Effects of pulse width and electrode placement on the efficacy and cognitive effects of electroconvulsive therapy

doi:10.1016/j.brs.2008.03.001

Brain Stimulation

Volume 1, Issue 2, April 2008, Pages 71-83

https://doi.org/10.1016/j.brs.2008.03.001 Get rights and content

Background

Although electroconvulsive therapy (ECT) in major depression is effective, cognitive effects limit its use. Reducing the width of the electrical pulse and by using the right unilateral electrode placement may decrease adverse cognitive effects, while preserving efficacy.

Methods

In a double-masked study, we randomly assigned 90 depressed patients to right unilateral ECT at 6 times seizure threshold or bilateral ECT at 2.5 times seizure threshold, using either a traditional brief pulse (1.5 milliseconds) or an ultrabrief pulse (0.3 millisecond). Depressive symptoms and cognition were assessed before, during, and immediately, 2, and 6 months after therapy. Patients who responded were monitored for a 1-year period.

Results

The final remission rate for ultrabrief bilateral ECT was 35%, compared with 73% for ultrabrief unilateral ECT, 65% for standard pulse width bilateral ECT, and 59% for standard pulse width unilateral ECT (all P < .05 after covariate adjustment). The ultrabrief right unilateral group had less severe cognitive side effects than the other three groups in virtually all primary outcome measures assessed in the acute postictal period, and during and immediately after therapy. Both the ultrabrief stimulus and right unilateral electrode placement produced less short- and long-term retrograde amnesia. Patients rated their memory deficits as less severe after ultrabrief right unilateral ECT compared with each of the other three conditions (P < .001).

Conclusions

The use of an ultrabrief stimulus markedly reduces adverse cognitive effects, and when coupled with markedly suprathreshold right unilateral ECT, also preserves efficacy. (ClinicalTrials.gov number, NCT00487500.)

Section snippets

General description

We conducted a prospective, randomized, double-masked trial contrasting four forms of ECT in 90 patients with major depression. All were inpatients at the New York State Psychiatric Institute, whose Institutional Review Board approved the study. An independent data and safety monitoring board monitored the safety of the study.

The first author (H.A.S.), who is also the senior scientist, designed the study in conjunction with the coauthors. Patient enrollment and data collection were supervised

Patient characteristics and treatment parameters

Demographic and clinical characteristics of the treatment groups were comparable (P > .05 for each comparison), except for a higher representation of psychotic depression in the ultrabrief pulse groups (Table 1). The doses of methohexital and succinylcholine and the measures of seizure duration were also comparable (Table 2). Replicating previous findings,5, 11, 19 initial seizure threshold was higher in the patients treated with BL compared with RUL ECT. However, pulse width exerted a larger

Discussion

This study demonstrated that the use of an ultrabrief pulse in ECT results in more efficient electrical stimulation than a traditional brief pulse. Further, ultrabrief pulse stimulation markedly reduces the acute, short-term, and long-term adverse cognitive effects of the treatment. This study confirmed that at high dosage relative to seizure threshold, RUL ECT administered with a traditional brief pulse does not differ in efficacy compared with a form of high-dosage bilateral ECT, but retains

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Cited by (411)

