Ictal Electroencephalographic Measures in Electroconvulsive Therapy Practice

Electroconvulsive therapy (ECT) is well established as one of the most effective and safe treatments in psychiatry, but concerns about adverse cognitive effects remain and provide the impetus for further research to refine ECT technique. Various approaches have been tried to ensure adequate treatments are administered, thereby maximising benefits whilst minimising adverse effects. Past discussions regarding ECT seizure adequacy have been dominated by seizure duration. However, inconsistent evidence regarding seizure duration as a seizure adequacy marker has prompted research into the use of electroencephalographic (EEG) indices from ECT treatments themselves to assess seizure adequacy and inform treatment decisions.

In this in-depth review, we examine the use of ictal EEG measures in ECT practice. We discuss the neuroscientific basis of the ictal EEG, before reviewing studies of variables affecting ictal EEG measures and of clinical applications of such measures. Existing research suggests that ictal EEG parameters can be appraised alongside clinical findings to help guide ECT administration. Consideration should therefore be given to training all ECT practitioners to systematically evaluate and interpret their potential significance, as part of an overall endeavour to promote sophisticated, evidence-based ECT practice. Correlative research incorporating study of ictal EEG measures alongside other investigations into the mode of action of ECT and its improved administration may contribute to these measures assuming a more definitive place alongside a range of approaches for optimising ECT technique.