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

Effect of quantitative consciousness index on seizure parameters during electroconvulsive therapy in patients with major depressive disorder

BACKGROUND

Electroconvulsive therapy (ECT) is both an effective treatment for patients with major depressive disorder (MDD) and a noxious stimulus. Although some studies have explored the effect of sedation depth on seizure parameters in ECT, there is little research on the noxious stimulation response to ECT. In this study, we used two electroencephalography (EEG)-derived indices, the quantitative consciousness (qCON) index and quantitative nociceptive (qNOX) index, to monitor sedation, hypnosis, and noxious stimulation response in patients with MDD undergoing acute ECT.

AIM

To evaluate the effect of anesthesia depth based on the qCON and qNOX indices on seizure parameters.

METHODS

Patients with MDD (n = 24) underwent acute bilateral temporal ECT under propofol anesthesia. Before ECT, the patients were randomly divided into three groups according to qCON scores (qCON60-70, qCON50-60, and qCON40-50). Continuous qCON monitoring was performed 3 minutes before and during ECT, and the qCON, qNOX, vital signs, EEG seizure parameters, and complications during the recovery period were recorded. The 24-item Hamilton Rating Scale for Depression, Zung’s Self-rating Depression Scale, and Montreal Cognitive Assessment scores were evaluated before the first ECT session, after the fourth ECT session, and after the full course of ECT.

RESULTS

A total of 193 ECT sessions were performed on 24 participants. The qCON index significantly affected the EEG seizure duration, peak mid-ictal amplitude, and maximum heart rate during ECT (P < 0.05). The qNOX index significantly affected the post-ictal suppression index (P < 0.05). Age, number of ECT sessions, and anesthetic-ECT time intervals also had a significant effect on EEG seizure parameters (P < 0.05). However, there were no significant differences in complications, 24-item Hamilton Rating Scale for Depression scores, Zung’s Self-rating Depression Scale scores, or Montreal Cognitive Assessment scores among the three groups (P > 0.05).

CONCLUSION

Electrical stimulation at a qCON index of 60-70 resulted in better EEG seizure parameters without increasing complications in patients with MDD undergoing bilateral temporal ECT under propofol anesthesia.

Perspectives in treatment-resistant depression: esketamine and electroconvulsive therapy

Modern electroconvulsive therapy (ECT) and the approval of nasal esketamine for clinical use have significantly improved the approach to treatment-resistant depression (TRD), which is defined as non-response to at least two different courses of antidepressants with verified adherence to treatment, adequate dosage, and duration of treatment. The goal of this literature review is to present the newest evidence regarding efficacy and safety. Furthermore, we aim to provide an overview of future perspectives in this field of research, for example, regarding structural and molecular effects. Both treatment methods will be critically evaluated for their individual advantages, disadvantages, and response rates. Firstly, we will discuss the well-established method of ECT and its different treatment modalities. Secondly, we will discuss the properties of ketamine, the discovery of its antidepressive effects and the route to clinical approval of the esketamine nasal spray. We will comment on research settings which have evaluated intravenous ketamine against ECT. The decision-making process between esketamine nasal spray or ECT should include the assessment of contraindications, age, severity of disease, presence of psychotic symptoms, patient preference and treatment accessibility. We conclude that both treatment options are highly effective in TRD. If both are indicated, pragmatically esketamine will be chosen before ECT; however, ECT studies in ketamine non-responders are missing.

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.

Effects of electroconvulsive therapy on cerebral A1 adenosine receptor availability: a PET study in patients suffering from treatment-resistant major depressive disorder

Introduction

Sleep deprivation and electroconvulsive therapy (ECT) effectively ameliorate symptoms in major depressive disorder (MDD). In rodents, both are associated with an enhancement of cerebral adenosine levels, which in turn likely influence adenosinergic receptor expression. The aim of the current study was to investigate cerebral A1 adenosine receptor (A1AR) availability in patients with MDD as a potential mediating factor of antidepressant effects of ECT using [18F]CPFPX and positron emission tomography (PET).

