefkes C. Age affects the contribution of ipsilateral brain regions to movement kinematics. Hum Brain Mapp 2019; 41:640-655. [PMID: 31617272 PMCID: PMC7268044 DOI: 10.1002/hbm.24829] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 10/02/2019] [Accepted: 10/04/2019] [Indexed: 12/21/2022] Open
Abstract
Healthy aging is accompanied by changes in brain activation patterns in the motor system. In older subjects, unilateral hand movements typically rely on increased recruitment of ipsilateral frontoparietal areas. While the two central concepts of aging‐related brain activity changes, “Hemispheric Asymmetry Reduction in Older Adults” (HAROLD), and “Posterior to Anterior Shift in Aging” (PASA), have initially been suggested in the context of cognitive tasks and were attributed to compensation, current knowledge regarding the functional significance of increased motor system activity remains scarce. We, therefore, used online interference transcranial magnetic stimulation in young and older subjects to investigate the role of key regions of the ipsilateral frontoparietal cortex, that is, (a) primary motor cortex (M1), (b) dorsal premotor cortex (dPMC), and (c) anterior intraparietal sulcus (IPS) in the control of hand movements of different motor demands. Our data suggest a change of the functional roles of ipsilateral brain areas in healthy age with a reduced relevance of ipsilateral M1 and a shift of importance toward dPMC for repetitive high‐frequency movements. These results support the notion that mechanisms conceptualized in the models of “PASA” and “HAROLD” also apply to the motor system.
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Affiliation(s)
- Caroline Tscherpel
- Medical Faculty, University of Cologne and Department of Neurology, University Hospital Cologne, Cologne, Germany.,Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, Jülich, Germany
| | - Lukas Hensel
- Medical Faculty, University of Cologne and Department of Neurology, University Hospital Cologne, Cologne, Germany
| | - Katharina Lemberg
- Medical Faculty, University of Cologne and Department of Neurology, University Hospital Cologne, Cologne, Germany
| | - Jana Freytag
- Medical Faculty, University of Cologne and Department of Neurology, University Hospital Cologne, Cologne, Germany
| | - Jochen Michely
- Medical Faculty, University of Cologne and Department of Neurology, University Hospital Cologne, Cologne, Germany.,Wellcome Trust Centre for Neuroimaging, University College London, London, UK
| | - Lukas J Volz
- Medical Faculty, University of Cologne and Department of Neurology, University Hospital Cologne, Cologne, Germany
| | - Gereon R Fink
- Medical Faculty, University of Cologne and Department of Neurology, University Hospital Cologne, Cologne, Germany.,Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, Jülich, Germany
| | - Christian Grefkes
- Medical Faculty, University of Cologne and Department of Neurology, University Hospital Cologne, Cologne, Germany.,Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, Jülich, Germany
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26
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Hamidian S, Vachha B, Jenabi M, Karimi S, Young RJ, Holodny AI, Peck KK. Resting-State Functional Magnetic Resonance Imaging and Probabilistic Diffusion Tensor Imaging Demonstrate That the Greatest Functional and Structural Connectivity in the Hand Motor Homunculus Occurs in the Area of the Thumb. Brain Connect 2019; 8:371-379. [PMID: 29987948 DOI: 10.1089/brain.2018.0589] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The primary hand motor region is classically believed to be in the "hand knob" area in the precentral gyrus (PCG). However, hand motor task-based activation is often localized outside this area. The purpose of this study is to investigate the structural and functional connectivity driven by different seed locations corresponding to the little, index, and thumb in the PCG using probabilistic diffusion tractography (PDT) and resting-state functional magnetic resonance imaging (rfMRI). Twelve healthy subjects had three regions of interest (ROIs) placed in the left PCG: lateral to the hand knob (thumb area), within the hand knob (index finger area), and medial to the hand knob (little finger area). Connectivity maps were generated using PDT and rfMRI. Individual and group level analyses were performed. Results show that the greatest hand motor connectivity between both hemispheres was obtained using the ROI positioned just lateral to the hand knob in the PCG (the thumb area). The number of connected voxels in the PCG between the two hemispheres was greatest in the lateral-most ROI (the thumb area): 279 compared with 13 for the medial-most ROI and 9 for the central hand knob ROI. Similarly, the highest white matter connectivity between the two hemispheres resulted from the ROI placed in the lateral portion of PCG (p < 0.003). The maximal functional and structural connectivity of the hand motor area between hemispheres occurs in the thumb area, located laterally at the "hand knob." Thus, this location appears maximal for rfMRI and PDT seeding of the motor area.
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Affiliation(s)
- Shaminta Hamidian
- 1 Department of Radiology, Memorial Sloan-Kettering Cancer Center , New York, New York
| | - Behroze Vachha
- 1 Department of Radiology, Memorial Sloan-Kettering Cancer Center , New York, New York
| | - Mehrnaz Jenabi
- 1 Department of Radiology, Memorial Sloan-Kettering Cancer Center , New York, New York
| | - Sasan Karimi
- 1 Department of Radiology, Memorial Sloan-Kettering Cancer Center , New York, New York
| | - Robert J Young
- 1 Department of Radiology, Memorial Sloan-Kettering Cancer Center , New York, New York
| | - Andrei I Holodny
- 1 Department of Radiology, Memorial Sloan-Kettering Cancer Center , New York, New York
| | - Kyung K Peck
- 1 Department of Radiology, Memorial Sloan-Kettering Cancer Center , New York, New York.,2 Department of Medical Physics, Memorial Sloan-Kettering Cancer Center , New York, New York
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27
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Pitkänen M, Yazawa S, Airaksinen K, Lioumis P, Nurminen J, Pekkonen E, Mäkelä JP. Localization of Sensorimotor Cortex Using Navigated Transcranial Magnetic Stimulation and Magnetoencephalography. Brain Topogr 2019; 32:873-881. [PMID: 31093863 PMCID: PMC6707977 DOI: 10.1007/s10548-019-00716-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 05/06/2019] [Indexed: 12/17/2022]
Abstract
The mapping of the sensorimotor cortex gives information about the cortical motor and sensory functions. Typical mapping methods are navigated transcranial magnetic stimulation (TMS) and magnetoencephalography (MEG). The differences between these mapping methods are, however, not fully known. TMS center of gravities (CoGs), MEG somatosensory evoked fields (SEFs), corticomuscular coherence (CMC), and corticokinematic coherence (CKC) were mapped in ten healthy adults. TMS mapping was performed for first dorsal interosseous (FDI) and extensor carpi radialis (ECR) muscles. SEFs were induced by tactile stimulation of the index finger. CMC and CKC were determined as the coherence between MEG signals and the electromyography or accelerometer signals, respectively, during voluntary muscle activity. CMC was mapped during the activation of FDI and ECR muscles separately, whereas CKC was measured during the waving of the index finger at a rate of 3–4 Hz. The maximum CMC was found at beta frequency range, whereas maximum CKC was found at the movement frequency. The mean Euclidean distances between different localizations were within 20 mm. The smallest distance was found between TMS FDI and TMS ECR CoGs and longest between CMC FDI and CMC ECR sites. TMS-inferred localizations (CoGs) were less variable across participants than MEG-inferred localizations (CMC, CKC). On average, SEF locations were 8 mm lateral to the TMS CoGs (p < 0.01). No differences between hemispheres were found. Based on the results, TMS appears to be more viable than MEG in locating motor cortical areas.
