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Van Malderen S, Hehl M, Verstraelen S, Swinnen SP, Cuypers K. Dual-site TMS as a tool to probe effective interactions within the motor network: a review. Rev Neurosci 2023; 34:129-221. [PMID: 36065080 DOI: 10.1515/revneuro-2022-0020] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 07/02/2022] [Indexed: 02/07/2023]
Abstract
Dual-site transcranial magnetic stimulation (ds-TMS) is well suited to investigate the causal effect of distant brain regions on the primary motor cortex, both at rest and during motor performance and learning. However, given the broad set of stimulation parameters, clarity about which parameters are most effective for identifying particular interactions is lacking. Here, evidence describing inter- and intra-hemispheric interactions during rest and in the context of motor tasks is reviewed. Our aims are threefold: (1) provide a detailed overview of ds-TMS literature regarding inter- and intra-hemispheric connectivity; (2) describe the applicability and contributions of these interactions to motor control, and; (3) discuss the practical implications and future directions. Of the 3659 studies screened, 109 were included and discussed. Overall, there is remarkable variability in the experimental context for assessing ds-TMS interactions, as well as in the use and reporting of stimulation parameters, hindering a quantitative comparison of results across studies. Further studies examining ds-TMS interactions in a systematic manner, and in which all critical parameters are carefully reported, are needed.
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Affiliation(s)
- Shanti Van Malderen
- Department of Movement Sciences, Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Heverlee 3001, Belgium.,Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, Diepenbeek 3590, Belgium
| | - Melina Hehl
- Department of Movement Sciences, Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Heverlee 3001, Belgium.,Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, Diepenbeek 3590, Belgium
| | - Stefanie Verstraelen
- Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, Diepenbeek 3590, Belgium
| | - Stephan P Swinnen
- Department of Movement Sciences, Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Heverlee 3001, Belgium.,KU Leuven, Leuven Brain Institute (LBI), Leuven, Belgium
| | - Koen Cuypers
- Department of Movement Sciences, Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Heverlee 3001, Belgium.,Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, Diepenbeek 3590, Belgium
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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: 116] [Impact Index Per Article: 58.0] [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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Beynel L, Davis SW, Crowell CA, Dannhauer M, Lim W, Palmer H, Hilbig SA, Brito A, Hile C, Luber B, Lisanby SH, Peterchev AV, Cabeza R, Appelbaum LG. Site-Specific Effects of Online rTMS during a Working Memory Task in Healthy Older Adults. Brain Sci 2020; 10:E255. [PMID: 32349366 PMCID: PMC7287855 DOI: 10.3390/brainsci10050255] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 12/04/2022] Open
Abstract
The process of manipulating information within working memory is central to many cognitive functions, but also declines rapidly in old age. Improving this process could markedly enhance the health-span in older adults. The current pre-registered, randomized and placebo-controlled study tested the potential of online repetitive transcranial magnetic stimulation (rTMS) applied at 5 Hz over the left lateral parietal cortex to enhance working memory manipulation in healthy elderly adults. rTMS was applied, while participants performed a delayed-response alphabetization task with two individually titrated levels of difficulty. Coil placement and stimulation amplitude were calculated from fMRI activation maps combined with electric field modeling on an individual-subject basis in order to standardize dosing at the targeted cortical location. Contrary to the a priori hypothesis, active rTMS significantly decreased accuracy relative to sham, and only in the hardest difficulty level. When compared to the results from our previous study, in which rTMS was applied over the left prefrontal cortex, we found equivalent effect sizes but opposite directionality suggesting a site-specific effect of rTMS. These results demonstrate engagement of cortical working memory processing using a novel TMS targeting approach, while also providing prescriptions for future studies seeking to enhance memory through rTMS.
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Affiliation(s)
- Lysianne Beynel
- Department of Psychiatry and Behavioral Science, Duke University School of Medicine, 200 Trent Drive, Box 3620 DUMC, Durham, NC 27710, USA; (C.A.C.); (M.D.); (W.L.); (H.P.); (S.A.H.); (A.B.); (C.H.); (S.H.L.); (A.V.P.); (L.G.A.)
| | - Simon W. Davis
- Department of Neurology, Duke University School of Medicine, 3116 N Duke Street, Durham, NC 27704, USA;
- Center for Cognitive Neuroscience, Duke University, 308 Research Drive, Durham, NC 27710, USA;
| | - Courtney A. Crowell
- Department of Psychiatry and Behavioral Science, Duke University School of Medicine, 200 Trent Drive, Box 3620 DUMC, Durham, NC 27710, USA; (C.A.C.); (M.D.); (W.L.); (H.P.); (S.A.H.); (A.B.); (C.H.); (S.H.L.); (A.V.P.); (L.G.A.)
- Center for Cognitive Neuroscience, Duke University, 308 Research Drive, Durham, NC 27710, USA;
| | - Moritz Dannhauer
- Department of Psychiatry and Behavioral Science, Duke University School of Medicine, 200 Trent Drive, Box 3620 DUMC, Durham, NC 27710, USA; (C.A.C.); (M.D.); (W.L.); (H.P.); (S.A.H.); (A.B.); (C.H.); (S.H.L.); (A.V.P.); (L.G.A.)
| | - Wesley Lim
- Department of Psychiatry and Behavioral Science, Duke University School of Medicine, 200 Trent Drive, Box 3620 DUMC, Durham, NC 27710, USA; (C.A.C.); (M.D.); (W.L.); (H.P.); (S.A.H.); (A.B.); (C.H.); (S.H.L.); (A.V.P.); (L.G.A.)
| | - Hannah Palmer
- Department of Psychiatry and Behavioral Science, Duke University School of Medicine, 200 Trent Drive, Box 3620 DUMC, Durham, NC 27710, USA; (C.A.C.); (M.D.); (W.L.); (H.P.); (S.A.H.); (A.B.); (C.H.); (S.H.L.); (A.V.P.); (L.G.A.)
| | - Susan A. Hilbig
- Department of Psychiatry and Behavioral Science, Duke University School of Medicine, 200 Trent Drive, Box 3620 DUMC, Durham, NC 27710, USA; (C.A.C.); (M.D.); (W.L.); (H.P.); (S.A.H.); (A.B.); (C.H.); (S.H.L.); (A.V.P.); (L.G.A.)