Methods

Regional A1AR availability was determined before and after a series of ECT applications (mean number ± SD 10.4 ± 1.2) in 14 subjects (4 males, mean age 49.5 ± 11.8 years). Clinical outcome, measured by neuropsychological testing, and ECT parameters were correlated with changes in A1AR availability.

Results

ECT had a strong antidepressive effect (p < 0.01) while on average cerebral A1AR availability remained unaltered between pre-and post-ECT conditions (F = 0.65, p = 0.42, mean difference ± SD 3.93% ± 22.7%). There was no correlation between changes in clinical outcome parameters and regional A1AR availability, although individual patients showed striking bidirectional alterations of up to 30-40% in A1AR availability after ECT. Solely, for the mean seizure quality index of the applied ECTs a significant association with changes in A1AR availability was found (rs = -0.6, p = 0.02).

Discussion

In the present study, therapeutically effective ECT treatment did not result in coherent changes of A1AR availability after a series of ECT treatments. These findings do not exclude a potential role for cerebral A1ARs in ECT, but shift attention to rather short-termed and adaptive mechanisms during ECT-related convulsive effects.

Effects of Anesthesia Changes During Maintenance ECT: A Longitudinal Comparison of Seizure Quality Under Anesthesia Using Propofol/Esketamine Versus Methohexital

INTRODUCTION

The effectiveness of ECT relies on the induction of a generalized cerebral seizure. Among others, seizure quality (SQ) is potentially influenced by the anesthetic drug used. Commonly used anesthetics comprise barbiturates, etomidate, propofol, and esketamine, with different characteristics and impacts on seizure parameters. So far, no studies have compared the influence of methohexital vs. a combination of propofol/esketamine on established SQ parameters.

METHODS

This retrospective longitudinal study compared eight established SQ parameters (PSI, ASEI, MSC, midictal amplitude, motor and electroencephalography (EEG) seizure duration, concordance, PHR) before and after the change from propofol/esketamine to methohexital in 34 patients under maintenance ECT. Each patient contributed four measurements, two before and two after the anesthesia change. Anesthesia dose, stimulus dose, electrode placement, and concomitant medication remained unchanged throughout the analyzed treatments.

RESULTS

Under methohexital (M=88.97 mg), ASEI (p=0.039 to 0.013) and midictal amplitude (p=0.022 to<0.001) were significantly lower, whereas seizure duration (motor and EEG) was significantly longer when compared to propofol/esketamine (M=64.26 mg/51.18 mg; p=0.012 to<0.001). PSI, MSC, seizure concordance, and PHR were not affected by the anesthetic used.

DISCUSSION

Although to what extent these parameters correlate with the therapeutic effectiveness remains ambiguous, a decision for or against a particular anesthetic could be considered if a specific SQ parameter needs optimization. However, no general superiority for one specific substance or combination was found in this study. In the next step, anesthetic effects on treatment response and tolerability should be focused on.

Comparison of etomidate and methohexital as anesthetic agents for continuation and maintenance electroconvulsive therapy: A retrospective analysis of seizure quality and safety

BACKGROUND

The ideal hypnotic agent for electroconvulsive therapy (ECT) is still under debate and previous studies comparing etomidate and methohexital have produced conflicting results. This retrospective study compares etomidate and methohexital as anesthetic agents in continuation and maintenance (m)ECT with regard to seizure quality and anesthetic outcomes.

METHODS

All subjects undergoing mECT at our department between October 1st, 2014 and February 28th, 2022 were included in this retrospective analysis. Data for each ECT session were obtained from the electronic health records. Anesthesia was performed with either methohexital/succinylcholine or etomidate/succinylcholine. Standard seizure quality parameters, anesthesiological monitoring data, pharmacological interventions and side-effects were recorded.