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Affiliation(s)
- Minna Pitkänen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland. .,Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland. .,A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, P. O. Box 1627, 70211, Kuopio, Finland.
| | - Shogo Yazawa
- Department of Systems Neuroscience, Sapporo Medical University, Sapporo, Japan
| | - Katja Airaksinen
- BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.,Department of Neurology, Helsinki University Hospital, Helsinki, Finland.,Department of Clinical Neurosciences (Neurology), University of Helsinki, Helsinki, Finland
| | - Pantelis Lioumis
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland.,BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Jussi Nurminen
- BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Eero Pekkonen
- Department of Neurology, Helsinki University Hospital, Helsinki, Finland.,Department of Clinical Neurosciences (Neurology), University of Helsinki, Helsinki, Finland
| | - Jyrki P Mäkelä
- BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
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Can electric fields explain inter-individual variability in transcranial direct current stimulation of the motor cortex? Sci Rep 2019; 9:626. [PMID: 30679770 PMCID: PMC6345748 DOI: 10.1038/s41598-018-37226-x] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 12/04/2018] [Indexed: 01/08/2023] Open
Abstract
The effects of transcranial direct current stimulation (tDCS) on motor cortical excitability are highly variable between individuals. Inter-individual differences in the electric fields generated in the brain by tDCS might play a role in the variability. Here, we explored whether these fields are related to excitability changes following anodal tDCS of the primary motor cortex (M1). Motor evoked potentials (MEPs) were measured in 28 healthy subjects before and after 20 min sham or 1 mA anodal tDCS of right M1 in a double-blind crossover design. The electric fields were individually modelled based on magnetic resonance images. Statistical analysis indicated that the variability in the MEPs could be partly explained by the electric fields, subjects with the weakest and strongest fields tending to produce opposite changes in excitability. To explain the findings, we hypothesized that the likely locus of action was in the hand area of M1, and the effective electric field component was that in the direction normal to the cortical surface. Our results demonstrate that a large part of inter-individual variability in tDCS may be due to differences in the electric fields. If this is the case, electric field dosimetry could be useful for controlling the neuroplastic effects of tDCS.
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Nunes D, Ianus A, Shemesh N. Layer-specific connectivity revealed by diffusion-weighted functional MRI in the rat thalamocortical pathway. Neuroimage 2019; 184:646-657. [PMID: 30267858 PMCID: PMC6264401 DOI: 10.1016/j.neuroimage.2018.09.050] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 09/17/2018] [Accepted: 09/18/2018] [Indexed: 12/18/2022] Open
Abstract
Investigating neural activity from a global brain perspective in-vivo has been in the domain of functional Magnetic Resonance Imaging (fMRI) over the past few decades. The intricate neurovascular couplings that govern fMRI's blood-oxygenation-level-dependent (BOLD) functional contrast are invaluable in mapping active brain regions, but they also entail significant limitations, such as non-specificity of the signal to active foci. Diffusion-weighted functional MRI (dfMRI) with relatively high diffusion-weighting strives to ameliorate this shortcoming as it offers functional contrasts more intimately linked with the underlying activity. Insofar, apart from somewhat smaller activation foci, dfMRI's contrasts have not been convincingly shown to offer significant advantages over BOLD-driven fMRI, and its activation maps relied on significant modelling. Here, we study whether dfMRI could offer a better representation of neural activity in the thalamocortical pathway compared to its (spin-echo (SE)) BOLD counterpart. Using high-end forepaw stimulation experiments in the rat at 9.4 T, and with significant sensitivity enhancements due to the use of cryocoils, we show for the first time that dfMRI signals exhibit layer specificity, and, additionally, display signals in areas devoid of SE-BOLD responses. We find that dfMRI signals in the thalamocortical pathway cohere with each other, namely, dfMRI signals in the ventral posterolateral (VPL) thalamic nucleus cohere specifically with layers IV and V in the somatosensory cortex. These activity patterns are much better correlated (compared with SE-BOLD signals) with literature-based electrophysiological recordings in the cortex as well as thalamus. All these findings suggest that dfMRI signals better represent the underlying neural activity in the pathway. In turn, these advanatages may have significant implications towards a much more specific and accurate mapping of neural activity in the global brain in-vivo.
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Affiliation(s)
- Daniel Nunes
- Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Andrada Ianus
- Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon, Portugal; Centre for Medical Image Computing, University College London, London, UK
| | - Noam Shemesh
- Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon, Portugal.
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Grab J, Zewdie E, Carlson H, Kuo HC, Ciechanski P, Hodge J, Giuffre A, Kirton A. Robotic TMS mapping of motor cortex in the developing brain. J Neurosci Methods 2018; 309:41-54. [DOI: 10.1016/j.jneumeth.2018.08.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 08/08/2018] [Accepted: 08/08/2018] [Indexed: 12/22/2022]
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Barz A, Noack A, Baumgarten P, Seifert V, Forster MT. Motor Cortex Reorganization in Patients with Glioma Assessed by Repeated Navigated Transcranial Magnetic Stimulation-A Longitudinal Study. World Neurosurg 2018; 112:e442-e453. [PMID: 29360588 DOI: 10.1016/j.wneu.2018.01.059] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 01/06/2018] [Accepted: 01/11/2018] [Indexed: 10/18/2022]
Abstract
OBJECTIVE Evidence for cerebral reorganization after resection of low-grade glioma has mainly been obtained by serial intraoperative cerebral mapping. Noninvasively collected data on cortical plasticity in tumor patients over a surgery-free period are still scarce. The present study therefore aimed at evaluating motor cortex reorganization by navigated transcranial magnetic stimulation (nTMS) in patients after perirolandic glioma surgery. METHODS nTMS was performed preoperatively and postoperatively in 20 patients, separated by 26.1 ± 24.8 months. Further nTMS mapping was conducted in 14 patients, resulting in a total follow-up period of 46.3 ± 25.4 months. Centers of gravity (CoGs) were calculated for every muscle representation area, and Euclidian distances between CoGs over time were defined. Results were compared with data from 12 healthy individuals, who underwent motor cortex mapping by nTMS in 2 sessions. RESULTS Preoperatively and postoperatively pooled CoGs from the area of the dominant abductor pollicis brevis muscle and of the nondominant leg area differed significantly compared with healthy individuals (P < 0.05). Most remarkably, during the ensuing follow-up period, a reorganization of all representation areas was observed in 3 patients, and a significant shift of hand representation areas was identified in further 3 patients. Complete functional recovery of postoperative motor deficits was exclusively associated with cortical reorganization. CONCLUSIONS Despite the low potential of remodeling within the somatosensory region, long-term reorganization of cortical motor function can be observed. nTMS is best suited for a noninvasive evaluation of this reorganization.
