EEG manifestations during ECT: effects of electrode placement and stimulus intensity

Ketamine as an Alternative Anesthetic for Augmenting Seizure Durations During Electroconvulsive Therapy: A Retrospective Observational Study

OBJECTIVE

Electroconvulsive therapy (ECT) is highly effective for severe psychiatric disorders; however, short seizure durations may lead to ineffective therapy. This retrospective study aimed to examine the risks and benefits of switching to ketamine anesthesia to augment seizure durations during an acute course of ECT.

METHODS

We included 33 patients who underwent ketamine anesthesia due to suboptimal seizures during an acute course of ECT. We assessed seizure duration, stimulus dose, hemodynamic variability, and postseizure complications before and after switching to ketamine.

RESULTS

Age was significantly associated with suboptimal seizures during ECT ( P = 0.040). After switching to ketamine, 32 patients (97%) experienced prolonged seizure duration. Ketamine significantly prolonged both electroencephalogram and motor seizure durations with a mean difference of 34.6 seconds (95% confidence interval [CI], 26.4-42.7 seconds; P < 0.001) and 26.6 seconds (95% CI, 19.6-33.6 seconds; P < 0.001), respectively. It also significantly reduced stimulus dose (mean difference, -209.5 mC [95% CI, -244.9 to -174.1 mC]; P < 0.001). In addition, maximum changes in systolic blood pressure and heart rate during ECT sessions significantly increased with ketamine (mean difference, 27.2 mm Hg [95% CI, 12.0-42.4 mm Hg; P = 0.001]; 25.7 beats per minute [95% CI, 14.5-36.8 beats per minute; P < 0.001], respectively). Patients reported more headaches with ketamine ( P = 0.041).

CONCLUSIONS

Our results provide evidence that ketamine as an alternative anesthetic can augment seizure durations in specific patients experiencing suboptimal seizures during an acute course of ECT. However, its use requires greater attention to circulatory management and postseizure complications.

Clinical efficacy of adjunctive esketamine anesthesia in electroconvulsive therapy for major depressive disorders: A pragmatic, randomized, controlled trial

Electroconvulsive therapy (ECT) is an effective treatment for depression, and esketamine has been shown to have antidepressant effects. However, it is currently unclear whether adjunctive esketamine can enhance the clinical efficacy of ECT in real-world clinical practice. In this pragmatic clinical trial, patients with major depression were randomly assigned into two groups: patients received 0.25 mg/kg esketamine plus propofol (esketamine group) or the same volume of saline (control group) plus propofol. Results indicated that there was no difference in response and remission rates between the two groups. However, patients receiving esketamine had a higher remission rate of SI and lower psychotic scores. Patients receiving esketamine also required a lower electric dose, but the seizure duration and cognitive function were comparable between the two groups. Diastolic blood pressure increased after esketamine injection, but there was no increased risk of hypertension. Furthermore, incidence of delirium and confusion were comparable between the groups. Conclusively, adjunctive esketamine anesthesia does not provide any advantage in improving the response and remission rates of ECT. However, it can improve remission of SI and alleviate accompanying psychotic symptoms in depressive patients. With adjunctive usage, the adverse cardiovascular and neuropsychiatric events associated with esketamine appear to be tolerable.

Exploring New Electroencephalogram Parameters in Electroconvulsive Therapy

OBJECTIVE

This pilot study aims to evaluate a novel metric based on the power spectrum of the EEG recordings from ECT-induced seizures-its association to volume changes in the hippocampus after ECT and improvement in depression rating scores.

METHODS

Depressed patients treated with ECT underwent brain magnetic resonance imaging before and after treatment and the EEG from each seizure was recorded (N = 29). Hippocampal volume changes and EEG parameters were recorded in addition to clinician-rated and self-reported measures of depressive symptoms. The slope of the power law in the power spectral density of the EEG was calculated. Multivariate linear models relating seizure parameters to volume change or clinical outcome were systematically and successively simplified. The best models were selected according to Akaike information criterion.

RESULTS

The slope of the power law was steeper in the right than the left hemisphere (P < 0.001). Electroencephalogram measures were included in the best models of volume change for both hippocampi as well as in the models explaining clinical outcome ( P = 0.014, P = 0.004).

CONCLUSIONS

In this pilot study, novel EEG measures were explored and contributed in models explaining the variation in volume change in the hippocampus and in clinical outcome after ECT.

No Effect of Serum Electrolyte Levels on Electroconvulsive Therapy Seizure Quality Parameters

INTRODUCTION

Seizure quality is considered to be associated with treatment outcomes of electroconvulsive therapy (ECT). A wide range of treatment parameters and patient characteristics are known to influence seizure quality. However, conflicting results exist for the role of serum electrolyte levels and seizure quality.

METHODS

We retrospectively analyzed a total of 454 patients and a total of 2119 individual acute ECT sessions irrespective of diagnosis where a clinical evaluation of serum levels of sodium, potassium, and calcium took place routinely up to 2 days before the ECT session. To assess the impact of serum electrolyte levels on seizure quality parameters, we used mixed-effects linear regression analysis with Bonferroni correction for multiple testing.

RESULTS

Serum sodium, potassium, and calcium levels were not associated with seizure quality markers after correcting the significance level for multiple testing. Younger age was consistently associated with higher postictal suppression, interhemispheric coherence, midictal amplitude, and peak heart rate. Lower dose was consistently associated with longer electroencephalogram and motor seizure duration.

CONCLUSIONS

Our results suggest that there is no clinically relevant effect of serum electrolyte levels on seizure quality, at least within clinically commonly observed ranges of serum electrolyte concentrations.

Association between postictal suppression and the therapeutic effects of electroconvulsive therapy: A systematic review

Electroconvulsive therapy (ECT) is an effective and safe medical treatment for patients with severe mood and neuropsychiatric disorders. Since the advent of ECT, extensive research has been performed to identify the predictive factors for response to ECT. In recent decades, postictal suppression on an electroencephalogram (EEG) has been considered a potential predictor of response to ECT. We aimed to investigate the direct association between postictal suppression and the therapeutic effects of ECT. In this systematic review, all articles in the field of the association between postictal suppression and the therapeutic effects of ECT published between 1990 and 2021 were identified. The full texts of these articles, which include clinical trials and retrospective and cross-sectional studies, are available in scholarly research databases and search engines, including PubMed, Google Scholar, OVID, Web of Science, and Scopus. Of all retrieved articles, eight studies, including four retrospective cohort articles and four clinical trials, met the inclusion criteria for further analyses. The findings of this study showed a significant association between postictal suppression and the therapeutic efficacy of ECT. Factors such as electrode placement, tachycardia, type of anesthetic agent, and EEG amplitude were also directly related to postictal suppression and the efficacy of ECT. Postictal suppression on EEG can be considered a predictor of response to ECT. To increase the effectiveness of treatment with ECT and increase postictal suppression, factors including electrode placement, tachycardia, type of anesthesia, and EEG amplitude should be considered, which highlights the need for further research.