RESULTS

573 mECT treatments in 88 patients were included (methohexital n = 458, etomidate n = 115). Seizures lasted significantly longer after using etomidate (electroencephalography: +12.80 s [95 %-CI:8.64-16.95]; electromyogram +6.59 s [95 %-CI:4.14-9.04]). Time to maximum coherence was significantly longer with etomidate (+7.34 s [95 %-CI:3.97-10.71]. Use of etomidate was associated with longer procedure duration (+6.51 min [95 %-CI:4.84-8.17]) and higher maximum postictal systolic blood pressure (+13.64 mmHg [95 %-CI:9.33-17.94]). Postictal systolic blood pressure > 180 mmHg, the use of antihypertensives, benzodiazepines and clonidine (for postictal agitation), as well as the occurrence of myoclonus was significantly more common under etomidate.

CONCLUSIONS

Due to longer procedure duration and an unfavorable side effect profile, etomidate appears inferior to methohexital as an anesthetic agent in mECT despite longer seizure durations.

Dynamic impedance is correlated with static impedance and seizure quality parameters in bifrontal electroconvulsive therapy

BACKGROUND

To evoke a therapeutically effective seizure, electrical stimulation in electroconvulsive therapy (ECT) has to overcome the combined resistivity of scalp, skull and other tissues. Static impedances are measured prior to stimulation using high-frequency electrical alternating pulses, dynamic impedances during passage of the stimulation current. Static impedance can partially be influenced by skin preparation techniques. Earlier studies showed a correlation between dynamic and static impedance in bitemporal and right unilateral ECT.

OBJECTIVE

This study aims at assessing the correlation of dynamic and static impedance with patient characteristics and seizure quality criteria in bifrontal ECT.

METHODS

We performed a cross-sectional single-centre retrospective analysis of ECT treatments at the Psychiatric University Hospital Zurich between May 2012 and March 2020 and used linear mixed-effects regression models in 78 patients with a total of 1757 ECT sessions.

RESULTS

Dynamic and static impedance were strongly correlated. Dynamic impedance was significantly correlated with age and higher in women. Energy set and factors positively (caffeine) and negatively (propofol) affecting seizure at the neuronal level were not associated with dynamic impedance. For secondary outcomes, dynamic impedance was significantly related to Maximum Sustained Power and Average Seizure Energy Index. Other seizure quality criteria showed no significant correlation with dynamic impedance.

CONCLUSION

Aiming for low static impedance might reduce dynamic impedance, which is correlated with positive seizure quality parameters. Therefore, good skin preparation to achieve low static impedance is recommended.

Accounting for symptom heterogeneity can improve neuroimaging models of antidepressant response after electroconvulsive therapy

Depression symptom heterogeneity limits the identifiability of treatment‐response biomarkers. Whether improvement along dimensions of depressive symptoms relates to separable neural networks remains poorly understood. We build on work describing three latent symptom dimensions within the 17‐item Hamilton Depression Rating Scale (HDRS) and use data‐driven methods to relate multivariate patterns of patient clinical, demographic, and brain structural changes over electroconvulsive therapy (ECT) to dimensional changes in depressive symptoms. We included 110 ECT patients from Global ECT‐MRI Research Collaboration (GEMRIC) sites who underwent structural MRI and HDRS assessments before and after treatment. Cross validated random forest regression models predicted change along symptom dimensions. HDRS symptoms clustered into dimensions of somatic disturbances (SoD), core mood and anhedonia (CMA), and insomnia. The coefficient of determination between predicted and actual changes were 22%, 39%, and 39% (all p < .01) for SoD, CMA, and insomnia, respectively. CMA and insomnia change were predicted more accurately than HDRS‐6 and HDRS‐17 changes (p < .05). Pretreatment symptoms, body‐mass index, and age were important predictors. Important imaging predictors included the right transverse temporal gyrus and left frontal pole for the SoD dimension; right transverse temporal gyrus and right rostral middle frontal gyrus for the CMA dimension; and right superior parietal lobule and left accumbens for the insomnia dimension. Our findings support that recovery along depressive symptom dimensions is predicted more accurately than HDRS total scores and are related to unique and overlapping patterns of clinical and demographic data and volumetric changes in brain regions related to depression and near ECT electrodes.

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.

An Observational Retrospective Study Investigating Changes in Seizure Adequacy Parameters of Electroconvulsive Therapy and Their Relationships to Clinical Outcome in Schizophrenia and Schizoaffective Disorder

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.

