An Investigation of the Feasibility and Limitations of Epicranial Current Stimulation Using Concentric-ring Electrodes

Abstract

Introduction: Invasive cortical stimulation (ICS) via implanted electrodes can have therapeutic effects on a number of neurological and psychiatric disorders. ICS has the advantage of delivering continuous, relatively strong and focused electrical stimulation. The main disadvantage of ICS is its invasiveness. On the other hand, transcranial electric stimulation (TES) is a non-invasive technique in which electrodes are attached to the scalp. However, with TES it is difficult to deliver continuous therapy and the cortical field is relatively weak and spatially broad. Epicranial cortical stimulation (ECS) is a novel minimally-invasive neuromodulation method where a subcutaneous electrode is implanted directly over the skull. ECS has been proposed as an alternative to ICS and TES. Here we investigate the feasibility and limitations of ECS in humans using concentric-ring electrodes.