Does electroconvulsive therapy cause brain damage?

Systematic Review of the Neural Effect of Electroconvulsive Therapy in Patients with Schizophrenia: Hippocampus and Insula as the Key Regions of Modulation

OBJECTIVE

Electroconvulsive therapy (ECT) has been the most potent treatment option for treatment-resistant schizophrenia (TRS). However, the underlying neural mechanisms of ECT in schizophrenia remain largely unclear. This paper examines studies that investigated structural and functional changes after ECT in patients with schizophrenia.

METHODS

We carried out a systematic review with following terms: 'ECT', 'schizophrenia', and the terms of various neuroimaging modalities.

RESULTS

Among the 325 records available from the initial search in May 2020, 17 studies were included. Cerebral blood flow in the frontal, temporal, and striatal structures was shown to be modulated (n=3), although the results were divergent. Magnetic resonance spectroscopy (MRS) studies suggested that the ratio of N-acetyl-aspartate/creatinine was increased in the left prefrontal cortex (PFC; n=2) and left thalamus (n=1). The hippocampus and insula (n=6, respectively) were the most common regions of structural/functional modulation, which also showed symptom associations. Functional connectivity of the default mode network (DMN; n=5), PFC (n=4), and thalamostriatal system (n=2) were also commonly modulated.

CONCLUSION

Despite proven effectiveness, there has been a dearth of studies investigating the neurobiological mechanisms underlying ECT. There is preliminary evidence of structural and functional modulation of the hippocampus and insula, functional changes in the DMN, PFC, and thalamostriatal system after ECT in patients with schizophrenia. We discuss the rationale and implications of these findings and the potential mechanism of action of ECT. More studies evaluating the mechanisms of ECT are needed, which could provide a unique window into what leads to treatment response in the otherwise refractory TRS population.

Electroconvulsive therapy: a review on indications, methods, risks and medication

This paper reviews and presents data of practical impact for those administering electroconvulsive therapy (ECT). In the first section, physical and physiological aspects of the stimulus as well as methods of stimulation are discussed. The second section deals with indications for ECT, efficacy and treatment modalities such as seizure duration, treatment frequency and total number of ECT applications. The last section is devoted to side effects, risks, comedication and comorbidity.

Effects of continuation electroconvulsive therapy on quality of life in elderly depressed patients: A randomized clinical trial

We examined whether electroconvulsive therapy (ECT) plus medications ("STABLE + PHARM" group) had superior HRQOL compared with medications alone ("PHARM" group) as continuation strategy after successful acute right unilateral ECT for major depressive disorder (MDD). We hypothesized that scores from the Medical Outcomes Study Short Form-36 (SF-36) would be higher during continuation treatment in the "STABLE + PHARM" group versus the "PHARM" group. The overall study design was called "Prolonging Remission in Depressed Elderly" (PRIDE). Remitters to the acute course of ECT were re-consented to enter a 6 month RCT of "STABLE + PHARM" versus "PHARM". Measures of depressive symptoms and cognitive function were completed by blind raters; SF-36 measurements were patient self-report every 4 weeks. Participants were 120 patients >60 years old. Patients with dementia, schizophrenia, bipolar disorder, or substance abuse were excluded. The "PHARM" group received venlafaxine and lithium. The "STABLE + PHARM" received the same medications, plus 4 weekly outpatient ECT sessions, with additional ECT session as needed. Participants were mostly female (61.7%) with a mean age of 70.5 ± 7.2 years. "STABLE + PHARM" patients received 4.5 ± 2.5 ECT sessions during Phase 2. "STABLE + PHARM" group had 7 point advantage (3.5-10.4, 95% CI) for Physical Component Score of SF-36 (P < 0.0001), and 8.2 point advantage (4.2-12.2, 95% CI) for Mental Component Score (P < 0.0001). Additional ECT resulted in overall net health benefit. Consideration should be given to administration of additional ECT to prevent relapse during the continuation phase of treatment of MDD. CLINICAL TRIALS.GOV: NCT01028508.

Use of ECT in patients with an intellectual disability: review

Aims and method

The literature on the use of electroconvulsive therapy (ECT) in patients with an intellectual disability is scarce, despite a higher prevalence of psychiatric disorders than in the general adult population. We carried out a review of articles published before March 2010. All age ranges, severity of disability and diagnoses were included.

Results

We found 72 case reports, a retrospective chart review study and other reviews, but no controlled studies. Most patients (79%) showed a positive outcome following ECT. Complications were seen only in 13% and there were no reports of cognitive decline. Many patients relapsed following ECT (32%) and the majority were maintained with medication at follow-up (71%).

