Effects of electroconvulsive therapy upon brain electrical activity

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.

Cognitive rehabilitation: assessment and treatment of persistent memory impairments following ECT

Few tests address the types of memory problem commonly reported after electroconvulsive therapy (ECT). Here, we focus on the importance of neuropsychological assessment in ECT-treated patients and describe a number of tasks that may be useful in measuring the everyday memory problems of such patients with ongoing memory difficulties. At the time of writing, no attempts have been made to rehabilitate patients who experience persistent adverse cognitive effects, but clinicians should be aware of the potential beneficial role of cognitive rehabilitation in the treatment and management of these effects.

Cognitive and Neurophysiological Recovery Following Electroconvulsive Therapy: A Study Protocol

Electroconvulsive therapy (ECT) employs the elective induction of generalizes seizures as a potent treatment for severe psychiatric illness. As such, ECT provides an opportunity to rigorously study the recovery of consciousness, reconstitution of cognition, and electroencephalographic (EEG) activity following seizures. Fifteen patients with major depressive disorder refractory to pharmacologic therapy will be enrolled (Clinicaltrials.gov, NCT02761330). Adequate seizure duration will be confirmed following right unilateral ECT under etomidate anesthesia. Patients will then undergo randomization for the order in which they will receive three sequential treatments: etomidate + ECT, ketamine + ECT, and ketamine + sham ECT. Sessions will be repeated in the same sequence for a total of six treatments. Before each session, sensorimotor speed, working memory, and executive function will be assessed through a standardized cognitive test battery. After each treatment, the return of purposeful responsiveness to verbal command will be determined. At this point, serial cognitive assessments will begin using the same standardized test battery. The presence of delirium and changes in depression severity will also be ascertained. Sixty-four channel EEG will be acquired throughout baseline, ictal, and postictal epochs. Mixed-effects models will correlate the trajectories of cognitive recovery, clinical outcomes, and EEG metrics over time. This innovative research design will answer whether: (1) time to return of responsiveness will be prolonged with ketamine + ECT compared with ketamine + sham ECT; (2) time of restoration to baseline function in each cognitive domain will take longer after ketamine + ECT than after ketamine + sham ECT; (3) postictal delirium is associated with delayed restoration of baseline function in all cognitive domains; and (4) the sequence of reconstitution of cognitive domains following the three treatments in this study is similar to that occurring after an isoflurane general anesthetic (NCT01911195). Sub-studies will assess the relationships of cognitive recovery to the EEG preceding, concurrent, and following individual ECT sessions. Overall, this study will lead the development of biomarkers for tailoring the cogno-affective recovery of patients undergoing ECT.

Electroconvulsive therapy stimulus parameters: rethinking dosage

In this article, we review the parameters that define the electroconvulsive therapy (ECT) electrical stimulus and discuss their biophysical roles. We also present the summary metrics of charge and energy that are conventionally used to describe the dose of ECT and the rules commonly deployed to individualize the dose for each patient. We then highlight the limitations of these summary metrics and dosing rules in that they do not adequately capture the roles of the distinct stimulus parameters. Specifically, there is strong theoretical and empirical evidence that stimulus parameters (pulse amplitude, shape, and width, and train frequency, directionality, polarity, and duration) exert unique neurobiological effects that are important for understanding ECT outcomes. Consideration of the distinct stimulus parameters, in conjunction with electrode placement, is central to further optimization of ECT dosing paradigms to improve the risk-benefit ratio. Indeed, manipulation of specific parameters, such as reduction of pulse width and increase in number of pulses, has already resulted in dramatic reduction of adverse effects, while maintaining efficacy. Furthermore, the manipulation of other parameters, such as current amplitude, which are commonly held at fixed, high values, might be productively examined as additional means of targeting and individualizing the stimulus, potentially reducing adverse effects. We recommend that ECT dose be defined using all stimulus parameters rather than a summary metric. All stimulus parameters should be noted in treatment records and published reports. To enable research on optimization of dosing paradigms, we suggest that ECT devices provide capabilities to adjust and display all stimulus parameters.