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Affiliation(s)
- Anne Barz
- Department of Neurosurgery, Goethe University Hospital, Frankfurt, Germany
| | - Anika Noack
- Department of Neurosurgery, Goethe University Hospital, Frankfurt, Germany
| | - Peter Baumgarten
- Department of Neurosurgery, Goethe University Hospital, Frankfurt, Germany
| | - Volker Seifert
- Department of Neurosurgery, Goethe University Hospital, Frankfurt, Germany; University Cancer Center Frankfurt (UCT), Goethe University Hospital, Frankfurt, Germany
| | - Marie-Therese Forster
- Department of Neurosurgery, Goethe University Hospital, Frankfurt, Germany; University Cancer Center Frankfurt (UCT), Goethe University Hospital, Frankfurt, Germany.
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32
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Where and what TMS activates: Experiments and modeling. Brain Stimul 2018; 11:166-174. [DOI: 10.1016/j.brs.2017.09.011] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 06/22/2017] [Accepted: 09/22/2017] [Indexed: 11/21/2022] Open
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Sankarasubramanian V, Machado AG, Conforto AB, Potter-Baker KA, Cunningham DA, Varnerin NM, Wang X, Sakaie K, Plow EB. Inhibition versus facilitation of contralesional motor cortices in stroke: Deriving a model to tailor brain stimulation. Clin Neurophysiol 2017; 128:892-902. [PMID: 28402865 DOI: 10.1016/j.clinph.2017.03.030] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 03/08/2017] [Accepted: 03/14/2017] [Indexed: 02/07/2023]
Abstract
OBJECTIVE The standard approach to brain stimulation in stroke is based on the premise that ipsilesional M1 (iM1) is important for motor function of the paretic upper limb, while contralesional cortices compete with iM1. Therefore, the approach typically advocates facilitating iM1 and/or inhibiting contralesional M1 (cM1). But, this approach fails to elicit much improvement in severely affected patients, who on account of extensive damage to ipsilesional pathways, cannot rely on iM1. These patients are believed to instead rely on the undamaged cortices, especially the contralesional dorsal premotor cortex (cPMd), for support of function of the paretic limb. Here, we tested for the first time whether facilitation of cPMd could improve paretic limb function in severely affected patients, and if a cut-off could be identified to separate responders to cPMd from responders to the standard approach to stimulation. METHODS In a randomized, sham-controlled crossover study, fifteen patients received the standard approach of stimulation involving inhibition of cM1 and a new approach involving facilitation of cPMd using repetitive transcranial magnetic stimulation (rTMS). Patients also received rTMS to control areas. At baseline, impairment [Upper Extremity Fugl-Meyer (UEFMPROXIMAL, max=36)] and damage to pathways [fractional anisotropy (FA)] was measured. We measured changes in time to perform proximal paretic limb reaching, and neurophysiology using TMS. RESULTS Facilitation of cPMd generated more improvement in severely affected patients, who had experienced greater damage and impairment than a cut-off value of FA (0.5) and UEFMPROXIMAL (26-28). The standard approach instead generated more improvement in mildly affected patients. Responders to cPMd showed alleviation of interhemispheric competition imposed on iM1, while responders to the standard approach showed gains in ipsilesional excitability in association with improvement. CONCLUSIONS A preliminary cut-off level of severity separated responders for standard approach vs. facilitation of cPMd. SIGNIFICANCE Cut-offs identified here could help select candidates for tailored stimulation in future studies so patients in all ranges of severity could potentially achieve maximum benefit in function of the paretic upper limb.
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Affiliation(s)
| | - Andre G Machado
- Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Adriana B Conforto
- Neurology Clinical Division, Neurology Department, Hospital das Clinicas, São Paulo University, 05508-090 São Paulo, SP, Brazil; Hospital Israelita Albert Einstein, 05652-900 São Paulo, SP, Brazil
| | - Kelsey A Potter-Baker
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - David A Cunningham
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; School of Biomedical Sciences, Kent State University, Kent, OH 44242, USA
| | - Nicole M Varnerin
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Xiaofeng Wang
- Department of Quantitative Health Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Ken Sakaie
- Department of Diagnostic Radiology, Imaging Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Ela B Plow
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Department of Physical Medicine and Rehabilitation, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
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Weiss Lucas C, Tursunova I, Neuschmelting V, Nettekoven C, Oros-Peusquens AM, Stoffels G, Faymonville AM, Jon SN, Langen KJ, Lockau H, Goldbrunner R, Grefkes C. Functional MRI vs. navigated TMS to optimize M1 seed volume delineation for DTI tractography. A prospective study in patients with brain tumours adjacent to the corticospinal tract. NEUROIMAGE-CLINICAL 2016; 13:297-309. [PMID: 28050345 PMCID: PMC5192048 DOI: 10.1016/j.nicl.2016.11.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 11/18/2016] [Accepted: 11/19/2016] [Indexed: 01/01/2023]
Abstract
BACKGROUND DTI-based tractography is an increasingly important tool for planning brain surgery in patients suffering from brain tumours. However, there is an ongoing debate which tracking approaches yield the most valid results. Especially the use of functional localizer data such as navigated transcranial magnetic stimulation (nTMS) or functional magnetic resonance imaging (fMRI) seem to improve fibre tracking data in conditions where anatomical landmarks are less informative due to tumour-induced distortions of the gyral anatomy. We here compared which of the two localizer techniques yields more plausible results with respect to mapping different functional portions of the corticospinal tract (CST) in brain tumour patients. METHODS The CSTs of 18 patients with intracranial tumours in the vicinity of the primary motor area (M1) were investigated by means of deterministic DTI. The core zone of the tumour-adjacent hand, foot and/or tongue M1 representation served as cortical regions of interest (ROIs). M1 core zones were defined by both the nTMS hot-spots and the fMRI local activation maxima. In addition, for all patients, a subcortical ROI at the level of the inferior anterior pons was implemented into the tracking algorithm in order to improve the anatomical specificity of CST reconstructions. As intra-individual control, we additionally tracked the CST of the hand motor region of the unaffected, i.e., non-lesional hemisphere, again comparing fMRI and nTMS M1 seeds. The plausibility of the fMRI-ROI- vs. nTMS-ROI-based fibre trajectories was assessed by a-priori defined anatomical criteria. Moreover, the anatomical relationship of different fibre courses was compared regarding their distribution in the anterior-posterior direction as well as their location within the posterior limb of the internal capsule (PLIC). RESULTS Overall, higher plausibility rates were observed for the use of nTMS- as compared to fMRI-defined cortical ROIs (p < 0.05) in tumour vicinity. On the non-lesional hemisphere, however, equally good plausibility rates (100%) were observed for both localizer techniques. fMRI-originated fibres generally followed a more posterior course relative to the nTMS-based tracts (p < 0.01) in both the lesional and non-lesional hemisphere. CONCLUSION NTMS achieved better tracking results than fMRI in conditions when the cortical tract origin (M1) was located in close vicinity to a brain tumour, probably influencing neurovascular coupling. Hence, especially in situations with altered BOLD signal physiology, nTMS seems to be the method of choice in order to identify seed regions for CST mapping in patients.
