Blood oxygenation changes modulated by coil orientation during prefrontal transcranial magnetic stimulation

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Prefrontal transcranial magnetic stimulation (TMS) is being investigated as a treatment for several neurological and psychiatric disorders. The direction of the cortical current induced by TMS can be modulated by the coil orientation and this influences the extent of neural depolarization. Although the optimal coil orientation has previously been established for motor cortex, identifying an optimal coil orientation for prefrontal areas is more challenging due to the absence of a motor response. The current study used near infra-red spectroscopy (NIRS) to investigate the impact of coil orientation on TMS induced changes in prefrontal blood oxygenation (HbO). It was hypothesized that a greater change in HbO would be observed when current was induced in a posterior to anterior direction. Methods: Single pulse and trains of 1 Hz repetitive TMS (rTMS) were administered to the left prefrontal cortex while simultaneously recording HbO response bilaterally. The effect of coil orientation was examined at 45, 135, and 225 counterclockwise from midline. Results: Greatest changes in HbO were observed at a 45 orientation when both single and rTMS were applied, and only minor changes were observed at 135 and 225. Application of short trains of rTMS at 45 resulted in transient increases in HbO that were significantly greater in magnitude than when the coil orientation was reversed. Conclusions: The utility of NIRS for examining the TMS evoked physiological response at non-motor areas is highlighted in this study. Prefrontal HbO response evoked by TMS is sensitive to the direction of induced cortical current and it appears that the de facto 45 angle utilized in most clinical studies may prove to be optimal. ? 2013 Elsevier Inc. All rights reserved.
Original languageEnglish
Pages (from-to)576 - 581
Number of pages6
JournalBrain Stimulation
Volume6
Issue number4
DOIs
Publication statusPublished - 2013

Cite this

@article{2379e235bf99435b8da8c9737bef3800,
title = "Blood oxygenation changes modulated by coil orientation during prefrontal transcranial magnetic stimulation",
abstract = "Prefrontal transcranial magnetic stimulation (TMS) is being investigated as a treatment for several neurological and psychiatric disorders. The direction of the cortical current induced by TMS can be modulated by the coil orientation and this influences the extent of neural depolarization. Although the optimal coil orientation has previously been established for motor cortex, identifying an optimal coil orientation for prefrontal areas is more challenging due to the absence of a motor response. The current study used near infra-red spectroscopy (NIRS) to investigate the impact of coil orientation on TMS induced changes in prefrontal blood oxygenation (HbO). It was hypothesized that a greater change in HbO would be observed when current was induced in a posterior to anterior direction. Methods: Single pulse and trains of 1 Hz repetitive TMS (rTMS) were administered to the left prefrontal cortex while simultaneously recording HbO response bilaterally. The effect of coil orientation was examined at 45, 135, and 225 counterclockwise from midline. Results: Greatest changes in HbO were observed at a 45 orientation when both single and rTMS were applied, and only minor changes were observed at 135 and 225. Application of short trains of rTMS at 45 resulted in transient increases in HbO that were significantly greater in magnitude than when the coil orientation was reversed. Conclusions: The utility of NIRS for examining the TMS evoked physiological response at non-motor areas is highlighted in this study. Prefrontal HbO response evoked by TMS is sensitive to the direction of induced cortical current and it appears that the de facto 45 angle utilized in most clinical studies may prove to be optimal. ? 2013 Elsevier Inc. All rights reserved.",
author = "Thomson, {Richard Hilton Siddall} and Cleve, {Terrence J} and Neil Bailey and Rogasch, {Nigel Craig} and Maller, {Jerome Joseph} and Daskalakis, {Zafiris Jeff} and Fitzgerald, {Paul Bernard}",
year = "2013",
doi = "10.1016/j.brs.2012.12.001",
language = "English",
volume = "6",
pages = "576 -- 581",
journal = "Brain Stimulation",
issn = "1935-861X",
publisher = "Elsevier",
number = "4",

}

Blood oxygenation changes modulated by coil orientation during prefrontal transcranial magnetic stimulation. / Thomson, Richard Hilton Siddall; Cleve, Terrence J; Bailey, Neil; Rogasch, Nigel Craig; Maller, Jerome Joseph; Daskalakis, Zafiris Jeff; Fitzgerald, Paul Bernard.

