Electroconvulsive Therapy: A Model for Seizure Detection by a Wavelet Packet Algorithm

Electroconvulsive therapy (ECT) is the most effective treatment for severe depression and is often the last resort in patients with medically treatment-resistant depression.1 The clinical effect of ECT relies upon the quality of the seizures elicited.2 In a patient not responding to ECT due to poor seizure quality, eliciting an adequate seizure may be the initial challenge. Anesthesia influences seizure quality.3 Etomidate is an ultrashort-acting, non-barbiturate hypnotic intravenous anesthetic agent with minimal cardiovascular effects, making it suitable for ECT. Etomidate lacks the strong anticonvulsant properties of standard ECT anesthetics (i.e., thiopental and propofol4) and leads to higher-quality and longer seizures.5 However, etomidate inhibits 11β-hydroxylase and steroid biosynthesis, including corticosteroids.6 A major concern is the potential for adrenocortical suppression in rapid-sequence induction of anesthesia in critically ill patients. We present a patient who had null seizures at the maximal stimulus dosage until a change in anesthesia to etomidate, and review the literature on the effect of anesthesia on ECT seizure quality. A 61-year-old man with recurrent major depressive disorder was hospitalized due to moderate depression with suicidal ideation (17-item Hamilton Depression Rating Scale [HAM-D] score = 21). Several treatment regimens with combinations of antidepressants failed, and he consented to ECT. ECT was administered thrice weekly (Table 1). The initial three ECT sessions with rising stimulation doses to the maximal 1021 mC with 3.5-mg/kg thiopental as standard anesthesia completely failed to elicit a seizure. Even 0.5-mg alfentanil augmentation and 50 mg chlorprothixene the evening before ECT to lower the seizure threshold had no effect. Anesthesia was changed to 0.2 mg/kg etomidate and elicited high-quality seizures of >60 s with clinical effect (HAM-D score = 16 after seven seizures), which allowed a down-titration of stimulus, potentially reducing the associated cognitive side-effects of ECT. The patient received 11 high-quality and clinically effective ECT treatments as an inpatient. He was discharged shortly after with fewer depressive symptoms (HAM-D score = 9) and was followed up in outpatient care with once-weekly maintenance ECT. The morning before his 25th maintenance ECT, his serum cortisol was 179 nM and the following morning 212 nM, which is higher than the minimum expected morning plasma cortisol concentration of 133 nM. Similarly, 24-h measurement of total urine cortisol production after the 25th ECT was 101 nmol (reference interval 10–124 nmol), indicating no adrenal suppression. At one of the ECT sessions, after etomidate administration, he had limb contractions before a muscle relaxant was administered. The contractions were confused with a seizure and lasted for ~30 s before termination with 5 mg diazepam and ECT was aborted. Follow-up MRI, electroencephalography (EEG), and neurological assessment concluded that the contractions were myoclonus due to late injection of the muscle relaxant. The patient received 26 successful ECT treatments with etomidate and gave written consent to publishing this case report. We present how etomidate enabled high-quality seizures in a patient unresponsive to ECT during standard thiopental anesthesia. Although >35 treatments using etomidate were given, the patient showed no signs of corticoadrenal suppression in terms of lower circulating levels of cortisol. This is in line with evidence that, although three ECT sessions weekly constitutes repeated use of etomidate in a relatively short time interval, serum levels of cortisol and adrenocorticotropin do not reach abnormally low levels during or after a sequence of ECT with etomidate in this patient population.7 Myoclonus is a very common side-effect during induction with etomidate and can be misinterpreted as a seizure. Unlike thiopental and propofol, which have strong anticonvulsant properties; etomidate has a disinhibitory effect on extrapyramidal motor activity responsible for the majority of myoclonus observed. A more specific and potent etomidate analogue was abandoned during phase II studies due to involuntary muscle movements.8 While involuntary muscle movements are undesirable in a non-ECT setting, they may be desirable for ECT as the cortical disinhibitory effect may be what enables etomidate to provide higher-quality seizures. Etomidate leads to higher-quality seizures and longer motor seizures in ECT.5, 9 In the most recent review of anesthesia for ECT, etomidate and ketamine yielded the longest seizures.3 The same review found that etomidate and a 1:1 (racemic)-ketamine and propofol mixture yielded the highest-quality seizures. The only comparison between etomidate and s-ketamine suggests that s-ketamine showed no difference in seizure duration but may provide higher-quality seizures based on higher postictal suppression, EEG coherence, ictal amplitude, and peak heart rate.10 Given the limited study size and adverse side-effects of s-ketamine (i.e., dissociative symptoms, vomiting, and hypertension), etomidate appears favorable. Our case highlights the impact of anesthesia on seizure generation during ECT, and how etomidate, largely abandoned in intensive care settings, may be considered the anesthetic of choice when patients fail to achieve high-quality seizures and clinical effect during ECT. All authors declare that they have no financial interests or any other conflict of interest with other people or organizations that could inappropriately influence this work.

