Value of the initial stimulus dose in right unilateral and bifrontal electroconvulsive therapy

Background. The outcome of electroconvulsive therapy (ECT) is affected by t he placement and dose of the stimulus. In general, the ECT dose can be sele cted either by the dose-titration method (on which the measured seizure thr eshold level is based), or the method of predetermined dose (e.g. the age-b ased dosing and the fixed high dose method). Methods. Seizure thresholds were measured in 50 patients with right unilate ral (RUL) and in 30 patients with experimental bifrontal (BF) ECT stimulus. The ECT dose (mC) of the age-based dosing was calculated by multiplying th e age (years) by 5.0 (age method) or 2.5 (half-age method). The fixed high dose was set to 378 mC. Results. The seizure thresholds had only a moderate correlation with the ag e of the patients. The methods based on the predetermined dose would have l ed us to give patients with the lowest seizure thresholds in the RUL ECT gr oup very high stimulus doses, up to 12 (age method) or 15 (fixed high dose method) times the individual seizure threshold. In contrast, the RUL ECT pa tients with the highest seizure thresholds would have received low stimulus doses down to 1.5 times (half-age method) the initial seizure threshold. I n the BF ECT group the-age based dose would have been similarly dependent o n the initial seizure threshold level. Conclusion. The use of the dose-titration method is recommended, because it is the only method that allows for the individual selection of ECT stimulu s dose relative to the seizure threshold.