| | - Alexandra Brito
- Department of Psychiatry and Behavioral Science, Duke University School of Medicine, 200 Trent Drive, Box 3620 DUMC, Durham, NC 27710, USA; (C.A.C.); (M.D.); (W.L.); (H.P.); (S.A.H.); (A.B.); (C.H.); (S.H.L.); (A.V.P.); (L.G.A.)
| | - Connor Hile
- Department of Psychiatry and Behavioral Science, Duke University School of Medicine, 200 Trent Drive, Box 3620 DUMC, Durham, NC 27710, USA; (C.A.C.); (M.D.); (W.L.); (H.P.); (S.A.H.); (A.B.); (C.H.); (S.H.L.); (A.V.P.); (L.G.A.)
| | - Bruce Luber
- National Institute of Mental Health, 6001 Executive Boulevard, Bethesda, MD 20852, USA;
| | - Sarah H. Lisanby
- Department of Psychiatry and Behavioral Science, Duke University School of Medicine, 200 Trent Drive, Box 3620 DUMC, Durham, NC 27710, USA; (C.A.C.); (M.D.); (W.L.); (H.P.); (S.A.H.); (A.B.); (C.H.); (S.H.L.); (A.V.P.); (L.G.A.)
- National Institute of Mental Health, 6001 Executive Boulevard, Bethesda, MD 20852, USA;
| | - Angel V. Peterchev
- Department of Psychiatry and Behavioral Science, Duke University School of Medicine, 200 Trent Drive, Box 3620 DUMC, Durham, NC 27710, USA; (C.A.C.); (M.D.); (W.L.); (H.P.); (S.A.H.); (A.B.); (C.H.); (S.H.L.); (A.V.P.); (L.G.A.)
- Department of Biomedical Engineering, Duke University, 305 Teer Engineering Building, Box 90271, Durham, NC 27708, USA
- Department of Electrical and Computer Engineering, Duke University, 305 Teer Engineering Building, Box 90271, Durham, NC 27708, USA
- Department of Neurosurgery, Duke University School of Medicine, 200 Trent Drive, Box 3807 DUMC, Durham, NC 27710, USA
| | - Roberto Cabeza
- Center for Cognitive Neuroscience, Duke University, 308 Research Drive, Durham, NC 27710, USA;
- Department of Psychology & Neuroscience, Duke University, 417 Chapel Drive, Durham, NC 27708, USA
| | - Lawrence G. Appelbaum
- Department of Psychiatry and Behavioral Science, Duke University School of Medicine, 200 Trent Drive, Box 3620 DUMC, Durham, NC 27710, USA; (C.A.C.); (M.D.); (W.L.); (H.P.); (S.A.H.); (A.B.); (C.H.); (S.H.L.); (A.V.P.); (L.G.A.)
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Kramer, Duran, Soder, Applegate, Youssef, Criscione, Keenan. The Special Brain: Subclinical Grandiose Narcissism and Self-Face Recognition in the Right Prefrontal Cortex. AMERICAN JOURNAL OF PSYCHOLOGY 2020. [DOI: 10.5406/amerjpsyc.133.4.0487] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Hashemirad F, Zoghi M, Fitzgerald PB, Jaberzadeh S. Reliability of Motor Evoked Potentials Induced by Transcranial Magnetic Stimulation: The Effects of Initial Motor Evoked Potentials Removal. Basic Clin Neurosci 2017; 8:43-50. [PMID: 28446949 PMCID: PMC5396172 DOI: 10.15412/j.bcn.03080106] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
INTRODUCTION Transcranial magnetic stimulation (TMS) is a useful tool for assessment of corticospinal excitability (CSE) changes in both healthy individuals and patients with brain disorders. The usefulness of TMS-elicited motor evoked potentials (MEPs) for the assessment of CSE in a clinical context depends on their intra-and inter-session reliability. This study aimed to evaluate if removal of initial MEPs elicited by using two types of TMS techniques influences the reliability scores and whether this effect is different in blocks with variable number of MEPs. METHODS Twenty-three healthy participants were recruited in this study. The stimulus intensity was set at 120% of resting motor threshold (RMT) for one group while the stimulus intensity was adjusted to record MEPs up to 1 mV for the other group. Twenty MEPs were recorded at 3 time points on 2 separate days. An intra-class correlation coefficient (ICC) reliability with absolute agreement and analysis of variance model were used to assess reliability of the MEP amplitudes for blocks with variable number of MEPs. RESULTS A decrease in ICC values was observed with removal of 3 or 5 MEPs in both techniques when compared to all MEP responses in any given block. Therefore, removal of the first 3 or 5 MEPs failed to further increase the reliability of MEP responses. CONCLUSION Our findings revealed that a greater number of trials involving averaged MEPs can influence TMS reliability more than removal of the first trials.
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Affiliation(s)
- Fahimeh Hashemirad
- Department of Physiotherapy, School of Primary Health Care, Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia
| | - Maryam Zoghi
- Department of Medicine at Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia
| | - Paul B Fitzgerald
- Monash Alfred Psychiatry Research Centre, Alfred and Monash University Central Clinical School, Melbourne, Australia
| | - Shapour Jaberzadeh
- Department of Physiotherapy, School of Primary Health Care, Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia
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Combining non-invasive transcranial brain stimulation with neuroimaging and electrophysiology: Current approaches and future perspectives. Neuroimage 2016; 140:4-19. [DOI: 10.1016/j.neuroimage.2016.02.012] [Citation(s) in RCA: 197] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 01/26/2016] [Accepted: 02/07/2016] [Indexed: 12/23/2022] Open
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Hashemirad F, Zoghi M, Fitzgerald PB, Jaberzadeh S. The effect of anodal transcranial direct current stimulation on motor sequence learning in healthy individuals: A systematic review and meta-analysis. Brain Cogn 2015; 102:1-12. [PMID: 26685088 DOI: 10.1016/j.bandc.2015.11.005] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 11/13/2015] [Accepted: 11/17/2015] [Indexed: 11/25/2022]
Abstract
A large number of studies have indicated the effect of anodal transcranial direct current stimulation (a-tDCS) on the primary motor cortex (M1) during motor skill training. The effects of a-tDCS on different stages of motor sequence learning are not yet completely understood. The purpose of this meta-analysis was to determine the effects of single and multiple sessions of a-tDCS on two different tasks: the sequential finger tapping task/serial reaction time task (SEQTAP/SRTT) and the sequential visual isometric pinch task (SVIPT). We searched electronic databases for M1 a-tDCS studies. Thirteen studies met the inclusion criteria. The results indicate that application of multiple sessions of a-tDCS, compared to single session a-tDCS induced a significant improvement in skill in both SEQTAP/SRTT and SVIPT. Retention after a single day and multiple days of a-tDCS was statistically significant for the SEQTAP/SRTT task but not for SVIPT. Therefore, our findings suggest that application of M1 a-tDCS across the three or five consecutive days can be helpful to improve motor sequence learning.