Memory disorders during electroconvulsive therapy
2024, Annales Medico-Psychologiques
L’électroconvulsivothérapie (ECT) est la plus ancienne technique encore utilisée en psychiatrie. Néanmoins, ses effets indésirables cognitifs sont fréquents, notamment les plaintes mnésiques. L’objectif principal de cette revue est de décrire la nature des troubles mnésiques liés à L’ECT, l’évolution à court et à long terme et les facteurs de risques associés puis de proposer des recommandations d’évaluation et de suivi appropriées.
Une revue systématique de la littérature a été réalisée au mois d’avril 2022, suivant la méthodologie PRISMA. Les équations de recherche ont été entrées dans PubMed et Cochrane en utilisant les termes suivants : « cognition » et « electroconvulsivetherapy » ou « amnesia » et « electroconvulsive therapy » ou « adverse effects » et « electroconvulsivetherapy ». La recherche a été réalisée de l’année 2000 à 2022.
Notre revue a permis d’inclure vingt articles dont quatre sur la nature et l’évolution des troubles mnésiques, trois sur les mécanismes, six sur les facteurs de risque, trois sur l’évaluation et les tests cognitifs et quatre sur la prise en charge. Les données ont montré une atteinte de la mémoire antérograde et rétrograde. Dans les jours qui suivent la séance, les capacités de se souvenir des événements survenus après l’ECT ainsi que des connaissances générales et autobiographiques sont altérées. Mais la plupart des fonctions cognitives s’améliorent au bout de quatre semaines. Certains patients néanmoins peuvent présenter des déficits de la mémoire autobiographique trois à six mois après l’ECT. La durée de la période confusionnelle est un facteur prédictif de la persistance des troubles de la mémoire. Les plaintes subjectives ne sont pas corrélées aux troubles mnésiques objectifs mais plutôt à la sévérité de la dépression. Ils durent plus longtemps que les troubles objectifs. L’atteinte est d’autant plus marquée que les événements sont proches de l’ECT. Nous avons trouvé, à la lumière des études incluses, l’absence d’origine lésionnelle, une altération du fonctionnement de l’hippocampe et un ralentissement cérébral. En effet, la présence d’ondes thêta à l’EEG dans les régions frontotemporales était associée à la durée de la confusion post-ictale et à une amnésie rétrograde. Il existe plusieurs facteurs associés à l’apparition des troubles mnésiques. Ces facteurs sont la nature et la charge du courant, le placement des électrodes, la fréquence des séances, le produit anesthésique, ainsi que des facteurs individuels tels que l’âge et le sexe. L’utilisation d’un courant ultrabref avec placement des électrodes en unilatéral droit réduit considérablement les effets cognitifs indésirables et préserve également l’efficacité. Différents tests cognitifs ont été utilisés en fonction du domaine cognitif à évaluer. Le test Mini-Mental State Examination (MMSE) était le test le plus utilisé pour une évaluation globale. Certaines études ont mis en place une batterie cognitive avec des délais d’évaluation allant d’un à six mois. Différentes molécules ont été essayées au cours de l’ECT, notamment les anticholinesthérasiques et le piracetam sans trouver de résultats concluants. Toutefois, les résultats des essais par la kétamine et la mémantine étaient encourageants.
L’électroconvulsivothérapie a montré son efficacité dans le traitement de plusieurs troubles psychiatriques. Il est primordial de faire un suivi cognitif en pré- et post-ECT pour détecter d’éventuels troubles mnésiques et assurer une meilleure prise en charge.
Electroconvulsive therapy (ECT) is the oldest technique still in use in psychiatry. Nevertheless, its adverse cognitive side effects are frequent, particularly complaints about memory. The main objective of this review is to describe the nature of ECT-related memory disorders, their short- and long-term evolution and associated risk factors, and to propose recommendations for appropriate evaluation and follow-up.
À systematic review of the literature was conducted in April 2022, using the PRISMA methodology. The English search equations gleaned from the literature published were entered into PubMed and Cochrane using the search queries: ‘cognition’ and ‘electroconvulsive therapy’ or ‘amnesia’ and ‘electroconvulsive therapy’ or ‘adverse effects’ and electroconvulsive therapy’. The search was carried out on literature published between 2000 to 2022.
Our review included 20 articles, including 4 articles on types of memory disorders, 3 articles on mechanisms, 6 articles on risk factors, 3 articles on cognitive testing and 4 articles on treatment. The data indicated impairment of both anterograde and retrograde memory. In the days following the session of ECT, the ability to recall events that occurred post-treatment, as well as general and autobiographical knowledge, was impaired. However, most cognitive functions improve within 4 weeks. Nevertheless, some patients, may show autobiographical memory deficits for from 3 to 6 months after ECT. The duration of the confusion is a predictive factor for the persistence of memory disorders. Subjective complaints are not correlated with objective memory disorders, but rather with the severity of depression. They last longer than objective disorders. The greater the proximity of the events to the ECT, the greater the impairment. In light of the studies included, we found altered hippocampal function and cerebral slowing. Indeed, the presence of EEG theta waves in frontotemporal regions was associated with the duration of post-ictal confusion and retrograde amnesia. There are several factors associated with the onset of memory disorders. These include the nature and charge of the electrical current, electrode placement, frequency of sessions, anaesthetic product administered, as well as individual factors such as age and gender. The use of ultra-short current with right unilateral electrode placement considerably reduces undesirable cognitive effects and preserves efficacy. Different cognitive tests were used, depending on the cognitive domain to be assessed. The Mini-Mental State Examination (MMSE) was the most widely used test for global assessment. Some studies used a cognitive array of tests with evaluation ranging from 1 to 6 months after treatment. Various molecules have been tried during ECT, notably anticholinesterase drugs and piracetam, with no conclusive results. However, the results of trials with ketamine and memantine were encouraging.
Electroconvulsive therapy has been shown to be effective in the treatment of several psychiatric disorders. It is essential, however, to carry out cognitive testing before and after ECT to detect possible memory disorders and to ensure better management.
The Role of Psychotherapy in the Management of Treatment-Resistant Depression
2023, Psychiatric Clinics of North America
Correlates of electroconvulsive therapy with neurocognitive functioning, subjective memory and depression
2022, Journal of Affective Disorders Reports
Citation Excerpt :
al. found that compared to sine wave technology, brief pulse technology correlated with relatively decreased subjective memory complaints over the course of ECT (Prudic et al., 2000). Further studies using ultrabrief pulse widths have shown less post-ictal impairment as well as fewer cognitive side effects over multiple domains, including global cognition, anterograde learning/recall, retrograde memory, delayed recall, and verbal fluency (Sackheim et al., 2008; Tor et al., 2015). Compared to bilateral placement of electrodes, unilateral placement has been associated with decreased post-ictal confusion and cognitive impairment immediately after treatments and may be associated with decreased anterograde amnesia at more distant time points (Lisanby et al., 2000; Prudic, 2008).