Epilepsy, characterized by unpredictable seizures caused by abnormal brain activity, presents significant diagnostic challenges due to the complexity of interpreting electroencephalogram (EEG) signals. Current EEG analysis methods rely heavily on manual annotations by neurophysiologists, limiting scalability and efficient utilization of vast clinical datasets. In this study, we propose a self-supervised learning (SSL) model for seizure detection and localization, designed to reduce dependence on labeled data while maintaining high performance. The pretext task of signal transformation recognition enables the model to learn generalized spatiotemporal features from EEG data, effectively leveraging unlabeled recordings. This is followed by fine-tuning with a limited set of labeled data for precise seizure detection. Our model integrates an attention mechanism that enhances interpretability by focusing on the most relevant EEG electrodes, improving both detection accuracy and seizure localization. The proposed solution demonstrates competitive performance on the CHB-MIT dataset, achieving a sensitivity of 93.1% and an AUC of 91% with only 30% labeled data, and consistent localization accuracy of 83.33%. Extensive experiments across multiple datasets and under various configurations validate the robustness and generalizability of the proposed approach. This work not only introduces a data-efficient and interpretable solution for EEG-based seizure detection but also sets the stage for future research on applying SSL to broader neurological disorders, opening new avenues for trustworthy and optimal medical diagnostics.

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.

Background: Depression is a disorder of concern that affects globally and has become the second leading cause of disability-adjusted life years. The disorder is characterized by persistent sad mood, loss of interest in previous pleasurable activities, reduced energy level, suicidal thoughts, and cognitive disturbances. Electroconvulsive therapy (ECT) is a rapid and effective treatment for severe depression. However, there was stigma toward the application of modified ECT (MECT), the major among them is diminished cognitive particularly memory disturbance. Studies claim that memory disturbances are transient and short-lived. Hence, the current study’s aim is to assess the cognitive status of severe depression patients before and after ECT. Materials and Methods: It is a hospital-based longitudinal analytical study conducted in the psychiatry inpatient department. Ninety-two patients fulfilling the criteria for depression as per DSM-5 were taken into the study after inclusion and exclusion criteria and informed consent. The symptoms of depression are assessed using the Hamilton Depression Rating Scale (HAM-D) and cognitive functions are assessed with Addenbrooke’s Cognitive Examination Scale - Revised (ACE-R). The scale is administered before ECT, post-ECT on day 3, 1 month, and 3 months, respectively. Results: The mean age was 34 years. The majority belonged to the age group of 20–30 years (50%) and were educated up to high school (35%). Before ECT, the mean ACE-R score was 79.39. On day 3 after ECT, the mean score was 78.97. One month after ECT, the mean score was 82.82. Three months after ECT, the mean score was 85.15. The ACE-R scores started to increase at 1 month and at 3 months after ECT, which was statistically significant ( P < 0.05). Before ECT, the mean HAM-D score was 24.41. On day 3 after ECT, the mean HAM-D score was 14.84. One month after ECT, the mean HAM D score was 9.06. Three months after ECT, the mean HAM-D score was 4.43. The decline in HAM-D score from baseline to 3 months after ECT (24.41–4.43) was statistically significant ( P < 0.05). Conclusion: The cognitive impairments due to MECT occur only in the immediate phase following MECT. The impairments are transient and short-lived and improvement in cognition occurs over time.