Factors Associated With Seizure Adequacy Along the Course of Electroconvulsive Therapy

OBJECTIVES

Eliciting a generalized seizure is essential to electroconvulsive therapy (ECT), but there is still a need to understand how patient and session variables interact to generate a seizure of adequate quality. Here, we investigate factors associated with motor seizure length as a measure of quality in a large database of patients who underwent ECT.

METHODS

This is a retrospective cohort including data from all adult inpatients who underwent ECT at a university hospital in Brazil from 2009 to 2015. We used linear mixed models to investigate the effects of patient, session, and medication on seizure length.

RESULTS

Session information was available for 387 patients, a total of 3544 sessions and 4167 individual stimulations. Multiple stimulations were necessary in 12.4% of sessions. Median seizure length was 30 seconds. Seizure length was directly correlated with stimulus dosage and inversely correlated with the session number, patient age, prescription of anticonvulsants in the day before and β-blockers during the session, and the thiopental dose. Use of benzodiazepines was not associated with a shorter seizure duration, irrespective of dose.

CONCLUSIONS

We demonstrate here how motor seizure length evolves during a course of ECT. With a large number of sessions, we are able to integrate a host of factors in a prediction model. Seizure quality was influenced by a number of the studied factors, many of which are potentially modifiable and could be assessed before initiating and handled during treatment.

Empirical ratio of the combined use of S-ketamine and propofol in electroconvulsive therapy and its impact on seizure quality

Electroconvulsive therapy (ECT) is an effective treatment for depressive disorders. In certain cases, ECT-associated anaesthesia can be improved by the use of ketofol (i.e., S-ketamine + propofol). We aimed to evaluate the empirical mixing ratio of ketofol in these cases for better clinical implementation. We retrospectively investigated n = 52 patients who received 919 ECT sessions with S-ketamine plus propofol as anaesthetic agents. Several anaesthesia and ECT-related parameters including doses of S-ketamine and propofol were analysed. The mean empirically determined S-ketamine/propofol ratio was 1.38 (SD ± 0.57) for 919 individual ECT sessions and 1.52 (SD ± 0.62) for 52 patients, respectively. The mean relative dose was 0.72 (± 0.18) mg/kg S-ketamine and 0.54 (± 0.21) mg/kg propofol. Higher propofol dose was associated with poorer seizure quality. Seizure quality and time in recovery room were significantly influenced by age. Ketofol could be an option to exploit the advantageous qualities of S-ketamine and propofol, if both doses are reduced compared with single use of S-ketamine or propofol. Patients with poor seizure quality may benefit from lower propofol doses, which are applicable by the addition of ketamine. An empirically determined mixing ratio in favour of ketamine turned out to be preferable in a clinical setting. Recovery time was primarily prolonged by higher age rather than by ketamine dose, which had previously often been associated with a prolonged monitoring time in the recovery room. These new findings could improve electroconvulsive therapy and should be replicated in a prospective manner.

The novel seizure quality index for the antidepressant outcome prediction in electroconvulsive therapy: association with biomarkers in the cerebrospinal fluid

For patients with depression treated with electroconvulsive therapy (ECT), the novel seizure quality index (SQI) can predict the risk of non-response (and non-remission)-as early as after the second ECT session-based the extent of several ictal parameters of the seizure. We aim to test several CSF markers on their ability to predict the degree of seizure quality, measured by the SQI to identify possible factors, that could explain some variability of the seizure quality. Baseline CSF levels of metabolites from the kynurenine pathway, markers of neurodegeneration (tau proteins, β-amyloids and neurogranin), elements of the innate immune system, endocannabinoids, sphingolipids, neurotrophic factors (VEGF) and Klotho were measured before ECT in patients with depression (n = 12) to identify possible correlations with the SQI by Pearson's partial correlation. Negative, linear relationships with the SQI for response were observed for CSF levels of T-tau (r_partial = - 0.69, p = 0.019), phosphatidylcholines (r_partial = - 0.52, p = 0.038) and IL-8 (r_partial = - 0.67, p = 0.047). Regarding the SQI for remission, a negative, linear relationship was noted with CSF levels of the endocannabinoid AEA (r_partial = - 0.70, p = 0.024) and CD163 (r_partial = - 0.68, p = 0.029). In sum, CSF Markers for the innate immune system, for neurodegeneration and from lipids were found to be associated with the SQI for response and remission after adjusting for age. Consistently, higher CSF levels of the markers were always associated with lower seizure quality. Based on these results, further research regarding the mechanism of seizure quality in ECT is suggested.

