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Sridhar K, Evers J, Lowery M. Nonlinear effects at the electrode-tissue interface of deep brain stimulation electrodes. J Neural Eng 2024; 21:016024. [PMID: 38306713 DOI: 10.1088/1741-2552/ad2582] [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: 05/31/2023] [Accepted: 02/02/2024] [Indexed: 02/04/2024]
Abstract
Objective.The electrode-tissue interface provides the critical path for charge transfer in neurostimulation therapies and exhibits well-established nonlinear properties at high applied currents or voltages. These nonlinear properties may influence the efficacy and safety of applied stimulation but are typically neglected in computational models. In this study, nonlinear behavior of the electrode-tissue interface impedance was incorporated in a computational model of deep brain stimulation (DBS) to simulate the impact on neural activation and safety considerations.Approach.Nonlinear electrode-tissue interface properties were incorporated in a finite element model of DBS electrodesin vitroandin vivo,in the rat subthalamic nucleus, using an iterative approach. The transition point from linear to nonlinear behavior was determined for voltage and current-controlled stimulation. Predicted levels of neural activation during DBS were examined and the region of linear operation of the electrode was compared with the Shannon safety limit.Main results.A clear transition of the electrode-tissue interface impedance to nonlinear behavior was observed for both current and voltage-controlled stimulation. The transition occurred at lower values of activation overpotential for simulatedin vivothanin vitroconditions (91 mV and 165 mV respectively for current-controlled stimulation; 110 mV and 275 mV for voltage-controlled stimulation), corresponding to an applied current of 30μA and 45μA, or voltage of 330 mV at 1 kHz. The onset of nonlinearity occurred at lower values of the overpotential as frequency was increased. Incorporation of nonlinear properties resulted in activation of a higher proportion of neurons under voltage-controlled stimulation. Under current-controlled stimulation, the predicted transition to nonlinear behavior and Faradaic charge transfer at stimulation amplitudes of 30μA, corresponds to a charge density of 2.29μC cm-2and charge of 1.8 nC, well-below the Shannon safety limit.Significance.The results indicate that DBS electrodes may operate within the nonlinear region at clinically relevant stimulation amplitudes. This affects the extent of neural activation under voltage-controlled stimulation and the transition to Faradaic charge transfer for both voltage- and current-controlled stimulation with important implications for targeting of neural populations and the design of safe stimulation protocols.
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Affiliation(s)
- K Sridhar
- Neuromuscular Systems Lab, School of Electrical and Electronic Engineering, University College Dublin, Dublin, Ireland
| | - J Evers
- Neuromuscular Systems Lab, School of Electrical and Electronic Engineering, University College Dublin, Dublin, Ireland
| | - M Lowery
- Neuromuscular Systems Lab, School of Electrical and Electronic Engineering, University College Dublin, Dublin, Ireland
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Gomez-Tames J, Laakso I, Hirata A. Review on biophysical modelling and simulation studies for transcranial magnetic stimulation. ACTA ACUST UNITED AC 2020; 65:24TR03. [DOI: 10.1088/1361-6560/aba40d] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Klooster DC, Vos IN, Caeyenberghs K, Leemans A, David S, Besseling RM, Aldenkamp AP, Baeken C. Indirect frontocingulate structural connectivity predicts clinical response to accelerated rTMS in major depressive disorder. J Psychiatry Neurosci 2020; 45:243-252. [PMID: 31990490 PMCID: PMC7828925 DOI: 10.1503/jpn.190088] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Repetitive transcranial magnetic stimulation (rTMS) is an established treatment for major depressive disorder (MDD), but its clinical efficacy remains rather modest. One reason for this could be that the propagation of rTMS effects via structural connections from the stimulated area to deeper brain structures (such as the cingulate cortices) is suboptimal. METHODS We investigated whether structural connectivity — derived from diffusion MRI data — could serve as a biomarker to predict treatment response. We hypothesized that stronger structural connections between the patient-specific stimulation position in the left dorsolateral prefrontal cortex (dlPFC) and the cingulate cortices would predict better clinical outcomes. We applied accelerated intermittent theta burst stimulation (aiTBS) to the left dlPFC in 40 patients with MDD. We correlated baseline structural connectivity, quantified using various metrics (fractional anisotropy, mean diffusivity, tract density, tract volume and number of tracts), with changes in depression severity scores after aiTBS. RESULTS Exploratory results (p < 0.05) showed that structural connectivity between the patient-specific stimulation site and the caudal and posterior parts of the cingulate cortex had predictive potential for clinical response to aiTBS. LIMITATIONS We used the diffusion tensor to perform tractography. A main limitation was that multiple fibre directions within voxels could not be resolved, which might have led to missing connections in some patients. CONCLUSION Stronger structural frontocingular connections may be of essence to optimally benefit from left dlPFC rTMS treatment in MDD. Even though the results are promising, further investigation with larger numbers of patients, more advanced tractography algorithms and classic daily rTMS treatment paradigms is warranted. CLINICAL TRIAL REGISTRATION http://clinicaltrials.gov/show/NCT01832805
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Affiliation(s)
- Deborah C.W. Klooster