Prescribing electroconvulsive therapy for depression: Not as simple as it used to be

In the last century, prescribing electroconvulsive therapy usually involved considering the relative merits of unilateral versus bilateral electroconvulsive therapy, with most other parameters fixed. However, research over the last 30 years has discovered that several parameters of the electroconvulsive therapy stimulus can have a significant impact on efficacy and cognitive side effects. The stimulus dose relative to seizure threshold was shown to significantly affect efficacy, especially for right unilateral electroconvulsive therapy, where suprathreshold doses in the vicinity of 5-6 times seizure threshold were far more efficacious than doses closer to threshold. However, this did not hold for bitemporal electroconvulsive therapy, where near-threshold stimuli were equally effective as suprathreshold stimuli. Then, changes in stimulus pulse width were found to also have a significant impact on both efficacy and side effects, with ultrabrief pulse widths of 0.3 ms having significantly fewer cognitive side effects in unilateral electroconvulsive therapy than standard brief pulse widths of 1.0 ms, with only slightly reduced efficacy. Therefore, choosing the optimum electroconvulsive therapy prescription for an individual patient now requires consideration of placement, pulse width and stimulus dose relative to seizure threshold, and how these three interact with each other. This viewpoint aims to raise awareness of these issues for psychiatrists involved in electroconvulsive therapy practice.

Seizure EEG Quality in Right Unilateral Ultrabrief ECT

OBJECTIVE

The aims of this study were to compare threshold and suprathreshold ictal electroencephalograms (EEGs) in right unilateral (RUL) ultrabrief (UB) electroconvulsive therapy (ECT) and to identify the differences between these EEGs.

METHODS

This study is a retrospective review of 125 pairs EEGs from titration and subsequent sessions across a 2-year period. All EEGs were independently rated for by 2 assessors using a scale based on qualities of an EEG used to guide ECT treatment dose adequacy, for example, midictal amplitude, regularity, interhemispheric coherence, seizure end point, and postictal suppression. The scores of threshold and suprathreshold EEGs were compared within and between groups based on 2 ECT types, that is, RUL UB ECT and RUL brief pulse (BP) ECT.

RESULTS

Paired t tests showed a statistically significant difference in between threshold and suprathreshold EEG scores in RUL UB ECT. There were no statistically significant differences between corresponding scores for RUL UB ECT and RUL BP ECT threshold and suprathreshold EEGs.

CONCLUSIONS

There is a significant difference between the quality of threshold and suprathreshold EEGs in RUL UB ECT when measured with an EEG rating scale. Visual rating of ictal EEGs is as reliable in discriminating between threshold and suprathreshold seizure in RUL UB ECT as it is in RUL BP ECT.

Ictal Electroencephalogram Visual Pattern Recognition of Seizure Adequacy During Electroconvulsive Therapy Treatment: A Step-by-Step Approach

Background

The NEURON (Neuropsychiatry and Neuromodulation Unit) electroconvulsive therapy electroencephalogram (ECT-EEG) Algorithmic Rating Scale (NEARS) is a step-by-step approach to ictal electroencephalogram visual pattern recognition of seizure adequacy based on recruitment, amplitude, symmetry, duration and degree of post-ictal suppression. The objectives of this clinical audit were to determine the degree of agreement on the NEARS operational criteria between two neuropsychiatrists, the reliability of electroconvulsive therapy practitioners' administration of NEARS during ECT procedures and the correlation of NEARS scores with Clinical Global Impression scale scores after each ECT treatment session.

Methods

Systematic random sampling was conducted. Even numbers of ictal tracings were selected for analysis from the total samples collected over 8 consecutive days of ECT overseen by a total of eight different ECT practitioners. Cohen's kappa coefficient was used to measure the inter-rater reliability of the two neuropsychiatrists and determine the level of agreement between NEARS scores and those of the ECT practitioners. The correlation using NEARS scores and post-ECT Clinical Global Impression scores was measured with Spearman's test. The significance level was set at P < 0.05.

Results

Cohen's kappa showed perfect agreement between the two neuropsychiatrists, at κ = 1.00 (SE = 0.001; P < 0.001), and strong agreement between NEARS scores of overall seizure adequacy and the scores interpreted by the ECT practitioners, at κ = 0.83 (95% CI: 0.66, 0.99; P < 0.001). Spearman's test showed a weak negative association between NEARS scores and post-ECT Clinical Global Impression scores (r = -0.018; P = 0.900).

Conclusion

NEARS may facilitate a brief, objectively reliable and practical assessment of ictal electroencephalogram quality. The scale is readily applicable by any trained ECT practitioner during an ongoing ECT procedure, especially when a prompt treatment decision is required.

Two-handed facemask technique effectively causes hyperventilation in electroconvulsive therapy: an observational study

BACKGROUND

Electroconvulsive therapy (ECT) remains the mainstay treatment option for patients with psychiatric diseases, such as severe depression. Although various anesthetic techniques provide adequate therapeutic seizures, hyperventilation is a useful adjunct to augment seizure duration and improve seizure quality. We investigated how to efficiently use a facemask to accomplish protocolized hyperventilation and evaluate its effect on ECT seizure.

METHODS

We studied 60 patients aged ≥18 years who underwent ECT. The patients were divided into two groups according to the technique of facemask ventilation used: the one-handed (n = 30) and two-handed (n = 30) groups. Following anesthesia induction under preoxygenation conditions, hyperventilation induced hypocapnia in the one-handed facemask group with manual bag ventilation was compared to that in the two-handed facemask group with assisted pressure-controlled ventilation. Ictal and peri-ictal electroencephalogram parameters and cardiovascular responses were monitored and compared between the one-handed and two-handed groups.

RESULTS

The two-handed technique demonstrated better electroencephalogram regularity and minimized cardiovascular stress compared to the one-handed technique. These conclusions come from the fact that the one-handed technique induced a substantial volume of leaks around the facemask (201.7 ± 98.6 mL/breath), whereas minimal leaks (25.8 ± 44.6 mL/breath) with stabler and higher ventilation rate led to greater inhaled minute ventilation in the two-handed group (the one-handed group, 9.52 ± 3.94 L/min; the two-handed group, 11.95 ± 2.29 L/min; p <  0.005). At the end of ECT treatment, all parameters of blood pressure and heart rate increased significantly in both groups equally, with lower SpO₂ and more ST-segment depression on the electrocardiogram in the one-handed group. Comparing baseline values before anesthesia, ECT treatment significantly depressed ST-segment in both groups, while the degree of depression in ST-segment increased significantly in the one-handed group compared to that in the two-handed group.

CONCLUSIONS

End-tidal carbon dioxide monitoring for hyperventilation can reliably ensure hypocapnia only in the two-handed group. In ECT, the two-handed technique assisted by pressure-controlled ventilation is an effective and practical method for hyperventilation to induce adequate therapeutic seizures. While, the two-handed group with sufficient preoxygenation did not cause more cardiovascular stress than the one-handed group.

TRIAL REGISTRATION

UMIN Clinical Trials Registry 000046544, Date of registration 05/01/2022.

Quiescence during burst suppression and postictal generalized EEG suppression are distinct patterns of activity

OBJECTIVE

Periods of low-amplitude electroencephalographic (EEG) signal (quiescence) are present during both anesthetic-induced burst suppression (BS) and postictal generalized electroencephalographic suppression (PGES). PGES following generalized seizures induced by electroconvulsive therapy (ECT) has been previously linked to antidepressant response. The commonality of quiescence during both BS and PGES motivated trials to recapitulate the antidepressant effects of ECT using high doses of anesthetics. However, there have been no direct electrographic comparisons of these quiescent periods to address whether these are distinct entities.