Neurobiological correlates of the cognitive side effects of electroconvulsive therapy

Although electroconvulsive therapy (ECT) is a highly effective form of treatment, its use is limited by the emergence of cognitive side effects, notably anterograde and retrograde amnesia. Despite a large literature on the neurobiology of therapeutic mechanisms of ECT, very little is known about the neurobiological underpinnings of its cognitive effects. On theoretical grounds, structures within the medial temporal lobes, especially the hippocampus, are predicted to be critical regions mediating anterograde and, possibly, retrograde amnesia. However, functional neuroimaging studies in normal volunteers have demonstrated that frontal cortical regions are also involved in human memory processes. This review will highlight some of the biochemical, electrophysiological, and neuroimaging correlates of the amnestic side effects of ECT. In terms of electrophysiological and functional imaging studies, there are data that implicate both medial temporal and frontal regions as being associated with cognitive dysfunction. Interestingly, such data also appear to indicate a dissociation of the neural systems critical to the efficacy and adverse cognitive effects of ECT.

[Adverse cognitive effects and ECT]

Electroconvulsive therapy (ECT) is a rapidly acting and highly effective treatment for severe and life threatening conditions seen in affective and schizophrenic diseases. Notwithstanding its therapeutic benefits, ECT remains controversial because of seizure induction, cognitive side effects, memory dysfunction and effects on cerebral physiology. These factors have raised the concern that ECT produces structural and functional brain damages. This issue continues to have a major impact on the acceptance of ECT as a therapeutic modality, both within the medical community and in public opinion. A close look at incidence, type, severity, neurofunctional and -anatomical correlates, aetiology and therapeutic approaches of the adverse cognitive effects attributed to ECT may contribute to rational and objective handling of this topic. The final chapter deals with the issue of whether ECT causes brain damage.

The sham ECT literature: implications for consent to ECT

The author reviewed the placebo-controlled literature on electroconvulsive therapy (ECT) for depression. No study demonstrated a significant difference between real and placebo (sham) ECT at 1 month posttreatment. Many studies failed to find a difference between real and sham ECT even during the period of treatment. Claims in textbooks and review articles that ECT is effective are not consistent with the published data. A large, properly designed study of real versus sham ECT should be undertaken. In the absence of such a study, consent forms for ECT should include statements that there is no controlled evidence demonstrating any benefit from ECT at 1 month posttreatment. Consent forms should also state that real ECT is only marginally more effective than placebo.

A retrospective controlled study into memory complaints reported by depressed patients after treatment with electroconvulsive therapy and pharmacotherapy or pharmacotherapy only

Few studies have been conducted comparing complaints of memory problems using objective and subjective memory scales in depressed patients who received electroconvulsive therapy (ECT) + pharmacotherapy or treatment with pharmacotherapy only. Patients who suffer from depression according to the Diagnostic and Statistical Manual of Mental Disorder (Fourth Edition) criteria and who were admitted within the past 5 years before this study in a general psychiatric hospital were screened for inclusion. Objective retrograde amnesia was assessed using the Autobiographical Memory Interview and the Amsterdam Media Questionnaire (AMQ). Subjective retrograde amnesia was assessed using the Squire Subjective Memory Questionnaire and the ECT Retrograde Amnesia and Perception Scale (ERAPS), a newly developed scale. Twenty of the 84 patients who received ECT + pharmacotherapy and 30 of the 196 patients who received pharmacotherapy only participated in the study. Patients' ERAPS memory scores were compared with proxies' ERAPS memory scores of the patients to assess the reliability of memory complaints. The ECT + pharmacotherapy group was found to suffer more from memory problems using the AMQ 1990 test. There was also a difference for the proxy's ERAPS memory score, reflecting the conviction of proxies from the ECT + pharmacotherapy patients that these patients suffer more memory problems due to the illness, treatment with pharmacotherapy, or ECT. The differences could not be explained by the influence of determinants for retrograde amnesia. ECT + pharmacotherapy patients did not attribute their memory problems mainly to ECT but put equal "blame" on the depressive illness, treatment with pharmacotherapy, and ECT. The analyses suggest that the AMQ 1990s test is (more) sensitive in registering retrograde amnesia than the other scales used in the study.

