Data Sheet 1_MRI-guided personalized tDCS planning for target engagement of the swallowing motor cortex after stroke: a finite-element modeling study.xlsx

Transcranial direct current stimulation (tDCS) therapeutic efficacy depends on the electrode montage and interindividual anatomical differences. The use of the standard C5/C6 placement based on 10–20 electroencephalography (EEG) coordinates to guide electrode placements may result in misalignment with the target position.</p>Objective<p>To investigate whether computational modeling leads to improved electric field (EF) parameters compared with those generated with standard electrode placement methods, and whether smaller sized electrodes can yield more focal results, we compared EF values across three tDCS montages targeting the cortical swallowing area (CSA): (i) optimized circular (Opt-C, 1.5 cm radius), (ii) EEG-based, conventional circular (Conv-C, 1.5 cm radius), and (iii) conventional square (Conv-S, 5 × 5 cm) electrode montages.</p>Methods<p>Structural MRI data from 50 PSD patients were analyzed.

EF distributions were simulated using finite element method (FEM) analysis based on three-dimensional tetrahedral head models generated with the tES LAB 4.0 platform. Across montages, we compared EF strength, defined as the mean L2 norm of the EF (E_norm) across nodes within the target ROI, and target-specific focality, defined as the summed volume of target-ROI elements with E_norm values at or above the 75th percentile of the corresponding whole-brain gray and white matter E_norm distribution.</p>Results<p>Significant differences in EF strength (p < 0.001) and target-specific focality (p < 0.001) were identified across the three tDCS montages.