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Updated: Jun 19, 2026

Bilateral Assessment of the Corticospinal Pathways of the Ankle Muscles Using Navigated Transcranial Magnetic Stimulation
Published on: February 19, 2019
Activation site estimation using induced current simulation and motor evoked potential latency in transcranial
Takumi Tanabe1, Akimasa Hirata2, Keita Iijima3
1Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, Nagoya 466-8555, Japan.
Objective:
The exact part of the motor cortex activated by transcranial magnetic stimulation (TMS) remains debatable. This study investigates the electric field (EF) distribution induced by TMS coils in personalized head models, focusing on group-level evaluation considering motor-evoked potential (MEP) latency differences.
Methods:
Thirteen healthy right-handed men (mean age 22.9 ± 1.04 years) participated in this study. Two TMS coils, Figure-of-8 (Fo8) and a double cone (DC), were employed to deliver single pulses at various coil positions. MEPs were recorded from the first dorsal interosseous muscle. The EF distribution was computed in personalized head models using finite-difference methods and mapped to the standard brain space.
Results:
MEP latencies differed significantly between Fo8 and DC coils in seven participants but were similar in six. Group-level EF analysis revealed distinct activation patterns, with the highest EF strength in the crowns of the gyri. In cases with minimal MEP latency differences, EF-motor threshold correlation highlighted activation in the anterior wall of the central sulcus, consistent with fMRI studies.
Conclusions:
Our findings underscore the variability in EF distribution across participants and coils, offering novel insights into the relationship between the EF and MEP latencies.
Significance:
EF computation considering MEP latency differences may enable high-resolution imaging of the activation sites.
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09:52Measuring and Manipulating Functionally Specific Neural Pathways in the Human Motor System with Transcranial Magnetic Stimulation
Published on: February 23, 2020
08:24Conventional and Threshold-Tracking Transcranial Magnetic Stimulation Tests for Single-handed Operation
Published on: August 16, 2021
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