Interictal slow-wave focus in left medial temporal lobe during bilateral electroconvulsive therapy

The interictal state between two electroconvulsive therapy (ECT) sessions is clinically characterised by possible cognitive adverse effects like mild amnestic syndrome. ECT-induced amnestic deficits can persist for several weeks after ECT. Electrophysiologically, slowing of brain electrical activity in the interictal state has often been reported. Especially, for bilateral ECT a correlation between enhanced left frontotemporal theta activity and retrograde amnesia has been demonstrated. This study focuses on the topographic distribution of cortical slow-wave oscillations during the interictal state of a bilateral ECT cycle. Twelve patients with major depression have been investigated with 32-channel resting EEG 24 h after the 6th ECT session. As controls, 8 major depressive patients were investigated prior to antidepressive treatment. The generating sources of slow-wave activity are estimated within the theta frequency band with low-resolution brain electromagnetic tomography. Source analysis revealed a distinct pattern of theta activity in the depth of the left temporal lobe (fusiform and parahippocampal gyri, Brodmann areas 37 and 36, respectively; p< 0.05) during the interictal state. This finding suggests a dysfunction of the left medial temporal lobe memory system during the interictal state of a bilateral ECT cycle. It will further be discussed whether it is possible to obtain information about activity of deep brain structures like the hippocampal formation from scalp-recorded signals.

Propofol reduces cognitive impairment after electroconvulsive therapy

BACKGROUND

Cognitive impairments are the main complication after electroconvulsive therapy (ECT). Modification of treatment parameters has been shown to affect the magnitude of these impairments, but the role of anesthetic type remains unclear. This study tested whether there is a difference in cognitive impairments immediately after ECT with propofol compared to thiopental anesthesia.

METHODS

This randomized, double-blind, crossover study included 15 patients receiving right unilateral ECT for depression. Patients received propofol or thiopental on alternating ECTs up to 6 treatments. Immediate and delayed verbal memory, motor speed, reaction speed, visuospatial, and executive functions were assessed 45 minutes after each ECT. Differences were assessed with repeated measures analysis of variance.

RESULTS

Cognitive impairments were reduced after ECT with propofol compared to thiopental. Time to emergence was quicker and EEG seizure duration was shorter after propofol treatments. There was no significant correlation between seizure duration and neuropsychological test performance.

CONCLUSIONS

Our results indicate that cognitive impairments in the early recovery period after ECT are reduced with propofol compared to thiopental anesthesia. We suggest that, in addition to ECT parameters, the type of anesthetic agent should be considered to reduce cognitive impairments after ECT.

Putative common pathways in therapeutic brain stimulation for affective disorders

Brain stimulation methods in the treatment of affective disorder are electroconvulsive therapy (ECT), transcranial magnetic stimulation (TMS), vagus nerve stimulation (VNS), and deep brain stimulation (DBS). Clinically, ECT is considered the strongest remedy in the treatment of severe depression, especially depression with psychotic features, and in the elderly. TMS, despite positive reports, is somewhat more controversial. VNS has, so far, only been used in treatment-resistant depression with limited results. DBS may be of potential use in rare cases of treatment-resistant cases of affective disorder. This article highlights the similarities and differences between the four stimulation methods. The main difference is the seizures necessary in ECT. A stronger involvement of the hippocampus following experimental seizures compared with effects in that region induced by TMS and VNS might explain the consistent findings of the superiority of ECT in the most severe cases of affective disorder.

Cortisol levels predict cognitive impairment induced by electroconvulsive therapy

BACKGROUND

Elevated glucocorticoids may increase the vulnerability of the brain to the adverse effects of repeated seizures. This study tested the hypothesis that higher ambient cortisol levels would predict increased cognitive impairment in depressed patients subsequent to receiving electroconvulsive therapy (ECT) for major depression.