- From the Eindhoven University of Technology, Department of Electrical Engineering, Eindhoven, the Netherlands (Klooster, Vos, Besseling, Aldenkamp); the Academic Center for Epileptology Kempenhaeghe, Department of Research and Development, Heeze, the Netherlands (Klooster, Aldenkamp); Ghent University, Ghent Experimental Psychiatry Laboratory, Ghent, Belgium (Baeken); the Australian Catholic University, Faculty of Health Sciences, Mary MacKillop Institute for Health Research, Melbourne, Australia (Caeyenberghs); the PROVIDI Lab, Image Sciences Institute, University Medical Center Utrecht and Utrecht University, Utrecht, the Netherlands (Leemans, David); the Brussel University Hospital, Department of Psychiatry, Brussels, Belgium (Baeken)
| | - Iris N. Vos
- From the Eindhoven University of Technology, Department of Electrical Engineering, Eindhoven, the Netherlands (Klooster, Vos, Besseling, Aldenkamp); the Academic Center for Epileptology Kempenhaeghe, Department of Research and Development, Heeze, the Netherlands (Klooster, Aldenkamp); Ghent University, Ghent Experimental Psychiatry Laboratory, Ghent, Belgium (Baeken); the Australian Catholic University, Faculty of Health Sciences, Mary MacKillop Institute for Health Research, Melbourne, Australia (Caeyenberghs); the PROVIDI Lab, Image Sciences Institute, University Medical Center Utrecht and Utrecht University, Utrecht, the Netherlands (Leemans, David); the Brussel University Hospital, Department of Psychiatry, Brussels, Belgium (Baeken)
| | - Karen Caeyenberghs
- From the Eindhoven University of Technology, Department of Electrical Engineering, Eindhoven, the Netherlands (Klooster, Vos, Besseling, Aldenkamp); the Academic Center for Epileptology Kempenhaeghe, Department of Research and Development, Heeze, the Netherlands (Klooster, Aldenkamp); Ghent University, Ghent Experimental Psychiatry Laboratory, Ghent, Belgium (Baeken); the Australian Catholic University, Faculty of Health Sciences, Mary MacKillop Institute for Health Research, Melbourne, Australia (Caeyenberghs); the PROVIDI Lab, Image Sciences Institute, University Medical Center Utrecht and Utrecht University, Utrecht, the Netherlands (Leemans, David); the Brussel University Hospital, Department of Psychiatry, Brussels, Belgium (Baeken)
| | - Alexander Leemans
- From the Eindhoven University of Technology, Department of Electrical Engineering, Eindhoven, the Netherlands (Klooster, Vos, Besseling, Aldenkamp); the Academic Center for Epileptology Kempenhaeghe, Department of Research and Development, Heeze, the Netherlands (Klooster, Aldenkamp); Ghent University, Ghent Experimental Psychiatry Laboratory, Ghent, Belgium (Baeken); the Australian Catholic University, Faculty of Health Sciences, Mary MacKillop Institute for Health Research, Melbourne, Australia (Caeyenberghs); the PROVIDI Lab, Image Sciences Institute, University Medical Center Utrecht and Utrecht University, Utrecht, the Netherlands (Leemans, David); the Brussel University Hospital, Department of Psychiatry, Brussels, Belgium (Baeken)
| | - Szabolcs David
- From the Eindhoven University of Technology, Department of Electrical Engineering, Eindhoven, the Netherlands (Klooster, Vos, Besseling, Aldenkamp); the Academic Center for Epileptology Kempenhaeghe, Department of Research and Development, Heeze, the Netherlands (Klooster, Aldenkamp); Ghent University, Ghent Experimental Psychiatry Laboratory, Ghent, Belgium (Baeken); the Australian Catholic University, Faculty of Health Sciences, Mary MacKillop Institute for Health Research, Melbourne, Australia (Caeyenberghs); the PROVIDI Lab, Image Sciences Institute, University Medical Center Utrecht and Utrecht University, Utrecht, the Netherlands (Leemans, David); the Brussel University Hospital, Department of Psychiatry, Brussels, Belgium (Baeken)
| | - René M.H. Besseling
- From the Eindhoven University of Technology, Department of Electrical Engineering, Eindhoven, the Netherlands (Klooster, Vos, Besseling, Aldenkamp); the Academic Center for Epileptology Kempenhaeghe, Department of Research and Development, Heeze, the Netherlands (Klooster, Aldenkamp); Ghent University, Ghent Experimental Psychiatry Laboratory, Ghent, Belgium (Baeken); the Australian Catholic University, Faculty of Health Sciences, Mary MacKillop Institute for Health Research, Melbourne, Australia (Caeyenberghs); the PROVIDI Lab, Image Sciences Institute, University Medical Center Utrecht and Utrecht University, Utrecht, the Netherlands (Leemans, David); the Brussel University Hospital, Department of Psychiatry, Brussels, Belgium (Baeken)
| | - Albert P. Aldenkamp
- From the Eindhoven University of Technology, Department of Electrical Engineering, Eindhoven, the Netherlands (Klooster, Vos, Besseling, Aldenkamp); the Academic Center for Epileptology Kempenhaeghe, Department of Research and Development, Heeze, the Netherlands (Klooster, Aldenkamp); Ghent University, Ghent Experimental Psychiatry Laboratory, Ghent, Belgium (Baeken); the Australian Catholic University, Faculty of Health Sciences, Mary MacKillop Institute for Health Research, Melbourne, Australia (Caeyenberghs); the PROVIDI Lab, Image Sciences Institute, University Medical Center Utrecht and Utrecht University, Utrecht, the Netherlands (Leemans, David); the Brussel University Hospital, Department of Psychiatry, Brussels, Belgium (Baeken)
| | - Chris Baeken
- From the Eindhoven University of Technology, Department of Electrical Engineering, Eindhoven, the Netherlands (Klooster, Vos, Besseling, Aldenkamp); the Academic Center for Epileptology Kempenhaeghe, Department of Research and Development, Heeze, the Netherlands (Klooster, Aldenkamp); Ghent University, Ghent Experimental Psychiatry Laboratory, Ghent, Belgium (Baeken); the Australian Catholic University, Faculty of Health Sciences, Mary MacKillop Institute for Health Research, Melbourne, Australia (Caeyenberghs); the PROVIDI Lab, Image Sciences Institute, University Medical Center Utrecht and Utrecht University, Utrecht, the Netherlands (Leemans, David); the Brussel University Hospital, Department of Psychiatry, Brussels, Belgium (Baeken)
