Original ArticlesQuantitative EEG During Seizures Induced by Electroconvulsive Therapy: Relations to Treatment Modality and Clinical Features. I. Global AnalysesNobler, Mitchell S. M.D; Luber, Bruce Ph.D; Moeller, James R. Ph.D; Katzman, Gary P. B.A; Prudic, Joan M.D; Devanand, D. P. M.D*; Dichter, Gabriel S. B.A; Sackeim, Harold A. Ph.D†Author Information Department of Biological Psychiatry, New York State Psychiatric Institute, New York; and Departments of Psychiatry, *Neurology, and †Radiology, College of Physicians and Surgeons of Columbia University, New York, New York, U.S.A. Received March 16, 1999; accepted May 6, 1999. Address correspondence and reprint requests to Dr. H. A. Sackeim, Department of Biological Psychiatry, New York State Psychiatric Institute, 1051 Riverside Dr., New York, NY 10032, U.S.A. The Journal of ECT: September 2000 - Volume 16 - Issue 3 - p 211-228 Buy Abstract This study examined the effects of electroconvulsive therapy (ECT) treatment conditions, patient individual difference factors, and clinical outcome on global electroencephalogram (EEG) power during and immediately following ECT-induced seizures. Sixty-two patients were randomized to ECT conditions differing in electrode placement (right unilateral versus bilateral) and stimulus dosage (just above seizure threshold versus 2.5 times seizure threshold). At the second and penultimate treatments, global total power (1.5–28.5 Hz) and global power in specific frequency bands were quantified in 19-lead EEG recordings of the generalized seizure and the immediate postictal period. Seizures induced with high dosage, and to lesser extent, with bilateral electrode placement, resulted in greater global power. Patient age, initial seizure threshold, and baseline depression severity were inversely related to global power during seizures. While superior clinical outcome following ECT was associated with greater global power during seizures, this effect was small. The factors associated with more robust seizure expression also resulted in greater postictal bioelectric suppression. Associations with treatment parameters and patient variables were stronger at the second than penultimate treatment. We conclude that manipulations of ECT technique strongly determine the magnitude of seizure expression, but relations with clinical outcome are weak. The findings raise doubt about the clinical utility of algorithms based on analysis of EEG features to guide ECT parameter selection. © 2000 Lippincott Williams & Wilkins, Inc.