METHODS

We compared periods of EEG quiescence recorded from two human studies: BS induced in 29 healthy adult volunteers by isoflurane general anesthesia and PGES in 11 patients undergoing right unilateral ECT for treatment-resistant depression. An automated algorithm allowed detection of EEG quiescence based on a 10-microvolt amplitude threshold. Spatial, spectral, and temporal analyses compared quiescent epochs during BS and PGES.

RESULTS

The median (interquartile range) voltage for quiescent periods during PGES was greater than during BS (1.81 (0.22) microvolts vs 1.22 (0.33) microvolts, p < 0.001). Relative power was greater for quiescence during PGES than BS for the 1-4 Hz delta band (p < 0.001), at the expense of power in the theta (4-8 Hz, p < 0.001), beta (13-30 Hz, p = 0.04) and gamma (30-70 Hz, p = 0.006) frequency bands. Topographic analyses revealed that amplitude across the scalp was consistently higher for quiescent periods during PGES than BS, whose voltage was within the noise floor.

CONCLUSIONS

Quiescent epochs during PGES and BS have distinct patterns of EEG signals across voltage, frequency, and spatial domains.

SIGNIFICANCE

Quiescent epochs during PGES and BS, important neurophysiological markers for clinical outcomes, are shown to have distinct voltage and frequency characteristics.

Effects of electroconvulsive therapy on cognition and quality of life in schizophrenia

INTRODUCTION

The effects of electroconvulsive therapy (ECT) on quality of life (QoL), and its relationship with symptom and cognitive change remains unclear. We aim to examine the association of QoL changes with psychiatric symptom and cognitive changes among patients with schizophrenia who underwent ECT.

METHODS

This is a retrospective cohort study of 132 patients who received ECT from July 2017 to December 2019. Sociodemographic and clinical characteristics were obtained from medical records. Changes in QoL, psychiatric symptoms and cognition function were examined after 6 sessions of ECT. Generalised linear regression was used to examine the associations of Brief Psychiatric Rating Scale (BPRS) scores and Montreal Cognitive Assessment (MoCA) scores with QoL as measured by EQ-5D scores.

RESULTS

The mean (standard error) improvements after ECT were statistically significant for the assessment scales of EQ-5D utility score: 0.77 (0.02) to 0.89 (0.02), P<0.001; EuroQol-5-Dimension (EQ-5D) visual analogue scale score: 66.82 (2.61) to 73.05 (1.93), P=0.012; and EQ-5D subdomain scores. Both improvement in BPRS (adjusted β coefficient -0.446, 95% confidence interval [CI] -0.840 to -0.052) and MoCA (adjusted β 12.068, 95% CI 0.865 to 12.271) scores were significantly associated with improvement in EQ-5D utility scores after adjustment for sociodemographic and clinical characteristics. Improvement of BPRS scores (psychiatric symptoms) was significantly associated with improvement of the patients' mental health that was assessed by EQ-5D subdomain scores of pain (adjusted β coefficient 0.012, 95% CI 0.004 to 0.021) and anxiety (adjusted β coefficient 0.013, 95% CI 0.002 to 0.024). Improvement of MoCA scores (cognitive function) was significantly associated with patients' physical health as assessed by EQ-5D subdomain score of usual activity (adjusted β coefficient -0.349, 95% CI -0.607 to -0.09).

CONCLUSION

ECT was associated with an overall improvement of QoL among patients with schizophrenia. The improvement of psychiatric symptoms was found to be significantly associated with better mental health while the improvement of cognitive function was associated with better physical health.

A Retrospective Study of Postictal Suppression during Electroconvulsive Therapy

Background: electroconvulsive therapy (ECT) is the most effective treatment in treatment-resistant depression (TRD), but its response remains partial. Identifying useful indicators to guide decision making for treatment and improve clinical response remains a major issue. The objective of the present retrospective study was to determine if clinical response—early (after 5 ECT sessions) or longer-term (after 12 ECT sessions)—was associated with postictal suppression during the first ECT course and/or with postictal suppression frequency during the whole ECT course. Methods: in a retrospective study, the data of 42 patients suffering from treatment-resistant depression and receiving at least 5 ECT sessions were collected. Two sessions per week of bitemporal brief-pulse ECT sessions were administered to patients. Each of the electroencephalography (EEG) recordings were assessed to determine the presence of postictal suppression. Results: the postictal suppression from the first ECT session predicted a better long-term clinical response (after 12 ECT sessions), but not early clinical response (after only 5 ECT sessions). The postictal suppression frequency was associated with neither the short- nor the long-term clinical response. In addition, postictal suppression and short-term cognitive performances were not associated. Conclusions: this EEG indicator is clinically useful if it appears in the first ECT sessions, but it is no longer relevant in the following sessions.

Shaping plasticity with non-invasive brain stimulation in the treatment of psychiatric disorders: Present and future

The final chapter of this book addresses plasticity in the setting of treating psychiatric disorders. This chapter largely focuses on the treatment of depression and reviews the established antidepressant brain stimulation treatments, focusing on plasticity and maladaptive plasticity. Depression is a unique neuropsychiatric disease in that the brain goes from a healthy state into a pathologic state, and then, with appropriate treatment, can return to health often without permanent sequelae. Depression thus differs fundamentally from neurodegenerative brain diseases like Parkinson's disease or stroke. Some have theorized that depression involves a lack of flexibility or a lack of plasticity. The proven brain stimulation methods for treating depression cause plastic changes and include acute and maintenance electroconvulsive therapy (ECT), acute and maintenance transcranial magnetic stimulation (TMS), and chronically implanted cervical vagus nerve stimulation (VNS). These treatments vary widely in their speed of onset and durability. This variability in onset speed and durability raises interesting, and so far, largely unanswered questions about the underlying neurobiological mechanisms and forms of plasticity being invoked. The chapter also covers exciting recent work with vagus nerve stimulation (VNS) that is delivered paired with behaviors to cause learning and memory and plasticity changes. Taken together these current and future brain stimulation treatments for psychiatric disorders are especially promising. They are unlocking how to shape the brain in diseases to restore balance and health, with an increasing understanding of how to effectively and precisely induce therapeutic neuroplastic changes in the brain.

Short and long-term effects of single and multiple sessions of electroconvulsive therapy on brain gray matter volumes

BACKGROUND

Electroconvulsive therapy (ECT) has been shown to induce broadly distributed cortical and subcortical volume increases, more prominently in the amygdala and the hippocampus. Structural changes after one ECT session and in the long-term have been understudied.

OBJECTIVE

The aim of this study was to describe short-term and long-term volume changes induced in cortical and subcortical regions by ECT.

METHODS

Structural brain data were acquired from depressed patients before and 2 h after their first ECT session, 7-14 days after the end of the ECT series and at 6 months follow up (N = 34). Healthy, age and gender matched volunteers were scanned according to the same schedule (N = 18) and patients affected by atrial fibrillation were scanned 1-2 h before and after undergoing electrical cardioversion (N = 16). Images were parcelled using FreeSurfer and estimates of cortical gray matter volume and subcortical volume changes were obtained using Quarc.

RESULTS

Volume increase was observable in most of gray matter regions after 2 h from the first ECT session, with significant results in brain stem, bilateral hippocampi, right putamen and left thalamus, temporal and occipital regions in the right hemisphere. At the end of treatment series, widespread significant volume changes were observed. After six months, the right amygdala volume was still significantly increased. No significant changes were observed in the comparison groups.