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Guyader JM, Huizinga W, Poot DHJ, van Kranenburg M, Uitterdijk A, Niessen WJ, Klein S. Groupwise image registration based on a total correlation dissimilarity measure for quantitative MRI and dynamic imaging data. Sci Rep 2018; 8:13112. [PMID: 30166626 PMCID: PMC6117310 DOI: 10.1038/s41598-018-31474-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 08/20/2018] [Indexed: 02/07/2023] Open
Abstract
The most widespread technique used to register sets of medical images consists of selecting one image as fixed reference, to which all remaining images are successively registered. This pairwise scheme requires one optimization procedure per pair of images to register. Pairwise mutual information is a common dissimilarity measure applied to a large variety of datasets. Alternative methods, called groupwise registrations, have been presented to register two or more images in a single optimization procedure, without the need of a reference image. Given the success of mutual information in pairwise registration, we adapt one of its multivariate versions, called total correlation, in a groupwise context. We justify the choice of total correlation among other multivariate versions of mutual information, and provide full implementation details. The resulting total correlation measure is remarkably close to measures previously proposed by Huizinga et al. based on principal component analysis. Our experiments, performed on five quantitative imaging datasets and on a dynamic CT imaging dataset, show that total correlation yields registration results that are comparable to Huizinga's methods. Total correlation has the advantage of being theoretically justified, while the measures of Huizinga et al. were designed empirically. Additionally, total correlation offers an alternative to pairwise mutual information on quantitative imaging datasets.
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Affiliation(s)
- Jean-Marie Guyader
- Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Erasmus MC - University Medical Centre Rotterdam, Rotterdam, The Netherlands.
| | - Wyke Huizinga
- Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Erasmus MC - University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - Dirk H J Poot
- Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Erasmus MC - University Medical Centre Rotterdam, Rotterdam, The Netherlands
- Imaging Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Delft, The Netherlands
| | - Matthijs van Kranenburg
- Departments of Radiology, Erasmus MC - University Medical Centre Rotterdam, Rotterdam, The Netherlands
- Department of Cardiology, Erasmus MC - University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - André Uitterdijk
- Department of Cardiology, Erasmus MC - University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - Wiro J Niessen
- Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Erasmus MC - University Medical Centre Rotterdam, Rotterdam, The Netherlands
- Imaging Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Delft, The Netherlands
| | - Stefan Klein
- Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Erasmus MC - University Medical Centre Rotterdam, Rotterdam, The Netherlands
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Wilson MT, Fulcher BD, Fung PK, Robinson P, Fornito A, Rogasch NC. Biophysical modeling of neural plasticity induced by transcranial magnetic stimulation. Clin Neurophysiol 2018; 129:1230-1241. [DOI: 10.1016/j.clinph.2018.03.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 02/28/2018] [Accepted: 03/14/2018] [Indexed: 10/17/2022]
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Valero-Cabré A, Amengual JL, Stengel C, Pascual-Leone A, Coubard OA. Transcranial magnetic stimulation in basic and clinical neuroscience: A comprehensive review of fundamental principles and novel insights. Neurosci Biobehav Rev 2017; 83:381-404. [DOI: 10.1016/j.neubiorev.2017.10.006] [Citation(s) in RCA: 190] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 09/29/2017] [Accepted: 10/06/2017] [Indexed: 01/13/2023]
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Goetz SM, Deng ZD. The development and modelling of devices and paradigms for transcranial magnetic stimulation. Int Rev Psychiatry 2017; 29:115-145. [PMID: 28443696 PMCID: PMC5484089 DOI: 10.1080/09540261.2017.1305949] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 03/03/2017] [Accepted: 03/09/2017] [Indexed: 12/20/2022]
Abstract
Magnetic stimulation is a non-invasive neurostimulation technique that can evoke action potentials and modulate neural circuits through induced electric fields. Biophysical models of magnetic stimulation have become a major driver for technological developments and the understanding of the mechanisms of magnetic neurostimulation and neuromodulation. Major technological developments involve stimulation coils with different spatial characteristics and pulse sources to control the pulse waveform. While early technological developments were the result of manual design and invention processes, there is a trend in both stimulation coil and pulse source design to mathematically optimize parameters with the help of computational models. To date, macroscopically highly realistic spatial models of the brain, as well as peripheral targets, and user-friendly software packages enable researchers and practitioners to simulate the treatment-specific and induced electric field distribution in the brains of individual subjects and patients. Neuron models further introduce the microscopic level of neural activation to understand the influence of activation dynamics in response to different pulse shapes. A number of models that were designed for online calibration to extract otherwise covert information and biomarkers from the neural system recently form a third branch of modelling.