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Key Words
- APB, Abductor pollicis brevis muscle
- BOLD, Blood-oxygenation-level dependent
- CST
- CST, Corticospinal tract
- DCS, Direct cortical stimulation
- DTI, Diffusion tensor imaging
- Deterministic
- EF, Electric field
- EMG, Electromyography
- FA(T), Fractional anisotropy (threshold)
- FACT, Fibre assignment by continuous tracking
- FOV, Field-of-view
- FWE, Family-wise error
- KPS, Karnofsky performance scale
- LT, Lateral tongue muscle, anterior third
- M1, Primary motor cortex
- MEP, Motor-evoked potential
- MFL, Minimal fibre length
- MPRAGE, Magnetization prepared rapid acquisition gradient echo (T1 MR seq.)
- OR, Odd's ratio
- PLIC, Posterior limb of the internal capsule
- PM, Plantar muscle
- Pyramidal tract
- RMT, Resting motor threshold
- ROI
- ROI, Region-of-interest
- SD, Standard deviation
- SE, Standard error
- Somatotopic
- X-sq, X-squared (Pearson's chi-square test)
- dMRI, Diffusion magnetic resonance imaging (i.e., diffusion-weighted imaging, DWI)
- fMRI
- fMRI, Functional magnetic resonance imaging
- nTMS
- nTMS, Neuronavigated transcranial magnetic stimulation
- pxsq, p-value according to Pearson's chi-square test
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Affiliation(s)
| | - Irada Tursunova
- University of Cologne, Center of Neurosurgery, 50924 Cologne, Germany
| | | | | | | | - Gabriele Stoffels
- Institute of Neuroscience and Medicine, Research Centre Jülich, 52425 Jülich, Germany
| | | | - Shah N Jon
- Institute of Neuroscience and Medicine, Research Centre Jülich, 52425 Jülich, Germany; RWTH Aachen University, University Clinic Aachen, Departments of Nuclear Medicine and Neurology, 52074 Aachen, Germany; Department of Electrical and Computer Systems Engineering, Monash University, Melbourne, Victoria, Australia; Monash Institute of Medical Engineering, Monash University, Melbourne, Victoria, Australia; Monash Biomedical Imaging, School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Karl Josef Langen
- Institute of Neuroscience and Medicine, Research Centre Jülich, 52425 Jülich, Germany; RWTH Aachen University, University Clinic Aachen, Departments of Nuclear Medicine and Neurology, 52074 Aachen, Germany
| | - Hannah Lockau
- University of Cologne, Department of Radiology, 50937 Cologne, Germany
| | | | - Christian Grefkes
- Institute of Neuroscience and Medicine, Research Centre Jülich, 52425 Jülich, Germany; University of Cologne, Department of Neurology, 50924 Cologne, Germany
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Mapping the visual brain areas susceptible to phosphene induction through brain stimulation. Exp Brain Res 2016; 235:205-217. [PMID: 27683006 PMCID: PMC5225174 DOI: 10.1007/s00221-016-4784-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 09/22/2016] [Indexed: 01/24/2023]
Abstract
Transcranial magnetic stimulation (TMS) is a non-invasive brain stimulation technique whose effects on neural activity can be uncertain. Within the visual cortex, phosphenes are a useful marker of TMS: They indicate the induction of neural activation that propagates and creates a conscious percept. However, we currently do not know how susceptible different areas of the visual cortex are to TMS-induced phosphenes. In this study, we systematically map out locations in the visual cortex where stimulation triggered phosphenes. We relate this to the retinotopic organization and the location of object- and motion-selective areas, identified by functional magnetic resonance imaging (fMRI) measurements. Our results show that TMS can reliably induce phosphenes in early (V1, V2d, and V2v) and dorsal (V3d and V3a) visual areas close to the interhemispheric cleft. However, phosphenes are less likely in more lateral locations (hMT+/V5 and LOC). This suggests that early and dorsal visual areas are particularly amenable to TMS and that TMS can be used to probe the functional role of these areas.
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Kallioniemi E, Pitkänen M, Könönen M, Vanninen R, Julkunen P. Localization of cortical primary motor area of the hand using navigated transcranial magnetic stimulation, BOLD and arterial spin labeling fMRI. J Neurosci Methods 2016; 273:138-148. [PMID: 27615740 DOI: 10.1016/j.jneumeth.2016.09.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Revised: 07/12/2016] [Accepted: 09/07/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND Although the relationship between neuronavigated transcranial magnetic stimulation (nTMS) and functional magnetic resonance imaging (fMRI) has been widely studied in motor mapping, it is unknown how the motor response type or the choice of motor task affect this relationship. NEW METHOD Centers of gravity (CoGs) and response maxima were measured with blood-oxygen-level dependent (BOLD) and arterial spin labeling (ASL) fMRI during motor tasks against nTMS CoGs and response maxima, which were mapped with motor evoked potentials (MEPs) and silent periods (SPs). RESULTS No differences in motor representations (CoGs and response maxima) were observed in lateral-medial direction (p=0.265). fMRI methods localized the motor representation more posterior than nTMS (p<0.001). This was not affected by the BOLD fMRI motor task (p>0.999) nor nTMS response type (p>0.999). ASL fMRI maxima did not differ from the nTMS nor BOLD fMRI CoGs (p≥0.070), but the ASL CoG was deeper in comparison to other methods (p≤0.042). The BOLD fMRI motor task did not influence the depth of the motor representation (p≥0.745). The median Euclidean distances between the nTMS and fMRI motor representations varied between 7.7mm and 14.5mm and did not differ between the methods (F≤1.23, p≥0.318). COMPARISON WITH EXISTING METHODS The relationship between fMRI and nTMS mapped excitatory (MEP) and inhibitory (SP) responses, and whether the choice of motor task affects this relationship, have not been studied before. CONCLUSIONS The congruence between fMRI and nTMS is good. The choice of nTMS motor response type nor BOLD fMRI motor task had no effect on this relationship.
