Abstract| Volume 14, ISSUE 6, P1665, November 2021

Quantitative ictal electroencephalography (qEEG) comparison of Focal Electrically-Administered Seizure Therapy (FEAST) and Ultrabrief Pulse Right Unilateral Electroconvulsive Therapy (UBP-RUL ECT)

      Background: Focal Electrically-Administered Seizure Therapy (FEAST) is designed to focus the ECT electrical stimulus to initiate seizure activity in right orbitofrontal cortex. Prior research suggests that FEAST is more focal than traditional forms of ECT, but there is a lack of supporting quantitative electroencephalography (qEEG) data . We compared qEEG recordings in participants receiving FEAST or ultrabrief pulse right unilateral (UBP-RUL) ECT.
      Methods: Using a non-randomized, open-label design, 38 depressed adults were recruited after referral for ECT. Twenty patients elected FEAST (14 women; age 45.2±12.7), and 18 elected UBP-RUL ECT (15 women; age 42.9±16.9). At every treatment we used a four-lead EEG montage (bilateral frontal and temporal sites) referenced to the ipsilateral mastoids, and quantified EEG power and coherence . A blinded rater artifacted the qEEG and identified epochs corresponding to baseline, early, peak, and total seizure and postictal periods, averaging across sessions for each participant. We conducted repeated measures ANOVAs on log-transformed delta band (1.6-3.8 Hz) data, with between-subject factors of condition, sex, age, average charge, and number of sessions, with electrode site (4) as the repeated measure.
      Results: During the 10 seconds of peak seizure activity, across all EEG electrodes FEAST produced significantly lower delta band power than UBP-RUL (p = 0.015) despite being delivered at a higher charge. At the early seizure timepoint (defined as the 6 seconds following ECT administration), there was a trending effect of condition on seizure magnitude with the conditions differing least in the right frontal site..
      Conclusions: These qEEG data suggest that FEAST may produce lower amplitude seizures than UBP-RUL. This reduced seizure strength may be due to a smaller population of neurons synchronously firing with FEAST supporting increased focality. Future directions include linking these neurophysiologic effects to behavioral outcomes, and examining this preliminary effect in a larger sample size.
      Keywords: ECT, EEG, FEAST, Depression