The study purpose was to evaluate the impact of a series of electroconvulsive therapy treatments (ECT) on depression and neurocognitive functioning. Secondary objectives were to evaluate the relationships among depression, neurocognitive functioning and subjective memory post-treatment.
Data from 44 participants was analyzed over the course of ECT. Montreal Cognitive Assessment (MoCA) scores were gathered pre-ECT, post-acute ECT, and 6-7 weeks subsequently. Montgomery-Asberg Depression Rating Scale (MADRS) data, Patient Health Questionnaire-9 (PHQ-9) data, and patient's subjective memory impairment ratings were gathered pre-ECT and post-acute ECT. Neither patients nor clinicians were blinded.
There was a significant decrease of 4.3 points over the acute series of ECT from the first to second MoCA with a p value of <0.001. There was a non-significant score increase of 0.26 after a period of recovery from the first to last MoCA. No significant relationship was found between patients’ perception of memory impairment and their cognitive score (as measured by MoCA) or their depression level (as measured by MADRS and PHQ-9). There was a significant decrease in clinician-rated depression as measured by MADRS over the course of ECT, with average decrease of 16.9 points (p <0.001). There was a significant decrease in self-rated depression as measured by PHQ-9 over the course of ECT, with an average decrease of 11.3 points (p <0.001). There was a significant decrease in the difficulty caused by these depressive symptoms as noted on the PHQ-9 at the last time point (p <0.001).
The primary limitation of this study was relatively small sample size.
Neurocognitive functioning, as measured by MoCA, decreased during the acute phase and then recovered to pre-ECT levels after a limited period of time. Patients’ subjective rating of memory impairment was not correlated with depression scores on MADRS or PHQ nor with the MoCA score. ECT treatment correlated with decreased self-rated depression (PHQ-9) and clinician-rated depression (MADRS). Decrease in self-reported difficulty associated with depressive symptoms decreased significantly over the course of ECT.
Blood cell ratios in mood and cognitive outcomes following electroconvulsive therapy
2022, Journal of Psychiatric Research
Systemic inflammation is commonly reported in depression, with dysregulation of both the innate and adaptive arms of the immune system documented. Obtaining ratios of neutrophils, platelets, and monocytes to counts of lymphocytes (NLR, PLR, MLR, respectively) represents a low-cost and easily reproducible measure of an individual's inflammatory burden that can be calculated effortlessly from routine clinical full white blood cell counts. Electroconvulsive therapy (ECT) remains the most effective acute antidepressant treatment for depression but is often limited by its cognitive side-effects. Here, we examined differences in blood cell ratios in subgroups of depressed patients (unipolar/bipolar, psychotic/non-psychotic, early-onset/late-onset) and ECT-related subgroups (responder/non-responder, remitter/non-remitter). We also explored the relationships between blood cell ratios and depression severity and immediate cognitive outcomes post-ECT. Our results show baseline NLR was raised in patients with psychotic depression. In the entire group of patients, significant negative correlations were noted between the PLR and SII and baseline HAM-D24 score, signifying that lower systemic inflammation is associated with more severe depressive symptoms. Significant positive correlations were noted between various blood cell ratios and mean time to recovery of orientation in the entire group of patients and in depression subgroups, indicating that increased peripheral inflammation is linked to worse cognitive outcomes post-ECT. Overall, our results suggest that assessment of blood cell ratios could be useful for predicting mood changes in patients at risk of developing depressive episodes or relapse following successful treatment or for identifying those at risk for cognitive side-effects following ECT.
Long-term Outcome Following Electroconvulsive Therapy for Late-Life Depression: Five-Year Follow-up Data From the MODECT Study
2022, American Journal of Geriatric Psychiatry
Electroconvulsive therapy (ECT) is the most effective treatment for late-life depression (LLD). Research addressing long-term outcome following an acute course of ECT for LLD is limited. We aimed to describe relapse, cognitive impairment and survival 5 years after a treatment with ECT for severe LLD, and assess the association of clinical characteristics with all three outcome measures.
This cohort study was part of the Mood Disorders in Elderly treated with ECT (MODECT) study, which included patients aged 55 years and older with major depressive disorder. Data regarding clinical course, cognitive impairment and mortality were collected 5 years after the index ECT course. We used multivariable Cox proportional hazards models and logistic regression models to assess the association of clinical characteristics with relapse and survival, and cognitive impairment, respectively.
We studied 110 patients with a mean age of 72.9 years. 67.1% of patients who showed response at the end of the index ECT course relapsed, and the included clinical characteristics were not significantly associated with the risk of relapse. 38.8% of patients with available data showed cognitive impairment at five-year follow-up. 27.5% were deceased; higher age and a higher number of previous psychiatric admissions were significantly associated with increased risk of mortality.
Five-year outcome after a course of ECT for severe LLD seems to be in line with long-term outcome following other acute treatments for severe LLD in terms of relapse, cognitive impairment and survival. Additional studies aimed at improving long-term outcome in severe LLD are warranted.
Cerebral oxygen saturation in the prefrontal cortex during electroconvulsive therapy and its relation with the postictal reorientation time
2022, Journal of Psychiatric Research
The therapeutic effect of Electroconvulsive Therapy (ECT) has been attributed to generalised seizure. Although patients are well oxygenated prior to and during treatment, critics have associated ECT with brain tissue hypoxemia. In this study, the regional oxygen saturation (rSO₂) was measured continuously during ECT in the prefrontal cortex (PFC) of both hemispheres using 2-channel Near Infrared Spectroscopy (NIRS). Additionally, the postictal reorientation time (PRT) was determined and related to the rSO₂ course. We evaluated 72 ECT treatments in 22 adult patients who were treated for a therapy-resistant depressive syndrome. The therapy was performed according to our standard clinical procedures deploying right unilateral (RUL) and left anterior versus right temporal (LART) electrode placements. According to our results, the rSO₂ courses showed an increase during hyperventilation, a sharp drop immediately after the stimulus, and a long recovery period with values far exceeding the baseline. In 55,6% of treatments the rSO₂ course stayed above the baseline. In the others, the drop fell below it for an average of 12.6 s. According to a cardio surgical standard no signs of hypoxemia occurred during ECT treatments. The rSO₂ drop at seizure onset was the only parameter of the oxygen course related to the PRT in the multivariate analysis and might therefore be a characteristic feature of the seizure. It could reflect its physiological intensity and thereby be involved in the mechanism of action of ECT. NIRS seems to be an interesting non-invasive tool for monitoring and studying ECT.

