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

Magnetic seizure therapy and electroconvulsive therapy increase aperiodic activity

Major depressive disorder (MDD) is a leading cause of disability worldwide. One of the most efficacious treatments for treatment-resistant MDD is electroconvulsive therapy (ECT). Recently, magnetic seizure therapy (MST) was developed as an alternative to ECT due to its more favorable side effect profile. While these approaches have been very successful clinically, the neural mechanisms underlying their therapeutic effects are unknown. For example, clinical "slowing" of the electroencephalogram beginning in the postictal state and extending days to weeks post-treatment has been observed in both treatment modalities. However, a recent longitudinal study of a small cohort of ECT patients revealed that, rather than delta oscillations, clinical slowing was better explained by increases in aperiodic activity, an emerging EEG signal linked to neural inhibition. Here we investigate the role of aperiodic activity in a cohort of patients who received ECT and a cohort of patients who received MST treatment. We find that aperiodic neural activity increases significantly in patients receiving either ECT or MST. Although not directly related to clinical efficacy in this dataset, increased aperiodic activity is linked to greater amounts of neural inhibition, which is suggestive of a potential shared neural mechanism of action across ECT and MST.

Magnetic seizure therapy and electroconvulsive therapy increase aperiodic activity

Major depressive disorder (MDD) is a leading cause of disability worldwide. One of the most efficacious treatments for treatment-resistant MDD is electroconvulsive therapy (ECT). Recently, magnetic seizure therapy (MST) was developed as an alternative to ECT due to its more favorable side effect profile. While these approaches have been very successful clinically, the neural mechanisms underlying their therapeutic effects are unknown. For example, clinical "slowing" of the electroencephalogram beginning in the postictal state and extending days to weeks post-treatment has been observed in both treatment modalities. However, a recent longitudinal study of a small cohort of ECT patients revealed that, rather than delta oscillations, clinical slowing was better explained by increases in aperiodic activity, an emerging EEG signal linked to neural inhibition. Here we investigate the role of aperiodic activity in a cohort of patients who received ECT and a cohort of patients who received MST treatment. We find that aperiodic neural activity increases significantly in patients receiving either ECT or MST. Although not directly related to clinical efficacy in this dataset, increased aperiodic activity is linked to greater amounts of neural inhibition, which is suggestive of a potential shared neural mechanism of action across ECT and MST.

Comparison of Efficacy and Safety of Magnetic Seizure Therapy and Electroconvulsive Therapy for Depression: A Systematic Review

Objectives: As a new physical therapeutic technique, magnetic seizure therapy (MST) has established efficacy in the treatment of depression with few cognitive side effects, and thus appears to be a potential alternative to electroconvulsive therapy (ECT). The findings of randomized controlled trials (RCTs) examining the efficacy and safety of MST versus ECT for depression are inconsistent. This systematic review of RCTs was designed with the aim of assessing the safety and efficacy of MST versus ECT for patients with depression. Methods: The WanFang, Chinese Journal Net (CNKI), EMBASE, PubMed, Cochrane Library, and PsycINFO databases were systematically searched by three independent investigators, from their inceptions to July 24, 2021. Results: In total, four RCTs (n = 86) were included and analyzed. Meta-analyses of study-defined response (risk ratio (RR) = 1.36; 95% CI = 0.78 to 2.36; p = 0.28; I2 = 0%), study-defined remission (RR = 1.17; 95% CI = 0.61 to 2.23; p = 0.64; I2 = 0%), and the improvement in depressive symptoms (standardized mean difference (SMD) = 0.21; 95% CI = −0.29 to 0.71; p = 0.42; I2 = 0%) did not present significant differences between MST and ECT. Three RCTs evaluated the cognitive effects of MST compared with ECT using different cognitive measuring tools, but with mixed findings. Only two RCTs reported adverse drug reactions (ADRs), but these lacked specific data. Only one RCT reported discontinuation due to any reason. Conclusions: This preliminary study suggests that MST appears to have a similar antidepressant effect as ECT for depression, but mixed findings on adverse cognitive effects were reported.