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Affiliation(s)
- Stefan M Goetz
- a Department of Psychiatry & Behavioral Sciences, Division for Brain Stimulation & Neurophysiology , Duke University , Durham , NC , USA
- b Department of Electrical & Computer Engineering , Duke University , Durham , NC , USA
- c Department of Neurosurgery , Duke University , Durham , NC , USA
| | - Zhi-De Deng
- a Department of Psychiatry & Behavioral Sciences, Division for Brain Stimulation & Neurophysiology , Duke University , Durham , NC , USA
- d Intramural Research Program, Experimental Therapeutics & Pathophysiology Branch, Noninvasive Neuromodulation Unit , National Institutes of Health, National Institute of Mental Health , Bethesda , MD , USA
- e Duke Institute for Brain Sciences , Duke University , Durham , NC , USA
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Iwahashi M, Gomez-Tames J, Laakso I, Hirata A. Evaluation method for in situ electric field in standardized human brain for different transcranial magnetic stimulation coils. Phys Med Biol 2017; 62:2224-2238. [DOI: 10.1088/1361-6560/aa5b70] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Mandija S, Petrov PI, Neggers SFW, Luijten PR, van den Berg CAT. MR-based measurements and simulations of the magnetic field created by a realistic transcranial magnetic stimulation (TMS) coil and stimulator. NMR IN BIOMEDICINE 2016; 29:1590-1600. [PMID: 27669678 DOI: 10.1002/nbm.3618] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 07/04/2016] [Accepted: 08/12/2016] [Indexed: 06/06/2023]
Abstract
Transcranial magnetic stimulation (TMS) is an emerging technique that allows non-invasive neurostimulation. However, the correct validation of electromagnetic models of typical TMS coils and the correct assessment of the incident TMS field (BTMS ) produced by standard TMS stimulators are still lacking. Such a validation can be performed by mapping BTMS produced by a realistic TMS setup. In this study, we show that MRI can provide precise quantification of the magnetic field produced by a realistic TMS coil and a clinically used TMS stimulator in the region in which neurostimulation occurs. Measurements of the phase accumulation created by TMS pulses applied during a tailored MR sequence were performed in a phantom. Dedicated hardware was developed to synchronize a typical, clinically used, TMS setup with a 3-T MR scanner. For comparison purposes, electromagnetic simulations of BTMS were performed. MR-based measurements allow the mapping and quantification of BTMS starting 2.5 cm from the TMS coil. For closer regions, the intra-voxel dephasing induced by BTMS prohibits TMS field measurements. For 1% TMS output, the maximum measured value was ~0.1 mT. Simulations reflect quantitatively the experimental data. These measurements can be used to validate electromagnetic models of TMS coils, to guide TMS coil positioning, and for dosimetry and quality assessment of concurrent TMS-MRI studies without the need for crude methods, such as motor threshold, for stimulation dose determination.
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Affiliation(s)
- Stefano Mandija
- Center for Image Sciences, University Medical Center Utrecht, Utrecht, the Netherlands.
| | - Petar I Petrov
- Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Sebastian F W Neggers
- Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Peter R Luijten
- Center for Image Sciences, University Medical Center Utrecht, Utrecht, the Netherlands
- Department of Radiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Cornelis A T van den Berg
- Center for Image Sciences, University Medical Center Utrecht, Utrecht, the Netherlands
- Department of Radiotherapy, University Medical Center Utrecht, Utrecht, the Netherlands
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De Geeter N, Lioumis P, Laakso A, Crevecoeur G, Dupré L. How to include the variability of TMS responses in simulations: a speech mapping case study. Phys Med Biol 2016; 61:7571-7585. [DOI: 10.1088/0031-9155/61/21/7571] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Mandija S, Petrov PI, Neggers SFW, Luijten PR, van den Berg CAT. Noninvasive Electric Current Induction for Low-Frequency Tissue Conductivity Reconstruction: Is It Feasible With a TMS-MRI Setup? ACTA ACUST UNITED AC 2016; 2:203-214. [PMID: 30042964 PMCID: PMC6024402 DOI: 10.18383/j.tom.2016.00232] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Noninvasive quantification of subject-specific low-frequency brain tissue conductivity ( σLF ) will be valuable in different fields, for example, neuroscience. Magnetic resonance (MR)-electrical impedance tomography allows measurements of σLF . However, the required high level of direct current injection leads to an undesirable pain sensation. Following the same principles, but avoiding pain sensation, we evaluate the feasibility of inductively inducing currents using a transcranial magnetic stimulation (TMS) device and recording the magnetic field variations arising from the induced tissue eddy currents using a standard 3 T MR scanner. Using simulations, we characterize the strength of the incident TMS magnetic field arising from the current running in the TMS coil, the strength of the induced magnetic field arising from the induced currents in tissues by TMS pulses, and the MR phase accuracy required to measure this latter magnetic field containing information about σLF . Then, using TMS-MRI measurements, we evaluate the achievable phase accuracy for a typical TMS-MRI setup. From measurements and simulations, it is crucial to discriminate the incident from the induced magnetic field. The incident TMS magnetic field range is ±10-4 T, measurable with standard MR scanners. In contrast, the induced TMS magnetic field is much weaker (±10-8 T), leading to an MR phase contribution of ∼10-4 rad. This phase range is too small to be measured, as the phase accuracy for TMS-MRI experiments is ∼10-2 rads. Thus, although highly attractive, noninvasive measurements of the induced TMS magnetic field, and therefore estimations of σLF , are experimentally not feasible.