In: Brain Stimulation, Vol. 6, No. 4, 2013, p. 576 - 581.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Blood oxygenation changes modulated by coil orientation during prefrontal transcranial magnetic stimulation

AU - Thomson, Richard Hilton Siddall

AU - Cleve, Terrence J

AU - Bailey, Neil

AU - Rogasch, Nigel Craig

AU - Maller, Jerome Joseph

AU - Daskalakis, Zafiris Jeff

AU - Fitzgerald, Paul Bernard

PY - 2013

Y1 - 2013

N2 - Prefrontal transcranial magnetic stimulation (TMS) is being investigated as a treatment for several neurological and psychiatric disorders. The direction of the cortical current induced by TMS can be modulated by the coil orientation and this influences the extent of neural depolarization. Although the optimal coil orientation has previously been established for motor cortex, identifying an optimal coil orientation for prefrontal areas is more challenging due to the absence of a motor response. The current study used near infra-red spectroscopy (NIRS) to investigate the impact of coil orientation on TMS induced changes in prefrontal blood oxygenation (HbO). It was hypothesized that a greater change in HbO would be observed when current was induced in a posterior to anterior direction. Methods: Single pulse and trains of 1 Hz repetitive TMS (rTMS) were administered to the left prefrontal cortex while simultaneously recording HbO response bilaterally. The effect of coil orientation was examined at 45, 135, and 225 counterclockwise from midline. Results: Greatest changes in HbO were observed at a 45 orientation when both single and rTMS were applied, and only minor changes were observed at 135 and 225. Application of short trains of rTMS at 45 resulted in transient increases in HbO that were significantly greater in magnitude than when the coil orientation was reversed. Conclusions: The utility of NIRS for examining the TMS evoked physiological response at non-motor areas is highlighted in this study. Prefrontal HbO response evoked by TMS is sensitive to the direction of induced cortical current and it appears that the de facto 45 angle utilized in most clinical studies may prove to be optimal. ? 2013 Elsevier Inc. All rights reserved.

AB - Prefrontal transcranial magnetic stimulation (TMS) is being investigated as a treatment for several neurological and psychiatric disorders. The direction of the cortical current induced by TMS can be modulated by the coil orientation and this influences the extent of neural depolarization. Although the optimal coil orientation has previously been established for motor cortex, identifying an optimal coil orientation for prefrontal areas is more challenging due to the absence of a motor response. The current study used near infra-red spectroscopy (NIRS) to investigate the impact of coil orientation on TMS induced changes in prefrontal blood oxygenation (HbO). It was hypothesized that a greater change in HbO would be observed when current was induced in a posterior to anterior direction. Methods: Single pulse and trains of 1 Hz repetitive TMS (rTMS) were administered to the left prefrontal cortex while simultaneously recording HbO response bilaterally. The effect of coil orientation was examined at 45, 135, and 225 counterclockwise from midline. Results: Greatest changes in HbO were observed at a 45 orientation when both single and rTMS were applied, and only minor changes were observed at 135 and 225. Application of short trains of rTMS at 45 resulted in transient increases in HbO that were significantly greater in magnitude than when the coil orientation was reversed. Conclusions: The utility of NIRS for examining the TMS evoked physiological response at non-motor areas is highlighted in this study. Prefrontal HbO response evoked by TMS is sensitive to the direction of induced cortical current and it appears that the de facto 45 angle utilized in most clinical studies may prove to be optimal. ? 2013 Elsevier Inc. All rights reserved.

UR - http://www.sciencedirect.com/science/article/pii/S1935861X12002070

U2 - 10.1016/j.brs.2012.12.001

DO - 10.1016/j.brs.2012.12.001

M3 - Article

VL - 6

SP - 576

EP - 581

JO - Brain Stimulation

JF - Brain Stimulation

SN - 1935-861X

IS - 4

ER -