Fronto-Medial Electrode Placement For ECT: Computational Modeling Electric Field Study

Out on Pubmed, from authors in the UK and Germany, is this paper:

Fronto-medial electrode placement for electroconvulsive treatment of depression.

Steele JD, Farnan T, Semple DM, Bai S.Front Neurosci. 2022 Oct 20;16:1029683. doi: 10.3389/fnins.2022.1029683. eCollection 2022.PMID: 36340770

The abstract is copied below:

Electroconvulsive therapy (ECT) is the most effective treatment for severe treatment-resistant depression but concern about cognitive side-effects, particularly memory loss, limits its use. Recent observational studies on large groups of patients who have received ECT report that cognitive side-effects were associated with electric field (EF) induced increases in hippocampal volume, whereas therapeutic efficacy was associated with EF induced increases in sagittal brain structures. The aim in the present study was to determine whether a novel fronto-medial (FM) ECT electrode placement would minimize electric fields in bilateral hippocampi (HIP) whilst maximizing electric fields in dorsal sagittal cortical regions. An anatomically detailed computational head model was used with finite element analysis, to calculate ECT-induced electric fields in specific brain regions identified by translational neuroimaging studies of treatment-resistant depressive illness, for a range of electrode placements. As hypothesized, compared to traditional bitemporal (BT) electrode placement, a specific FM electrode placement reduced bilateral hippocampal electric fields two-to-three-fold, whilst the electric fields in the dorsal anterior cingulate (dAC) were increased by approximately the same amount. We highlight the clinical relevance of this specific FM electrode placement for ECT, which may significantly reduce cognitive and non-cognitive side-effects and suggest a clinical trial is indicated.

Keywords: ECT; computational modeling; depression; electric fields; side-effects.

The pdf is here.

And from the text:

This is a purely theoretical study, no clinical trial, not even a pilot, involved. The idea is simple: limit the electric field (EF) to the hippocampi, with presumed less effect on cognition. The brain images are excellent, but the tiny photos of the novel electrode placements are poor, making it somewhat hard to actually visualize the suggested optimized placements. The referencing of this paper is a bit Anglo-centric and slim.

Of course the discussion/investigation of electrode placements goes back to the earliest times in ECT. Whether or not this continues to be a useful thread for research, or a distraction from the more pressing clinical issues of access to, and acceptance of, ECT, remains a matter of opinion.