Topography of seizures induced by electroconvulsive therapy and magnetic seizure therapy

We present the first topographical characterization of seizures induced by ultrabrief pulse width right unilateral electroconvulsive therapy (ECT) and magnetic seizure therapy (MST). Topographical electroencephalogram (EEG) was acquired during treatments in a randomized controlled trial contrasting the efficacy and safety of ECT and MST. EEG power topography within delta, theta, alpha, and beta frequency bands were assessed using wavelet and current source density analysis. ECT showed greater increases in EEG power relative to baseline in all frequencies during the early and mid-ictal periods, and decrease in power during the post-ictal period. MST seizures showed little change in ictal EEG power and post-ictal suppression relative to baseline. Compared to MST, ECT showed greater changes in power in all frequencies. Contrasting the seizure topography induced by ECT and MST can provide insights into the impact of stimulation focality on the patterns of seizure onset and spread, factors thought to be critical to the efficacy and side effects of convulsive therapy.