Computational models of Bitemporal, Bifrontal and Right Unilateral ECT predict differential stimulation of brain regions associated with efficacy and cognitive side effects

2017 ◽  
Vol 41 (1) ◽  
pp. 21-29 ◽  
Author(s):  
S. Bai ◽  
V. Gálvez ◽  
S. Dokos ◽  
D. Martin ◽  
M. Bikson ◽  
...  
Keyword(s):  
Side Effects ◽  
Computational Models ◽  
Computational Modelling ◽  
Human Head ◽  
Distribution Patterns ◽  
Brain Regions ◽  
Electrode Placement ◽  
Direct Stimulation ◽  
Cognitive Side Effects ◽  
Stimulation Of

AbstractBackgroundExtensive clinical research has shown that the efficacy and cognitive outcomes of electroconvulsive therapy (ECT) are determined, in part, by the type of electrode placement used. Bitemporal ECT (BT, stimulating electrodes placed bilaterally in the frontotemporal region) is the form of ECT with relatively potent clinical and cognitive side effects. However, the reasons for this are poorly understood.ObjectiveThis study used computational modelling to examine regional differences in brain excitation between BT, Bifrontal (BF) and Right Unilateral (RUL) ECT, currently the most clinically-used ECT placements. Specifically, by comparing similarities and differences in current distribution patterns between BT ECT and the other two placements, the study aimed to create an explanatory model of critical brain sites that mediate antidepressant efficacy and sites associated with cognitive, particularly memory, adverse effects.MethodsHigh resolution finite element human head models were generated from MRI scans of three subjects. The models were used to compare differences in activation between the three ECT placements, using subtraction maps.Results and conclusionIn this exploratory study on three realistic head models, Bitemporal ECT resulted in greater direct stimulation of deep midline structures and also left temporal and inferior frontal regions. Interpreted in light of existing knowledge on depressive pathophysiology and cognitive neuroanatomy, it is suggested that the former sites are related to efficacy and the latter to cognitive deficits. We hereby propose an approach using binarised subtraction models that can be used to optimise, and even individualise, ECT therapies.

scholarly journals Computational comparison of conventional and novel electroconvulsive therapy electrode placements for the treatment of depression

2019 ◽  
Vol 60 ◽  
pp. 71-78 ◽  
Author(s):  
Siwei Bai ◽  
Donel Martin ◽  
Tianruo Guo ◽  
Socrates Dokos ◽  
Colleen Loo
Keyword(s):  
Electroconvulsive Therapy ◽  
Regional Differences ◽  
Computational Modelling ◽  
Human Head ◽  
Brain Regions ◽  
Electrical Stimulus ◽  
Electrode Placement ◽  
Treatment Of Depression ◽  
Mri Scans ◽  
Average Electric Field

AbstractBackground:Electroconvulsive therapy (ECT) is a highly effective treatment for severe psychiatric disorders. Despite its high efficacy, the use of ECT would be greater if the risk of cognitive side effects were reduced. Over the last 20 years, developments in ECT technique, including improvements in the dosing methodology and modification of the stimulus waveform, have allowed for improved treatment methods with reduced adverse cognitive effects. There is increasing evidence that the electrode placement is important for orienting the electrical stimulus and therefore modifying treatment outcomes, with potential for further improvement of the placements currently used in ECT.Objective:We used computational modelling to perform an in-depth examination into regional differences in brain excitation by the ECT stimulus for several lesser known and novel electrode placements, in order to investigate the potential for an electrode placement that may optimise clinical outcomes.Methods:High resolution finite element human head models were generated from MRI scans of three subjects. The models were used to compare regional differences in average electric field (EF) magnitude among a total of thirteen bipolar ECT electrode placements, i.e. three conventional placements as well as ten lesser known and novel placements.Results and conclusion:In this exploratory study on a systemic comparison of thirteen ECT electrode placements, the EF magnitude at regions of interest (ROIs) was highly dependent upon the position of both electrodes, especially the ROIs close to the cortical surface. Compared to conventional right-unilateral (RUL) ECT using a temporo-parietal placement, fronto-parietal and supraorbito-parietal RUL also robustly stimulated brain regions considered important for efficacy, while sparing regions related to cognitive functions, and may be a preferrable approach to the currently used placement for RUL ECT. The simulations also found that regional average EF magnitude varied between individual subjects, due to factors such as head size, and results also depended on the size of the defined ROI.

scholarly journals Alfentanil anesthetic augmentation lengthens seizure duration in electroconvulsive therapy with older people

2016 ◽  
Vol 28 (6) ◽  
pp. 1051-1052
Author(s):  
Craig D'Cunha ◽  
Christos Plakiotis ◽  
Daniel W. O'Connor
Keyword(s):  
Side Effects ◽  
Older People ◽  
Electroconvulsive Therapy ◽  
Electrode Placement ◽  
Seizure Threshold ◽  
Dose Titration ◽  
Seizure Duration ◽  
New Learning ◽  
Prescription Rates ◽  
Cognitive Side Effects

Electroconvulsive therapy (ECT) prescription rates rise with age, making it important that treatments be made as effective and safe as possible (Plakiotis et al., 2012). Older people are vulnerable to post-treatment confusion and to subsequent deficits in attention, new learning, and autobiographical memory (Gardner and O'Connor, 2008). Strategies to minimize cognitive side-effects include unilateral electrode placement and stimulus dose titration whereby electrical charge is individually calibrated to seizure threshold (Sackeim et al., 2000). It remains the case, however, that threshold levels typically rise over the treatment course, leading to an increase both in delivered charge and the risk of adverse sequelae.