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Affiliation(s)
- Stefano Mandija
- Center for Image Sciences, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Petar I Petrov
- Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Sebastian F W Neggers
- Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Peter R Luijten
- Center for Image Sciences, University Medical Center Utrecht, Utrecht, The Netherlands.,Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands; and
| | - Cornelis A T van den Berg
- Center for Image Sciences, University Medical Center Utrecht, Utrecht, The Netherlands.,Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands
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Paffi A, Camera F, Lucano E, Apollonio F, Liberti M. Time resolved dosimetry of human brain exposed to low frequency pulsed magnetic fields. Phys Med Biol 2016; 61:4452-65. [PMID: 27223143 DOI: 10.1088/0031-9155/61/12/4452] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
An accurate dosimetry is a key issue to understanding brain stimulation and related interaction mechanisms with neuronal tissues at the basis of the increasing amount of literature revealing the effects on human brain induced by low-level, low frequency pulsed magnetic fields (PMFs). Most literature on brain dosimetry estimates the maximum E field value reached inside the tissue without considering its time pattern or tissue dispersivity. Nevertheless a time-resolved dosimetry, accounting for dispersive tissues behavior, becomes necessary considering that the threshold for an effect onset may vary depending on the pulse waveform and that tissues may filter the applied stimulatory fields altering the predicted stimulatory waveform's size and shape. In this paper a time-resolved dosimetry has been applied on a realistic brain model exposed to the signal presented in Capone et al (2009 J. Neural Transm. 116 257-65), accounting for the broadband dispersivity of brain tissues up to several kHz, to accurately reconstruct electric field and current density waveforms inside different brain tissues. The results obtained by exposing the Duke's brain model to this PMF signal show that the E peak in the brain is considerably underestimated if a simple monochromatic dosimetry is carried out at the pulse repetition frequency of 75 Hz.
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Affiliation(s)
- Alessandra Paffi
- Department of Information Engineering, Electronics and Telecommunications, Sapienza University of Rome, via Eudossiana 18, 00184 Rome, Italy
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Klooster DCW, de Louw AJA, Aldenkamp AP, Besseling RMH, Mestrom RMC, Carrette S, Zinger S, Bergmans JWM, Mess WH, Vonck K, Carrette E, Breuer LEM, Bernas A, Tijhuis AG, Boon P. Technical aspects of neurostimulation: Focus on equipment, electric field modeling, and stimulation protocols. Neurosci Biobehav Rev 2016; 65:113-41. [PMID: 27021215 DOI: 10.1016/j.neubiorev.2016.02.016] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 02/05/2016] [Accepted: 02/17/2016] [Indexed: 12/31/2022]
Abstract
Neuromodulation is a field of science, medicine, and bioengineering that encompasses implantable and non-implantable technologies for the purpose of improving quality of life and functioning of humans. Brain neuromodulation involves different neurostimulation techniques: transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), vagus nerve stimulation (VNS), and deep brain stimulation (DBS), which are being used both to study their effects on cognitive brain functions and to treat neuropsychiatric disorders. The mechanisms of action of neurostimulation remain incompletely understood. Insight into the technical basis of neurostimulation might be a first step towards a more profound understanding of these mechanisms, which might lead to improved clinical outcome and therapeutic potential. This review provides an overview of the technical basis of neurostimulation focusing on the equipment, the present understanding of induced electric fields, and the stimulation protocols. The review is written from a technical perspective aimed at supporting the use of neurostimulation in clinical practice.
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Affiliation(s)
- D C W Klooster
- Kempenhaeghe Academic Center for Epileptology, P.O. Box 61, 5590 AB Heeze, The Netherlands; Department of Electrical Engineering, University of Technology Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
| | - A J A de Louw
- Kempenhaeghe Academic Center for Epileptology, P.O. Box 61, 5590 AB Heeze, The Netherlands; Department of Electrical Engineering, University of Technology Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands; Department of Neurology, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands.
| | - A P Aldenkamp
- Kempenhaeghe Academic Center for Epileptology, P.O. Box 61, 5590 AB Heeze, The Netherlands; Department of Electrical Engineering, University of Technology Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands; Department of Neurology, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands; School for Mental Health and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands; Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
| | - R M H Besseling
- Department of Electrical Engineering, University of Technology Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
| | - R M C Mestrom
- Department of Electrical Engineering, University of Technology Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
| | - S Carrette
- Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
| | - S Zinger
- Kempenhaeghe Academic Center for Epileptology, P.O. Box 61, 5590 AB Heeze, The Netherlands; Department of Electrical Engineering, University of Technology Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
| | - J W M Bergmans
- Department of Electrical Engineering, University of Technology Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
| | - W H Mess
- Departments of Clinical Neurophysiology, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands.
| | - K Vonck
- Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
| | - E Carrette
- Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
| | - L E M Breuer
- Kempenhaeghe Academic Center for Epileptology, P.O. Box 61, 5590 AB Heeze, The Netherlands.