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Affiliation(s)
- Fahimeh Hashemirad
- Department of Physiotherapy, School of Primary Health Care, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia.
| | - Maryam Zoghi
- Department of Medicine at Royal Melbourne Hospital, The University of Melbourne, Melbourne, Australia
| | - Paul B Fitzgerald
- Monash Alfred Psychiatry Research Centre, The Alfred and Monash University Central Clinical School, Melbourne, Australia
| | - Shapour Jaberzadeh
- Department of Physiotherapy, School of Primary Health Care, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia
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Tanaka LL, Dessing JC, Malik P, Prime SL, Crawford JD. The effects of TMS over dorsolateral prefrontal cortex on trans-saccadic memory of multiple objects. Neuropsychologia 2014; 63:185-93. [PMID: 25192630 DOI: 10.1016/j.neuropsychologia.2014.08.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 07/04/2014] [Accepted: 08/20/2014] [Indexed: 10/24/2022]
Abstract
Humans typically make several rapid eye movements (saccades) per second. It is thought that visual working memory can retain and spatially integrate three to four objects or features across each saccade but little is known about this neural mechanism. Previously we showed that transcranial magnetic stimulation (TMS) to the posterior parietal cortex and frontal eye fields degrade trans-saccadic memory of multiple object features (Prime, Vesia, & Crawford, 2008, Journal of Neuroscience, 28(27), 6938-6949; Prime, Vesia, & Crawford, 2010, Cerebral Cortex, 20(4), 759-772.). Here, we used a similar protocol to investigate whether dorsolateral prefrontal cortex (DLPFC), an area involved in spatial working memory, is also involved in trans-saccadic memory. Subjects were required to report changes in stimulus orientation with (saccade task) or without (fixation task) an eye movement in the intervening memory interval. We applied single-pulse TMS to left and right DLPFC during the memory delay, timed at three intervals to arrive approximately 100 ms before, 100 ms after, or at saccade onset. In the fixation task, left DLPFC TMS produced inconsistent results, whereas right DLPFC TMS disrupted performance at all three intervals (significantly for presaccadic TMS). In contrast, in the saccade task, TMS consistently facilitated performance (significantly for left DLPFC/perisaccadic TMS and right DLPFC/postsaccadic TMS) suggesting a dis-inhibition of trans-saccadic processing. These results are consistent with a neural circuit of trans-saccadic memory that overlaps and interacts with, but is partially separate from the circuit for visual working memory during sustained fixation.
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Affiliation(s)
- L L Tanaka
- Centre for Vision Research and Canadian Action and Perception Network, York University, Toronto, Canada; Neuroscience Graduate Diploma Program and Departments of Psychology, Biology, and Kinesiology and Health Sciences, York University, Toronto, Canada
| | - J C Dessing
- Centre for Vision Research and Canadian Action and Perception Network, York University, Toronto, Canada; School of Psychology, Queen׳s University Belfast, Northern Ireland
| | - P Malik
- Centre for Vision Research and Canadian Action and Perception Network, York University, Toronto, Canada; Neuroscience Graduate Diploma Program and Departments of Psychology, Biology, and Kinesiology and Health Sciences, York University, Toronto, Canada
| | - S L Prime
- Department of Psychology, University of Saskatchewan, Canada
| | - J D Crawford
- Centre for Vision Research and Canadian Action and Perception Network, York University, Toronto, Canada; Neuroscience Graduate Diploma Program and Departments of Psychology, Biology, and Kinesiology and Health Sciences, York University, Toronto, Canada.
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Chipchase L, Schabrun S, Cohen L, Hodges P, Ridding M, Rothwell J, Taylor J, Ziemann U. A checklist for assessing the methodological quality of studies using transcranial magnetic stimulation to study the motor system: an international consensus study. Clin Neurophysiol 2012; 123:1698-704. [PMID: 22647458 DOI: 10.1016/j.clinph.2012.05.003] [Citation(s) in RCA: 173] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2012] [Revised: 04/30/2012] [Accepted: 05/03/2012] [Indexed: 11/16/2022]
Abstract
In the last decade transcranial magnetic stimulation (TMS) has been the subject of more than 20,000 original research articles. Despite this popularity, TMS responses are known to be highly variable and this variability can impact on interpretation of research findings. There are no guidelines regarding the factors that should be reported and/or controlled in TMS studies. This study aimed to develop a checklist to be recommended to evaluate the methodology and reporting of studies that use single or paired pulse TMS to study the motor system. A two round international web-based Delphi study was conducted. Panellists rated the importance of a number of subject, methodological and analytical factors to be reported and/or controlled in studies that use single or paired pulse TMS to study the motor system. Twenty-seven items for single pulse studies and 30 items for paired pulse studies were included in the final checklist. Eight items related to subjects (e.g. age, gender), 21 to methodology (e.g. coil type, stimulus intensity) and two to analysis (e.g. size of the unconditioned motor evoked potential). The checklist is recommended for inclusion when submitting manuscripts for publication to ensure transparency of reporting and could also be used to critically appraise previously published work. It is envisaged that factors could be added and deleted from the checklist on the basis of future research. Use of the TMS methodological checklist should improve the quality of data collection and reporting in TMS studies of the motor system.