Electroconvulsive therapy: Brief versus ultrabrief pulse right unilateral electroconvulsive therapy

2016 ◽  
Vol 33 (S1) ◽  
pp. S618-S618
Author(s):  
M.R. Raposo ◽  
M.L. Medina ◽  
A.L. González ◽  
I. Martínez ◽  
A. Gil ◽  
...  
Keyword(s):  
Side Effects ◽  
Electroconvulsive Therapy ◽  
Meta Analysis ◽  
Electrode Placement ◽  
Current Evidence ◽  
List Type ◽  
Treatment Of Depression ◽  
The Subject ◽  
Competing Interest ◽  
Cognitive Side Effects

IntroductionElectroconvulsive therapy (ECT) is an effective depression treatment, but it has potential cognitive side effects. Bitemporal ECT has been traditionally used, but in recent decades, right unilateral (RUL) electrode placement has been proposed to decrease the cognitive side effects of ECT. Ultrabrief pulse (UBP) right unilateral (RUL) ECT is an increasingly used treatment option that can potentially combine efficacy with lesser cognitive side effects.ObjectivesTo evaluate whether ultrabrief pulse (UBP) right unilateral (RUL) electroconvulsive therapy (ECT) is as effective as brief pulse (BP) RUL ECT in addition to cause lesser cognitive side effects.Material and methodsA search is performed in the available scientific literature on systematic review and meta-analysis of the subject under study, through the database PubMed.Results– Current evidence supports the efficacy of right unilateral (RUL) electroconvulsive therapy (ECT) given with an ultrabrief pulse width in the treatment of depression;– ultrabrief pulse RUL ECT leads to lesser cognitive side effects than traditional forms of ECT;– ultrabrief pulse RUL ECT may be slightly less effective than traditional forms of ECT.ConclusionsBP compared with UBP RUL ECT was slightly more efficacious in treating depression and required fewer treatment sessions, but led to greater cognitive side effects. The decision of whether to use BP or UBP RUL ECT should be made on an individual patient basis and should be based on a careful weighing of the relative priorities of efficacy versus minimization of cognitive impairment.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Bitemporal v. high-dose right unilateral electroconvulsive therapy for depression: a systematic review and meta-analysis of randomized controlled trials

2016 ◽  
Vol 47 (3) ◽  
pp. 518-530 ◽  
Author(s):  
E. Kolshus ◽  
A. Jelovac ◽  
D. M. McLoughlin
Keyword(s):  
Side Effects ◽  
Electroconvulsive Therapy ◽  
Verbal Memory ◽  
Randomized Trials ◽  
Electrode Placement ◽  
Seizure Threshold ◽  
Cochrane Library ◽  
High Dose ◽  
Moderate Dose ◽  
Cognitive Side Effects

BackgroundBrief-pulse electroconvulsive therapy (ECT) is the most acutely effective treatment for severe depression though concerns persist about cognitive side-effects. While bitemporal electrode placement is the most commonly used form worldwide, right unilateral ECT causes less cognitive side-effects though historically it has been deemed less effective. Several randomized trials have now compared high-dose (>5× seizure threshold) unilateral ECT with moderate-dose (1.0–2.5× seizure threshold) bitemporal ECT to investigate if it is as effective as bitemporal ECT but still has less cognitive side-effects. We aimed to systematically review these trials and meta-analyse clinical and cognitive outcomes where appropriate.MethodWe searched PubMed, PsycINFO, Web of Science, Cochrane Library and EMBASE for randomized trials comparing these forms of ECT using the terms ‘electroconvulsive’ OR ‘electroshock’ AND ‘trial’.ResultsSeven trials (n = 792) met inclusion criteria. Bitemporal ECT did not differ from high-dose unilateral ECT on depression rating change scores [Hedges's g = −0.03, 95% confidence interval (CI) −0.17 to 0.11], remission (RR 1.06, 95% CI 0.93–1.20), or relapse at 12 months (RR 1.42, 95% CI 0.90–2.23). There was an advantage for unilateral ECT on reorientation time after individual ECT sessions (mean difference in minutes = −8.28, 95% CI −12.86 to −3.70) and retrograde autobiographical memory (Hedges's g = −0.46, 95% CI −0.87 to −0.04) after completing an ECT course. There were no differences for general cognition, category fluency and delayed visual and verbal memory.ConclusionsHigh-dose unilateral ECT does not differ from moderate-dose bitemporal ECT in antidepressant efficacy but has some cognitive advantages.