| | - A Bernas
- Department of Electrical Engineering, University of Technology Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
| | - A G Tijhuis
- Department of Electrical Engineering, University of Technology Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
| | - P Boon
- Kempenhaeghe Academic Center for Epileptology, P.O. Box 61, 5590 AB Heeze, The Netherlands; Department of Electrical Engineering, University of Technology Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands; Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
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14
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Geeter ND, Dupré L, Crevecoeur G. Modeling transcranial magnetic stimulation from the induced electric fields to the membrane potentials along tractography-based white matter fiber tracts. J Neural Eng 2016; 13:026028. [PMID: 26934301 DOI: 10.1088/1741-2560/13/2/026028] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Transcranial magnetic stimulation (TMS) is a promising non-invasive tool for modulating the brain activity. Despite the widespread therapeutic and diagnostic use of TMS in neurology and psychiatry, its observed response remains hard to predict, limiting its further development and applications. Although the stimulation intensity is always maximum at the cortical surface near the coil, experiments reveal that TMS can affect deeper brain regions as well. APPROACH The explanation of this spread might be found in the white matter fiber tracts, connecting cortical and subcortical structures. When applying an electric field on neurons, their membrane potential is altered. If this change is significant, more likely near the TMS coil, action potentials might be initiated and propagated along the fiber tracts towards deeper regions. In order to understand and apply TMS more effectively, it is important to capture and account for this interaction as accurately as possible. Therefore, we compute, next to the induced electric fields in the brain, the spatial distribution of the membrane potentials along the fiber tracts and its temporal dynamics. MAIN RESULTS This paper introduces a computational TMS model in which electromagnetism and neurophysiology are combined. Realistic geometry and tissue anisotropy are included using magnetic resonance imaging and targeted white matter fiber tracts are traced using tractography based on diffusion tensor imaging. The position and orientation of the coil can directly be retrieved from the neuronavigation system. Incorporating these features warrants both patient- and case-specific results. SIGNIFICANCE The presented model gives insight in the activity propagation through the brain and can therefore explain the observed clinical responses to TMS and their inter- and/or intra-subject variability. We aspire to advance towards an accurate, flexible and personalized TMS model that helps to understand stimulation in the connected brain and to target more focused and deeper brain regions.
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Affiliation(s)
- Nele De Geeter
- Department of Electrical Energy, Systems and Automation, Ghent University, Technologiepark 913, B-9052 Zwijnaarde, Belgium
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15
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Huizinga W, Poot DHJ, Guyader JM, Klaassen R, Coolen BF, van Kranenburg M, van Geuns RJM, Uitterdijk A, Polfliet M, Vandemeulebroucke J, Leemans A, Niessen WJ, Klein S. PCA-based groupwise image registration for quantitative MRI. Med Image Anal 2015; 29:65-78. [PMID: 26802910 DOI: 10.1016/j.media.2015.12.004] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 12/10/2015] [Accepted: 12/10/2015] [Indexed: 11/17/2022]
Abstract
Quantitative magnetic resonance imaging (qMRI) is a technique for estimating quantitative tissue properties, such as the T1 and T2 relaxation times, apparent diffusion coefficient (ADC), and various perfusion measures. This estimation is achieved by acquiring multiple images with different acquisition parameters (or at multiple time points after injection of a contrast agent) and by fitting a qMRI signal model to the image intensities. Image registration is often necessary to compensate for misalignments due to subject motion and/or geometric distortions caused by the acquisition. However, large differences in image appearance make accurate image registration challenging. In this work, we propose a groupwise image registration method for compensating misalignment in qMRI. The groupwise formulation of the method eliminates the requirement of choosing a reference image, thus avoiding a registration bias. The method minimizes a cost function that is based on principal component analysis (PCA), exploiting the fact that intensity changes in qMRI can be described by a low-dimensional signal model, but not requiring knowledge on the specific acquisition model. The method was evaluated on 4D CT data of the lungs, and both real and synthetic images of five different qMRI applications: T1 mapping in a porcine heart, combined T1 and T2 mapping in carotid arteries, ADC mapping in the abdomen, diffusion tensor mapping in the brain, and dynamic contrast-enhanced mapping in the abdomen. Each application is based on a different acquisition model. The method is compared to a mutual information-based pairwise registration method and four other state-of-the-art groupwise registration methods. Registration accuracy is evaluated in terms of the precision of the estimated qMRI parameters, overlap of segmented structures, distance between corresponding landmarks, and smoothness of the deformation. In all qMRI applications the proposed method performed better than or equally well as competing methods, while avoiding the need to choose a reference image. It is also shown that the results of the conventional pairwise approach do depend on the choice of this reference image. We therefore conclude that our groupwise registration method with a similarity measure based on PCA is the preferred technique for compensating misalignments in qMRI.
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Affiliation(s)
- W Huizinga
- Biomedical Imaging Group Rotterdam, Departments of Radiology & Medical Informatics, Erasmus MC, Rotterdam, The Netherlands.