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Affiliation(s)
- Lucy Chipchase
- The University of Queensland, NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury and Health, Australia.
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Transcranial magnetic stimulation intensities in cognitive paradigms. PLoS One 2011; 6:e24836. [PMID: 21980359 PMCID: PMC3182987 DOI: 10.1371/journal.pone.0024836] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 08/22/2011] [Indexed: 11/19/2022] Open
Abstract
Background Transcranial magnetic stimulation (TMS) has become an important experimental tool for exploring the brain's functional anatomy. As TMS interferes with neural activity, the hypothetical function of the stimulated area can thus be tested. One unresolved methodological issue in TMS experiments is the question of how to adequately calibrate stimulation intensities. The motor threshold (MT) is often taken as a reference for individually adapted stimulation intensities in TMS experiments, even if they do not involve the motor system. The aim of the present study was to evaluate whether it is reasonable to adjust stimulation intensities in each subject to the individual MT if prefrontal regions are stimulated prior to the performance of a cognitive paradigm. Methods and Findings Repetitive TMS (rTMS) was applied prior to a working memory task, either at the ‘fixed’ intensity of 40% maximum stimulator output (MSO), or individually adapted at 90% of the subject's MT. Stimulation was applied to a target region in the left posterior middle frontal gyrus (pMFG), as indicated by a functional magnetic resonance imaging (fMRI) localizer acquired beforehand, or to a control site (vertex). Results show that MT predicted the effect size after stimulating subjects with the fixed intensity (i.e., subjects with a low MT showed a greater behavioral effect). Nevertheless, the individual adaptation of intensities did not lead to stable effects. Conclusion Therefore, we suggest assessing MT and account for it as a measure for general cortical TMS susceptibility, even if TMS is applied outside the motor domain.
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Wong C, Gallate J. Low-frequency repetitive transcranial magnetic stimulation of the anterior temporal lobes does not dissociate social versus nonsocial semantic knowledge. Q J Exp Psychol (Hove) 2011; 64:855-70. [DOI: 10.1080/17470218.2010.526232] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Social conceptual knowledge is imperative to communicate with, interact with, and interpret human society; however, little is known about the neural basis of social concepts. Previous research has predominantly suggested that the right anterior temporal lobe (ATL) may specifically represent social conceptual knowledge, whereas the left ATL is necessary for general semantic processing. However, this view has not always been supported by empirical studies. Employing a lateralized design and two different semantic tasks and a nonsemantic control task, we aimed to clarify some of these ambiguities by potentially dissociating left from right functionality and social from nonsocial concepts, using inhibitory repetitive transcranial magnetic stimulation (rTMS) coupled with a sham and control site stimulation ( N = 56). The results showed that stimulation of the left ATL led to overall faster processing times without affecting accuracy, whilst the right ATL and control groups did not significantly change in reaction times or accuracy. No difference occurred between social and nonsocial concepts after stimulation. This study is the first to show that inhibition of the left temporal lobe may improve performance on a semantic task and provides evidence that the ATLs may be lateralized in conceptual processing. The results do not confirm that the right temporal lobe is crucial for social conceptual processing, as inhibition did not significantly affect performance for social concepts.
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Affiliation(s)
- Cara Wong
- School of Psychology, University of Sydney, Sydney, New South Wales, Australia
| | - Jason Gallate
- Centre for the Mind, University of Sydney, Sydney, New South Wales, Australia
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Pell GS, Roth Y, Zangen A. Modulation of cortical excitability induced by repetitive transcranial magnetic stimulation: Influence of timing and geometrical parameters and underlying mechanisms. Prog Neurobiol 2011; 93:59-98. [DOI: 10.1016/j.pneurobio.2010.10.003] [Citation(s) in RCA: 223] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Revised: 10/14/2010] [Accepted: 10/20/2010] [Indexed: 01/10/2023]
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Senior C. Principles, safety and utility of transcranial magnetic stimulation in cognitive neuropsychology. AUSTRALIAN JOURNAL OF PSYCHOLOGY 2010. [DOI: 10.1080/00049530210001706503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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14
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Casarotto S, Romero Lauro LJ, Bellina V, Casali AG, Rosanova M, Pigorini A, Defendi S, Mariotti M, Massimini M. EEG responses to TMS are sensitive to changes in the perturbation parameters and repeatable over time. PLoS One 2010; 5:e10281. [PMID: 20421968 PMCID: PMC2858649 DOI: 10.1371/journal.pone.0010281] [Citation(s) in RCA: 157] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Accepted: 03/30/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND High-density electroencephalography (hd-EEG) combined with transcranial magnetic stimulation (TMS) provides a direct and non-invasive measure of cortical excitability and connectivity in humans and may be employed to track over time pathological alterations, plastic changes and therapy-induced modifications in cortical circuits. However, the diagnostic/monitoring applications of this technique would be limited to the extent that TMS-evoked potentials are either stereotypical (non-sensitive) or random (non-repeatable) responses. Here, we used controlled changes in the stimulation parameters (site, intensity, and angle of stimulation) and repeated longitudinal measurements (same day and one week apart) to evaluate the sensitivity and repeatability of TMS/hd-EEG potentials. METHODOLOGY/PRINCIPAL FINDINGS In 10 volunteers, we performed 92 single-subject comparisons to evaluate the similarities/differences between pairs of TMS-evoked potentials recorded in the same/different stimulation conditions. For each pairwise comparison, we used non-parametric statistics to calculate a Divergence Index (DI), i.e., the percentage of samples that differed significantly, considering all scalp locations and the entire post-stimulus period. A receiver operating characteristic analysis showed that it was possible to find an optimal DI threshold of 1.67%, yielding 96.7% overall accuracy of TMS/hd-EEG in detecting whether a change in the perturbation parameters occurred or not. CONCLUSIONS/SIGNIFICANCE These results demonstrate that the EEG responses to TMS essentially reflect deterministic properties of the stimulated neuronal circuits as opposed to stereotypical responses or uncontrolled variability. To the extent that TMS-evoked potentials are sensitive to changes and repeatable over time, they may be employed to detect longitudinal changes in the state of cortical circuits.
