Electroconvulsive therapy: electric stimulus variables and the convulsive response

The ability of an electrical stimulus to induce a grand mal convulsion during electroconvulsive therapy (ECT) was investigated using four clinical treatment protocols during which the stimulus waveform, the electrical energy and/or the electrode placement were varied. The statistically significant results support the view that a pulsatile square wave stimulus is effective in inducing convulsions, provided that the d'Elia and not the Muller unilateral electrode placement is used. Higher stimulus energy may be required for older patients. The results illustrate successive attempts to remedy a previously reported problem with the effectiveness of the pulsatile waveform as a convulsive stimulus. The benefit of maintaining a database of treatment variables in order to monitor the effect of changes in the protocol under conditions of routine clinical practice is also demonstrated.