2012 Volume 24 Issue 2 Pages 118-126
To optimize the effectiveness of pulse-wave electroconvulsive therapy (ECT), determination of seizure adequacy and methods of stimulus dosing are essential. In Japan, however, this has been poorly recognized. There are four important points in the clinical practice of pulse-wave ECT. The first is to determine seizure adequacy by confirming ictal “regularity” and greater postictal suppression on electroencephalogram instead of measuring seizure duration. It is very unfortunate that not a few Japanese psychiatrists still believe that a longer duration indicates seizure adequacy. When the stimulus is barely suprathreshold, increasing stimulus intensity is associated with a longer seizure duration. However, when the stimulus greatly exceeds the seizure threshold, the higher the intensity becomes, the shorter the seizure duration is expected to be. The second is to induce adequate seizures at a stimulus intensity above the “therapeutic threshold,” which means 1.5 to 2.5 times above the seizure threshold in bilateral electrode placement. Given that the seizure threshold rises through the ECT course in an unpredictable fashion, it is appropriate to increase the stimulus dose by 1.5 times the previous dose during the following session after an inadequate seizure, which is considered a product of barely suprathreshold stimulation. The method of increasing the dose by 5 to 10% (with Thymatron System IV), often observed in Japanese clinical settings, is considered inappropriate. The resulting barely suprathreshold seizure is not effective and can be a prolonged or late seizure. Starting ECT at maximum dose of 100% is also irrational, because the fixed high dose may not only accentuate cognitive disturbances but also enhance the extent and speed of the rise of the seizure threshold. The third is to use the optimal class and dose of anesthetics and stop administering benzodiazepines (BZ), in order to avoid possible rise of the seizure threshold. If BZ is hard to discontinue, flumazenil is recommended as pre-anesthetic agent. The fourth is to apply augmentation methods of seizure induction (if necessary) including oral theophylline the night before ECT. ECT is no doubt an essential treatment in psychiatry. These above techniques and methods do support its effectiveness and safety.