METHODS

Sixteen subjects provided three samples of saliva the day before receiving unilateral nondominant ECT. Measures of mood, global cognitive functioning, attention, executive function, verbal and visuospatial memory, and visuospatial processing speed were obtained 1 day before the first ECT and 1 day after the sixth ECT treatment. The relationship between basal salivary cortisol obtained before the first ECT treatment and the change score of each cognitive measure after the sixth ECT treatment was examined and tested with Pearson correlation coefficients.

RESULTS

Electroconvulsive therapy treatments delivered over 2 weeks resulted in a significant improvement in mood and a decline in most measures of cognitive performance. Elevated basal cortisol was associated with a greater decline in performance of executive function, visuospatial processing speed, and verbal memory.

CONCLUSIONS

Although this study is limited by the small number of subjects and the high number of comparisons, all significant correlations were consistent with the hypothesis that elevated cortisol predicts a greater degree of ECT-induced cognitive impairment.

EEG effects of ECT: implications for rTMS

Electroconvulsive therapy (ECT) involves the use of electrical stimulation to elicit a series of generalized tonic-clonic seizures for therapeutic purposes and is the most effective treatment known for major depression. These treatments have significant neurophysiologic effects, many of which are manifest in the electroencephalogram (EEG). The relationship between EEG data and the response to ECT has been studied since the 1940s, but for many years no consistent correlates were found. Recent studies indicate that a number of specific EEG features recorded during the induced seizures (ictal EEG) as well as before and after a course of treatment (interictal EEG) are related to both the therapeutic efficacy and cognitive side effects. Similar to ECT, repetitive transcranial magnetic stimulation (rTMS), which involves focal electromagnetic stimulation of cortical neurons, has also been studied as an antidepressant therapy and also appears to have neurophysiologic effects, although these have not been as fully investigated as is the case with ECT. Given the similarity of these treatments, it is natural to consider whether advances in understanding the electrophysiologic correlates of the ECT response might have implications for rTMS. The present article reviews the literature on the EEG effects of ECT and discusses the implications in terms of the likely efficacy and side effects associated with rTMS in specific anatomic locations, the potential for producing an antidepressant response with rTMS without eliciting seizure activity, eliciting focal seizures with rTMS, and the possibility of using rTMS to focally modulate seizure induction and spread with ECT to optimize treatment.

Prediction of the utility of a switch from unilateral to bilateral ECT in the elderly using treatment 2 ictal EEG indices

BACKGROUND

The choice of whether to administer nondominant unilateral (UL) or bilateral (BL) ECT remains controversial.

METHODS

A study in which moderately suprathreshold UL nonresponders at treatment 6 were randomized to UL or BL ECT offered the opportunity to explore whether ictal EEG indices at treatment 2 might predict response to UL ECT, and also which UL ECT nonresponders are likely to respond to BL ECT.

RESULTS

We found that less postictal suppression in response to the second UL ECT stimulus was predictive of a poorer subsequent therapeutic response to UL ECT, but of a better therapeutic response if switched to BL ECT. A multivariate ictal EEG model was developed that had a significant capacity to differentiate those who will respond to UL ECT versus those who will not respond to UL ECT, but who will be therapeutic responders when switched to BL ECT.

CONCLUSIONS

This study raises the possibility that ictal EEG indices at treatment 2 may identify situations when UL ECT is physiologically and therapeutically inadequate, and when BL ECT is likely to be more effective. The determination of whether such predictive physiologic models are of clinical utility for the prediction of outcome awaits further study.

