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

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Electroconvulsive therapy (ECT) is a primary treatment for treatment-resistant depression.
• Cognitive adverse effects significantly impact patient treatment outcomes.
• A predictive safety biomarker is needed to identify patients at risk for cognitive impairment during ECT.

Purpose of the Study:

• To assess the relationship between ECT dose, ictal electroencephalography (EEG) power, and cognitive outcomes.
• To identify a potential safety biomarker for predicting cognitive risk in ECT patients.

Main Methods:

• Seventeen treatment-resistant depression patients received right unilateral ECT.
• Structural MRI was used for electric field modeling to determine ECT dose.
• Serial 24-lead EEG captured ictal activity; clinical and cognitive assessments were performed pre- and post-ECT.

Main Results:

• Ictal theta power (4-8 Hz) in Fp1/Fp2 channels correlated with whole-brain electric field strength.
• Ictal theta power was significantly associated with changes in Delis Kaplan Executive Function Verbal Fluency Letter Fluency scores.
• Other EEG frequency bands (beta, alpha, delta, gamma) did not show this association.

Conclusions:

• Ictal theta power shows promise as a safety biomarker in ECT, related to ECT dose strength.
• This EEG measure could help clinicians identify patients susceptible to cognitive impairment early.
• Further research is needed to explore longitudinal changes in ictal theta power during ECT treatment.