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.

ECT stimulus intensity: are present ECT devices too limited?

Objective: The maximum output charge for ECT devices is limited to 576 millicoulombs in the United States, although there are no data ensuring that this limit will allow consistently effective treatments. The authors examined whether this limit has a negative impact on therapeutic response and, therefore, whether a higher stimulus charge should be available.

Method: They retrospectively reviewed the records of 471 patients who received a clinical index course of ECT at Duke University between 1991 and 1998.

Stationarity and redundancy of multichannel EEG data recorded during generalized tonic-clonic seizures.

To improve our understanding of the physiology of generalized tonic-clonic (GTC) seizures, we have investigated the stationarity and redundancy of 21-electrode EEG data recorded from ten patients during GTC seizures elicited by electroconvulsive therapy (ECT). Stationarity was examined by calculating probability density functions (pdfs) and power spectra over small equal-length non-overlapping time windows and then by studying, visually and quantitatively, the evolution of these quantities over the duration of the seizures. Our analysis shows that some seizures had no demonstrable stationarity, that most seizures had time intervals of at least a few seconds that were statistically stationary by several criteria, and that, in some seizures, there were leads which were delayed in manifesting the statistical changes associated with seizure onset evident in other leads.

New methods of time series analysis of non-stationary EEG data: eigenstructure decompositions of time varying autoregressions.

Objective: Those who analyze EEG data require quantitative techniques that can be validly applied to time series exhibiting ranges of non-stationary behavior. Our objective is to introduce a new analysis technique based on formal non-stationary time series models. This novel method provides a decomposition of the time series into a set of 'latent' components with time-varying frequency content.

Zolpidem for persistent insomnia in SSRI-treated depressed patients.

Background: Depressed individuals effectively treated with selective serotonin reuptake inhibitors (SSRIs) often report persistent insomnia and require adjunctive sleep-promoting therapy.

Method: Men (N = 40) and women (N = 150) with a mean age of 41.6 years who had persistent insomnia in the presence of effective and stable treatment (at least 2 weeks) with fluoxetine (< or =40 mg/day), sertraline (< or =100 mg/day), or paroxetine (< or =40 mg/day) for DSM-IV major depressive disorder, dysthymic disorder, or minor depressive disorder of mild-to-moderate severity (and score of < or =2 on item 3 of the Hamilton Rating Scale for Depression [HAM-D]) participated in this randomized, double-blind, parallel-group study.

EEG correlates of the response to ECT: a possible antidepressant role of brain-derived neurotrophic factor.

Studies on the relationship of electroencephalographic (EEG) data to the therapeutic response to electroconvulsive therapy (ECT) have been carried out since the 1940s, but for many years they did not yield any consistent correlates. Recent studies, however, are providing a growing body of evidence of relationships between the antidepressant response to ECT and both the ictal (recorded during ECT seizures) and interictal (recorded during waking) EEG. These studies appear to be consistent in pointing to the importance of electrophysiologic changes in the prefrontal cortex as a potential mediator of the antidepressant response to ECT.

The use of flumazenil in the anxious and benzodiazepine-dependent ECT patient.

Many patients who receive electroconvulsive therapy (ECT) are benzodiazepine dependent or are anxious and require benzodiazepine drugs. Because these agents may diminish the therapeutic effectiveness of ECT, we explored the dosing, safety, and efficacy of pre-ECT flumazenil administration, a benzodiazepine-competitive antagonist, in patients receiving benzodiazepine medications. We report our experience with 35 patients who received both flumazenil and benzodiazepine drugs during their ECT course.

Changes in seizure threshold over the course of electroconvulsive therapy affect therapeutic response and are detected by ictal EEG ratings.

Therapeutic effectiveness of electroconvulsive therapy is influenced by the degree to which the stimulus intensity exceeds the seizure threshold. However, the threshold rises variably over the treatment course, confounding maintenance of desired relative stimulus intensity. In 47 depressed patients, decreases in relative stimulus intensity between treatments 1 and 6 were associated with diminished therapeutic response at treatment 6 for unilateral (UL) ECT.

The largest Lyapunov exponent of the EEG during ECT seizures as a measure of ECT seizure adequacy.

Attributes of the electroencephalogram (EEG) recorded during electroconvulsive therapy (ECT) seizures appear promising for decreasing the uncertainty that exists about how to define a therapeutically adequate seizure. In the present report we study whether one promising and not yet tested ictal EEG measure, the largest Lyapunov exponent (lambda1), is useful in this regard. We calculated lambda1 from 2 channel ictal EEG data recorded in 25 depressed subjects who received right unilateral ECT.

Implementing a hospital-wide pain management strategy.

The purpose of this article is to describe the process of undertaking a large scale nursing pain management initiative, that we entitled "Pain Month." Several educational resources and strategies were employed in an effort to increase nurse's knowledge on the subject of pain management. Pre and post patient satisfaction surveys were conducted to test the effect of the education on actual pain management.

Neuropsychiatric considerations in the use of electroconvulsive therapy.

ECT is an effective and rapidly acting treatment for certain major psychiatric disorders, even in patients with neurologic illness. Further, in some cases the neurologic illness itself also responds to ECT. Patients with some types of neurologic illness may be at increased risk of neurologic or cognitive side effects from ECT, but these risks can be lowered by careful pre-ECT evaluation and optimal ECT technique.