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.

When to consider electroconvulsive therapy (ECT)

OBJECTIVE

To familiarize the reader with the role of electroconvulsive therapy (ECT) in current psychiatric medicine.

METHOD

We review clinical indications for ECT, patient selection, contemporary ECT practice, maintenance treatment and ECT in major treatment guidelines.

RESULTS

ECT is underutilized largely due to persisting stigma and lack of knowledge about modern ECT technique.

CONCLUSION

ECT remains a vital treatment for patients with severe mood disorders, psychotic illness and catatonia.

Overlooking the obvious? Influence of electrolyte concentrations on seizure quality parameters in electroconvulsive therapy

Clinical response to electroconvulsive therapy (ECT) depends on eliciting a generalized seizure. Though there are multiple ictal and other parameters to assess seizure quality, factors that influence these parameters have only been identified to a limited extend in antecedent studies (e.g., stimulus dosage, age). In the context of ECT, electrolyte concentrations have hardly been investigated so far-although hyponatremia is one well-known clinical factor to increase the risk of spontaneous seizures. In 31 patients with unipolar or bipolar depressive disorder, blood concentrations of sodium (Na), potassium (K), and calcium (Ca) were measured immediately prior to repeated sessions of maintenance ECT. Generalized linear mixed models were used to analyze the influence of Na, K, and Ca on seven seizure quality parameters: postictal suppression index (PSI), maximum sustained coherence (MSC), midictal amplitude, average seizure energy index, seizure duration (EEG/motor), and peak heart rate. Results show a statistically significant relationship between the serum sodium level and MSC: in the model, a reduction of 1 mmol/l led to an increase in interhemispheric coherence of 0.678%. The further markers remained unaffected by changes in electrolyte concentrations. This finding provides first evidence that a lower blood concentration of sodium could enhance the quality of ECT-induced seizures in terms of higher interhemispheric coherence.

Cytokine-mediated cellular immune activation in electroconvulsive therapy: A CSF study in patients with treatment-resistant depression

Objectives: Evidence points towards an important relationship between the antidepressant effects of electroconvulsive therapy (ECT) and the modulation of the immune system. To further elucidate this interplay, we performed a study on the effects of the antidepressant treatment by ECT on 25 cytokines in patients with depression.Methods: We measured 25 different cytokines (interleukin (IL)-1β, IL-1RA, Il-2, IL-2R, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12 (p40/p70), IL-13, IL-15, IL-17, tumor necrosis factor-α, interferon (IFN)-α, IFN-γ, granulocyte-macrophage colony-stimulating factor, macrophage inflammatory protein (MIP)-1α, MIP-1β, IFN-γ-induced protein 10 (IP-10), monokine induced by IFN-γ, Eotaxin, Rantes and monocyte chemoattractant protein 1) in the cerebrospinal fluid (CSF) and blood of 12 patients with a severe and treatment-resistant depressive episode before and after a course of ECT.Results: CSF levels of IP-10, IL-5 and IL-8 were elevated after ECT and more ECT sessions were associated with the differences of CSF levels before and after ECT of IFN-γ, IL-2RA, Rantes, IL-6 and IL-1β. Responders and/or remitters had a decrease of CSF levels of IL-17, MIP-1α, Rantes and IL-2R during ECT. CSF IP-10 levels increased less during ECT in patients who had a remission.Conclusions: Although the sample size was small, we found different effects of the ECT treatment per se and of the antidepressant action induced by ECT in CSF and blood.

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.