Updated scalp heuristics for localizing the dorsolateral prefrontal cortex based on convergent evidence of lesion and brain stimulation studies in depression

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) x 0.3167 ; X = HC x 0.1359] for the left anterior DLPFC[Y = ((NI + TrTr)/2) x 0.2884; X = HC x 0.1352] for the right anterior DLPFC[Y = ((NI + TrTr)/2) x 0.2480; X = HC x 0.1847] for the left posterior DLPFC[Y = ((NI + TrTr)/2) x 0.2316 ; X = HC x 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. (C) 2022 The Authors. Published by Elsevier Inc.

Automated summary

The study aims to create a scalp heuristic for localizing the dorsolateral prefrontal cortex (DLPFC) based on convergent evidence of lesion and brain stimulation studies, and provides a calculation tool for this heuristic.