ELECTROCONVULSIVE THERAPY (ECT) IS ONE OF THE most controversial treatments in all of medicine. There are a number of reasons for this. The discovery in the 1930s that inducing a series of generalized seizures, initially with chemicals, later with electric current, could cause the recovery of patients with severe and previously untreatable mental disorders produced a wave of enthusiasm that eventually led to a period of indiscriminate use and misuse in the middle decades of the 20th century. This period of abuse created, perhaps deservedly at that time, a bad reputation for an effective treatment modality. That reputation was enhanced by the immediate adverse effects of bitten tongues and even fractured bones and teeth caused by the induction of generalized seizures, and the painful effects of electroshocks administered without anesthesia when they did not successfully induce a seizure with loss of consciousness. The 1975 movie One Flew Over the Cuckoo’s Nest contributed to an erroneous view of ECT as a punitive, painful, and assaultive procedure used by authorities to control inconvenient creativity. That view has been associated with attempts to regulate, or even eliminate, the use of ECT through legislation in a number of jurisdictions, and public fears and distrust about the use of ECT have persisted. The best response to such concerns on the part of physicians is to be aware of the facts about current use of ECT, including its efficacy and possible adverse effects, so they can respond to questions from patients, families, and the public. The indications, possible adverse effects, and current recommendations for treatment procedures have been summarized in a task force report just published by the American Psychiatric Association Committee on Electroconvulsive Therapy. An effective and safe treatment for severe major depression, ECT has had response rates reported in the range of 80% to 90% as a first-line treatment, and in the range of 50% to 60% for patients who have not responded to 1 or more trials of treatment with antidepressant drugs. Electroconvulsive therapy may also be seriously considered as treatment for patients with acute mania, and for patients with schizophrenia who have not responded to adequate trials of antipsychotic medications. As currently practiced, ECT involves the use of informed consent, ultra-brief general anesthesia and muscle relaxants (thus attenuating motor seizure activity) with appropriate airway management, and use of ECT devices to provide adequate ictal responses. Most patients in the United States receive 3 treatments per week, and a course of ECT for major depression generally consists of 6 to 12 treatments, with the course ended or tapered as soon as maximum response has been reached. This usually occurs more quickly than the 4 to 6 weeks required for an adequate trial of an antidepressant drug. There continues to be some controversy about the use of right unilateral or bilateral electrode placement, with right unilateral ECT causing less cognitive adverse effects, but bilateral ECT often viewed as being more effective. A recent randomized controlled trial showed that right unilateral ECT at high dosage was as effective as bilateral ECT in many patients and caused less impairment on several measures of anterograde and retrograde memory. The issue of cognitive adverse effects from ECT is central to its reputation for harm and requires careful consideration to separate facts from myths. Studies of this issue have been reviewed and summarized by the American Psychiatric Association Committee on Electroconvulsive Therapy. Patients experience a variable but usually brief period of disorientation (postictal confusion) immediately after seizure induction. Electroconvulsive therapy also typically results in retrograde amnesia, greatest immediately after the course of treatment and for events that occurred temporally close to the treatment. The extent of the retrograde amnesia usually decreases substantially with time, but many patients have persistent loss of memory for some events that occurred in the interval starting several months before and extending to several weeks after their ECT course. Anterograde amnesia, characterized by rapid forgetting of learned information, also may occur during and immediately following ECT but resolves within a few weeks. Importantly, there is no objective evidence that ECT has any long-term effect on the capacity to learn and retain new information. Assessment of cognitive effects from ECT is complicated by the cognitive impairments associated with the mental disorders being treated. For example, patients with severe depression may have substantial impairments in cognitive function, and patients with schizophrenia or other psychotic

