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Optimal Coil Orientation for Transcranial Magnetic Stimulation
We study the impact of coil orientation on the motor threshold (MT) and present an optimal coil orientation for stimulation of the foot. The result can be compared to results of models that predict this orientation from electrodynamic properties of the media in the skull and from orientations of cel...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2013
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3623976/ https://www.ncbi.nlm.nih.gov/pubmed/23593200 http://dx.doi.org/10.1371/journal.pone.0060358 |
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author | Richter, Lars Neumann, Gunnar Oung, Stephen Schweikard, Achim Trillenberg, Peter |
author_facet | Richter, Lars Neumann, Gunnar Oung, Stephen Schweikard, Achim Trillenberg, Peter |
author_sort | Richter, Lars |
collection | PubMed |
description | We study the impact of coil orientation on the motor threshold (MT) and present an optimal coil orientation for stimulation of the foot. The result can be compared to results of models that predict this orientation from electrodynamic properties of the media in the skull and from orientations of cells, respectively. We used a robotized TMS system for precise coil placement and recorded motor-evoked potentials with surface electrodes on the abductor hallucis muscle of the right foot in 8 healthy control subjects. First, we performed a hot-spot search in standard (lateral) orientation and then rotated the coil in steps of 10° or 20°. At each step we estimated the MT. For navigated stimulation and for correlation with the underlying anatomy a structural MRI scan was obtained. Optimal coil orientation was 33.1±18.3° anteriorly in relation to the standard lateral orientation. In this orientation the threshold was 54±18% in units of maximum stimulator output. There was a significant difference of 8.0±5.9% between the MTs at optimal and at standard orientation. The optimal coil orientations were significantly correlated with the direction perpendicular to the postcentral gyrus ([Image: see text]). Robotized TMS facilitates sufficiently precise coil positioning and orientation to study even small variations of the MT with coil orientation. The deviations from standard orientation are more closely matched by models based on field propagation in media than by models based on orientations of pyramidal cells. |
format | Online Article Text |
id | pubmed-3623976 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2013 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-36239762013-04-16 Optimal Coil Orientation for Transcranial Magnetic Stimulation Richter, Lars Neumann, Gunnar Oung, Stephen Schweikard, Achim Trillenberg, Peter PLoS One Research Article We study the impact of coil orientation on the motor threshold (MT) and present an optimal coil orientation for stimulation of the foot. The result can be compared to results of models that predict this orientation from electrodynamic properties of the media in the skull and from orientations of cells, respectively. We used a robotized TMS system for precise coil placement and recorded motor-evoked potentials with surface electrodes on the abductor hallucis muscle of the right foot in 8 healthy control subjects. First, we performed a hot-spot search in standard (lateral) orientation and then rotated the coil in steps of 10° or 20°. At each step we estimated the MT. For navigated stimulation and for correlation with the underlying anatomy a structural MRI scan was obtained. Optimal coil orientation was 33.1±18.3° anteriorly in relation to the standard lateral orientation. In this orientation the threshold was 54±18% in units of maximum stimulator output. There was a significant difference of 8.0±5.9% between the MTs at optimal and at standard orientation. The optimal coil orientations were significantly correlated with the direction perpendicular to the postcentral gyrus ([Image: see text]). Robotized TMS facilitates sufficiently precise coil positioning and orientation to study even small variations of the MT with coil orientation. The deviations from standard orientation are more closely matched by models based on field propagation in media than by models based on orientations of pyramidal cells. Public Library of Science 2013-04-11 /pmc/articles/PMC3623976/ /pubmed/23593200 http://dx.doi.org/10.1371/journal.pone.0060358 Text en © 2013 Richter et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. |
spellingShingle | Research Article Richter, Lars Neumann, Gunnar Oung, Stephen Schweikard, Achim Trillenberg, Peter Optimal Coil Orientation for Transcranial Magnetic Stimulation |
title | Optimal Coil Orientation for Transcranial Magnetic Stimulation |
title_full | Optimal Coil Orientation for Transcranial Magnetic Stimulation |
title_fullStr | Optimal Coil Orientation for Transcranial Magnetic Stimulation |
title_full_unstemmed | Optimal Coil Orientation for Transcranial Magnetic Stimulation |
title_short | Optimal Coil Orientation for Transcranial Magnetic Stimulation |
title_sort | optimal coil orientation for transcranial magnetic stimulation |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3623976/ https://www.ncbi.nlm.nih.gov/pubmed/23593200 http://dx.doi.org/10.1371/journal.pone.0060358 |
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