The relative ability of three ictal EEG frequency bands to differentiate ECT seizures on the basis of electrode placement, stimulus intensity, and therapeutic response.

Abstract

Ictal EEG indices show promise for separating individual ECT seizures on the basis of treatment electrode placement (ELPL), relative stimulus intensity (Dose), and expected therapeutic response. One factor impeding the effective clinical implementation of ictal EEG indices for these purposes is uncertainty as to the relative utility of lower and higher frequency EEG activity. Recent articles are contradictory in this regard, but no data exist addressing this issue. As a result, we reanalyzed data from 44 subjects in two studies and compared the relative ability of ictal EEG data in three frequency bands to differentiate seizures as a function of ELPL, Dose, and therapeutic response. We found that the frequency band that best differentiated these groups depended on the EEG measure used, the temporal portion of the seizure, and whether ELPL, Dose, or therapeutic response was being compared.