Related Experiment Video
Updated: Oct 5, 2025
Neuroimaging-Guided TMS–EEG for Real-Time Cortical Network Mapping
Published on: June 13, 2025
Updated scalp heuristics for localizing the dorsolateral prefrontal cortex based on convergent evidence of lesion and
Arsalan Mir-Moghtadaei1, Shan H Siddiqi2, Kamran Mir-Moghtadaei3
1Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Krembil Research Institute and Centre for Mental Health, University Health Network, Toronto, ON, Canada.
Background:
Repetitive transcranial magnetic stimulation (rTMS) is entering wider use as a therapeutic intervention for many psychiatric illnesses. The efficacy of this therapeutic intervention may depend on accurately localizing target brain regions. Recent work investigating whole-brain maps of circuits associated with depression and its successful treatment has identified foci of interest within the dorsolateral prefrontal cortex (DLPFC).
Objective:
To create an updated scalp heuristic for localizing the DLPFC based on convergent evidence of lesion and brain stimulation studies in depression.
Methods:
Using the standard MNI ICBM152 anatomical template, we localized the scalp sites at minimum Euclidean distance from target MNI coordinates and performed nasion-inion, tragus-tragus, and head-circumference measurements on the anatomical template. We then derived equations to localize these scalp sites.
Results:
The derived equations to calculate the arc length X and Y for these new targets are as follows: [Y=((NI+TrTr)/2)×0.3167 ; X=HC×0.1359] for the left anterior DLPFC[ Y=((NI+TrTr)/2)×0.2884; X=HC×0.1352] for the right anterior DLPFC[ Y=((NI+TrTr)/2)×0.2480; X=HC×0.1847] for the left posterior DLPFC[ Y=((NI+TrTr)/2)×0.2316 ; X=HC×0.1968] for the right posterior DLPFC CONCLUSIONS: This heuristic may help localize DLPFC targets identified in previous lesion-/stimulation-mapping work. A spreadsheet calculation tool is offered to support use of this heuristic.
