From the beginnings of convulsive therapy, the need for some way to assess the therapeutic adequacy of individual treatments has been apparent. Recent work suggests that seizure therapeutic adequacy and adverse effects are dependent on the extent to which the stimulus exceeds the seizure threshold (relative stimulus intensity). Applying this information in clinical practice is problematic because of the variable rise in the seizure threshold that takes place over the treatment course. Attributes of the ictal electroencephalogram (EEG) show promise for alleviating this problem by serving as a marker of relative stimulus intensity. Obstacles that need to be overcome in order to implement ictal EEG indices as a relative stimulus intensity marker in clinical practice are discussed and include artifacts, how to determine a threshold for deciding adequacy, variation in technique between sites, and inter-individual EEG variation; some strategies for overcoming these hurdles are described. It is anticipated that an ictal EEG algorithm that addresses these issues is likely to be of substantial clinical benefit in the practice of electroconvulsive therapy.
© Lippincott-Raven Publishers.