Automated Epileptic Seizure Detection in Pediatric Subjects of CHB-MIT EEG Database-A Survey

Epilepsy is a neurological disorder of the brain that causes frequent occurrence of seizures. Electroencephalography (EEG) is a tool that assists neurologists in detecting epileptic seizures caused by an unexpected flow of electrical activities in the brain. Automated detection of an epileptic seizure is a crucial task in diagnosing epilepsy which overcomes the drawback of a visual diagnosis. The dataset analyzed in this article, collected from Children's Hospital Boston (CHB) and the Massachusetts Institute of Technology (MIT), contains long-term EEG records from 24 pediatric patients. This review paper focuses on various patient-dependent and patient-independent personalized medicine approaches involved in the computer-aided diagnosis of epileptic seizures in pediatric subjects by analyzing EEG signals, thus summarizing the existing body of knowledge and opening up an enormous research area for biomedical engineers. This review paper focuses on the features of four domains, such as time, frequency, time-frequency, and nonlinear features, extracted from the EEG records, which were fed into several classifiers to classify between seizure and non-seizure EEG signals. Performance metrics such as classification accuracy, sensitivity, and specificity were examined, and challenges in automatic seizure detection using the CHB-MIT database were addressed.

Resting-state electroencephalographic functional network alterations in major depressive disorder following magnetic seizure therapy

Magnetic seizure therapy (MST) is emerging as a safe and well-tolerated experimental intervention for major depressive disorder (MDD), with very minimal cognitive side-effects. However, the underlying mechanism of action of MST remains uncertain. Here, we used resting-state electroencephalography (RS-EEG) to characterise the physiological effects of MST for treatment resistant MDD. We recorded RS-EEG in 21 patients before and after an open label trial of MST applied over the prefrontal cortex using a bilateral twin coil. RS-EEG was analysed for changes in functional connectivity, network topology, and spectral power. We also ran further baseline comparisons between the MDD patients and a cohort of healthy controls (n = 22). Network-based connectivity analysis revealed a functional subnetwork of significantly increased theta connectivity spanning frontal and parieto-occipital channels following MST. The change in theta connectivity was further found to predict clinical response to treatment. An additional widespread subnetwork of reduced beta connectivity was also elucidated. Graph-based topological analyses showed an increase in functional network segregation and reduction in integration in the theta band, with a decline in segregation in the beta band. Finally, delta and theta power were significantly elevated following treatment, while gamma power declined. No baseline differences between MDD patients and healthy subjects were observed. These results highlight widespread changes in resting-state brain dynamics following a course of MST in MDD patients, with changes in theta connectivity providing a potential physiological marker of treatment response. Future prospective studies are required to confirm these initial findings.

Adjunctive Magnetic Seizure Therapy for Schizophrenia: A Systematic Review

Objective: The efficacy and safety of adjunctive magnetic seizure therapy (MST) for patients with schizophrenia are unclear. This systematic review was conducted to examine the efficacy and safety of adjunctive MST for schizophrenia. Methods: Chinese (WanFang and Chinese Journal Net) and English (PubMed, EMBASE, PsycINFO, and the Cochrane Library) databases were systematically searched. Results: Two open-label self-controlled studies (n = 16) were included and analyzed in this review. In these studies, the Positive and Negative Syndrome Scale (PANSS) total scores and Brief Psychiatric Rating Scale (BPRS) total scores significantly decreased from baseline to post-MST (all Ps < 0.05), without serious adverse neurocognitive effects. Mixed findings on the neurocognitive effects of adjunctive MST for schizophrenia were reported in the two studies. A discontinuation rate of treatment of up to 50% (4/8) was reported in both studies. The rate of adverse drug reactions (ADRs) was evaluated in only one study, where the most common ADRs were found to be dizziness (25%, 2/8) and subjective memory loss (12.5%, 1/8). Conclusion: There is inconsistent evidence for MST-related adverse neurocognitive effects and preliminary evidence for the alleviation of psychotic symptoms in schizophrenia.