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Affiliation(s)
- Elisa Kallioniemi
- Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland; Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
| | - Minna Pitkänen
- Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland; Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
| | - Mervi Könönen
- Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland; Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland
| | - Ritva Vanninen
- Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland; Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
| | - Petro Julkunen
- Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland; Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
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Neuromuscular Plasticity: Disentangling Stable and Variable Motor Maps in the Human Sensorimotor Cortex. Neural Plast 2016; 2016:7365609. [PMID: 27610248 PMCID: PMC5004060 DOI: 10.1155/2016/7365609] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 06/28/2016] [Accepted: 07/19/2016] [Indexed: 02/02/2023] Open
Abstract
Motor maps acquired with transcranial magnetic stimulation (TMS) are evolving as a biomarker for monitoring disease progression or the effects of therapeutic interventions. High test-retest reliability of this technique for long observation periods is therefore required to differentiate daily or weekly fluctuations from stable plastic reorganization of corticospinal connectivity. In this study, a novel projection, interpolation, and coregistration technique, which considers the individual gyral anatomy, was applied in healthy subjects for biweekly acquired TMS motor maps over a period of twelve weeks. The intraclass correlation coefficient revealed long-term reliability of motor maps with relevant interhemispheric differences. The sensorimotor cortex and nonprimary motor areas of the dominant hemisphere showed more extended and more stable corticospinal connectivity. Long-term correlations of the MEP amplitudes at each stimulation site revealed mosaic-like clusters of consistent corticospinal excitability. The resting motor threshold, centre of gravity, and mean MEPs across all TMS sites, as highly reliable cortical map parameters, could be disentangled from more variable parameters such as MEP area and volume. Cortical TMS motor maps provide high test-retest reliability for long-term monitoring when analyzed with refined techniques. They may guide restorative interventions which target dormant corticospinal connectivity for neurorehabilitation.
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Electric fields of motor and frontal tDCS in a standard brain space: A computer simulation study. Neuroimage 2016; 137:140-151. [DOI: 10.1016/j.neuroimage.2016.05.032] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 04/15/2016] [Accepted: 05/10/2016] [Indexed: 02/01/2023] Open
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Colon-Perez LM, Tran K, Thompson K, Pace MC, Blum K, Goldberger BA, Gold MS, Bruijnzeel AW, Setlow B, Febo M. The Psychoactive Designer Drug and Bath Salt Constituent MDPV Causes Widespread Disruption of Brain Functional Connectivity. Neuropsychopharmacology 2016; 41:2352-65. [PMID: 26997298 PMCID: PMC4946066 DOI: 10.1038/npp.2016.40] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 03/11/2016] [Accepted: 03/16/2016] [Indexed: 01/16/2023]
Abstract
The abuse of 'bath salts' has raised concerns because of their adverse effects, which include delirium, violent behavior, and suicide ideation in severe cases. The bath salt constituent 3,4-methylenedioxypyrovalerone (MDPV) has been closely linked to these and other adverse effects. The abnormal behavioral pattern produced by acute high-dose MDPV intake suggests possible disruptions of neural communication between brain regions. Therefore, we determined if MDPV exerts disruptive effects on brain functional connectivity, particularly in areas of the prefrontal cortex. Male rats were imaged following administration of a single dose of MDPV (0.3, 1.0, or 3.0 mg/kg) or saline. Resting state brain blood oxygenation level-dependent (BOLD) images were acquired at 4.7 T. To determine the role of dopamine transmission in MDPV-induced changes in functional connectivity, a group of rats received the dopamine D1/D2 receptor antagonist cis-flupenthixol (0.5 mg/kg) 30 min before MDPV. MDPV dose-dependently reduced functional connectivity. Detailed analysis of its effects revealed that connectivity between frontal cortical and striatal areas was reduced. This included connectivity between the prelimbic prefrontal cortex and other areas of the frontal cortex and the insular cortex with hypothalamic, ventral, and dorsal striatal areas. Although the reduced connectivity appeared widespread, connectivity between these regions and somatosensory cortex was not as severely affected. Dopamine receptor blockade did not prevent the MDPV-induced decrease in functional connectivity. The results provide a novel signature of MDPV's in vivo mechanism of action. Reduced brain functional connectivity has been reported in patients suffering from psychosis and has been linked to cognitive dysfunction, audiovisual hallucinations, and negative affective states akin to those reported for MDPV-induced intoxication. The present results suggest that disruption of functional connectivity networks involving frontal cortical and striatal regions could contribute to the adverse effects of MDPV.
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Affiliation(s)
- Luis M Colon-Perez
- Department of Psychiatry, McKnight Brain Institute, University of Florida, Gainesville, FL, USA,Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA
| | - Kelvin Tran
- Department of Psychiatry, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Khalil Thompson
- Department of Psychiatry, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Michael C Pace
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Kenneth Blum
- Department of Psychiatry, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Bruce A Goldberger
- Department of Psychiatry, McKnight Brain Institute, University of Florida, Gainesville, FL, USA,Departments of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, USA,William R Maples Center for Forensic Medicine, University of Florida, Gainesville, FL, USA
| | - Mark S Gold
- Department of Psychiatry, McKnight Brain Institute, University of Florida, Gainesville, FL, USA,Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Adriaan W Bruijnzeel
- Department of Psychiatry, McKnight Brain Institute, University of Florida, Gainesville, FL, USA,Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA,Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Barry Setlow
- Department of Psychiatry, McKnight Brain Institute, University of Florida, Gainesville, FL, USA,Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA,Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Marcelo Febo
- Department of Psychiatry, McKnight Brain Institute, University of Florida, Gainesville, FL, USA,Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA,Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA,Department of Psychiatry, University of Florida Brain Institute, PO Box 100256, Gainesville, FL 32610, USA, Tel: +1 352 294 4911, Fax: +1 352 392 8217, E-mail:
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40
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Williams RJ, Reutens DC, Hocking J. Influence of BOLD Contributions to Diffusion fMRI Activation of the Visual Cortex. Front Neurosci 2016; 10:279. [PMID: 27445654 PMCID: PMC4923189 DOI: 10.3389/fnins.2016.00279] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 06/06/2016] [Indexed: 11/24/2022] Open
Abstract
Reliance on the hemodynamic response as a surrogate marker of neural activity imposes an intrinsic limit on the spatial specificity of functional MRI. An alternative approach based on diffusion-weighted functional MRI (DfMRI) has been reported as a contrast less reliant on hemodynamic effects, however current evidence suggests that both hemodynamic and unique neural sources contribute to the diffusion signal. Here we compare activation patterns obtained with the standard blood oxygenation level-dependent (BOLD) contrast to DfMRI in order to gain a deeper understanding of how the BOLD proportion contributes to the observable diffusion signal. Both individual and group-level activation patterns obtained with DfMRI and BOLD to a visual field stimulation paradigm were analyzed. At the individual level, the DfMRI contrast showed a strong, positive relationship between the volumes of cortex activated in response to quadrant- and hemi-field visual stimulation. This was not observed in the corresponding BOLD experiment. Overall, the DfMRI response indicated less between-subject variability, with random effects analyses demonstrating higher statistical values at the peak voxel for DfMRI. Furthermore, the spatial extent of the activation was more restricted to the primary visual region for DfMRI than BOLD. However, the diffusion signal was sensitive to the hemodynamic response in a manner dependent on experimental manipulation. It was also limited by its low signal-to-noise ratio (SNR), demonstrating lower sensitivity than BOLD. Together these findings both support DfMRI as a contrast that bears a closer spatial relationship to the underlying neural activity than BOLD, and raise important caveats regarding its utilization. Models explaining the DfMRI signal change need to consider the dynamic vascular contributions that may vary with neural activity.
