A case of schizophrenia successfully treated by mECT using ‘long’ brief pulse

Introduction: Modified­Electroconvulsive Therapy (m­ECT) is administered for the treatment of various psychiatric disorders. The Seizure Generalization Hypothesis holds that propagation of the induced seizure throughout the entire brain is essential for effective ECT intervention. However, there are many clinical cases where, due to high thresholds, seizure is not induced by the maximum dose of electrical charge. Several studies have indicated that the ultrabrief pulse method, in which the pulse width is less than 0.5 millisecond (ms), is more effective for inducing seizures than the conventional brief pulse (0.5­2.0 ms). Case Report: A 35­year­old Japanese male schizophrenic with psychomotor excitement was admitted to our hospital. In a series of m­ECT interventions, trials with 1.0 and 1.5 ms width pulses (referred to as ‘long’ brief pulse as 0.5 ms width pulse is the default in Japan) succeeded in inducing seizures, whereas the ultrabrief pulse failed. Conclusion: This case suggests that seizure threshold depends on pulse width. We speculate that in our patient the strength­ duration curve involved in ECT­induced seizures might be right­shifted resulting in prolonged chronaxie to about 1.0 ms. Therefore, in cases where neither the default width pulse nor the ultrabrief pulse induces seizures, patients should be considered for treatment using a wider width pulse.