Stimulus Dosing Methods in ECT: Review From Norway

Out on PubMed, from ECT Scholars in Norway, is this paper:

Dosing methods in electroconvulsive therapy: should the Scandinavian time-titration method be resumed?

Bergsholm P, Bjølseth TM.Nord J Psychiatry. 2021 Aug 1:1-7. doi: 10.1080/08039488.2021.1946590. Online ahead of print.PMID: 34338117

The abstract is copied below:

Aim: To describe and evaluate the different dosing methods in ECT, and bringing back into focus the Scandinavian time-titration method.

Method: A narrative, unsystematic, and selective review and discussion.

Results: There are five dosing methods: 1) The Scandinavian time-titration to tonic convulsion, using low-frequency pulses and a long maximal pulse train duration, was highly efficacious with right unilateral (RUL) ECT, comparable to bitemporal (BT) ECT. However, the device used went out of production in the 1990s. Because US devices until 1990 had a short maximal pulse train duration, time-titration went out of use. 2) Fixed high dosing at 50-100% of the device's maximal output, and 3) Formula-based dosing, initially the Age method, long prevailed in USA. Later, the Half-Age method was introduced for BT ECT. 4) Charge-dosing as a multiple of titrated seizure threshold (ST) demonstrated RUL and BT ECT to have comparable outcomes when dosed about six and two times the ST, respectively. 5) Dosing from benchmark is based on a high dose at the first session, to ensure a high peak heart rate and tonic-clonic convulsions. In later sessions the lowest dose producing similar outcomes is chosen.

Conclusions: No dosing method is documented superior to the others. Seizure threshold-based and benchmark dosing seems to be more accurate than fixed high and formula-based dosing. However, time-titration dosing makes it possible to adjust the dose at every session, and may be the most efficient method.

Keywords: Electroconvulsive therapy; dosing; pulse frequency; pulse train; titration.

The pdf is here.

And from the text:

(Introduction)

...The optimal method for individualizing the stimulus dose in ECT is not known [18–21]. Consequently, several techniques are in use. In the 1980s, one of us (P. B.), supervised by Giacomo d’Elia, practiced the Scandinavian technique, which we think may have advantages. Therefore, we present a narrative, unsystematic and selective review and discussion of dosing strategies, that has the explicit aim of bringing back into focus the Scandinavian time-titration dosing.

(Discussion)

...Direct observation of tonic convulsion as the dosing criterion may seem crude, however, so is the dosing criteria of the other methods, including seizure threshold determination. Formal reliability studies are lacking for all the methods. However, the validity of the time-titration dosing is supported by good clinical results over several decades. It requires experience by the observer, pressing and releasing the stimulus button, and the feet must not be covered with socks or clothes. As soon as the feet and big toes are extended maximally in a tonic position the current is interrupted. A common error is releasing the button too early. This may result in one of two submaximal convulsions [17]. The one is ‘dissociate convulsion,’ which superficially resembles an optimal seizure, but is followed by early awakening. The other is ‘clonic convulsion’, which has no tonic phase, ends abruptly and simultaneously in the whole body, and usually lasts only 10–20 s. The dose of succinylcholine chloride should be 0.50–0.75 mg/kg [17]. If a larger dose is required the Hamilton cuff technique used on the right ankle may be applied [37,75]. In conclusion, the optimal method for individualizing the stimulus dose in ECT is not known. The previously established Scandinavian time-titration dosing may be the simplest and most efficacious stimulation method for individualized dosing [3,6]. Time-titration secures a sufficient and individualized number of pulses with an efficacious low pulse frequency, given a device delivering a long maximal pulse train duration. A sufficiently long PRT may be the ultimate sign of a therapeutic seizure. The Scandinavian time-titration dosing has not been tested against other methods. We think it was prematurely abandoned, should be resumed, studied more closely, and compared to other methods.

I have often praised our Scandinavian colleagues for their leadership in clinical and research matters in ECT; here, they praise themselves. This review, admittedly subjective, as the authors clearly state, is a formidable body of work, comprehensively referenced and clearly organized. Dosing methods, and what ECT researchers have written about them over the decades, are well chronicled. The reminder that low pulse frequency is more efficient at seizure elicitation is well taken.

I am impressed by this work, but ultimately left with a feeling that it is clouded by nostalgia; retrogressive, not progressive. The Scandinavian time-titration dosing method may have a fancy name, but it seems crude. And how easy is it to standardize the moment when "the feet and big toes are extended maximally in a tonic position," as the signal to release the button?

The idea of an optimal postictal reorientation time (PRT) that is not too short again comes perilously close to saying that efficacy and cognitive effects are not fully separable; this too, while plausible, and never proven one way or the other, seems retrogressive.

Kudos to Drs. Bergsholm and Bjølseth for their

meticulous review and for opening up this conversation. I hope every ECT practitioner will read this paper (maybe twice, ~ 20 minutes each time) and weigh in with an opinion on how best to standardize ECT stimulus dosing, and thereby optimize ECT technique.