Technical Aspects of Electroconvulsive Therapy: An Update

2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
P. Sienaert
Keyword(s):  
Side Effects ◽  
Electroconvulsive Therapy ◽  
Pulse Width ◽  
Additional Treatment ◽  
Electrode Placement ◽  
Treatment Conditions ◽  
Antidepressant Efficacy ◽  
Remission Criteria ◽  
Standard Pulse ◽  
Cognitive Side Effects

In an ongoing attempt to improve efficacy of electroconvulsive therapy (ECT) while minimizing side-effects, both different electrode placements and stimulus parameters have been studied. It has been shown that the traditional bitemporal electrode placement and modern techniques such as bifrontal and unilateral ECT are efficacious, depending on the stimulus used. Modern ECT-devices deliver a square wave brief pulse stimulus. An unresolved issue in the use of brief pulse stimulation concerns the optimal pulse width. It has been suggested that the use of a stimulus with an ultra brief (UB) pulse width, i.e. 0.3 ms, is substantially more efficient in seizure induction, thus needing less energy, and producing less cognitive side-effects than standard pulse width (i.e. 0.5-2 ms) stimulation. There has been a concern, however, of lower antidepressant efficacy of UB ECT, with patients needing additional treatment sessions. Moreover, it has been suggested that the diminished antidepressive efficacy is encountered solely with the combination of an ultra-brief pulse width and bilateral electrode placement, as compared to unilateral UB ECT or standard pulse ECT. In a randomized trial, the antidepressive efficacy and cognitive side-effects of bifrontal and right unilateral UB ECT were compared. It was shown that, using an ultra-brief pulse width, BF ECT is as efficacious as UL ECT, although patients receiving UL ECT achieved response/remission-criteria after a smaller number of treatments. In both treatment conditions there was an improvement of cognitive function, both during and after the treatment course.

Right Unilateral Electroconvulsive Therapy at Six Times Seizure Threshold

2003 ◽  
Vol 37 (6) ◽  
pp. 715-719 ◽  
Author(s):  
John D. Little ◽  
Jo Munday ◽  
Gordon Lyall ◽  
Dennis Greene ◽  
Graeme Chubb ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Side Effects ◽  
Motor Activity ◽  
Electroconvulsive Therapy ◽  
Retrospective Review ◽  
Electrode Placement ◽  
Seizure Threshold ◽  
Eeg Activity ◽  
Cognitive Side Effects ◽  
Suppression Index

Objective: To examine the clinical practice of right unilateral electroconvulsive therapy (ECT) administered at six times seizure threshold (6 × RUL ECT). Method: A retrospective review of all patients who received 6 × RUL ECT between July 2000 and June 2002. Results: Twenty-one patients across a range of ages and diagnostic groups received D'Elia unilateral ECT at a seizure dosage at or above 388.8 milliCoumbs (mC). In order to sustain predetermined criteria for seizure adequacy, energy was increased in 71% of patients. Final seizure lengths of 45 s electroencephalographic (EEG) activity, 28 s motor activity (cuffed) and a post-ictal suppression index (PSI) of 83% were recorded. Eighty percent of patients responded after a mean of 7.0 treatments. Cognitive side-effects were noted in 21% of patients. Fifty-two percent relapsed on average 6.3 months after the last treatment despite continuation pharmacotherapy. Conclusions: 6 × RUL ECT was found to be clinically effective, associated with cognitive side-effects and relapse. The debate over electrode placement is likely to continue.

scholarly journals Causal Mapping of Emotion Networks in the Human Brain: Framework and Preliminary Findings

2017 ◽  
Author(s):  
Julien Dubois ◽  
Hiroyuki Oya ◽  
J. Michael Tyszka ◽  
Matthew Howard ◽  
Frederick Eberhardt ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Graphical Models ◽  
Brain Connectivity ◽  
Causal Structure ◽  
Brain Regions ◽  
Causal Discovery ◽  
Fmri Data ◽  
Direct Stimulation ◽  
Neurosurgical Patients ◽  
Stimulation Of

AbstractEmotions involve many cortical and subcortical regions, prominently including the amygdala. It remains unknown how these multiple network components interact, and it remains unknown how they cause the behavioral, autonomic, and experiential effects of emotions. Here we describe a framework for combining a novel technique, concurrent electrical stimulation with fMRI (es-fMRI), together with a novel analysis, inferring causal structure from fMRI data (causal discovery). We outline a research program for investigating human emotion with these new tools, and provide initial findings from two large resting-state datasets as well as case studies in neurosurgical patients with electrical stimulation of the amygdala. The overarching goal is to use causal discovery methods on fMRI data to infer causal graphical models of how brain regions interact, and then to further constrain these models with direct stimulation of specific brain regions and concurrent fMRI. We conclude by discussing limitations and future extensions. The approach could yield anatomical hypotheses about brain connectivity, motivate rational strategies for treating mood disorders with deep brain stimulation, and could be extended to animal studies that use combined optogenetic fMRI.

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