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Affiliation(s)
- Silvia Casarotto
- Department of Clinical Sciences “L. Sacco”, Università degli Studi di Milano, Milan, Italy
| | - Leonor J. Romero Lauro
- Department of Clinical Sciences “L. Sacco”, Università degli Studi di Milano, Milan, Italy
| | - Valentina Bellina
- Department of Clinical Sciences “L. Sacco”, Università degli Studi di Milano, Milan, Italy
| | - Adenauer G. Casali
- Department of Clinical Sciences “L. Sacco”, Università degli Studi di Milano, Milan, Italy
| | - Mario Rosanova
- Department of Clinical Sciences “L. Sacco”, Università degli Studi di Milano, Milan, Italy
| | - Andrea Pigorini
- Department of Clinical Sciences “L. Sacco”, Università degli Studi di Milano, Milan, Italy
| | - Stefano Defendi
- Department of Clinical Sciences “L. Sacco”, Università degli Studi di Milano, Milan, Italy
| | - Maurizio Mariotti
- Department of Clinical Sciences “L. Sacco”, Università degli Studi di Milano, Milan, Italy
| | - Marcello Massimini
- Department of Clinical Sciences “L. Sacco”, Università degli Studi di Milano, Milan, Italy
- * E-mail:
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15
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Sparing R, Hesse MD, Fink GR. Neuronavigation for transcranial magnetic stimulation (TMS): Where we are and where we are going. Cortex 2010; 46:118-20. [DOI: 10.1016/j.cortex.2009.02.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Revised: 09/23/2008] [Accepted: 02/01/2009] [Indexed: 10/21/2022]
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16
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Siebner HR, Hartwigsen G, Kassuba T, Rothwell JC. How does transcranial magnetic stimulation modify neuronal activity in the brain? Implications for studies of cognition. Cortex 2009; 45:1035-42. [PMID: 19371866 DOI: 10.1016/j.cortex.2009.02.007] [Citation(s) in RCA: 221] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Revised: 01/23/2009] [Accepted: 02/02/2009] [Indexed: 11/19/2022]
Abstract
Transcranial magnetic stimulation (TMS) uses a magnetic field to "carry" a short lasting electrical current pulse into the brain where it stimulates neurones, particularly in superficial regions of cerebral cortex. TMS can interfere with cognitive functions in two ways. A high intensity TMS pulse causes a synchronised high frequency burst of discharge in a relatively large population of neurones that is terminated by a long lasting GABAergic inhibition. The combination of artificial synchronisation of activity followed by depression effectively disrupts perceptual, motor and cognitive processes in the human brain. This transient neurodisruption has been termed a "virtual lesion". Smaller intensities of stimulation produce less activity; in such cases, cognitive operations can probably continue but are disrupted because of the added noisy input from the TMS pulse. It is usually argued that if a TMS pulse affects performance, then the area stimulated must provide an essential contribution to behaviour being studied. However, there is one exception to this: the pulse could be applied to an area that is not involved in the task but which has projections to the critical site. Activation of outputs from the site of stimulation could potentially disrupt processing at the distant site, interfering with behaviour without having any involvement in the task. A final important feature of the response to TMS is "context dependency", which indicates that the response depends on how excitable the cortex is at the time the stimulus is applied: if many neurones are close to firing threshold then the more of them are recruited by the pulse than at rest. Many studies have noted this context-dependent modulation. However, it is often assumed that the excitability of an area has a simple relationship to activity in that area. We argue that this is not necessarily the case. Awareness of the problem may help resolve some apparent anomalies in the literature.
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Affiliation(s)
- Hartwig R Siebner
- Danish Research Centre for Magnetic Resonance, Hvidovre University Hospital, Copenhagen, Denmark.
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17
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Miniussi C, Thut G. Combining TMS and EEG Offers New Prospects in Cognitive Neuroscience. Brain Topogr 2009; 22:249-56. [DOI: 10.1007/s10548-009-0083-8] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2008] [Accepted: 01/27/2009] [Indexed: 11/24/2022]
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Hoeft F, Wu DA, Hernandez A, Glover GH, Shimojo S. Electronically switchable sham transcranial magnetic stimulation (TMS) system. PLoS One 2008; 3:e1923. [PMID: 18398456 PMCID: PMC2271126 DOI: 10.1371/journal.pone.0001923] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2007] [Accepted: 02/29/2008] [Indexed: 11/27/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) is increasingly being used to demonstrate the causal links between brain and behavior in humans. Further, extensive clinical trials are being conducted to investigate the therapeutic role of TMS in disorders such as depression. Because TMS causes strong peripheral effects such as auditory clicks and muscle twitches, experimental artifacts such as subject bias and placebo effect are clear concerns. Several sham TMS methods have been developed, but none of the techniques allows one to intermix real and sham TMS on a trial-by-trial basis in a double-blind manner. We have developed an attachment that allows fast, automated switching between Standard TMS and two types of control TMS (Sham and Reverse) without movement of the coil or reconfiguration of the setup. We validate the setup by performing mathematical modeling, search-coil and physiological measurements. To see if the stimulus conditions can be blinded, we conduct perceptual discrimination and sensory perception studies. We verify that the physical properties of the stimulus are appropriate, and that successive stimuli do not contaminate each other. We find that the threshold for motor activation is significantly higher for Reversed than for Standard stimulation, and that Sham stimulation entirely fails to activate muscle potentials. Subjects and experimenters perform poorly at discriminating between Sham and Standard TMS with a figure-of-eight coil, and between Reverse and Standard TMS with a circular coil. Our results raise the possibility of utilizing this technique for a wide range of applications.
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Affiliation(s)
- Fumiko Hoeft
- Center for Interdisciplinary Brain Sciences Research, Stanford University School of Medicine, Palo Alto, California, United States of America.