Quantitative EEG during seizures induced by electroconvulsive therapy: relations to treatment modality and clinical features. I. Global analyses

This study examined the effects of electroconvulsive therapy (ECT) treatment conditions, patient individual difference factors, and clinical outcome on global electroencephalogram (EEG) power during and immediately following ECT-induced seizures. Sixty-two patients were randomized to ECT conditions differing in electrode placement (right unilateral versus bilateral) and stimulus dosage (just above seizure threshold versus 2.5 times seizure threshold). At the second and penultimate treatments, global total power (1.5-28.5 Hz) and global power in specific frequency bands were quantified in 19-lead EEG recordings of the generalized seizure and the immediate postictal period. Seizures induced with high dosage, and to lesser extent, with bilateral electrode placement, resulted in greater global power. Patient age, initial seizure threshold, and baseline depression severity were inversely related to global power during seizures. While superior clinical outcome following ECT was associated with greater global power during seizures, this effect was small. The factors associated with more robust seizure expression also resulted in greater postictal bioelectric suppression. Associations with treatment parameters and patient variables were stronger at the second than penultimate treatment. We conclude that manipulations of ECT technique strongly determine the magnitude of seizure expression, but relations with clinical outcome are weak. The findings raise doubt about the clinical utility of algorithms based on analysis of EEG features to guide ECT parameter selection.

Quantitative EEG during seizures induced by electroconvulsive therapy: relations to treatment modality and clinical features. II. Topographic analyses

This study tested three alternative theories of the mechanisms of therapeutic action of electroconvulsive therapy (ECT). The theories differed in predictions about the global and topographic effects of effective and ineffective forms of ECT on electroencephalogram (EEG) seizure expression. At the second treatment, 19-lead EEG recordings were obtained in 57 depressed patients randomized to conditions that differed in ECT electrode placement and stimulus dosage. Power in the delta frequency band was quantified during the seizure and analyzed with traditional multivariate methods and the Scaled Subprofile Model. Electrical dosage of the ECT stimulus had a powerful effect on ictal global delta power and, more so, than electrode placement. Greater ictal global delta power was associated with superior therapeutic outcome, but the magnitude of this effect was small. Effective forms of ECT resulted in a topography where delta power was accentuated in prefrontal EEG sites. High dosage right unilateral ECT also resulted in stronger asymmetry in prefrontal regions than the ineffective, low dosage right unilateral ECT. Greater bilateral generalization of seizure expression does not appear to be a prerequisite for therapeutic effects. Instead, more intense seizure expression in prefrontal regions may be critical for efficacy.

Electroconvulsive therapy and memory loss: a personal journey

The cause for the significant gap between research and anecdotal evidence regarding the extent of some memory loss after electroconvulsive therapy (ECT) has never been adequately explained. A patient's development of awareness and self-education about her severe side effects from ECT raises questions regarding many current assumptions about memory loss. ECT-specific studies, which conclude that side effects are short term and narrow in scope, have serious limitations, including the fact that they do not take into account broader scientific knowledge about memory function. Because of the potential for devastating and permanent memory loss with ECT, informed consent needs significant enhancement until advancing research on both improved techniques and on better predictive knowledge regarding memory loss progresses to making a greater impact on clinical applications. Follow-up care and education in coping skills need to be a regular part of ECT practice when patients do experience severe effects.

Electrophysiological correlates of the adverse cognitive effects of electroconvulsive therapy

Resting state, eyes closed, 19-lead EEG recordings were obtained at pre-ECT baseline and just prior to penultimate treatment and during the week following the ECT course in 59 patients with major depression. Patients had been randomized to ECT conditions that varied in electrode placement and stimulus intensity. The EEG data were submitted to power spectral analysis, and global and topographic effects were characterized for the delta and theta frequency bands. Relations between the EEG changes and scores on three cognitive measures were examined. The period of disorientation immediately following RUL ECT was associated with an accentuation of delta power in anterior frontal and temporal regions. Across the electrode placements, increased theta activity in left frontotemporal regions was associated with longer recovery of orientation. Post-ECT decrements in global cognitive status, as assessed by the modified Mini-Mental State exam, were associated with a greater increase in delta relative to theta power, globally across the cortex. The magnitude of retrograde amnesia for autobiographical events correlated with increased theta activity in left frontotemporal regions. The findings suggest that distinct neurophysiological changes subserve the therapeutic and adverse cognitive effects of ECT. Postictal disorientation and post-ECT retrograde amnesia appear to share a common physiological substrate.

