Out on PubMed is this study from Turkey, published in an EEG journal:An Observational Retrospective Study Investigating Changes in Seizure Adequacy Parameters of Electroconvulsive Therapy and Their Relationships to Clinical Outcome in Schizophrenia and Schizoaffective Disorder.
Clin EEG Neurosci. 2020 Jun 11:1550059420932076. doi: 10.1177/1550059420932076. Online ahead of print.PMID: 32525703
Not much can be concluded from this small study with unsophisticated methodology. But it does bring up the issue of seizure quality/adequacy, a subject that continues to obsess the field, perhaps rightly so. It is likely true that better seizures make for better outcome in group data (speaking here mostly about mood disorders, not schizophrenia), but beyond that, little can be said with certainty. The fixation on seizure duration, possibly misplaced, continues. At the individual patient level, all experienced ECT practitioners have seen geriatric depressed patients who do exceptionally well, despite short and poorly expressed seizures. Please do not misconstrue what I am saying; most patients do better with longer, higher amplitude seizures, and this is what we should aim for. But some patients remit quickly with less powerful forms of ECT (e.g.RUL-UBP) that elicit less convincing seizure adequacy, by conventional metrics. An antidepressant medication analogy might be: some patients remit with 10 mg of fluoxetine, but most require 20mg or more. Until we are able to predict which ECT patients will respond to which technique, clinical judgment will continue to be critical, and we should usually err on the side of efficacy, using proven ECT techniques that elicit adequately long, well-developed seizures, particularly in more urgently ill patients.
The abstract is at the above link, and copied here:
The aim of the current
study was to investigate a possible relationship between electroconvulsive
therapy (ECT) seizure adequacy parameters and clinical outcome as well as
differences between ECT responders and nonresponders in terms of ECT seizure
parameters in patients diagnosed with schizophrenia and schizoaffective
disorder. First and last ECT records data, sociodemographic variables, and
baseline and post ECT Positive and Negative Syndrome Scale scores were
obtained. Maximum sustained power was higher in last ECT in favor of responders
while peak heart rate was higher in ECT nonresponders than responders in first
ECT. Stimulus doses were higher in last ECT than in the first ECT in both
groups. No predictor variable was observed among baseline ECT seizure
parameters for clinical improvement. Study was insufficient to yield a precise
finding pointing a relationship between electrophysiological seizure parameters
and clinical outcome in schizophrenia and schizoaffective disorder.
This is a retrospective, observational study of 34 male inpatients diagnosed with schizophrenia or schizoaffective disorder. Seizure adequacy parameters from the Thymatron readout were obtained from the first and last ECT; response was assessed with the PANSS. 62% of patients met response criteria (25% reduction in PANSS score). The study had essentially negative results, with one minor positive finding ("maximum sustained power" higher at last ECT in responders) and one minor paradoxical finding (peak heart rate higher at first ECT in non responders).
The below post is from Max Fink:
ReplyDeleteSeizure adequacy
What is an effective seizure, one that favorably alters brain function and reduces clinical pathology? Inducing seizures as therapy appeared (1934) at the same time as electroencephalography (1929) and it was soon apparent that repeated seizures elicited progressive slowing and increased amplitudes of brain electrical frequencies. Initially,
Interseizure scalp recordings showed progressive slowing during the treatment course. High degrees of slowing was associated with greater degrees of clinical improvement.1
The degree of slowing was associated with number, frequency and durations of seizures, electrode placement and parameters of the currents. (BT placements and AC currents elicit greater degrees of EEG slowing.) It was the desire to measure the seizure quality itself that led Paul Blachly in 1977 to develop the technology for recording the seizure in the device that is now the MECTA. When Richard Abrams and Conrad Swartz established Somatics developing the Thymatron device, similar technologies with digital computer quantitative EEG measures were incorporated. These were adopted from the QEEG digital computer measures that were the basis for pharmaco-EEG, the neuroscience that characterized the effects of psychotropic drugs, identifying active from inactive treatments, and the type and rapidity of induced behavior change.2,
In monitoring the adequacy of seizures, duration of the EEG seizure is the first elementary measure. Examining the EEG frequencies and amplitudes before and during the course of treatment offers useful measures of the degree of slowing, that relate well to the course of treatment. 3
Alas, these measures are hardly used. The present study fails to guide us to effective treatments by ignoring measures that today's seizure inducing devices offer.
ECT reports commonly offer the electrical energy parameters that were used to induce the seizure. These are irrelevant trivia; it is the changes in brain function that tell us whether treatments were adequate or not. In addition to the EEG, measuring prolactin release offers useful measures of seizure adequacy. (see ECT Blog June 13, 2020).
More attention needs to be paid to the EEG measures available in today's ECT devices.
Max Fink
1. Fink M. Kahn RL. Relation of EEG delta activity to behavioral response in electroshock: Quantitative serial studies. Arch, Neurol. Psychiatry 1957; 78: 516-25.
2. Fink M. Remembering the lost neuroscience of pharmaco-EEG. Acta psychiatr Scand. 121:161-73, 2010.
3. Volavka J, Feldstein S, Abrams R, Fink M.EEG and clinical change after bilateral and unilateral electroconvulsive Therapy. Electroenceph. Clin. Neurophysiol., 1972; 32: 631-639