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19
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Noninvasive brain stimulation with transcranial magnetic or direct current stimulation (TMS/tDCS)—From insights into human memory to therapy of its dysfunction. Methods 2008; 44:329-37. [DOI: 10.1016/j.ymeth.2007.02.001] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Accepted: 02/12/2007] [Indexed: 11/20/2022] Open
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Sparing R, Buelte D, Meister IG, Paus T, Fink GR. Transcranial magnetic stimulation and the challenge of coil placement: a comparison of conventional and stereotaxic neuronavigational strategies. Hum Brain Mapp 2008; 29:82-96. [PMID: 17318831 PMCID: PMC6871049 DOI: 10.1002/hbm.20360] [Citation(s) in RCA: 207] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2006] [Revised: 11/13/2006] [Accepted: 12/07/2006] [Indexed: 11/07/2022] Open
Abstract
The combination of transcranial magnetic stimulation (TMS) with functional neuroimaging has expanded the potential of TMS for human brain mapping. The precise and reliable positioning of the TMS coil is not a simple task, however. Modern frameless stereotaxic systems allow investigators to base navigation either on the subject's structural magnetic resonance imaging (MRI), functional MRI data, or the use of functional neuroimaging data from the literature, so-called "probabilistic approach." The latter assumes consistency across individuals in the location of task-related "activations" in standardized stereotaxic space. Conventional nonstereotaxic localization of brain areas is also a common method for defining the coil position. Our aim was to evaluate the accuracy of five different localization strategies in one single study. The left primary motor cortex (left M1-Hand) was used as target region. Three approaches were based on real-time frameless stereotaxy using information based on either anatomical or functional MRI. The remaining two strategies relied either on standard cranial landmarks (i.e., the International 10-20 EEG system) or a standardized function-guided procedure (i.e., the spatial relationship between the left and right M1-Hand). The results were compared to a TMS-based mapping of the primary motor cortex; center of gravity of motor-evoked potentials (MEP-CoG) was calculated for each subject (n = 10). Our findings suggest that highest precision can be achieved with fMRI-guided stimulation, which was accurate within the range of millimeters. Very consistent results were also obtained with the "probabilistic" approach. In view of these findings, we discuss the methods and special characteristics of each localization strategy.
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Affiliation(s)
- Roland Sparing
- Department of Medicine, Institute of Neuroscience and Biophysics, Research Center Juelich, Juelich, Germany.
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21
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Que manque-t-il à la rTMS pour devenir une thérapie ? Encephale 2007; 33:982-9. [DOI: 10.1016/j.encep.2007.06.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2005] [Accepted: 06/15/2007] [Indexed: 11/23/2022]
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Kammer T, Vorwerg M, Herrnberger B. Anisotropy in the visual cortex investigated by neuronavigated transcranial magnetic stimulation. Neuroimage 2007; 36:313-21. [PMID: 17442592 DOI: 10.1016/j.neuroimage.2007.03.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2007] [Revised: 02/20/2007] [Accepted: 03/03/2007] [Indexed: 11/18/2022] Open
Abstract
Responses to transcranial magnetic stimulation (TMS) of the motor cortex depend on the direction of the induced current with an optimum perpendicular to the orientation of the precentral gyrus. Little is known about anisotropy in other cortical regions. We measured phosphene thresholds in the visual cortex using a frameless neuronavigation system. Comparing horizontal and vertical current orientation as well as monophasic and biphasic pulses in 7 subjects, we found lower thresholds with biphasic pulses and a tendency for lower thresholds with horizontal currents. When varying current directions in steps of 45 degrees centered on a hot spot over the occipital cortex, in 10 out of 12 measurements optimal current orientation ran perpendicular to the underlying gyrus (mean deviation 14.6 degrees). Optimal current orientation was determined as the orientation of the second eigenvector from the covariance matrix of the stimulation sites that had been shifted along the respective current direction by the amount of the measured threshold. Individual cortical architecture was obtained by segmentation of a 3d anatomical MR scan, with large interindividual differences among the orientations of the stimulated gyrus. As with the motor system, the optimum threshold with biphasic pulses was flipped about 180 degrees compared to the optimum with monophasic pulses (p<.02) throughout subjects, suggesting both similar anisotropic properties of networks in the visual and motor cortices and the existence of anisotropic behaviour in any cortical region. As a consequence, optimal TMS application should always take into account the individual orientation of the gyrus to be stimulated.
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Affiliation(s)
- Thomas Kammer
- Department of Cognitive Neurology, Hertie-Institute for Clinical Brain Research, University of Tuebingen, Germany.
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23
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Paine PA, Aziz Q, Gardener E, Hobson A, Mistry S, Thompson DG, Hamdy S. Assessing the temporal reproducibility of human esophageal motor-evoked potentials to transcranial magnetic stimulation. J Clin Neurophysiol 2006; 23:374-80. [PMID: 16885712 DOI: 10.1097/01.wnp.0000209578.08391.e2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Although the electrophysiological properties and reproducibility of somatic limb motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) are well characterized, little is known about the reproducibility of MEPs for viscerosomatic structures such as the esophagus. AIM To determine the temporal reproducibility of esophageal MEPs to TMS. METHODS MEPs to TMS were recorded from the proximal esophagus, using a swallowed catheter housing a pair of electrodes, in eight healthy subjects at five stimulus intensities (SI) (motor threshold [MT] to 20% above MT). For each SI, 20 consecutive TMS stimuli at 5-second intervals were delivered over a single scalp site (dominant hemisphere at site exhibiting MT at lowest SI) and repeated 40 and 80 minutes thereafter. MEP amplitudes and latencies were measured, and means were sequentially calculated for each SI and then log-transformed. The repeatability coefficients (RC) for the three time points were calculated across each set of 20 stimuli and presented as an exponential ratio. RESULTS Best RC (amplitude/latency) were achieved at 120% SI relative to MT, being 1.8/1.2 (optimal = 1.0). For lower intensities of 115%, 110%, 105%, and 100% SI, the RC were 2.1/1.2, 2.1/1.1, 2.4/1.2, and 2.6/1.4, respectively. For all SI, the greatest reductions in RC occurred over the first 10 stimuli, with little additional gain beyond this number. CONCLUSIONS Latencies of esophageal MEP to TMS across intensities are highly reproducible, whereas amplitudes are more stimulus intensity-dependent, being most reliable and reproducible at the highest stimulus strengths. SIGNIFICANCE Using careful parameters, TMS can be used reliably in future studies of viscerosomatic structures, although the size of the response variability needs to be taken into account when assessing changes in cortico-fugal activity.
