Regional electric field induced by electroconvulsive therapy: A finite element simulation study

The goal of this study is to investigate the regional distribution of the electric field (E-field) strength induced by electroconvulsive therapy (ECT), and to contrast clinically relevant electrode configurations through finite element (FE) analysis. An FE human head model incorporating tissue heterogeneity and white matter anisotropy was generated based on structural magnetic resonance imaging (MRI) and diffusion tensor MRI (DT-MRI) data. We simulated the E-field spatial distributions of three standard ECT electrode placements [bilateral (BL), bifrontal (BF), and right unilateral (RUL)] and an investigational electrode configuration [focal electrically administered seizure therapy (FEAST)]. A quantitative comparison of the E-field strength was subsequently carried out in various brain regions of interests (ROIs) that have putative role in the therapeutic action and/or adverse side effects of ECT. This study illustrates how the realistic FE head model provides quantitative insight in the biophysics of ECT, which may shed light on the differential clinical outcomes seen with various forms of ECT, and may guide the development of novel stimulation paradigms with improved risk/benefit ratio.