Closed-loop System Using Transcranial Direct Current Stimulation (tDCS) for Epilepsy

Study Summary

In this pilot study, the researchers investigated the feasibility of a closed-loop electroencephalography (EEG) / transcranial direct current stimulation (tDCS) system for treatment of epilepsy. They looked to see the feasibility of triggering tDCS stimulation within 10 seconds of a detected EEG partial-onset seizure, and also a proof-of-principle determination of whether tDCS applied during this vulnerable period may be feasible to prevent the oncoming seizure. This study required 5 visits over the course of approximately 8 weeks. Each visit was separated by at least 2 weeks. Two of the visits had 24-hour EEG monitoring sessions. During these two sessions, the EEG and tDCS were hooked into a closed loop system, such that when seizure activity wasdetected, the tDCS was triggered to deliver stimulation. Subjects received active stimulation or sham stimulation sessions during the first 24-hour visit, and the opposite during the second. The subjects were randomized and counterbalanced. We have also added a healthy subjects cohort to assess the feasibility of the closed loop system. In order to test the proof-of-concept of this system, the experiment will focus on detecting and acting upon alpha- and beta-band changes traced in the EEG activity that is being recorded, and provide tDCS stimulation based upon those changes. We will enroll 6 subjects who will have 2 visits each. During these two visits subjects will be randomized to active or sham stimulation sessions and receive the opposite during their second visit.

Primary Outcome

Measurement of seizure activity will take place in two visits of 24-hour seizure monitoring. During these visits, the EEG will record seizure information including (1) number of seizures, (2) severity of seizures, and (3) latency of seizures between sessions of stimulation.

Interventions

• DEVICE Transcranial Direct Current Stimulation