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Affiliation(s)
- P A Paine
- Department of Gastrointestinal Sciences and Statistics, Hope Hospital, Salford, University of Manchester, United Kingdom
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Coubard OA, Kapoula Z. Dorsolateral prefrontal cortex prevents short-latency saccade and vergence: a TMS study. ACTA ACUST UNITED AC 2005; 16:425-36. [PMID: 15958779 DOI: 10.1093/cercor/bhi122] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
This study explores whether vergence eye movements along the median plane can be triggered with short latencies, and the role of the dorsolateral prefrontal cortex (DLPFC) in controlling such movements. We used a gap paradigm and applied transcranial magnetic stimulation (TMS) in 10 humans making saccades or vergence. TMS over the motor cortex had no effect on any eye movement parameter. TMS over DLPFC influenced eye movement initiation but not their metrics. TMS over the right DLPFC accelerated the triggering of saccades bilaterally but did not influence divergence. TMS over the left DLPFC speeded up the triggering of ipsilateral saccades and exacerbated the anticipatory mode of triggering of divergence. For convergence, TMS effects were mild: rightward TMS increased the proportion of short latencies but failed to shorten the group mean latency; leftward TMS influenced triggering in some individuals only. For saccades and convergence under TMS, some subjects showed an emerging population of short latencies in their latency distribution. Horizontal saccadic intrusions (80% of trials) and vertical saccades (recorded in one subject) intruding on vergence were unlikely to assist vergence triggering. We conclude that the prefrontal mechanisms underlying voluntary eye movement control are similar for saccades and vergence although some specificities exist.
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Affiliation(s)
- Olivier A Coubard
- Laboratoire de Physiologie de la Perception et de l'Action, UMR 7152 CNRS-Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France.
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25
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Sparing R, Dambeck N, Stock K, Meister IG, Huetter D, Boroojerdi B. Investigation of the primary visual cortex using short-interval paired-pulse transcranial magnetic stimulation (TMS). Neurosci Lett 2005; 382:312-6. [PMID: 15925110 DOI: 10.1016/j.neulet.2005.03.036] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2004] [Revised: 01/31/2005] [Accepted: 03/15/2005] [Indexed: 11/15/2022]
Abstract
Previous studies using short-interval paired-pulse TMS have provided valuable insights into physiology of human motor cortex. Depending on the interstimulus interval (ISI) between the two pulses intra-cortical facilitation (ICF) or intra-cortical inhibition (ICI) can be observed. Similar patterns of inhibition and facilitation have also been demonstrated in prefrontal and parietal cortices. In order to prove whether principles that govern cortical excitability in the motor system also extend to the visual system and to further characterize possible neural correlates of phosphene generation, we applied short-interval paired-pulse TMS to the occipital cortex. In addition, we examined the effect of different coil orientations on perception of phosphenes induced by paired-pulse TMS. In all of 10 healthy subjects, a general facilitation of phosphene perception could be observed for interstimulus intervals of 2-12 ms (conditioning stimulus (CS) 90% and test stimulus (TS) 100% of subject's phosphene threshold) compared to TS alone. With CS intensity decreasing to 80% or less, the effect diminished. No significant changes occurred when TS intensity was increased to 110%. Phosphene perception was enhanced with an induced current direction from lateral to medial at an ISI of 12 ms. Inhibition was not observed in any condition. Our results indicate that the mechanisms underlying phosphene induction in the visual cortex are different from those underlying intracortical inhibition and facilitation in the motor cortex.
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Affiliation(s)
- Roland Sparing
- Department of Neurology, RWTH Aachen University, Pauwelsstr. 30, 52074 Aachen, Germany.
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26
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Bermpohl F, Fregni F, Boggio PS, Thut G, Northoff G, Otachi PTM, Rigonatti SP, Marcolin MA, Pascual-Leone A. Left prefrontal repetitive transcranial magnetic stimulation impairs performance in affective go/no-go task. Neuroreport 2005; 16:615-9. [PMID: 15812319 DOI: 10.1097/00001756-200504250-00020] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Functional neuroimaging studies have associated affective go/no-go function with lateral prefrontal activation, but they have not established a causal role and have not determined whether one hemisphere is predominantly engaged. In the present study, 11 normal volunteers underwent slow repetitive transcranial magnetic stimulation of the left and right dorsolateral prefrontal cortex, and the occipital cortex prior to performance of a picture-based affective go/no-go task. We found an interfering effect of left prefrontal repetitive transcranial magnetic stimulation compared with both right prefrontal and occipital repetitive transcranial magnetic stimulation. This impairment concerned positive and negative task stimuli to a similar extent, and tended to be greater in shift compared with nonshift blocks. Our findings demonstrate a functionally relevant lateralization of the prefrontal contribution to affective go/no-go tasks.
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Affiliation(s)
- Felix Bermpohl
- Psychiatry and Psychology Institute, University of Sao Paulo, Brazil.