CONCLUSIONS

Volume increases in gray matter areas can be detected 2 h after a single ECT session. Further studies are warranted to explore the underlying molecular mechanisms.

A wake-up call: Sleep physiology and related translational discrepancies in studies of rapid-acting antidepressants

Depression is frequently associated with sleep problems, and clinical improvement often coincides with the normalization of sleep architecture and realignment of circadian rhythm. The effectiveness of treatments targeting sleep in depressed patients, such as sleep deprivation, further demonstrates the confluence of sleep and mood. Moreover, recent studies showing that the rapid-acting antidepressant ketamine influences processes related to sleep-wake neurobiology have led to novel hypotheses explaining rapid and sustained antidepressant effects. Despite the available evidence, studies addressing ketamine’s antidepressant effects have focused on pharmacology and often overlooked the role of physiology. To explore this discrepancy in research on rapid-acting antidepressants, we examined articles published between 2009–2019. A keyword search algorithm indicated that vast majority of the articles completely ignored sleep. Out of the 100 most frequently cited preclinical and clinical research papers, 89 % and 71 %, respectively, did not mention sleep at all. Furthermore, only a handful of these articles disclosed key experimental variables, such as the times of treatment administration or behavioral testing, let alone considered the potential association between these variables and experimental observations. Notably, in preclinical studies, treatments were preferentially administered during the inactive period, which is the polar opposite of clinical practice and research. We discuss the potential impact of this practice on the results in the field. Our hope is that this perspective will serve as a wake-up call to (re)-examine rapid-acting antidepressant effects with more appreciation for the role of sleep and chronobiology.

Factors Predicting Ictal Quality in Bilateral Electroconvulsive Therapy Sessions

In electroconvulsive therapy (ECT), ictal characteristics predict treatment response and can be modified by changes in seizure threshold and in the ECT technique. We aimed to study the impact of ECT procedure-related variables that interact during each session and might influence the seizure results. Two hundred and fifty sessions of bilateral ECT in forty-seven subjects were included. Seizure results were evaluated by two different scales of combined ictal EEG parameters (seizure quality index (SQI) and seizure adequacy markers sum (SAMS) scores) and postictal suppression rating. Repeated measurement regression analyses were performed to identify predictors of each session’s three outcome variables. Univariate models identified age, physical status, hyperventilation, basal oxygen saturation, days between sessions, benzodiazepines, lithium, and tricyclic antidepressants as predictors of seizure quality. Days elapsed between sessions, higher oxygen saturation and protocolized hyperventilation application were significant predictors of better seizure quality in both scales used in multivariate models. Additionally, lower ASA classification influenced SQI scores as well as benzodiazepine use and lithium daily doses were predictors of SAMS scores. Higher muscle relaxant doses and lower applied stimulus intensities significantly influenced the postictal suppression rating. The study found several modifiable procedural factors that impacted the obtained seizure characteristics; they could be adjusted to optimize ECT session results.

Changes in seizure duration during acute course electroconvulsive therapy

BACKGROUND

Seizure duration has long been measured as a potential marker of ECT treatment efficacy, with concern that short seizures may be clinically ineffective. Relatively small studies have documented a trend towards shorter seizures during acute course ECT, but data from large cohorts would help provide normative data on seizure duration changes during treatment.

OBJECTIVE

This study analyzes the effects of age, sex, ECT dose, and treatment number on the duration of electrographic seizures during acute course ECT in a large single-center cohort.

METHODS

A single-center retrospective chart review was conducted of adult patients receiving a first course of ECT from 2000 to 2017 at a large freestanding psychiatric hospital.

RESULTS

3648 patients met inclusion criteria, receiving 32,879 acute course ECT treatments. There was a shortening of mean ECT seizure duration over the acute course, with the greatest decrease in duration over the first 3 treatments but continuing decreases over the entire acute course. Older age, higher ECT dose, and increasing treatment number were all associated with shorter seizures, while sex was not significantly associated. Increasing treatment dose was associated with shorter seizures relative to no dose increase, with those patients receiving the highest cumulative doses also having the shortest cumulative seizure time.

CONCLUSIONS

Among patients undergoing acute-course ECT treatment, seizure duration decreased over the treatment course, and increases in applied electrical charge were associated with shorter seizures.

Bi-Spectral Index-Guided Comparison of Propofol versus Etomidate for Induction in Electroconvulsive Therapy

Background:

Previous studies have compared varying doses of propofol and etomidate for electroconvulsive therapy (ECT) without monitoring the depth of anesthesia. Seizure duration may vary with the depth of anesthesia.

Aim:

This study aimed to compare the effects of bi-spectral index (BIS)-guided induction with propofol and etomidate on various parameters of ECT.

Settings and Design:

This was a prospective, randomized, double-blind study.

Materials and Methods:

Sixty patients undergoing ECT were randomly allocated to two groups. Group P received intravenous propofol 1–2 mg.kg ⁻¹ and Group E received etomidate 0.1–0.3 mg.kg ⁻¹ to attain a BIS of 40–60. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and BIS were recorded at various time points intraoperatively till 30 min following ECT. Seizure duration, recovery time, and adverse effects were also recorded.

Statistical Analysis:

Quantitative data were compared using unpaired t-test. Chi-square test or Fisher's exact test was used to compare categorical data. P < 0.05 was considered statistically significant.

Results:

The mean induction time and seizure duration were shorter (P < 0.001), and recovery time to obey commands was longer in Group P as compared to that of Group E (P = 0.031). HR, SBP, and DBP for 10 min after ECT had elevated more in Group E than that in Group P (P < 0.05). The incidence of myoclonus was higher in Group P compared to that of Group E (P = 0.012).

Conclusion:

During ECT, BIS-guided induction with propofol provides more stable hemodynamics than etomidate, but reduces induction time, seizure duration, and recovery time more as compared to that of etomidate.

Ventilation Adjustment in ECT During COVID-19: Voluntary Hyperventilation is an Effective Strategy

PURPOSE

Airway management is a key objective in adapted electroconvulsive therapy (ECT) protocols during the COVID-19 pandemic to prevent infection. The objective of this study was to describe the effectiveness of a modified ventilation procedure designed to reduce aerosol-generating bag-mask ventilation (BMV) and isolate possible droplets while maintaining adequate respiratory gas values in ECT sessions.

MATERIALS AND METHODS

This prospective study analyzed the results of the modified protocol applied over a month. Adaptations entailed preoxygenation and extension of the voluntary hyperventilation (VHV) time for two minutes before anesthesia induction, asking patients to hyperventilate with oxygen therapy via nasal cannula and while wearing a face mask. Thereafter, vigorous hyperventilation was avoided, and patients were only assisted with tightly sealed BMV until emergence from anesthesia, isolating the ventilation by using a single-use plastic device. Oxygen saturation (SpO2) and transcutaneous partial pressure of carbon dioxide (TcPCO2) were recorded throughout the session.

RESULTS

The study included 74 sessions of bilateral ECT with the modified ventilation protocol in 15 subjects. After VHV, the mean SpO2 increase was 2.12±2.14%, and the mean TcPCO2 decrease was 4.05±2.98 mmHg. TcPCO2 values at the moment of stimulus administration were 2.22±3.07 mmHg below pre-ECT values. The mean EEG seizure was 38.70±17.03 s, and postictal suppression was 68.31± 34.58% and 2.13±0.75 on a 0-3 scale. Brief desaturation (SpO2 <90) of 4-5 seconds duration was observed in 4 sessions.

