Ictal Theta Power as a Biomarker in ECT: New Study in JECT

 Out on PubMed, from researchers in New Mexico and the NIMH is this paper in JECT:

Ictal Theta Power as an Electroconvulsive Therapy Safety Biomarker: A Pilot Study.

Miller J, Jones T, Upston J, Deng ZD, McClintock SM, Ryman S, Quinn D, Abbott CC.J ECT. 2022 Jun 1;38(2):88-94. doi: 10.1097/YCT.0000000000000812.PMID: 35613008

The abstract is copied below:

Objective: Electroconvulsive therapy (ECT) remains the benchmark for treatment resistant depression, yet its cognitive adverse effects have a negative impact on treatment. A predictive safety biomarker early in ECT treatment is needed to identify patients at cognitive risk to maximize therapeutic outcomes and minimize adverse effects. We used ictal electroencephalography frequency analysis from suprathreshold treatments to assess the relationships between ECT dose, ictal power across different frequency domains, and cognitive outcomes.

Methods: Seventeen subjects with treatment resistant depression received right unilateral ECT. Structural magnetic resonance imaging was obtained pre-ECT for electric field modeling to assess ECT dose. Serial assessments with 24-lead electroencephalography captured ictal activity. Clinical and cognitive assessments were performed before and after ECT. The primary cognitive outcome was the change in Delis Kaplan Executive Function Verbal Fluency Letter Fluency.

Results: Ictal theta (4-8 Hz) power in the Fp1/Fp2 channels was associated with both whole-brain electric field strength (t(2,12) = 19.5, P = 0.007)/(t(2,10) = 21.85, P = 0.02) and Delis Kaplan Executive Function Verbal Fluency Letter Fluency scores (t(2,12) = -2.05, P = 0.05)/(t(2,10) = -2.20, P = 0.01). Other frequency bands (beta, alpha, delta, and gamma) did not demonstrate this relationship.

Conclusions: This pilot data identify ictal theta power as a potential safety biomarker in ECT and is related to the strength of the ECT dose. Ictal theta power could prove to be a convenient and powerful tool for clinicians to identify those patients most susceptible to cognitive impairment early in the treatment series. Additional studies are needed to assess the role of longitudinal changes in ictal theta power throughout the ECT series.

The paper is here.

And from the text:

This is an add-on study from a previously published study comparing clinical outcomes of three pulse amplitudes in ECT.
I will leave it to readers to decide whether you think that theta power has a chance to become an ECT biomarker.
I take issue with the characterization of cognitive effects (typically transient and often mild or moderate with modern ECT techniques) as a "safety" issue; IMO they should be considered, and called, a tolerability issue. These authors are to be commended for their efforts to increase ECT's tolerability; and of course it is important to be transparent about cognitive effects in consent discussions with patients, and not downplay them. But exaggerating them increases the stigma of the treatment, paradoxically something the authors state they are trying to reduce.