Convulsive threshold differences in right unilateral and bilateral ECT

This study examines how the convulsive threshold in electroconvulsive therapy (ECT) varies with electrode placement (bilateral [BL] versus right unilateral [RUL], age, gender, weight, and the nasion-inion measurements of the head. Method: Twenty-eight subjects underwent stimulus dose titration to determine the convulsive threshold. Titration was accomplished for each subject with both electrode placements during the first and second ECT in a balanced design. Head measurements were made prior to the first ECT. Results indicated that the convulsive threshold was higher for BL than RUL, higher for men than women, increased with age, and increased with an increasing nasion-inion measurement in women but not in men. We concluded that the convulsive threshold varies according to the choice of electrode placement, gender, and age as has been reported by others. We additionally report that the convulsive threshold increases with increasing head size as reflected in the nasion-inion distance.