A Preliminary Study of the Impact of Lateral Head Orientations on the Current Distributions During tDCS

Abstract

This numerical study pre-validated the impact of lateral head orientations on the current distributions in the brain region during transcranial direct current stimulation (tDCS). A four-layer (scalp, skull, CSF, brain) real shape human head model was constructed with two electrodes configurations (C3-C4, C3-Fp2) and incremental downward displacement (0.5 mm) of the brain due to gravitational force. Sensitivity analysis was conducted on the influence of brain displacement during tDCS. Results of this preliminary study demonstrated that the cerebral current distribution was sensitive to the gravity-induced downward movement of the brain during tDCS, which suggested that lateral head orientations could be a new parameter to consider during tDCS and further research resources could be allocated in the realistic human head based studies to follow up this study. This finding should help both tDCS research and clinical trials to predict the stimulation result more precisely.