View all citing articles on Scopus

: This study was supported in part by grants R01 MH35636 and R01 MH47739 from the National Institute of Mental Health.

: Dr. Sackeim serves as an unpaid consultant to the MECTA Corporation, which donated the electroconvulsive therapy devices used in this study.

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Original researchEffects of pulse width and electrode placement on the efficacy and cognitive effects of electroconvulsive therapy

Background

Methods

Results

Conclusions

Section snippets

General description

Patient characteristics and treatment parameters

Discussion

Brain Res

Neuropsychologia

J Verbal Learn Verbal Behav

Neuropsychologia

The practice of ECT: recommendations for treatment, training and privileging

The cognitive effects of electroconvulsive therapy

Memory functions as affected by electroconvulsive therapy

Ann NY Acad Sci

Autobiographical memory and mood: effects of electroconvulsive therapy

Neuropsychology

A prospective, randomized, double-blind comparison of bilateral and right unilateral electroconvulsive therapy at different stimulus intensities

Arch Gen Psychiatry

The cognitive effects of electroconvulsive therapy in community settings

Neuropsychopharmacology

Effects of stimulus parameters on cognitive side effects

Ann NY Acad Sci

Optimal stimulus duration for extracranial cortical stimulation

Neurosurgery

ECT and memory: brief pulse versus sine wave

Am J Psychiatry

Effects of stimulus intensity and electrode placement on the efficacy and cognitive effects of electroconvulsive therapy

N Engl J Med

Effects of electrode placement on the efficacy of titrated, low-dose ECT

Am J Psychiatry

Titrated moderately suprathreshold vs fixed high-dose right unilateral electroconvulsive therapy: acute antidepressant and cognitive effects

Arch Gen Psychiatry

Fixed high-dose electroconvulsive therapy in the elderly with depression: a double-blind, randomized comparison of efficacy and tolerability between unilateral and bilateral electrode placement

J ECT

Research diagnostic criteria: rationale and reliability

Arch Gen Psychiatry

Structured clinical interview for axis I DSM-IV disorders—patient dition (with psychotic ccreen) (SCID-I/P)

Development of a rating scale for primary depressive illness

Br J Soc Clin Psychol

Original research
Effects of pulse width and electrode placement on the efficacy and cognitive effects of electroconvulsive therapy