CONCLUSION

This modified ventilation protocol was effective during COVID-19, and it did not elicit significant side effects. In addition to avoiding vigorous BMV, it induced moderate hypocapnia, which has been tied to seizure optimization and less hypercapnia during the apnea period.

The ictal EEG in ECT: A systematic review of the relationships between ictal features, ECT technique, seizure threshold and outcomes

OBJECTIVE

To provide guidance for ECT practitioners in utilising the ictal EEG to inform treatment decisions.

METHODS

A systematic review of studies examining the ictal EEG, treatment technique, seizure threshold and treatment outcomes was conducted. MEDLINE, EMBASE and PsycINFO databases were searched up to July 31, 2019. Studies were included if they examined the use of ECT in human subjects and compared an ictal EEG analysis (either quantitative or manually rated) with either: a) clinical outcomes, b) seizure threshold/threshold change, c) ECT dosing decisions, or d) different aspects of ECT technique (comparison of different electrode placements, pulse widths, waveforms, or dose/dose relative to seizure threshold).

RESULTS

A total of 853 studies were identified, with 44 meeting inclusion criteria. A qualitative review revealed ictal EEG indices have been linked to therapeutic outcome, though the strength of this relationship appears modest. Ictal EEG features are influenced by variations in ECT treatment technique. Serial ictal EEG monitoring can detect changes in seizure threshold across an ECT course for right unilateral brief and ultrabrief pulse ECT.

CONCLUSION

While there is some relationship between ictal EEG manifestation and treatment outcomes, the primary utility of ictal EEG monitoring during an ECT course may lie in the capacity to detect changes in seizure threshold and adjust dosing accordingly. Prospective validation of a dosing regime informed by serial ictal EEG monitoring is warranted.

Electroconvulsive therapy, changes in immune cell ratios, and their association with seizure quality and clinical outcome in depressed patients

Major Depressive Disorder (MDD) is a major contributor to the global burden of disease. Approximately 30-50% of depressed patients fail to reach remission with standard treatment approaches. Electroconvulsive therapy (ECT) is one of the most effective options for these patients. Its exact therapeutic mechanism remains elusive, and reliable predictors of response are absent in the routine clinical practice. To characterize its mode of action and to facilitate treatment decision-making, we analyzed ECT's acute and chronic effects on various immune cell subsets. For this purpose, blood was withdrawn from depressed patients (n=21) directly before and 15 min after the first and last ECT session, respectively. After isolating peripheral blood mononuclear cells, we investigated defined populations of immune cells and their proportional changes upon ECT treatment using flow cytometry. By these means, we found ECT remitters (R; n=10) and non-remitters (NR; n=11) to differ in their relative proportion of putative immunoregulatory CD56^highCD16^-/dim and cytotoxic CD56^dimCD16⁺ natural killer (NK) cells (CD56^highCD16^-/dim/CD56^dimCD16⁺: R=0.064(±0.005), NR=0.047(±0.005), p<0.05; linear mixed models) and thus in their NK cell cytotoxicity. NK cell cytotoxicity was further increased after a single ECT session (before=0.066(±0.005), after=0.045(±0.005), p<0.001) and was associated with ECT quality parameters (maximum sustained coherence: r²=0.389, β=-0.656, p<0.001) and long-term BDI-II rating changes (r²=0.459, β=-0.726, p<0.05; both linear regression analysis). To conclude, particular NK cell subsets seem to be involved in ECT's acute effect and its clinical outcome. Due to the limited number of patients participating in our pilot study, future approaches are required to replicate our findings.

Lack of antidepressant effects of burst-suppressing isoflurane anesthesia in adult male Wistar outbred rats subjected to chronic mild stress

Post-ictal emergence of slow wave EEG (electroencephalogram) activity and burst-suppression has been associated with the therapeutic effects of the electroconvulsive therapy (ECT), indicating that mere “cerebral silence” may elicit antidepressant actions. Indeed, brief exposures to burst-suppressing anesthesia has been reported to elicit antidepressant effects in a subset of patients, and produce behavioral and molecular alterations, such as increased expression of brain-derived neurotrophic factor (BDNF), connected with antidepressant responses in rodents. Here, we have further tested the cerebral silence hypothesis by determining whether repeated exposures to isoflurane anesthesia reduce depressive-like symptoms or influence BDNF expression in male Wistar outbred rats (Crl:WI(Han)) subjected to chronic mild stress (CMS), a model which is responsive to repeated electroconvulsive shocks (ECS, a model of ECT). Stress-susceptible, stress-resilient, and unstressed rats were exposed to 5 doses of isoflurane over a 15-day time period, with administrations occurring every third day. Isoflurane dosing is known to reliably produce rapid EEG burst-suppression (4% induction, 2% maintenance; 15 min). Antidepressant and anxiolytic effects of isoflurane were assessed after the first, third, and fifth drug exposure by measuring sucrose consumption, as well as performance on the open field and the elevated plus maze tasks. Tissue samples from the medial prefrontal cortex and hippocampus were collected, and levels of BDNF (brain-derived neurotrophic factor) protein were assessed. We find that isoflurane anesthesia had no impact on the behavior of stress-resilient or anhedonic rats in selected tests; findings which were consistent—perhaps inherently related—with unchanged levels of BDNF.

Electroconvulsive therapy: a review on indications, methods, risks and medication

This paper reviews and presents data of practical impact for those administering electroconvulsive therapy (ECT). In the first section, physical and physiological aspects of the stimulus as well as methods of stimulation are discussed. The second section deals with indications for ECT, efficacy and treatment modalities such as seizure duration, treatment frequency and total number of ECT applications. The last section is devoted to side effects, risks, comedication and comorbidity.

Central-Positive Complexes: A Novel Characterization of Ictal Markers Induced During Electroconvulsive Therapy

OBJECTIVES

Electroencephalography (EEG) allows monitoring of generalized seizures induced during electroconvulsive therapy (ECT). Scalp EEG recordings show different phases of electroencephalographic ictal activity during ECT seizures, documenting a pattern of seizures that may vary within and across individuals. In this case series, we used 64-electrode high-density EEG recording to detect topographic electroencephalographic changes not typically evident with conventional limited montages commonly used during ECT.

METHODS

The EEG recordings were acquired from 5 participants (24 ECT sessions) during index courses for treatment-resistant depression. Using previously proposed staging criteria, the ictal EEG and simultaneously acquired video were interpreted by an expert reviewer blinded to study treatment parameters.

RESULTS

The EEG recordings of all seizures showed generalized, high-amplitude, central-positive complexes (CPCs), which emerged at the beginning of phase III (polyspike and slow wave activity), with median duration of 47 seconds (interquartile range, 77 seconds), ranging from 14 to 203 seconds. Although individuals showed variability in frequency and amplitude of CPCs, CPCs typically evolved from 4.0 to 1.5 Hz in frequency and decreased in amplitude as the seizure progressed. Elaborating on previously described phases of ECT-induced electrographic seizures, we describe variability in morphology at seizure termination. Initiation of CPCs typically corresponded with clonic movements, but often terminated after motor signs ceased.

CONCLUSIONS

Generalized, high-amplitude, CPCs during ECT are a previously uncharacterized ictal waveform during ECT, which may have important scientific and clinical value. These complexes offer a specific marker for correlating clinical outcomes in ECT and greater understanding of generalized tonic-clonic seizures.

