TY - JOUR
T1 - A New Angle on Transcranial Magnetic Stimulation Coil Orientation
T2 - A Targeted Narrative Review
AU - Cerins, Andris
AU - Thomas, Elizabeth H.X.
AU - Barbour, Tracy
AU - Taylor, Joseph J.
AU - Siddiqi, Shan H.
AU - Trapp, Nicholas
AU - McGirr, Alexander
AU - Caulfield, Kevin A.
AU - Brown, Joshua C.
AU - Chen, Leo
N1 - Publisher Copyright:
© 2024 Society of Biological Psychiatry
PY - 2024/8
Y1 - 2024/8
N2 - Transcranial magnetic stimulation (TMS) is used to treat several neuropsychiatric disorders including depression, where it is effective in approximately one half of patients for whom pharmacological approaches have failed. Treatment response is related to stimulation parameters such as the stimulation frequency, pattern, intensity, location, total number of pulses and sessions applied, and target brain network engagement. One critical but underexplored component of the stimulation procedure is the orientation or yaw angle of the commonly used figure-of-eight TMS coil, which is known to impact neuronal response to TMS. However, coil orientation has remained largely unchanged since TMS was first used to treat depression and continues to be based on motor cortex anatomy, which may not be optimal for the dorsolateral prefrontal cortex treatment site. In this targeted narrative review, we evaluate experimental, clinical, and computational evidence indicating that optimizing coil orientation may improve TMS treatment outcomes. The properties of the electric field induced by TMS, the changes to this field caused by the differing conductivities of head tissues, and the interaction between coil orientation and the underlying cortical anatomy are summarized. We describe evidence that the magnitude and site of cortical activation, surrogate markers of TMS dosing and brain network targeting considered central in clinical response to TMS, are influenced by coil orientation. We suggest that coil orientation should be considered when applying therapeutic TMS and propose several approaches to optimizing this potentially important treatment parameter.
AB - Transcranial magnetic stimulation (TMS) is used to treat several neuropsychiatric disorders including depression, where it is effective in approximately one half of patients for whom pharmacological approaches have failed. Treatment response is related to stimulation parameters such as the stimulation frequency, pattern, intensity, location, total number of pulses and sessions applied, and target brain network engagement. One critical but underexplored component of the stimulation procedure is the orientation or yaw angle of the commonly used figure-of-eight TMS coil, which is known to impact neuronal response to TMS. However, coil orientation has remained largely unchanged since TMS was first used to treat depression and continues to be based on motor cortex anatomy, which may not be optimal for the dorsolateral prefrontal cortex treatment site. In this targeted narrative review, we evaluate experimental, clinical, and computational evidence indicating that optimizing coil orientation may improve TMS treatment outcomes. The properties of the electric field induced by TMS, the changes to this field caused by the differing conductivities of head tissues, and the interaction between coil orientation and the underlying cortical anatomy are summarized. We describe evidence that the magnitude and site of cortical activation, surrogate markers of TMS dosing and brain network targeting considered central in clinical response to TMS, are influenced by coil orientation. We suggest that coil orientation should be considered when applying therapeutic TMS and propose several approaches to optimizing this potentially important treatment parameter.
KW - Current direction
KW - Gyral anatomy
KW - rTMS coil orientation
KW - TMS targeting
KW - TMS treatment
KW - Transcranial magnetic stimulation
UR - http://www.scopus.com/inward/record.url?scp=85198046423&partnerID=8YFLogxK
U2 - 10.1016/j.bpsc.2024.04.018
DO - 10.1016/j.bpsc.2024.04.018
M3 - Review Article
C2 - 38729243
AN - SCOPUS:85198046423
SN - 2451-9022
VL - 9
SP - 744
EP - 753
JO - Biological Psychiatry: Cognitive Neuroscience and Neuroimaging
JF - Biological Psychiatry: Cognitive Neuroscience and Neuroimaging
IS - 8
ER -