The effects of ECT stimulus dose and electrode placement on the Ictal electroencephalogram: An intraindividual crossover study

Andrew D. Krystal, Richard D. Weiner, W. Vaughn McCall, Frank E. Shelp, Rebecca Arias, Pamela Smith

Research output: Contribution to journalArticle

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Recent evidence suggests that electroconvulsive therapy (ECT) efficacy depends upon both electrode placement and the degree to which stimulus dosage exceeds seizure threshold (T), and not simply on surpassing a minimum seizure duration as has been assumed. In light of these findings and studies reporting ictal electroencephalogram (EEG) differences between bilateral and unilateral ECT, we performed this 19-subject intraindividual crossover study of the effects of dose and electrode placement on the ictal EEG. We found ictal EEG evidence of greater seizure intensity with bilateral than unilateral ECT and with higher dosage (2.25 T) compared with barely suprathreshold stimuli. Seizure duration was no longer with bilateral than unilateral ECT and actually decreased with increased dose. A number of ictal EEG variables separated the unilateral 2.25 T and unilateral T conditions, which reportedly differ in efficacy, and therefore, these EEG measures show promise as markers of treatment adequacy.

Original languageEnglish (US)
Pages (from-to)759-767
Number of pages9
JournalBiological Psychiatry
Issue number11
Publication statusPublished - Dec 1 1993
Externally publishedYes



  • ECT
  • EEG
  • electrode placement
  • seizure adequacy
  • stimulus dose

ASJC Scopus subject areas

  • Biological Psychiatry

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