Whither TMS: A One-Trick Pony or the Beginning of a Neuroscientific Revolution?

Psychiatry has been at the forefront of advancing clinical transcranial magnetic stimulation (TMS) since the mid-1990s, shortly after the invention of modern TMS in 1985 by Barker. Clinical TMS for psychiatric applications is advancing rapidly, with novel methods and innovations for treating depression, as well as a new clinical indication in obsessive-compulsive disorder. This review summarizes the recent findings and peers into the near future of this fertile and rapidly changing field. It is possible that many, perhaps even most, psychiatrists will be incorporating some form of brain stimulation into their practice within the next decade. The author summarizes the reasons for this optimistic view.

A novel seizure quality index based on ictal parameters for optimizing clinical decision-making in electroconvulsive therapy. Part 2: Validation

Early identification of patients who are at a high risk for an unfavorable outcome to ECT during the treatment course might be beneficial because it provides an opportunity for timely intensification or optimization of stimulus conditions. We aimed to validate a previously developed seizure quality index (SQI) that delivers a clinically relevant outcome prediction early in the treatment course and can be used within common clinical setting. Therefore, a prospective study was conducted. Patients (n = 26) below the age of 65 years with a depressive episode and the clinical decision for ECT (right unilateral, brief pulse) were included and several ictal parameters, the SQI for non-response and non-remission, and the clinical outcome of the patients were documented. Logistic regression analysis revealed a statistically significant association between the SQI and non-response (p = 0.035). A significant association between the clinical outcome of non-response and the classified outcome of non-response was detected (p = 0.041). The overall classification accuracy regarding response/non-response was 71.3%, and the model revealed a sensitivity of 84.6% and a specificity of 61.5% for non-response. In this study, we could validate the SQI for the clinical outcome of non-response, but not for non-remission. Based on our data, the SQI might become an interesting clinical tool for early outcome prediction for ECT in patients with depression.

An Electrophysiological Biomarker That May Predict Treatment Response to ECT

OBJECTIVE

Electroconvulsive therapy (ECT) is the most effective treatment for major depression but also carries risk of cognitive side effects. The ability to predict whether treatment will be effective before initiation of treatment could significantly improve quality of care, reduce suffering, and diminish costs. We sought to carry out a comprehensive and definitive study of the relationship between the background electroencephalography (EEG) and therapeutic response to ECT.

METHODS

Twenty-one channel resting EEG was collected pre-ECT and 2 to 3 days after ECT course from 2 separate data sets, one to develop an EEG model of therapeutic response (n = 30) and a second to test this model (n = 40). A 3-way principal components analysis was applied and coherence and spectral amplitude across 6 frequency bands were examined. The primary outcome measure was the Montgomery-Asberg Rating Scale (MADRS).

RESULTS

Four patterns of amplitude and coherence along with baseline MADRS score accounted for 85% of the variance in posttreatment course MADRS score in study 1 (R = 0.85, F = 11.7, P < 0.0002) and 53% of the variance in MADRS score in study 2 (R = 0.53, F = 5.5, P < 0.003). Greater pre-ECT course anterior delta coherence accounted for the majority of variance in therapeutic response (study 1: R = 0.44, P = 0.01; study 2: R = 0.16, P = 0.008).

CONCLUSIONS

These results suggest a putative electrophysiological biomarker that can predict therapeutic response before a course of ECT. Greater baseline anterior delta coherence is significantly associated with a better subsequent therapeutic response and could be indicative of intact circuitry allowing for improved seizure propagation.

The anaesthetic-ECT time interval with thiopentone-Impact on seizure quality

BACKGROUND

The time between anaesthetic induction and ECT stimulus administration has been hypothesised to significantly impact ictal EEG quality. In this study, our aim was to examine the effect of the time interval between anaesthetic induction and the ECT stimulus for ictal seizure quality in ECT sessions utilising thiopentone anaesthesia.

METHODS

413 EEG traces from 42 patients, collected retrospectively, were manually rated using a quantitative-qualitative structured rating scale (indices including seizure amplitude, regularity, post-ictal suppression and general seizure quality). Linear Mixed Effects Models were used to analyse the effect of the anaesthetic-ECT time interval on seizure quality indices, seizure duration and orientation scores after ECT, controlling for patient and ECT treatment factors.

RESULTS

The anaesthetic-ECT time interval had a significant impact on ictal EEG quality indices (p < 0.05), with longer times producing higher quality seizures. Seizure duration and orientation scores after ECT were not significantly influenced by the anaesthetic-ECT time interval. Age, anaesthetic dose, ECT type and ECT treatment number also had a significant impact on measures of seizure quality (p < 0.05).

LIMITATIONS

The effect of ventilation technique was not explicitly measured. Only manual ratings of ictal quality were analysed.

CONCLUSIONS

The time between anaesthetic induction and ECT stimulus administration has a significant impact on the ictal EEG seizure quality observed, with thiopentone anaesthetic. These results are consistent with prior findings with propofol anaesthesia, and suggest a need for routine clinical monitoring of this time interval. This variable warrants consideration when interpreting ictal EEGs, which often informs subsequent dosing decisions.

Predicting postictal suppression in electroconvulsive therapy using analysis of heart rate variability

BACKGROUND

Postictal suppression on an electroencephalogram (EEG) represents electrical silence during electroconvulsive therapy (ECT) and has been considered as a key feature associated with the efficacy of treatment. The present study aimed to predict postictal suppression using heart rate variability (HRV).

METHODS

Participants comprised 21 consecutive patients with depression who underwent bilateral pulse wave ECT. We analyzed the frequency domains of resting HRV before ECT. HRV indices such as the high-frequency component (HF) reflecting parasympathetic activity and the ratio of low-frequency component (LF)/HF reflecting sympathetic activity were natural log transformed for analysis. We evaluated ictal and peri-ictal EEG parameters and investigated their associations with HRV indices.

RESULTS

Postictal suppression and regularity were positively associated with ln[HF]. Postictal suppression remained significantly associated with ln[HF] after adjusting for age in multiple regression analysis of patients with depression.

LIMITATIONS

The present study could not examine the influence of diabetes mellitus, hypertension and polarity on HRV. In addition, the small sample size resulted in low statistical power.

CONCLUSIONS

These results suggested that ln[HF] before ECT could be utilized as a predictor of postictal suppression on EEG during ECT.

Low-charge electrotherapy for patients with schizophrenia: A double-blind, randomised controlled pilot clinical trial

A double-blind, randomised controlled pilot clinical trial was conducted to assess the potential effectiveness and safety of low-charge electrotherapy (LCE) for patients with schizophrenia. Bitemporal LCE (approximately 2.8 Joules) was administered three times a week. The Positive and Negative Syndrome Scale score was set as the outcome measure. Any adverse event (AE) was recorded. Three visits occurred at baseline, post-treatment, and after one month of follow-up. Twelve patients were randomised to the electroconvulsive therapy (ECT) group or LCE group (6 patients in each group). No patient withdrew during the study. The LCE group did not experience seizures during the trial. Patients in both groups showed significant improvements in clinical measures after treatment, and the reduction of all scale scores between the two groups was nonsignificant. The LCE group experienced significantly fewer AEs than the ECT group. Compared with ECT, LCE exerts similar antipsychotic effects while causing fewer AEs. Thus, LCE has the potential to be a safe and effective treatment for patients with schizophrenia, but further research is needed.

