Inverse relation between stimulus intensity and seizure duration: Implications for ECT procedure

A retrospective analysis of the effects of electroconvulsive therapy (ECT) was performed for two groups of 11 patients matched according to age (mean age, 52 years), sex, and diagnosis. Group 1 received ECT according to the a ge-dose protocol; group 2 was treated according to the titration method. A higher dose relative to the seizure threshold appeared to shorten the seizu re duration. At the first treatment, the correlation between stimulus inten sity and seizure duration was negative. In the titration group, the initial mean charge of 91 mC resulted in a seizure duration of 51 s, whereas in th e age-dose group the seizure duration of 31 a was significantly shorter des pite a higher mean charge of 312 mC. Seizure duration decreased during the ECT course in the group treated first at low dose (titrated) and then at 2. 5 times the initial threshold. High stimulus intensity represented adequate treatment, although it produced short seizures. Thus. seizure duration pro ved to be an unreliable guideline for effective treatment. Furthermore. foc us on seizure duration led to frequent high-dose restimulation in the elder ly. The titration method obviates inadequate or excessive charges because t he seizure threshold must first be determined.