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Affiliation(s)
- Rebecca J Williams
- Hotchkiss Brain Institute and Department of Radiology, University of CalgaryCalgary, AB, Canada; Centre for Advanced Imaging, The University of QueenslandSt. Lucia, QLD, Australia; Queensland Brain Institute, The University of QueenslandSt. Lucia, QLD, Australia; Centre for Clinical Research, The University of QueenslandBrisbane, QLD, Australia
| | - David C Reutens
- Centre for Advanced Imaging, The University of Queensland St. Lucia, QLD, Australia
| | - Julia Hocking
- School of Psychology and Counselling, Faculty of Health, Queensland University of Technology Kelvin Grove, QLD, Australia
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Säisänen L, Julkunen P, Kemppainen S, Danner N, Immonen A, Mervaala E, Määttä S, Muraja-Murro A, Könönen M. Locating and Outlining the Cortical Motor Representation Areas of Facial Muscles With Navigated Transcranial Magnetic Stimulation. Neurosurgery 2016; 77:394-405; discussion 405. [PMID: 26035404 DOI: 10.1227/neu.0000000000000798] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Navigated transcranial magnetic stimulation (nTMS) has become established as an accurate noninvasive technique for mapping the functional motor cortex for the representation areas of upper and lower limb muscles but not yet for facial musculature. OBJECTIVE To characterize the applicability and clinical impact of using nTMS to map cortical motor areas of facial muscles in healthy volunteers and neurosurgical tumor patients. METHODS Eight healthy volunteers and 12 patients with tumor were studied. The motor threshold (MT) was determined for the abductor pollicis brevis and mentalis muscles. The lateral part of the motor cortex was mapped with suprathreshold stimulation intensity, and motor evoked potentials were recorded from several facial muscles. The patient protocol was modified according to the clinical indication. RESULTS In all healthy subjects, motor evoked potentials were elicited in the mentalis (mean latency, 13.4 milliseconds) and orbicularis oris (mean latency, 12.6 milliseconds) muscles. At 110% of MT of the mentalis, the motor evoked potentials of facial muscles were elicited mainly in the precentral gyrus but also from one gyrus anterior and posterior to it. The cortical areas applicable for mapping were limited by an artifact attributable to direct peripheral nerve stimulation. The mapping protocol was successful in 10 of 12 tumor patients at locating the representation area of the lower facial muscles. The MT of the facial muscles was significantly higher than that of the abductor pollicis brevis. CONCLUSION nTMS is an applicable and clinically beneficial noninvasive method to preoperatively map the cortical representation areas of the facial muscles in the lower part of the face. Instead of using the MT of the abductor pollicis brevis, the stimulus intensity during mapping should be proportioned to the MT of a facial muscle.
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Affiliation(s)
- Laura Säisänen
- *Institute of Clinical Medicine, Faculty of Health Sciences and §Department of Applied Physics, University of Eastern Finland, Kuopio, Finland; ‡Departments of Clinical Neurophysiology, #Neurosurgery, and **Clinical Radiology, Kuopio University Hospital, Kuopio, Finland; ¶Department of Clinical Neurophysiology, NordLab Kajaani and ‖Kainuu Social and Health Care Joint Authority, Kainuu Central Hospital, Kajaani, Finland
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Ahdab R, Ayache SS, Brugières P, Farhat WH, Lefaucheur JP. The Hand Motor Hotspot is not Always Located in the Hand Knob: A Neuronavigated Transcranial Magnetic Stimulation Study. Brain Topogr 2016; 29:590-7. [PMID: 26980192 DOI: 10.1007/s10548-016-0486-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 03/10/2016] [Indexed: 10/22/2022]
Abstract
The hand motor hot spot (hMHS) is one of the most salient parameters in transcranial magnetic stimulation (TMS) practice, notably used for targeting. It is commonly accepted that the hMHS corresponds to the hand representation within the primary motor cortex (M1). Anatomical and imaging studies locate this representation in a region of the central sulcus called the "hand knob". The aim of this study was to determine if the hMHS location corresponds to its expected location at the hand knob. Twelve healthy volunteers and eleven patients with chronic neuropathic pain of various origins, but not related to a brain lesion, were enrolled. Morphological magnetic resonance imaging of the brain was normal in all participants. Both hemispheres were studied in all participants except four (two patients and two healthy subjects). Cortical mapping of the hand motor area was conducted using a TMS-dedicated navigation system and recording motor evoked potentials (MEPs) in the contralateral first dorsal interosseous (FDI) muscle. We then determined the anatomical position of the hMHS, defined as the stimulation site providing the largest FDI-MEPs. In 45 % of hemispheres of normal subjects and 25 % of hemispheres of pain patients, the hMHS was located over the central sulcus, most frequently at the level of the hand knob. However, in the other cases, the hMHS was located outside M1, most frequently anteriorly over the precentral or middle frontal gyrus. This study shows that the hMHS does not always correspond to the hand knob and M1 location in healthy subjects or patients. Therefore, image-guided navigation is needed to improve the anatomical accuracy of TMS targeting, even for M1.
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Affiliation(s)
- Rechdi Ahdab
- EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil, Créteil, France.,Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris, 51 avenue de Lattre de Tassigny, 94010, Créteil, France.,Neurology Division, University Medical Center Rizk Hospital, Beirut, Lebanon
| | - Samar S Ayache
- EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil, Créteil, France. .,Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris, 51 avenue de Lattre de Tassigny, 94010, Créteil, France. .,Neurology Division, University Medical Center Rizk Hospital, Beirut, Lebanon.
| | - Pierre Brugières
- Service de Neuroradiologie, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris, Créteil, France
| | - Wassim H Farhat
- EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil, Créteil, France.,Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris, 51 avenue de Lattre de Tassigny, 94010, Créteil, France
| | - Jean-Pascal Lefaucheur
- EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil, Créteil, France.,Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris, 51 avenue de Lattre de Tassigny, 94010, Créteil, France
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Reliability of negative BOLD in ipsilateral sensorimotor areas during unimanual task activity. Brain Imaging Behav 2016; 9:245-54. [PMID: 24788334 DOI: 10.1007/s11682-014-9302-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Research using functional magnetic resonance imaging has for numerous years now reported the existence of a negative blood oxygenation level dependent (BOLD) response. Based on accumulating evidence, this negative BOLD signal appears to represent an active inhibition of cortical areas in which it is found during task activity. This particularly important with respect to motor function given that it is fairly well-established that, in younger adults, the ipsilateral sensorimotor cortex exhibits negative BOLD during unimanual movements in fMRI. This interhemispheric suppression of cortical activity may have useful implications for our understanding of both basic motor function and rehabilitation of injury or disease. However, to date, we are aware of no study that has tested the reliability of evoked negative BOLD in ipsilateral sensorimotor cortex in individuals across sessions. The current study employs a unimanual finger opposition task previously shown to evoke negative BOLD in ipsilateral sensorimotor cortex across three sessions. Reliability metrics across sessions indicates that both the magnitude and location of ipsilateral sensorimotor negative BOLD response is relatively stable over each of the three sessions. Moreover, the volume of negative BOLD in ipsilateral cortex was highly correlated with volume of positive BOLD activity in the contralateral primary motor cortex. These findings show that the negative BOLD signal can be reliably evoked in unimanual task paradigms, and that the signal dynamic could represent an active suppression of the ipsilateral sensorimotor cortex originating from the contralateral motor areas.