| | - D H J Poot
- Biomedical Imaging Group Rotterdam, Departments of Radiology & Medical Informatics, Erasmus MC, Rotterdam, The Netherlands; Quantitative Imaging Group, Department of Imaging Physics, Faculty of Applied Sciences, Delft University of Technology, Delft, The Netherlands
| | - J-M Guyader
- Biomedical Imaging Group Rotterdam, Departments of Radiology & Medical Informatics, Erasmus MC, Rotterdam, The Netherlands
| | - R Klaassen
- Department of Medical Oncology, Academic Medical Center, Amsterdam, The Netherlands
| | - B F Coolen
- Department of Radiology, Academic Medical Center, Amsterdam, The Netherlands
| | - M van Kranenburg
- Department of Radiology, Erasmus MC, Rotterdam, The Netherlands; Department of Cardiology, Erasmus MC, Rotterdam, The Netherlands
| | - R J M van Geuns
- Department of Radiology, Erasmus MC, Rotterdam, The Netherlands; Department of Cardiology, Erasmus MC, Rotterdam, The Netherlands
| | - A Uitterdijk
- Department of Cardiology, Erasmus MC, Rotterdam, The Netherlands
| | - M Polfliet
- Vrije Universiteit Brussel, Department of Electronics and Informatics (ETRO), Brussels, Belgium; iMinds, Department of Medical IT, Ghent, Belgium
| | - J Vandemeulebroucke
- Vrije Universiteit Brussel, Department of Electronics and Informatics (ETRO), Brussels, Belgium; iMinds, Department of Medical IT, Ghent, Belgium
| | - A Leemans
- Image Sciences Institute, University Medical Center Utrecht, The Netherlands
| | - W J Niessen
- Biomedical Imaging Group Rotterdam, Departments of Radiology & Medical Informatics, Erasmus MC, Rotterdam, The Netherlands; Quantitative Imaging Group, Department of Imaging Physics, Faculty of Applied Sciences, Delft University of Technology, Delft, The Netherlands
| | - S Klein
- Biomedical Imaging Group Rotterdam, Departments of Radiology & Medical Informatics, Erasmus MC, Rotterdam, The Netherlands
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16
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Peterchev AV, Deng ZD, Goetz SM. Advances in Transcranial Magnetic Stimulation Technology. Brain Stimul 2015. [DOI: 10.1002/9781118568323.ch10] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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17
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De Geeter N, Crevecoeur G, Leemans A, Dupré L. Effective electric fields along realistic DTI-based neural trajectories for modelling the stimulation mechanisms of TMS. Phys Med Biol 2014; 60:453-71. [PMID: 25549237 DOI: 10.1088/0031-9155/60/2/453] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In transcranial magnetic stimulation (TMS), an applied alternating magnetic field induces an electric field in the brain that can interact with the neural system. It is generally assumed that this induced electric field is the crucial effect exciting a certain region of the brain. More specifically, it is the component of this field parallel to the neuron's local orientation, the so-called effective electric field, that can initiate neuronal stimulation. Deeper insights on the stimulation mechanisms can be acquired through extensive TMS modelling. Most models study simple representations of neurons with assumed geometries, whereas we embed realistic neural trajectories computed using tractography based on diffusion tensor images. This way of modelling ensures a more accurate spatial distribution of the effective electric field that is in addition patient and case specific. The case study of this paper focuses on the single pulse stimulation of the left primary motor cortex with a standard figure-of-eight coil. Including realistic neural geometry in the model demonstrates the strong and localized variations of the effective electric field between the tracts themselves and along them due to the interplay of factors such as the tract's position and orientation in relation to the TMS coil, the neural trajectory and its course along the white and grey matter interface. Furthermore, the influence of changes in the coil orientation is studied. Investigating the impact of tissue anisotropy confirms that its contribution is not negligible. Moreover, assuming isotropic tissues lead to errors of the same size as rotating or tilting the coil with 10 degrees. In contrast, the model proves to be less sensitive towards the not well-known tissue conductivity values.
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Affiliation(s)
- N De Geeter
- Department of Electrical Energy, Systems and Automation, Ghent University, Technologiepark 913, 9052 Zwijnaarde, Belgium
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18
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The effect of local anatomy on the electric field induced by TMS: evaluation at 14 different target sites. Med Biol Eng Comput 2014; 52:873-83. [DOI: 10.1007/s11517-014-1190-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 08/14/2014] [Indexed: 10/24/2022]
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19
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Diffusion tensor MRI of chemotherapy-induced cognitive impairment in non-CNS cancer patients: a review. Brain Imaging Behav 2014; 7:409-35. [PMID: 23329357 DOI: 10.1007/s11682-012-9220-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Patients with non-central nervous system cancers often experience subtle cognitive deficits after treatment with cytotoxic agents. Therapy-induced structural changes to the brain could be one of the possible causes underlying these reported cognitive deficits. In this review, we evaluate the use of diffusion tensor imaging (DTI) for assessing possible therapy-induced changes in the microstructure of the cerebral white matter (WM) and provide a critical overview of the published DTI research on therapy-induced cognitive impairment. Both cross-sectional and longitudinal DTI studies have demonstrated abnormal microstructural properties in WM regions involved in cognition. These findings correlated with cognitive performance, suggesting that there is a link between reduced "WM integrity" and chemotherapy-induced impaired cognition. In this paper, we will also introduce the basics of diffusion tensor imaging and how it can be applied to evaluate effects of therapy on structural changes in cerebral WM. The review concludes with considerations and discussion regarding DTI data interpretation and possible future directions for investigating therapy-induced WM changes in cancer patients. This review article is part of a Special Issue entitled: Neuroimaging Studies of Cancer and Cancer Treatment.
