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Effects of modifying the electrode placement and pulse width on cognitive side effects with unilateral ECT: A pilot
Donel M Martin1, Azam Ahmad Bakir2, Feng Lin3
1Black Dog Institute, Sydney, NSW, Australia; School of Psychiatry, University of New South Wales, Sydney, NSW, Australia.
Brain Stimulation
|October 9, 2021
Summary
Modifying electroconvulsive therapy (ECT) pulse width, not electrode placement, significantly improved retrograde memory. Ultrashort pulse width (UB) showed better outcomes than brief pulse (BP) for ECT cognitive side-effects.
Area of Science:
- Neuroscience
- Psychiatry
- Cognitive Science
Background:
- Electrode placement and pulse width are key electroconvulsive therapy (ECT) parameters influencing retrograde memory side effects.
- Right unilateral (RUL) ECT modifications may reduce these cognitive adverse effects.
Purpose of the Study:
- To investigate the efficacy of frontoparietal (FP) electrode placement versus temporoparietal (TP) placement in mitigating ECT-induced retrograde memory deficits.
- To compare ultrabrief (UB: 0.3 ms) pulse width ECT with brief pulse (BP: 1.0 ms) width ECT for retrograde memory outcomes.
Main Methods:
- A randomized, cross-over, double-blinded study involving participants receiving four types of RUL ECT: BP TP, BP FP, UB TP, and UB FP.
- Neuropsychological testing was performed pre- and post-treatment.
- Computational modeling assessed the relationship between electric fields (E-fields) in memory-related brain regions and cognitive side effects.
Main Results:
- Frontoparietal (FP) placement did not yield superior retrograde memory outcomes compared to temporoparietal (TP) placement.
- Ultrabrief (UB) pulse width significantly improved visual retrograde memory compared to brief pulse (BP) across both electrode placements (p < .05).
- With TP ECT, increased E-fields in the hippocampi, inferior frontal gyri, and middle frontal gyri correlated with greater visual retrograde memory side effects.
Conclusions:
- Pulse width modification, specifically UB ECT, demonstrated a greater impact on reducing retrograde memory side effects than electrode placement in RUL ECT.
- Preliminary evidence suggests a correlation between higher E-fields in specific brain regions and increased cognitive side effects during ECT.