Clinical neurophysiology using electroencephalography in geriatric psychiatry: neurobiologic implications and clinical utility

Electroencephalography (EEG) offers a unique contribution to the armamentarium of imaging technologies used in the evaluation of brain function. The primary clinical application of EEG is in the diagnosis of delirium, dementia, and epilepsy, which are frequently encountered in the practice of geropsychiatry. This review summarizes the principles behind generation of the EEG signal, its strengths and limitations as a technology, clinical indications for performing an EEG, the principles underlying quantitative EEG (QEEG), and how QEEG is allowing us to probe brain function and connectivity in new ways.

Effects of propofol anesthesia on cognitive recovery of patients undergoing electroconvulsive therapy

The effects of different doses of propofol on post-electroconvulsive therapy (ECT) cognitive recovery were evaluated together with the effects on seizure duration and hemodynamic changes during ECT in 15 depressive patients. Propofol attenuated the increase in arterial blood pressure and heart rate in a dose-dependent manner compared with thiamylal. Propofol showed a clinically significant anticonvulsant effect during ECT in a dose-dependent manner. There were no significant differences among the four different induction groups in the mean recovery time from anesthesia, however, a low dose of propofol suppressed the early recovery of cognitive function. For early cognitive recovery after ECT, a deep anesthetic level is necessary when the traditional ECT apparatus is used which produces sine curve wave stimuli.

A comparison of EEG signal dynamics in waking, after anesthesia induction and during electroconvulsive therapy seizures

Evidence suggests that quantitative dynamical measures of electroencephalogram (EEG) signals are more appropriate for characterizing the differences between states in an individual rather than as absolute indices. One such measure, the largest Lyapunov exponent (lambda 1), appears to have potential for identifying seizure activity and for being of clinical utility for characterizing electroconvulsive therapy (ECT) seizures. As a result, we compared lambda 1 for the EEG recorded in 8 depressed subjects in 3 states: (1) during right unilateral ECT seizures, (2) during the pre-ECT waking state, and (3) following anesthesia administration but prior to ECT. Spectral amplitude and autocorrelation were also calculated in these states, allowing a comparison of these measures with lambda 1. We hypothesized that lambda 1 would be lowest during the ECT seizures, suggestive of greater EEG signal predictability over time during the seizures. We found that during the seizures lambda 1 was smaller, while spectral amplitude was larger. Significant inter-state differences were not found for the left temporal and occipital regions suggesting that these measures might serve as markers of the degree of seizure involvement of specific brain regions. Spectral amplitude and lambda 1 were uncorrelated and varied independently in some cases. The autocorrelation time was shortest in the waking EEG, and longest for the post-anesthesia EEG, and did not account for the differences seen in lambda 1. In contrast, the persistence of oscillations in the autocorrelation functions was greater for the ictal EEG than the other two states and may relate to lambda 1.

Comparison of propofol and methohexitone in anaesthesia for ECT: effect on seizure duration and outcome

The effect of the induction agents propofol and methohexitone on seizure duration and clinical outcome was assessed in a prospective, randomised, double blind study in 32 depressed patients receiving electroconvulsive therapy (ECT). Assessments comprised Hamilton rating scales pre-ECT, weekly during the course, and at one month follow-up. Patients showed a significant improvement in depression as measured by the Hamilton rating scale across the course of the ECT treatment. This improvement was not significantly different in the propofol and methohexitone groups. Nor was the amount of improvement related to either the total duration of seizure experienced by the patient during the ECT series or the use of tricyclic antidepressants by some patients.