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.

The empirical identification of insomnia subtypes: a cluster analytic approach.

Over the past 15 years, there has been considerable debate concerning the extent to which insomnia patients can be classified into diagnostic subtypes. Despite this debate, relatively little research has been conducted to empirically determine whether naturally occurring insomnia subtypes might be identified within populations of sleep clinic patients. In the current study we used a hierarchical cluster analysis to empirically identify subtypes among a mixed group of normal sleepers and the insomnia outpatients who presented to our sleep center over the past decade.

Effect of ECT treatment number on the ictal EEG.

Recent evidence suggests that attributes of the ictal electroencephalogram (EEG) may be clinically useful for estimating the extent to which the electroconvulsive therapy (ECT) stimulus exceeds the seizure threshold (relative stimulus intensity). Such a tool could allow a practitioner, who chose, on the basis of expected therapeutic response and side effect rates, to implement stimulus dosing to maintain relative stimulus intensity over the treatment course, despite the uncertain rise in seizure threshold that occurs. One potential confounding factor is a possible systematic change in the ictal EEG over the treatment course that is not due to changes in seizure threshold.

The relative ability of three ictal EEG frequency bands to differentiate ECT seizures on the basis of electrode placement, stimulus intensity, and therapeutic response.

Ictal EEG indices show promise for separating individual ECT seizures on the basis of treatment electrode placement (ELPL), relative stimulus intensity (Dose), and expected therapeutic response. One factor impeding the effective clinical implementation of ictal EEG indices for these purposes is uncertainty as to the relative utility of lower and higher frequency EEG activity. Recent articles are contradictory in this regard, but no data exist addressing this issue.

ECT seizure duration: reliability of manual and computer-automated determinations.

Reliable monitoring of electroencephalographic (EEG) and electromyographic electroconvulsive therapy (ECT) seizure duration has become important as these assessments have become a routine part of the clinical practice of ECT. In this regard, accurate automated seizure duration determinations would be particularly valuable. As a result, the present study was performed to assess the reliability of available computer-automated determinations of seizure duration (Thymatron Model DGx ECT machine; Somatics, Inc.

Seizure threshold in electroconvulsive therapy (ECT) II. The anticonvulsant effect of ECT.

To measure the anticonvulsant effects of a course of electroconvulsive therapy (ECT), we used a flexible stimulus dosage titration procedure to estimate seizure threshold at the first and sixth ECT treatments in 62 patients with depression who were undergoing a course of brief pulse, constant current ECT given at moderately suprathreshold stimulus intensity. Seizure threshold increased by approximately 47% on average, but only 35 (56%) of the 62 patients showed a rise in seizure threshold. The rise in seizure threshold was associated with increasing age, but not with gender, stimulus electrode placement, or initial seizure threshold.

Seizure threshold in electroconvulsive therapy: I. Initial seizure threshold.

We measured initial seizure threshold by means of a structured stimulus dosage titration procedure in a clinical sample of 111 depressed patients undergoing brief-pulse, constant-current electroconvulsive therapy (ECT). Initial seizure threshold was approximately 60 millicoumbs (mc) (10 Joules) on average, but varied widely (6-fold) across patients. Initial seizure threshold was predicted by four variables: electrode placement (higher with bilateral), gender (higher in men), age (higher with increasing age), and dynamic impedance (inverse relationship).

Ambulatory cassette polysomnography: findings from a large cohort of drug-free insomnia patients.

Technology for conducting ambulatory polysomnography (APSG) has been available for more than a decade, but relatively few studies have used this technology to study the sleep of subjects in their usual home sleeping environments. Herein we suggest the usefulness of this technology for the study of normal sleepers and insomniacs, and we report our APSG findings with a large cohort (n = 117) of drug-free insomnia outpatients. All patients completed a sleep-history questionnaire, a clinical interview with a sleep-disorders clinician, and one night of APSG in their homes.

The ictal EEG as a marker of adequate stimulus intensity with unilateral ECT.

Relative stimulus intensity above seizure threshold has been shown to affect therapeutic outcome with unilateral ECT. The authors sought to explore whether a multivariate ictal EEG model would permit ongoing clinical assessment of this parameter. Twenty-five depressed subjects were randomized to either barely (T) or moderately (2.

ECT seizure therapeutic adequacy.

From the beginnings of convulsive therapy, the need for some way to assess the therapeutic adequacy of individual treatments has been apparent. Recent work suggests that seizure therapeutic adequacy and adverse effects are dependent on the extent to which the stimulus exceeds the seizure threshold (relative stimulus intensity). Applying this information in clinical practice is problematic because of the variable rise in the seizure threshold that takes place over the treatment course.

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.

The effects of ECT stimulus dose and electrode placement on the ictal electroencephalogram: an intraindividual crossover study.

Recent evidence suggests that electroconvulsive therapy (ECT) efficacy depends upon both electrode placement and the degree to which stimulus dosage exceeds seizure threshold (T), and not simply on surpassing a minimum seizure duration as has been assumed. In light of these findings and studies reporting ictal electroencephalogram (EEG) differences between bilateral and unilateral ECT, we performed this 19-subject intraindividual crossover study of the effects of dose and electrode placement on the ictal EEG. We found ictal EEG evidence of greater seizure intensity with bilateral than unilateral ECT and with higher dosage (2.