Related Experiment Video
Updated: May 11, 2026
Combined Transcranial Magnetic Stimulation and Electroencephalography of the Dorsolateral Prefrontal Cortex
Published on: August 17, 2018
Electric field variations across DLPFC targeting methods in TMS therapy for Alzheimer's disease
Nianshuang Wu1, Yuxuan Shao2, Zhen Wu1
1Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China; School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
Background:
The dorsolateral prefrontal cortex (DLPFC) is crucial for cognitive control and a primary target for transcranial magnetic stimulation (TMS) in Alzheimer's disease (AD). However, understanding the distribution of TMS-induced electric field (E-field) across different targeting methods remains limited, as does its relationship to therapeutic outcomes.
Objective:
This study assesses differences in TMS-induced E-field using functional versus anatomical targeting methods for DLPFC stimulation.
Methods:
Functional and anatomical targets were identified in 30 (11 M/19F) AD patients and 30 (13 M/17F) age-matched healthy controls (HCs) using T1 and fMRI data. E-field characteristics, including magnitude (EROI) and normal component (E⊥), were calculated via SimNIBS software for comparisons across stimulation targets.
Results:
Functional targeting showed greater spatial dispersion compared to anatomical targeting in both groups. Significant E-field differences were observed between the functional target and adjacent anatomical regions when the coil was positioned over the functional target in both groups. Optimal coil orientation exhibited directional specificity: parallel alignment with the LOI E-field produced higher field intensity in the functional target compared to the anatomical target (AD patients: P < 0.001; HCs: P = 0.052), while perpendicular orientation maintained functional stability with reduced anatomical interference (both groups: P < 0.001). And significant variations in E-field ratios were observed across coil orientations.
Conclusion:
This study reveals key E-field disparities across DLPFC targeting approaches and establishes coil orientation optimization as a critical strategy to improve TMS precision, offering actionable insights for developing personalized protocols in AD therapy that may enhance treatment efficacy while minimizing adverse effects.