The present use of electroconvulsive therapy

Physicians attempting to treat certain severe mental disorders have recently shown renewed interest in electroconvulsive therapy (ECT). A number of technical innovations have made ECT safer, as well as more effective. These innovations include oxygenation, muscular relaxation, unilateral nondominant electrode placement, use of brief-pulse stimuli, titrated stimulus dosing, electroencephalographic (EEG) monitoring, determination of seizure adequacy, and pharmacologic enhancement of treatment response.

A comparison of propofol and methohexital as anesthetic agents for ECT: effects on seizure duration, therapeutic outcome, and memory

The effects of the anesthetic agents propofol and methohexital on seizure duration, clinical outcome, recovery, and memory in electroconvulsive therapy (ECT) were studied in a double-blind trial. The study comprised 53 patients, 47 patients with major depression and six patients with other diagnoses according to DSM-III. Several recent clinical studies with a crossover design have shown a reduced seizure duration for anesthesia with propofol in comparison with both methohexital and thiopental. Propofol significantly reduced the seizure duration in this study without reducing the therapeutic outcome as measured by the Montgomery-Asberg Depression Rating Scale. Propofol did not significantly alter the length of the course of ECT; however, a slightly prolonged course for women cannot be completely ruled out. There were no significant differences between the two agents in effects on recovery times after anesthesia and on anterograde memory. In general, it seems that propofol is as effective as methohexital as an induction agent for ECT.

EEG manifestations during ECT: effects of electrode placement and stimulus intensity

This study examined the ictal electroencephalographic (EEG) characteristics of four forms of electroconvulsive therapy (ECT) known to differ in efficacy. Previously, we demonstrated that titrated, low-dose right unilateral ECT reliably produces generalized seizures of adequate duration, but is remarkably weak in antidepressant effects. Using a new rating scale, we found that specific features of the ictal and immediate postictal EEG varied significantly with ECT stimulus intensity and electrode placement. The low-dose right unilateral condition differed from more effective forms of ECT in having the longest polyspike phase duration, averaging twice that of the other conditions; it was also the condition least likely to manifest bioelectric suppression immediately following seizure termination. In contrast, high-dose bilateral ECT--a treatment with particularly rapid antidepressant effects--resulted in the greatest peak slow-wave amplitude in both hemispheres. Total seizure duration did not differ among the four treatment conditions. These findings indicate that seizure duration is not a useful marker of therapeutic efficacy, and instead provide preliminary evidence that other features of the EEG may be more useful markers of treatment adequacy.

Influence of Propofol on the Mood - a comparative study

The influence of propofol on mood was evaluated, considering the potential use of propofol as an anesthetic for electroconvulsive therapy. The mood state of 80 psychologically healthy subjects was assessed before and from 1/2 hour till 4 hours after surgery under anesthesia with either propofol or methohexitone. The mood was assessed with the Profile of Mood States (POMS). The propofol group was more elated from one hour until 4 hours after anesthesia (p<0,01 )(factor 1). 1 hour after anesthesia the propofol group was continuously more composed than the methohexitone group (p<0,01) (factor 4) and after two hours the propofol group was more agreeable (p<0,05) (factor 2). Moreover, patients, who received propofol, were less tired (factor 3) and confused (factor 5). It can be concluded that, compared with methohexitone, propofol has a favorable influence on different aspects of mood.

Propofol as an anaesthetic agent for ECT: effect on outcome and length of course

Recent reports of reduced seizure duration with ECT under propofol anaesthesia have led to concerns that propofol may diminish the efficacy of this treatment. To investigate the effect of propofol on the response to ECT, we reviewed records of 66 patients with primary depression treated with ECT, 37 of whom had been assessed prospectively with pre- and post-ECT Hamilton and Zung depression severity ratings. Despite demonstrating that the individual seizure duration was significantly reduced with propofol compared to thiopentone we found no evidence of reduced ECT efficacy with propofol. Courses under propofol anaesthesia were on an average two treatments longer than with thiopentone. Although this difference was not statistically significant this may have been due to a type II error. These results suggest that it is premature to abandon the use of this new anaesthetic agent in ECT without controlled prospective outcome studies.