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Kraus D, Gharabaghi A. Projecting Navigated TMS Sites on the Gyral Anatomy Decreases Inter-subject Variability of Cortical Motor Maps. Brain Stimul 2015; 8:831-7. [PMID: 25865772 DOI: 10.1016/j.brs.2015.03.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 02/17/2015] [Accepted: 03/23/2015] [Indexed: 10/23/2022] Open
Abstract
BACKGROUND Magnetic resonance images are being increasingly deployed in conjunction with navigated transcranial magnetic stimulation (nTMS) to account for inter-individual differences in brain anatomy as well as to reduce the variability of mapping findings. OBJECTIVE However, despite the fact that the individual gyral anatomy has a significant impact on the TMS-induced electrical field distributions, these approaches still project the TMS coil positions as a plane grid of target points on the brain surface and fail to account for differences in cortex morphology. METHODS In this study, we have introduced a technique for projecting nTMS sites onto the gyral anatomy to decrease the variability of cortical motor maps between subjects in normalized space. This involved interpolating the discrete map points in the normalized volume space and performing additional surface coregistration. RESULTS By applying this technique, we increased the spatial overlap between the cortical maps of the extensor digitorum communis muscle between subjects from 80% to 100%. We also managed to significantly reduce the mean Euclidean distance between the average center of gravity and the average hotspots to the respective individual spots from 8 mm to 6.5 mm. CONCLUSION Our approach facilitates the study of the functional topography of distinct behavioral properties with high spatial resolution, thereby constituting a valuable tool for precise group analysis of cortical TMS maps.
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Affiliation(s)
- Dominic Kraus
- Division of Functional and Restorative Neurosurgery, Department of Neurosurgery, Eberhard Karls University Tuebingen, Germany; Division of Translational Neurosurgery, Department of Neurosurgery, Eberhard Karls University Tuebingen, Germany; Neuroprosthetics Research Group, Werner Reichardt Centre for Integrative Neuroscience, Eberhard Karls University Tuebingen, Germany
| | - Alireza Gharabaghi
- Division of Functional and Restorative Neurosurgery, Department of Neurosurgery, Eberhard Karls University Tuebingen, Germany; Division of Translational Neurosurgery, Department of Neurosurgery, Eberhard Karls University Tuebingen, Germany; Neuroprosthetics Research Group, Werner Reichardt Centre for Integrative Neuroscience, Eberhard Karls University Tuebingen, Germany.
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Avants BB, Duda JT, Kilroy E, Krasileva K, Jann K, Kandel BT, Tustison NJ, Yan L, Jog M, Smith R, Wang Y, Dapretto M, Wang DJJ. The pediatric template of brain perfusion. Sci Data 2015; 2:150003. [PMID: 25977810 PMCID: PMC4413243 DOI: 10.1038/sdata.2015.3] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 12/11/2014] [Indexed: 12/14/2022] Open
Abstract
Magnetic resonance imaging (MRI) captures the dynamics of brain development with multiple modalities that quantify both structure and function. These measurements may yield valuable insights into the neural patterns that mark healthy maturation or that identify early risk for psychiatric disorder. The Pediatric Template of Brain Perfusion (PTBP) is a free and public neuroimaging resource that will help accelerate the understanding of childhood brain development as seen through the lens of multiple modality neuroimaging and in relation to cognitive and environmental factors. The PTBP uses cross-sectional and longitudinal MRI to quantify cortex, white matter, resting state functional connectivity and brain perfusion, as measured by Arterial Spin Labeling (ASL), in 120 children 7-18 years of age. We describe the PTBP and show, as a demonstration of validity, that global summary measurements capture the trajectories that demarcate critical turning points in brain maturation. This novel resource will allow a more detailed understanding of the network-level, structural and functional landmarks that are obtained during normal adolescent brain development.
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Affiliation(s)
- Brian B Avants
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Jeffrey T Duda
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Emily Kilroy
- Department of Neurology, University of California, Los Angeles, California 90095, USA
| | - Kate Krasileva
- Department of Neurology, University of California, Los Angeles, California 90095, USA
| | - Kay Jann
- Department of Neurology, University of California, Los Angeles, California 90095, USA
| | - Benjamin T Kandel
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Nicholas J Tustison
- Department of Radiology, University of Virginia, Charlottesville, Virginia 22904, USA
| | - Lirong Yan
- Department of Neurology, University of California, Los Angeles, California 90095, USA
| | - Mayank Jog
- Department of Neurology, University of California, Los Angeles, California 90095, USA
| | - Robert Smith
- Department of Neurology, University of California, Los Angeles, California 90095, USA
| | - Yi Wang
- Department of Neurology, University of California, Los Angeles, California 90095, USA
| | - Mirella Dapretto
- Department of Neurology, University of California, Los Angeles, California 90095, USA
| | - Danny J J Wang
- Department of Neurology, University of California, Los Angeles, California 90095, USA
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Curtis AT, Hutchison RM, Menon RS. Phase based venous suppression in resting-state BOLD GE-fMRI. Neuroimage 2014; 100:51-9. [PMID: 24907484 DOI: 10.1016/j.neuroimage.2014.05.079] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 05/12/2014] [Accepted: 05/29/2014] [Indexed: 11/30/2022] Open
Abstract
Resting-state functional MRI (RS-fMRI) is a widely used method for inferring connectivity between brain regions or nodes. As with task-based fMRI, the spatial specificity of the connectivity maps can be distorted by the strong biasing effect of the BOLD signal in macroscopic veins. In RS-fMRI this effect is exacerbated by the temporal coherences of physiological origin between large veins that are widely distributed in the brain. In gradient echo based EPI, used for the vast majority of RS-fMRI, macroscopic veins that carry BOLD-related changes exhibit a strong phase response. This allows for post-processing identification and removal of venous signals using a phase regressor technique. Here, we employ this approach to suppress macrovascular venous contributions in high-field whole-brain RS-fMRI data sets, resulting in significant changes to both the spatial localization of the networks and the correlations between the network nodes. These effects were observed at both the individual and group analysis level, suggesting that venous contamination is a confounding factor for RS-fMRI studies even at relatively low image resolutions. Suppression of the macrovascular signal using the phase regression approach may therefore help to better identify, delineate, and interpret the true structure of large-scale brain networks.