Shorter recovery times and better cognitive function-A comparative pilot study of magnetic seizure therapy and electroconvulsive therapy in patients with depressive episodes

INTRODUCTION

Magnetic seizure therapy (MST) is a new convulsive therapy that is as effective as traditional electroconvulsive therapy (ECT) in treating depression but with fewer cognitive side effects. The aim of this study was to compare the efficacy and cognitive effects between MST (100 Hz applied over the vertex) and bifrontal ECT for treating patients with depressive episodes.

METHODS

Forty-five patients with depressive episodes were enrolled, with 18 receiving MST and 27 receiving ECT. MST was administered over the vertex with 100 Hz frequency. Treatment consisted of six sessions. The 17-item Hamilton Rating Scale for Depression (HAMD-17) was used to assess the severity of depression. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was used to assess cognition. Assessments were performed at baseline and after the third and sixth treatment sessions.

RESULTS

Both MST and ECT improved the patients' depressive symptoms significantly, yet no significant difference was found between the two groups (p > .05). The response rates and remission rates of MST and ECT were 72.2% versus 81.5% and 61.1% versus 63.0%, respectively. The MST group showed significant improvements in immediate memory (p < .001), delayed memory (p = .002), and attention (p < .001) than ECT. The recovery times for consciousness (p < .001), spontaneous breathing (p < .001), and orientation (p < .001) were shorter in MST group than ECT group. RBANS improvements were negatively correlated with the recovery time for orientation (r = .561, p < .001).

CONCLUSION

Magnetic seizure therapy showed similar efficacy to bifrontal ECT for treating depressive episodes. While MST may be an effective alternative to ECT, larger randomized trials are needed.

Magnetic Seizure Therapy for Suicidality in Treatment-Resistant Depression

Importance

There is an unmet need for effective treatments for suicidality in mental disorders. Magnetic seizure therapy (MST) has been investigated as an alternative to electroconvulsive therapy, a known effective treatment for suicidality, in the management of treatment-resistant major depressive disorder, with promising findings. Yet, there are very limited data on the association of MST with suicidality directly. It is important to explore the potential of MST as a viable treatment alternative to electroconvulsive therapy for suicidality.

Objective

To determine the association of MST with suicidality in patients with treatment-resistant major depressive disorder.

Design, Setting, and Participants

This nonrandomized controlled trial took place at a single tertiary care psychiatric facility in Canada. It followed an open-label study design with consecutive treatment cohorts. Consecutive groupings of 67 patients with treatment-resistant major depressive disorder and with baseline suicidality present were treated for up to 24 treatments. The study was run from February 2012 through June 2019. Patients were followed up for 6 months at the end of the treatment period. This post hoc secondary analysis of the trial was performed from January to November 2019.

Interventions

MST was delivered at 100% stimulator output over the prefrontal cortex with low (25 Hz), moderate (50 or 60 Hz), or high (100 Hz) frequency, for a maximum of 24 sessions.

Main Outcomes and Measures

Remission from suicidality was measured as an end point score of 0 on the Beck Scale for Suicidal Ideation. A linear mixed model was used to assess the trajectory of Beck Scale for Suicidal Ideation scores.

Results

A total of 67 patients (mean [SD] age, 46.3 [13.6] years; 40 women [60.0%]) received a mean (SD) of 19.5 (5.1) MST treatments. The overall number of patients achieving remission was 32 (47.8%). Sixteen patients (55.2%) receiving low-frequency MST achieved remission, as well as 12 patients (54.5%) in the moderate-frequency group, and 4 patients (25.0%) in the high-frequency group. The linear mixed model revealed an association of time with Beck Scale for Suicidal Ideation scores (F8,293.95 = 5.73; P < .001).

Conclusions and Relevance

These findings suggest that MST may be an effective treatment for suicidality, and sensitivity analysis shows this may be particularly so at low and moderate frequencies. Future studies should directly compare MST with electroconvulsive therapy for treating suicidality and should evaluate MST as a treatment for suicidality across mental disorders.

Trial Registration

ClinicalTrials.gov Identifier: NCT01596608.