Brief vs. ultrabrief pulse ECT: focus on seizure quality

The effect of electroconvulsive therapy (ECT) performed with ultrabrief pulse (UBP) stimulation has been found inferior to brief pulse (BP) ECT in various studies. We reinvestigated this issue using a new dosing strategy that is based on seizure quality instead of seizure threshold. There is a long history of studies associating ictal characteristics of ECT with the clinical outcome. Accordingly, we used the clinical status of the patient and the quality of the prior seizure to determine the dosage for the upcoming treatment-referred to as Clinical and Seizure Based Stimulation (CASBAS). This approach aims at continuously providing high-quality seizures to optimize the outcome. While this dosing strategy was applied in our department, the pulse width was changed for a period of time from BP to UBP. It was hypothesized that the procedure would: (1) maintain seizure quality and clinical outcome under both conditions and would; and (2) compensate the lesser clinical efficacy of UBP by an increase in stimulus intensity. 245 patients received an ECT course according to the dosing strategy described, 162 with brief pulse (BP) and 83 with ultrabrief pulse ECT (UBP). In a retrospective evaluation, seizure quality and clinical outcome (available in a 20% subgroup of patients) did not differ between both groups in most of the examined parameters, while stimulus intensity was found to be significantly higher in the UBP group. As hypothesized, UBP was less efficient than BP in providing comparable ictal quality and clinical outcome. In a first test of concept the dosing strategy CASBAS seemed suitable to continuously adjust the stimulus intensity in ECT and maintain the seizure quality.

A novel Seizure Quality Index based on ictal parameters for optimizing clinical decision making in electroconvulsive therapy. Part 1: development

Early identification of patients at high risk for an unfavorable outcome to ECT during the course might be beneficial because it provides an opportunity for timely intensification or optimization of stimulus conditions. We aimed to develop a new Seizure Quality Index (SQI) that delivers a clinical relevant outcome prediction early in the treatment course and can be used within common clinical setting. An observational study was conducted. Patients (n = 86) with a depressive episode and the clinical decision for ECT (right unilateral, brief pulse) were included, and several ictal parameters derived from the second ECT session and the clinical outcome of the patients were documented. Optimal cut-off points for five different domains of ictal adequacy for younger and older patients for the prediction of "non-response" and "non-remission" based on seizure quality was determined by the Youden Index and a sum score was built. Logistic regression analyses tested the predictive power of derived models. For both outcome variables "non-response" and "non-remission", the logistic regression models were statistically significant, albeit for remission only for subjects below the age of 65 years (χ² = 17.9, p = 0.001) and (χ² = 6.4, p = 0.020), respectively. The models correctly classified 87.2% (non-response) and 50.0% (non-remission) of the cases. ROC curve analysis showed an AUC of 0.87 (non-response) and 0.70 (non-remission). In elderly patients (> 65), no such model could be established due to a response rate of 100%. Our data provide promising, clinically relevant results about the prediction of response to ECT at an early stage for patients with depression.

Estimating The Quality of Electroconvulsive Therapy Induced Seizures Using Decision Tree and Fuzzy Inference System Classifiers

Electroconvulsive therapy (ECT) is an effective and widely used treatment for major depressive disorder, in which a brief electric current is passed through the brain to trigger a brief seizure. This study aims to identify seizure quality rating by utilizing a set of seizure parameters. We used 750 ECT EEG recordings in this experiment. Four seizure related parameters, (time of slowing, regularity, stereotypy and post-ictal suppression) are used as inputs to two classifiers, decision tree and fuzzy inference system (FIS), to predict seizure quality ratings. The two classifiers produced encouraging results with error rate of 0.31 and 0.25 for FIS and decision tree, respectively. The classification results show that the four seizure parameters provide relevant information about the rating of seizure quality. Automatic scoring of seizure quality may be beneficial to clinicians working in this field.

Differences in Seizure Expression Between Magnetic Seizure Therapy and Electroconvulsive Shock

OBJECTIVE

Evidence suggests that magnetic seizure therapy (MST) results in fewer side effects than electroconvulsive treatment, both in humans treated with electroconvulsive therapy (ECT) as well as in the animal preclinical model that uses electroconvulsive shock (ECS). Evidence suggests that MST results in fewer cognitive side effects than ECT. Although MST offers enhanced control over seizure induction and spread, little is known about how MST and ECT seizures differ. Seizure characteristics are associated with treatment effect. This study presents quantitative analyses of electroencephalogram (EEG) power after electrical and magnetic seizure induction and anesthesia-alone sham in an animal model. The aim was to test whether differential neurophysiological characteristics of the seizures could be identified that support earlier observations that the powers of theta, alpha, and beta but not delta frequency bands were lower after MST when compared with those after ECS.

METHODS

In a randomized, sham-controlled trial, 24 macaca mulatte received 6 weeks of daily sessions while scalp EEG was recorded. Electroencephalogram power was quantified within delta, theta, alpha, and beta frequency bands.

RESULTS

Magnetic seizure therapy induced lower ictal expression in the theta, alpha and beta frequencies than ECS, but MST and ECS were indistinguishable in the delta band. Magnetic seizure therapy showed less postictal suppression than ECS. Increasing electrical dosage increased ictal power, whereas increasing MST dosage had no effect on EEG expression.

CONCLUSIONS

Magnetic seizure therapy seizures have less robust electrophysiological expression than ECS, and these differences are largest in the alpha and beta bands. The relevance of these differences in higher frequency bands to clinical outcomes deserves further exploration.

SIGNIFICANCE

Contrasting EEG in ECS and MST may lead to insights on the physiological underpinnings of seizure-induced amnesia and to finding ways to reduce cognitive side effects.

Characteristics of ictal EEG in Magnetic Seizure Therapy at various stimulation frequencies

OBJECTIVES

The first objective of this study aimed to elucidate the relationship between seizure characteristics and Magnetic Seizure Therapy (MST) treatment outcome. The second objective was to determine the effect of stimulation frequency on seizure characteristics.

METHODS

Using a between-subjects design, we compared the seizures of patients with unipolar depression receiving MST at three separate stimulation frequencies: 25 Hz (n = 34), 50 Hz (n = 16) and 100 Hz (n = 11). Seizures were rated for overall seizure adequacy on a scale of 0-6, with one point given for each measure that was considered to be adequate according to the ECT literature: (1) seizure EEG duration (2) motor duration, (3) post-ictal suppression, (4) ictal EEG maximum amplitude, (5) Global Seizure Strength, and (6) Symmetry. Mixed-effect models were used to evaluate the effect of frequency on seizure characteristics and the relationships between seizure characteristics and clinical outcome.

RESULTS

(1) 100 Hz induced seizures that were less adequate than seizures induced with 50 Hz and 25 Hz stimulations. Seizures induced by 50 Hz stimulations had longer slow-wave phase durations and total EEG durations than the 100 Hz and 25 Hz groups. Global seizure strength was less robust in seizures induced by 100 Hz MST compared to the other stimulation frequencies. (2) Shorter polyspike durations and smaller slow-wave amplitude predicted reductions in overall symptoms of depression as measured by the 24-item Hamilton Depression Scale.

CONCLUSION

Analysis of our first objective revealed stimulation frequency significantly influences measures of overall seizure adequacy. However, our results also revealed these descriptions of seizure adequacy based on ECT literature may not be useful for MST-induced seizures, as the characteristics of MST-induced seizure characteristics may predict clinical response in a different manner.