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20
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The effect of head and coil modeling for the calculation of induced electric field during transcranial magnetic stimulation. Int J Psychophysiol 2014; 93:167-71. [DOI: 10.1016/j.ijpsycho.2013.07.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 05/06/2013] [Accepted: 07/03/2013] [Indexed: 11/17/2022]
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21
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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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22
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P 2. Modeling the active neurodynamic behavior of rTMS in the prefrontal cortex of a realistic human head. Clin Neurophysiol 2013. [DOI: 10.1016/j.clinph.2013.04.081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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23
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Crevecoeur G, Geeter ND, Dupré L. P 218. Optimized small animal transcranial magnetic stimulators using distributed coils. Clin Neurophysiol 2013. [DOI: 10.1016/j.clinph.2013.04.295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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24
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Wagner T, Eden U, Rushmore J, Russo CJ, Dipietro L, Fregni F, Simon S, Rotman S, Pitskel NB, Ramos-Estebanez C, Pascual-Leone A, Grodzinsky AJ, Zahn M, Valero-Cabré A. Impact of brain tissue filtering on neurostimulation fields: a modeling study. Neuroimage 2013; 85 Pt 3:1048-57. [PMID: 23850466 DOI: 10.1016/j.neuroimage.2013.06.079] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 06/27/2013] [Accepted: 06/28/2013] [Indexed: 01/20/2023] Open
Abstract
Electrical neurostimulation techniques, such as deep brain stimulation (DBS) and transcranial magnetic stimulation (TMS), are increasingly used in the neurosciences, e.g., for studying brain function, and for neurotherapeutics, e.g., for treating depression, epilepsy, and Parkinson's disease. The characterization of electrical properties of brain tissue has guided our fundamental understanding and application of these methods, from electrophysiologic theory to clinical dosing-metrics. Nonetheless, prior computational models have primarily relied on ex-vivo impedance measurements. We recorded the in-vivo impedances of brain tissues during neurosurgical procedures and used these results to construct MRI guided computational models of TMS and DBS neurostimulatory fields and conductance-based models of neurons exposed to stimulation. We demonstrated that tissues carry neurostimulation currents through frequency dependent resistive and capacitive properties not typically accounted for by past neurostimulation modeling work. We show that these fundamental brain tissue properties can have significant effects on the neurostimulatory-fields (capacitive and resistive current composition and spatial/temporal dynamics) and neural responses (stimulation threshold, ionic currents, and membrane dynamics). These findings highlight the importance of tissue impedance properties on neurostimulation and impact our understanding of the biological mechanisms and technological potential of neurostimulatory methods.
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Affiliation(s)
- Tim Wagner
- Highland Instruments, Cambridge, MA, USA; Division of Health Sciences and Technology, Harvard Medical School/Massachusetts Institute of Technology, Boston, MA, USA.
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25
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Janssen AM, Rampersad SM, Lucka F, Lanfer B, Lew S, Aydin U, Wolters CH, Stegeman DF, Oostendorp TF. The influence of sulcus width on simulated electric fields induced by transcranial magnetic stimulation. Phys Med Biol 2013; 58:4881-96. [PMID: 23787706 DOI: 10.1088/0031-9155/58/14/4881] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Volume conduction models can help in acquiring knowledge about the distribution of the electric field induced by transcranial magnetic stimulation. One aspect of a detailed model is an accurate description of the cortical surface geometry. Since its estimation is difficult, it is important to know how accurate the geometry has to be represented. Previous studies only looked at the differences caused by neglecting the complete boundary between cerebrospinal fluid (CSF) and grey matter (Thielscher et al 2011 NeuroImage 54 234-43, Bijsterbosch et al 2012 Med. Biol. Eng. Comput. 50 671-81), or by resizing the whole brain (Wagner et al 2008 Exp. Brain Res. 186 539-50). However, due to the high conductive properties of the CSF, it can be expected that alterations in sulcus width can already have a significant effect on the distribution of the electric field. To answer this question, the sulcus width of a highly realistic head model, based on T1-, T2- and diffusion-weighted magnetic resonance images, was altered systematically. This study shows that alterations in the sulcus width do not cause large differences in the majority of the electric field values. However, considerable overestimation of sulcus width produces an overestimation of the calculated field strength, also at locations distant from the target location.
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Affiliation(s)
- A M Janssen
- Radboud University Nijmegen Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Reinier Postlaan 4, 6525 CG Nijmegen, The Netherlands.
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26
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Datta A, Dmochowski JP, Guleyupoglu B, Bikson M, Fregni F. Cranial electrotherapy stimulation and transcranial pulsed current stimulation: a computer based high-resolution modeling study. Neuroimage 2012; 65:280-7. [PMID: 23041337 DOI: 10.1016/j.neuroimage.2012.09.062] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 09/08/2012] [Accepted: 09/24/2012] [Indexed: 11/26/2022] Open
Abstract
The field of non-invasive brain stimulation has developed significantly over the last two decades. Though two techniques of noninvasive brain stimulation--transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS)--are becoming established tools for research in neuroscience and for some clinical applications, related techniques that also show some promising clinical results have not been developed at the same pace. One of these related techniques is cranial electrotherapy stimulation (CES), a class of transcranial pulsed current stimulation (tPCS). In order to understand further the mechanisms of CES, we aimed to model CES using a magnetic resonance imaging (MRI)-derived finite element head model including cortical and also subcortical structures. Cortical electric field (current density) peak intensities and distributions were analyzed. We evaluated different electrode configurations of CES including in-ear and over-ear montages. Our results confirm that significant amounts of current pass the skull and reach cortical and subcortical structures. In addition, depending on the montage, induced currents at subcortical areas, such as midbrain, pons, thalamus and hypothalamus are of similar magnitude than that of cortical areas. Incremental variations of electrode position on the head surface also influence which cortical regions are modulated. The high-resolution modeling predictions suggest that details of electrode montage influence current flow through superficial and deep structures. Finally we present laptop based methods for tPCS dose design using dominant frequency and spherical models. These modeling predictions and tools are the first step to advance rational and optimized use of tPCS and CES.
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Affiliation(s)
- Abhishek Datta
- Neural Engineering Laboratory, Department of Biomedical Engineering, The City College of New York of CUNY, New York, NY 10031, USA.
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