In this paper, a novel method for stator interturn short circuit fault diagnosis in induction motors using the wavelet packet analysis is presented. Wavelet packet analysis is the extension of wavelet analysis and decompose signal into the equal bandwidth, it can achieve better decomposition result than wavelet analysis does. In the operating induction motor, electromagnetic torque is sensitive to the asymmetry due to the fault. Research indicate that the interturn short circuit fault will give rise to the sidebands at some given harmonic components of the electromagnetic torque signal and some certain frequency components change evidently, the distribution of the energy in the certain frequency bands alter as well. In the proposed method, electromagnetic torque signal is analyzed via wavelet packet decomposition and the wavelet packet coefficients are extracted. Based on each coefficient's energy eigenvalue, an eigenvector is set up. The presence of the short circuit fault makes the eigenvector change by a special rule, and the fluctuation of the load or supply unbalance make it change in another way, so it is immune to the variety of load and supply. Experimental results demonstrate the validity and effectiveness of this method.

Fault degradation assessment of water hydraulic motor by impulse vibration signal with Wavelet Packet Analysis and Kolmogorov–Smirnov Test

The efficacy of electroconvulsive therapy in treating depressive symptoms has been established by means of innumerable studies developed along the last decades. Electroconvulsive therapy is the most effective biological treatment for depression currently available. The objective of this study was to demonstrate the role of electroconvulsive therapy in the treatment of depression and highlight present aspects related to its practice. We reviewed in the literature studies on efficacy, symptom remission, predictive response factors as well as current aspects regarding quality of life, the patients' perception, mechanism of action, technique and cognitive impairment. The main results found in the this revision were: 1) electroconvulsive therapy is more effective than any antidepressant medication; 2) the remission of depression with electroconvulsive therapy varies, in general, from 50 to 80%; 3) The effect of electroconvulsive therapy in brain-derived neurotrophic factor levels is still controversial; 4) electroconvulsive therapy has a positive effect in the improvement of quality of life; 5) patients submitted to electroconvulsive therapy have, in general, a positive perception about the treatment. Electroconvulsive therapy remains a highly efficacious treatment in treatment-resistant depression. With the improvement of its technique, electroconvulsive therapy has become an even safer and more useful procedure both for the acute phase and for the prevention of new depressive episodes.

Electroconvulsive therapy (ECT) is the most effective treatment of major depression, but autobiographical memory lossmay limit its use. Despite previous attempts to synthesise the literature, the nature of autobiographical memory loss after ECT is still debated. To provide an overview of the effect of ECT on autobiographical memory in patients with depression and explore whether the effect is temporary or permanent. Furthermore, we wanted to analyse if ECT parameters or clinical information are associated with this effect. PubMed, EMBASE, PsycINFO and Web of Science databases were searched on 26 January 2024. We included longitudinal studies measuring autobiographical memory before and after ECT in patients with depression compared to patients with depression receiving other treatment or healthy controls. Synthesis approach was a meta-analysis. PROSPERO ID: CRD42021267901. Nine studies were included (432 patients, 173 controls). At post-ECT, we found that ECT patients had larger autobiographical memory loss than controls (standardised mean difference (SMD) = 0.55; 95% CI = 0.35-0.75). Right unilateral (RUL) ECT entailed a small effect on autobiographical memory (SMD = 0.32; 95% CI = 0.06-0.57), while bilateral ECT yielded a large effect (SMD = 0.82; 95% CI = 0.49-1.15). Higher age was associated with smaller effect. Autobiographical memory was stable at long-term follow-up. The studies suggest that ECT causes autobiographical memory loss in patients with depression. Results also suggest that lost memories are not regained. Furthermore, results support that RUL ECT is less detrimental to autobiographical memory. Strangely, a higher age might mitigate the autobiographical memory loss. Our findings are limited by studies being mainly observational and generally consisting of small sample sizes. Future studies should prioritise long-term follow-up assessments of autobiographical memory.

The train safety guarantees the passenger travel. It is important to detect the train faults timely. This study proposes the audio analysis technology to detect the fault of train. Use the audio equipment to obtain the train audio, so as to analyze and deal with the train audio, obtain the train audio characteristic value, and finally use the eigenvalue to analyze the train audio fault analysis, effectively find out the audio fault. The wavelet packet algorithm and ART-2 Neural Network algorithm are applicated in the train fault detection. First, the wavelet packet analysis is used in the train audio analysis feature extraction, which is commonly used in modern signal analysis process. Then, the ART-2 Neural Network is used to identify the different states to judge the train fault effectively through simulation. Through the experiment found that the use of algorithms can accurately find out the audio failure. The wavelet packet analysis algorithm is not only good for low frequency signal analysis, but also can be used for high frequency signal analysis, can fully understand the characteristics of audio signals. Feature extraction refers to the state signal and equipment failure related to the information extracted.