SIGNIFICANCE

These results may help to distinguish the biological processes impacted by stimulation frequency and may suggest different mechanisms of action between convulsive therapies and challenge the current understanding of seizure adequacy for MST.

Anaesthesia for electroconvulsive therapy - new tricks for old drugs: a systematic review

OBJECTIVE

The objective of this review is to investigate existing literature in order to delineate whether the use of anaesthesia and timing of seizure induction in a new and optimised way may improve the efficacy of electroconvulsive therapy (ECT).

METHODS

PubMed/MEDLINE was searched for existing literature, last search on 24 June 2015. Relevant clinical studies on human subjects involving choice of anaesthetic, ventilation and bispectral index (BIS) monitoring in the ECT setting were considered. The references of relevant studies were likewise considered.

RESULTS

Propofol yields the shortest seizures, etomidate and ketamine the longest. Etomidate and ketamine+propofol 1 : 1 seems to yield the seizures with best quality. Seizure quality is improved when induction of ECT is delayed until the effect of the anaesthetic has waned - possibly monitored with BIS values. Manual hyperventilation with 100% O2 may increase the pO2/pCO2-ratio, which may be correlated with better seizure quality.

CONCLUSION

Etomidate or a 1 : 1 ketamine and propofol combination may be the best method to achieve general anaesthesia in the ECT setting. There is a need for large randomised prospective studies comparing the effect of methohexital, thiopental, propofol, ketamine, propofol+ketamine 1 : 1 and etomidate in the ECT treatment of major depressed patients. These studies should investigate safety and side effects, and most importantly have antidepressant efficacy and cognitive side effects as outcome measures instead of seizure quality.

The Clinical Alliance and Research in Electroconvulsive Therapy Network: An Australian Initiative for Improving Service Delivery of Electroconvulsive Therapy

OBJECTIVE

There is currently substantial heterogeneity in electroconvulsive therapy (ECT) treatment methods between clinical settings. Understanding how this variation in clinical practice is related to treatment outcomes is essential for optimizing service delivery. The Clinical Alliance and Research in ECT Network is a clinical and research framework with the aims of improving clinical practice, enabling auditing and benchmarking, and facilitating the collection of naturalistic clinical data.

METHODS

The network framework and clinical and treatment variables collected and rationale for the use of particular outcome measures are described. Survey results detailing the use of ECT across initial participating clinical centers were examined.

RESULTS

The data are reported from 18 of 22 participating centers, the majority based in Australia. Melancholic unipolar depression was the most common clinical indication (78%). Right unilateral (44%) and bifrontal (39%) were the most commonly used electrode placements. Eighty one percent of the centers used individual seizure titration for initial dosing.

CONCLUSIONS

There was substantial heterogeneity in the use of ECT between participating centers, indicating that the Network is representative of modern ECT practice. The Clinical Alliance and Research in ECT Network may therefore offer the opportunity to improve service delivery and facilitate the investigation of unresolved research questions pertaining to modern ECT practice.

S100B, Homocysteine, Vitamin B12, Folic Acid, and Procalcitonin Serum Levels in Remitters to Electroconvulsive Therapy: A Pilot Study

Background

Electroconvulsive therapy (ECT) is one of the most effective treatment options for refractory depressed patients. To date, there are only a few predictors of response.

Aim

The aim was to identify predictive biomarkers of remission to ECT on a molecular level.

Methods

11 patients suffering from a major depressive episode—according to the Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV)—underwent 10 ECT sessions. Blood samples were taken, and the depression severity was assessed before, one hour and 24 hours after sessions 1, 4, 7, and 10 using the Montgomery Asberg Depression Rating Scale (MADRS). A MADRS total score < 12 was interpreted as remission.

Results

Patients remitting under ECT had significantly higher homocysteine (p < 0.001), S100B (p < 0.001), and procalcitonin (PCT) (p = 0.027) serum levels. On the contrary, serum levels of vitamin B12 (p < 0.001) and folic acid (p = 0.007) were significantly lower in remitters compared to those in nonremitters. Levels remained unchanged throughout the whole ECT course.

Conclusions

Our findings indicate that lower levels of vitamin B12 and folic acid associated with higher levels of homocysteine, S100B, and PCT point to a subgroup of depressed patients sensitive to ECT. Due to the limited sample size, further studies are required to replicate our findings.

Seizure threshold increases can be predicted by EEG quality in right unilateral ultrabrief ECT

Increases in seizure threshold (ST) over a course of brief pulse ECT can be predicted by decreases in EEG quality, informing ECT dose adjustment to maintain adequate supra-threshold dosing. ST increases also occur over a course of right unilateral ultrabrief (RUL UB) ECT, but no data exist on the relationship between ST increases and EEG indices. This study (n = 35) investigated if increases in ST over RUL UB ECT treatments could be predicted by a decline in seizure quality. ST titration was performed at ECT session one and seven, with treatment dosing maintained stable (at 6-8 times ST) in intervening sessions. Seizure quality indices (slow-wave onset, mid-ictal amplitude, regularity, stereotypy, and post-ictal suppression) were manually rated at the first supra-threshold treatment, and last supra-threshold treatment before re-titration, using a structured rating scale, by a single trained rater blinded to the ECT session being rated. Twenty-one subjects (60%) had a ST increase. The association between ST changes and EEG quality indices was analysed by logistic regression, yielding a significant model (p < 0.001). Initial ST (p < 0.05) and percentage change in mid-ictal amplitude (p < 0.05) were significant predictors of change in ST. Percentage change in post-ictal suppression reached trend level significance (p = 0.065). Increases in ST over a RUL UB ECT course may be predicted by decreases in seizure quality, specifically decline in mid-ictal amplitude and potentially in post-ictal suppression. Such EEG indices may be able to inform when dose adjustments are necessary to maintain adequate supra-threshold dosing in RUL UB ECT.

Degree of Postictal Suppression Depends on Seizure Induction Time in Magnetic Seizure Therapy and Electroconvulsive Therapy

OBJECTIVES

Anesthesia is required for both magnetic seizure therapy (MST) and electroconvulsive therapy (ECT), although it has anticonvulsant properties. In this case, bispectral index (BIS) monitoring, a specific electroencephalogram-derived monitoring, can be used to find the optimal seizure induction time during anesthesia to elicit adequate seizures. A measurement of seizure adequacy in electroencephalogram is the postictal suppression. The purpose of this study was to investigate the influence of seizure induction time on the degree of postictal suppression by comparing BIS versus no-BIS monitoring in MST and ECT.

METHODS

Twenty patients with treatment-resistant depression were randomly assigned to either MST or ECT. Each patient underwent 3 treatments with the determination of seizure induction time by defined prestimulation BIS (BIS condition) and 3 treatments with determination of seizure induction time by controlled clinical trial protocol (no-BIS condition). Statistical analysis was calculated by repeated-measures analysis of variance.

RESULTS

The degree of postictal suppression was more pronounced in both MST and ECT, with BIS monitoring. In this connection, no differences between MST and ECT were found. Seizure induction time was significantly later in the BIS condition (181.3 ± 6 seconds) compared with the no-BIS condition (114.3 ± 12 seconds) (P < 0.001).

CONCLUSIONS

Adequacy of seizures, in the form of the degree of postictal suppression, was superior by determining the seizure induction time with BIS in both MST and ECT. Further research is needed to investigate the correlation between the degree of postictal suppression and treatment response.