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Abstract
Classical neuropsychology relies on patients with irreversible brain lesions and cognitive impairments give informations about normal brain function. Transcranial Magnetic Stimulation (TMS) is a non-invasive method which involves placing an electromagnetic coil on the scalp. A pulse generates a magnetic field and this one passes, unattenuated by the skin and scalp, into the cortex inducing a current which results in neural activity. The technique shows a good temporal resolution and, moreover, because it represents an interference technique, can be said to have excellent functional resolution. For this reason, TMS appears to be a new tool for research in neuropsychology, producing transitory 'virtual lesion'effects which could help to understand how, when and where cognitive tasks are performed. The purpose of this article is to review recent research using TMS in cognition and neuropsychology, in a non exhaustive way. In safety studies, single TMS over motor cortex can produce simple movements. Several groups have applied TMS to the study of visual processing and found an impaired detection of visual stimuli. In a same way, TMS can disrupt speech when it was delivered in the language dominant hemisphere. Studies on the memory effects of TMS have been conflicting and the results seem to depend on the choice of paradigm and parameters. Other study depicted improvements in executive functioning after TMS on the left middle frontal gyrus or a diminution in reaction time during an analogic reasoning task. Moreover, some facial emotions seem to be less recognizable after TMS. Although TMS seem to be a new tool for neuro-psychological investigations in healthy subjects, few studies reported cognitive effects of rTMS treatment in psychiatry. In a therapeutic view, many of these trials have supported a significant effect of TMS, but in some studies the effect is small and short lived. Several groups have reported on the use of rTMS as a treatment in resistant major depression and the impact on cognition functioning. Most of results tend to find no adverse cognitive effects after several weeks of daily rTMS in depressed patients, compared to Electroconvulsivo-therapy (ECT). The effects of transcranial magnetic stimulation (TMS) on hallucination severity and neurocognition were studied in a recent study. A statistically significant improvement was observed on a hallucination scale and on one cognitive measure. TMS is a promising tool for cognitive neuroscience and can provide complementary information to the one obtained using neuropsychological tests, and the one obtained using functional imaging techniques, which have superior spatial but inferior temporal resolution.
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Affiliation(s)
- C-M Verdon
- Unité de Recherche Clinique Romain-Rolland, EPS Ville-Evrard (Secteur 3), 5, rue du Docteur Delafontaine, 93200 Saint-Denis
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Kammer T, Beck S, Puls K, Roether C, Thielscher A. Chapter 19 Motor and phosphene thresholds: consequences of cortical anisotropy. TRANSCRANIAL MAGNETIC STIMULATION AND TRANSCRANIAL DIRECT CURRENT STIMULATION, PROCEEDINGS OF THE 2ND INTERNATIONAL TRANSCRANIAL MAGNETIC STIMULATION (TMS) AND TRANSCRANIAL DIRECT CURRENT STIMULATION (TDCS) SYMPOSIUM 2003; 56:198-203. [PMID: 14677395 DOI: 10.1016/s1567-424x(09)70222-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Thomas Kammer
- Department of Neurobiology, Max Planck Institute for Biological Cybernetics, Department of Neurology, University of Tübingen, Tübingen, Germany.
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Husain FT, Nandipati G, Braun AR, Cohen LG, Tagamets MA, Horwitz B. Simulating transcranial magnetic stimulation during PET with a large-scale neural network model of the prefrontal cortex and the visual system. Neuroimage 2002; 15:58-73. [PMID: 11771974 DOI: 10.1006/nimg.2001.0966] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) exerts both excitatory and inhibitory effects on the stimulated neural tissue, although little is known about the neurobiological mechanisms by which it influences neuronal function. TMS has been used in conjunction with PET to examine interregional connectivity of human cerebral cortex. To help understand how TMS affects neuronal function, and how these effects are manifested during functional brain imaging, we simulated the effects of TMS on a large-scale neurobiologically realistic computational model consisting of multiple, interconnected regions that performs a visual delayed-match-to-sample task. The simulated electrical activities in each region of the model are similar to those found in single-cell monkey data, and the simulated integrated summed synaptic activities match regional cerebral blood flow (rCBF) data obtained in human PET studies. In the present simulations, the excitatory and inhibitory effects of TMS on both locally stimulated and distal sites were studied using simulated behavioral measures and simulated PET rCBF results. The application of TMS to either excitatory or inhibitory units of the model, or both, resulted in an increased number of errors in the task performed by the model. In experimental studies, both increases and decreases in rCBF following TMS have been observed. In the model, increasing TMS intensity caused an increase in rCBF when TMS exerted a predominantly excitatory effect, whereas decreased rCBF following TMS occurred if TMS exerted a predominantly inhibitory effect. We also found that regions both directly and indirectly connected to the stimulating site were affected by TMS.
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Affiliation(s)
- F T Husain
- Language Section, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Kammer T, Beck S, Erb M, Grodd W. The influence of current direction on phosphene thresholds evoked by transcranial magnetic stimulation. Clin Neurophysiol 2001; 112:2015-21. [PMID: 11682339 DOI: 10.1016/s1388-2457(01)00673-3] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES To quantify phosphene thresholds evoked by transcranial magnetic stimulation (TMS) in the occipital cortex as a function of induced current direction. METHODS Phosphene thresholds were determined in 6 subjects. We compared two stimulator types (Medtronic-Dantec and Magstim) with monophasic pulses using the standard figure-of-eight coils and systematically varied hemisphere (left and right) and induced current direction (latero-medial and medio-lateral). Each measurement was made 3 times, with a new stimulation site chosen for each repetition. Only those stimulation sites were investigated where phosphenes were restricted to one visual hemifield. Coil positions were stereotactically registered. Functional magnetic resonance imaging (fMRI) of retinotopic areas was performed in 5 subjects to individually characterize the borders of visual areas; TMS stimulation sites were coregistered with respect to visual areas. RESULTS Despite large interindividual variance we found a consistent pattern of phosphene thresholds. They were significantly lower if the direction of the induced current was oriented from lateral to medial in the occipital lobe rather than vice versa. No difference with respect to the hemisphere was found. Threshold values normalized to the square root of the stored energy in the stimulators were lower with the Medtronic-Dantec device than with the Magstim device. fMRI revealed that stimulation sites generating unilateral phosphenes were situated at V2 and V3. Variability of phosphene thresholds was low within a cortical patch of 2x2cm(2). Stimulation over V1 yields phosphenes in both visual fields. CONCLUSIONS The excitability of visual cortical areas depends on the direction of the induced current with a preference for latero-medial currents. Although the coil positions used in this study were centered over visual areas V2 and V3, we cannot rule out the possibility that subcortical structures or V1 could actually be the main generator for phosphenes.
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Affiliation(s)
- T Kammer
- Department of Neurobiology, Max-Planck-Institute for Biological Cybernetics, Spemannstrasse 38, D-72076, Tübingen, Germany.
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