Optic nerve head in Alzheimer's disease patients

Cortisol levels rise sharply immediately after electroconvulsive therapy (ECT); the resultant stimulation of steroid receptors in the hippocampus may be beneficial or harmful to cognition, depending on the magnitude of the stimulation. Steroid mechanisms may therefore modulate ECT-induced amnesia. Using mifepristone (a glucocorticoid receptor antagonist) as a chemical probe, we sought to examine steroid mechanisms in an animal model of ECT-induced retrograde amnesia. Adult, male Wistar rats (n = 68) trained in a step-through passive-avoidance task were randomized to receive mifepristone (20 or 40 mg kg(-1) day(-1)) or vehicle (control). These treatments were administered 1 day before the electroconvulsive shock (ECS) course and, again, 1 h before each of five once-daily true (30 mC) or sham ECS. Recall of pre-ECS learning was tested 1 day after the last ECS. Relative to sham ECS, true ECS resulted in significant retrograde amnesia in the vehicle group but not in either of the mifepristone groups. In sham ECS-treated animals, mifepristone did not significantly influence recall. In ECS-treated rats, the higher but not the lower dose of mifepristone was associated with significant protection against the retrograde amnesia evident in the vehicle group. Mifepristone administered before the ECT seizure may attenuate ECT-induced retrograde amnesia. This suggests that glucocorticoid mechanisms may contribute to ECT-induced retrograde amnesia.

Comparing the effects of ECT and intravenous ketamine in psychiatric patients with major depressive episodes.

Electroconvulsive therapy is an effective treatment for severe and medication-resistant depression. There have been no reports describing how a volatile anaesthetic affects haemodynamic responses, seizure duration, and recovery characteristics during electroconvulsive therapy. We carried out a repeated-measure crossover study to compare the effects on haemodynamic responses, seizure duration, and recovery characteristics of the following types of anaesthesia in electroconvulsive therapy: propofol alone, sevoflurane alone, and propofol combined with sevoflurane. We recruited 50 patients requiring electroconvulsive therapy for depression. For anaesthesia induction, 1.5 mg/kg propofol (condition P), 5% sevoflurane in oxygen following a vital capacity rapid inhalation induction (condition S), or 1.5 mg/kg propofol followed by 5% sevoflurane in oxygen (condition PS) was administered. Succinylcholine 1.5 mg/kg was then given. Electrical stimulation was administered after fasciculation. Measurements were obtained before anaesthesia induction (baseline), prior to succinylcholine administration, prior to electroconvulsive therapy, and at the peak after electroconvulsive therapy. After electroconvulsive therapy, peak heart rate and peak mean arterial pressure were highest in condition S. Whereas recovery time was longest in condition PS, motor seizure duration was significantly shorter than in either condition P or S. Electroencephalographic seizure duration was significantly shorter in condition PS than in condition P and significantly shorter in condition S than in condition P. Sevoflurane anaesthesia alone is most disadvantageous in terms of haemodynamics. Propofol-sevoflurane anaesthesia is advantageous in terms of haemodynamics, but disadvantageous in terms of seizure duration and recovery time. Propofol alone is most advantageous in terms of seizure duration.

This paper presents a scintillation detector fault diagnosis method based on wavelet packet analysis and multi-classification support vector machine(multi-SVM) . In the proposed method, a wavelet packet algorithm is used to analyze waveform characteristics of output signals caused by different faults of detectors, then characteristic vectors can be extracted. The multi-SVM is employed to establish a fault recognition model and fault types can be concluded. Performances of the proposed method are validated by experimental data obtained from the plastic scintillation detector for the single fault diagnosis and hybrid fault diagnosis. The experimental results show that faults can be diagnosed automatically and quickly by analyzing signal waveform features.