General scientific summary Local electric field distributions generated by transcranial direct current stimulation (tDCS) with an extracephalic reference electrode were evaluated to address the safety issues of extracephalic tDCS. We compared the maximum current density and electric field intensity values generated by six different electrode montages. Our simulation results demonstrated that the electric fields in the brainstem generated by the extracephalic reference were comparable to, or even less than, those generated by the cephalic reference, suggesting that the use of extracephalic reference does not lead to unwanted modulation of brainstem autonomic centers.

via Evaluation of local electric fields generated by transcranial direct current stimulation with an extracephalic reference electrode based on realistic 3D body modeling.