Magnetic seizure therapy (MST) for major depressive disorder

Electroconvulsive therapy (ECT) is effective for major depressive disorder (MDD) but its effects on memory limit its widespread use. Magnetic seizure therapy (MST) is a potential alternative to ECT that may not adversely affect memory. In the current trial, consecutive patients with MDD consented to receive MST applied over the prefrontal cortex according to an open-label protocol. Depressive symptoms and cognition were assessed prior to, during and at the end of treatment. Patients were treated two to three times per week with high-frequency MST (i.e., 100 Hz) (N = 24), medium frequency MST (i.e., 60 or 50 Hz) (N = 26), or low-frequency MST (i.e., 25 Hz MST) (N = 36) using 100% stimulator output. One hundred and forty patients were screened; 86 patients with MDD received a minimum of eight treatments and were deemed to have an adequate course of MST; and 47 completed the trial per protocol, either achieving remission (i.e., 24-item Hamilton Rating Scale for Depression score <10 and a relative reduction of >60% at two consecutive assessments; n = 17) or received a maximum of 24 sessions (n = 30). High-frequency (100 Hz) MST produced the highest remission rate (33.3%). Performance on most cognitive measures remained stable, with the exception of significantly worsened recall consistency of autobiographical information and significantly improved brief visuospatial memory task performance. Under open conditions, MST led to clinically meaningful reduction in depressive symptoms in patients with MDD and produced minimal cognitive impairment. Future studies should compare MST and ECT under double-blind randomized condition.

Magnetic Seizure Therapy: Towards Personalized Seizure Therapy for Major Depression

Magnetic seizure therapy (MST) is a noninvasive neuromodulation therapy under investigation for the treatment of severe neuropsychiatric disorders. MST involves inducing a therapeutic seizure under anesthesia in a setting similar to electroconvulsive therapy (ECT). To date, randomized controlled trials suggest that MST has similar antidepressant efficacy as ECT, but without significant cognitive adverse effects. Large scale clinical trials are currently underway to confirm these preliminary findings. So far, there has only been one study evaluating the clinical predictors of response to MST and more research is needed. This study found that patients with fewer episodes of depression and a positive family history of depression had a better response to MST. Overall, the ability of MST to focus the delivery of the electric field and the resultant seizure makes targeting seizure therapy to specific brain regions possible, and further research will be helpful in identifying personalized targets to maximize clinical benefit. In this review, we describe MST methodology and how it could be individualized to each patient. We also summarize the clinical and cognitive effects of MST and provide indications of which patients may be most likely to benefit. Finally, we summarize the studied neurophysiological predictors of response.

A Critical Review and Synthesis of Clinical and Neurocognitive Effects of Noninvasive Neuromodulation Antidepressant Therapies

There is a plethora of current and emerging antidepressant therapies in the psychiatric armamentarium for the treatment of major depressive disorder. Noninvasive neuromodulation therapies are one such therapeutic category; they typically involve the transcranial application of electrical or magnetic stimulation to modulate cortical and subcortical brain activity. Although electroconvulsive therapy (ECT) has been used since the 1930s, with the prevalence of major depressive disorder and treatment-resistant depression (TRD), the past three decades have seen a proliferation of noninvasive neuromodulation antidepressant therapeutic development. The purpose of this critical review was to synthesize information regarding the clinical effects, neurocognitive effects, and possible mechanisms of action of noninvasive neuromodulation therapies, including ECT, transcranial magnetic stimulation, magnetic seizure therapy, and transcranial direct current stimulation. Considerable research has provided substantial information regarding their antidepressant and neurocognitive effects, but their mechanisms of action remain unknown. Although the four therapies vary in how they modulate neurocircuitry and their resultant antidepressant and neurocognitive effects, they are nonetheless useful for patients with acute and chronic major depressive disorder and TRD. Continued research is warranted to inform dosimetry, algorithm for administration, and integration among the noninvasive neuromodulation therapies and with other antidepressant strategies to continue to maximize their safety and antidepressant benefit.