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Affiliation(s)
- Andrew T Curtis
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western Ontario, 100 Perth Drive, London, Ontario, N6A 5K8, Canada; Department of Medical Biophysics, The University of Western Ontario, London, Ontario, N6A 5C1, Canada
| | - R Matthew Hutchison
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western Ontario, 100 Perth Drive, London, Ontario, N6A 5K8, Canada; Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Ravi S Menon
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, The University of Western Ontario, 100 Perth Drive, London, Ontario, N6A 5K8, Canada; Department of Medical Biophysics, The University of Western Ontario, London, Ontario, N6A 5C1, Canada.
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Opitz A, Zafar N, Bockermann V, Rohde V, Paulus W. Validating computationally predicted TMS stimulation areas using direct electrical stimulation in patients with brain tumors near precentral regions. NEUROIMAGE-CLINICAL 2014; 4:500-7. [PMID: 24818076 PMCID: PMC3984442 DOI: 10.1016/j.nicl.2014.03.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 03/12/2014] [Accepted: 03/13/2014] [Indexed: 12/03/2022]
Abstract
The spatial extent of transcranial magnetic stimulation (TMS) is of paramount interest for all studies employing this method. It is generally assumed that the induced electric field is the crucial parameter to determine which cortical regions are excited. While it is difficult to directly measure the electric field, one usually relies on computational models to estimate the electric field distribution. Direct electrical stimulation (DES) is a local brain stimulation method generally considered the gold standard to map structure–function relationships in the brain. Its application is typically limited to patients undergoing brain surgery. In this study we compare the computationally predicted stimulation area in TMS with the DES area in six patients with tumors near precentral regions. We combine a motor evoked potential (MEP) mapping experiment for both TMS and DES with realistic individual finite element method (FEM) simulations of the electric field distribution during TMS and DES. On average, stimulation areas in TMS and DES show an overlap of up to 80%, thus validating our computational physiology approach to estimate TMS excitation volumes. Our results can help in understanding the spatial spread of TMS effects and in optimizing stimulation protocols to more specifically target certain cortical regions based on computational modeling. Use of patient specific FEM models to predict electric fields in TMS and DES. Validation of TMS computational models with the DES gold standard. TMS electric fields have high overlap with the computationally predicted DES area. Realistic models outperform more commonly used spherical models. Computational physiology approach enables a more precise preoperative mapping.
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Affiliation(s)
- Alexander Opitz
- Department of Clinical Neurophysiology, Georg-August-University, Göttingen, Germany
| | - Noman Zafar
- Department of Neurosurgery, Georg-August-University, Göttingen, Germany
| | - Volker Bockermann
- Department of Neurosurgery, Georg-August-University, Göttingen, Germany
| | - Veit Rohde
- Department of Neurosurgery, Georg-August-University, Göttingen, Germany
| | - Walter Paulus
- Department of Clinical Neurophysiology, Georg-August-University, Göttingen, Germany
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Volz LJ, Hamada M, Rothwell JC, Grefkes C. What Makes the Muscle Twitch: Motor System Connectivity and TMS-Induced Activity. Cereb Cortex 2014; 25:2346-53. [PMID: 24610120 DOI: 10.1093/cercor/bhu032] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Transcranial magnetic stimulation (TMS) of the primary motor cortex (M1) evokes several volleys of corticospinal activity. While the earliest wave (D-wave) originates from axonal activation of cortico-spinal neurons (CSN), later waves (I-waves) result from activation of mono- and polysynaptic inputs to CSNs. Different coil orientations preferentially stimulate cortical elements evoking different outputs: latero-medial-induced current (LM) elicits D-waves and short-latency electromyographic responses (MEPs); posterior-anterior current (PA) evokes early I-waves. Anterior-posterior current (AP) is more variable and tends to recruit later I-waves, featuring longer onset latencies compared with PA-TMS. We tested whether the variability in response to AP-TMS was related to functional connectivity of the stimulated M1 in 20 right-handed healthy subjects who underwent functional magnetic resonance imaging while performing an isometric contraction task. The MEP-latency after AP-TMS (relative to LM-TMS) was strongly correlated with functional connectivity between the stimulated M1 and a network involving cortical premotor areas. This indicates that stronger premotor-M1 connectivity increases the probability that AP-TMS recruits shorter latency input to CSNs. In conclusion, our data strongly support the hypothesis that TMS of M1 activates distinct neuronal pathways depending on the orientation of the stimulation coil. Particularly, AP currents seem to recruit short latency cortico-cortical projections from premotor areas.
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Affiliation(s)
- Lukas J Volz
- Max Planck Institute for Neurological Research, 50931 Cologne, Germany Department of Neurology, University Hospital Cologne, 50937 Cologne, Germany
| | - Masashi Hamada
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London WC1N 3BG, UK Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - John C Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London WC1N 3BG, UK
| | - Christian Grefkes
- Max Planck Institute for Neurological Research, 50931 Cologne, Germany Department of Neurology, University Hospital Cologne, 50937 Cologne, Germany Institute of Neuroscience and Medicine (INM-3), Juelich Research Centre, Germany
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Age-related weakness of proximal muscle studied with motor cortical mapping: a TMS study. PLoS One 2014; 9:e89371. [PMID: 24586726 PMCID: PMC3931763 DOI: 10.1371/journal.pone.0089371] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 01/17/2014] [Indexed: 11/30/2022] Open
Abstract
Aging-related weakness is due in part to degeneration within the central nervous system. However, it is unknown how changes to the representation of corticospinal output in the primary motor cortex (M1) relate to such weakness. Transcranial magnetic stimulation (TMS) is a noninvasive method of cortical stimulation that can map representation of corticospinal output devoted to a muscle. Using TMS, we examined age-related alterations in maps devoted to biceps brachii muscle to determine whether they predicted its age-induced weakness. Forty-seven right-handed subjects participated: 20 young (22.6±0.90 years) and 27 old (74.96±1.35 years). We measured strength as force of elbow flexion and electromyographic activation of biceps brachii during maximum voluntary contraction. Mapping variables included: 1) center of gravity or weighted mean location of corticospinal output, 2) size of map, 3) volume or excitation of corticospinal output, and 4) response density or corticospinal excitation per unit area. Center of gravity was more anterior in old than in young (p<0.001), though there was no significant difference in strength between the age groups. Map size, volume, and response density showed no significant difference between groups. Regardless of age, center of gravity significantly predicted strength (β = −0.34, p = 0.005), while volume adjacent to the core of map predicted voluntary activation of biceps (β = 0.32, p = 0.008). Overall, the anterior shift of the map in older adults may reflect an adaptive change that allowed for the maintenance of strength. Laterally located center of gravity and higher excitation in the region adjacent to the core in weaker individuals could reflect compensatory recruitment of synergistic muscles. Thus, our study substantiates the role of M1 in adapting to aging-related weakness and subtending strength and muscle activation across age groups. Mapping from M1 may offer foundation for an examination of mechanisms that preserve strength in elderly.
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Laakso I, Hirata A, Ugawa Y. Effects of coil orientation on the electric field induced by TMS over the hand motor area. Phys Med Biol 2013; 59:203-18. [DOI: 10.1088/0031-9155/59/1/203] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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