Clinical implications

Electroconvulsive therapy is a valuable treatment for this patient group and should be considered earlier as opposed to as a last resort. Obstacles to its use include diagnostic difficulties, ethical and legal issues, a lack of objective measurements and uncertainty about its safety in this population.

Lightning-strike Injury

Although lightning-strike injury is uncommon, it is the cause of death in more people in the United States annu ally than any other natural disaster. Consequently, the emergency medicine specialist and intensivist should be familiar with the special problems of a lightning-strike victim. Lightning is a massive electrical discharge that results from a complex sequence of atmospheric events. When this massive electrical discharge strikes a human being, it causes predictable cardiac and neurological in juries. Synchronous myocardial contraction occurs at the moment of impact and is followed by a variable period of asystole. Prolonged asystole may cause isch emia and ventricular fibrillation. Alternatively, ventric ular fibrillation may occur primarily if the electrical discharge strikes during the vulnerable period of the cardiac cycle. Unconsciousness, depression of respira tory efforts, and seizures are also immediate conse quences of lightning strike. Respiratory arrest is pre sumed to be a consequence of inhibition of the medullary respiratory center. Retrograde and antegrade amnesia, confusion, disorientation, and vasomotor insta bility with transient paralysis of usually the lower ex tremities are commonly seen in lightning-strike victims. Other complications occur more variably, but should be carefully sought by the responsible clinician. These in clude burns at the exit and entrance sites of the light ning strike, eye injuries (e.g., cataracts, corneal lesions, intraocular bleeding), and rupture of the tympanic membrane. Besides describing the pathophysiology of these and other consequences of lightning strike, a com prehensive approach to the initial and long-term man agement of the lightning-strike victim is discussed.

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.

A case of lightning injury with delayed-onset psychiatric and cognitive symptoms

A case is presented of a man who was struck by lighting but, per his report, developed psychiatric and cognitive symptoms between 1-2 years after the incident. The case is discussed in light of the literature on lightning injury with particular emphasis on the aetiology of delayed symptoms. In this case it appears that some cognitive dysfunction may have occurred at the time of the lightning injury, but deficits were exacerbated after a delayed-onset of PTSD and other psychiatric symptoms. The author suggests possible mechanisms for delayed memory impairment in cases of lightning injury.

Electroconvulsive Shock Induces Neuron Death in the Mouse Hippocampus: Correlation of Neurodegeneration with Convulsive Activity

The relationship between convulsive activity evoked by repeated electric shocks and structural changes in the hippocampus of Balb/C mice was studied. Brains were fixed two and seven days after the completion of electric shocks, and sections were stained by the Nissl method and immunohistochemically for apoptotic nuclei (the TUNEL method). In addition, the activity of caspase-3, the key enzyme of apoptosis, was measured in brain areas immediately after completion of electric shocks. The number of neurons decreased significantly in field CA1 and the dentate fascia, but not in hippocampal field CA3. The numbers of cells in CA1 and CA3 were inversely correlated with the intensity of convulsions. Signs of apoptotic neuron death were not seen, while caspase-3 activity was significantly decreased in the hippocampus after electric shocks. These data support the notion that functional changes affect neurons after electric shock and deepen our understanding of this view, providing direct evidence that there are moderate (up to 10%) but significant levels of neuron death in defined areas of the hippocampus. Inverse correlations of the numbers of cells with the extent of convulsive activity suggest that the main cause of neuron death is convulsions evoked by electric shocks.

ECT use delayed in the presence of comorbid mental retardation: a review of clinical and ethical issues

The objective is to develop a clinically and ethically supportive literature for the use of electroconvulsive therapy (ECT) in patients with mental retardation who are concurrently experiencing a significant psychiatric illness. A review of both the clinical and ethical literature using traditional, manual library methods and the Medline and Psychlit databases was undertaken. In addition, a record of all patients who had undergone ECT at our facility between 1995 and 2000 was examined for patients with comorbid mental retardation. We found that the use of ECT for people who have both a psychiatric illness and comorbid mental retardation was significantly delayed. However, a rapid response to index, continuation, and maintenance ECT was also noted. Further, this response occurred with routine ECT administered irrespective of age, gender, diagnosis, stimulus parameters, electrode placement, or number of treatments. In addition, the successful use of right-sided unilateral ECT at six times the initial seizure threshold was reported in a patient who had previously responded to bilateral ECT. A cogent ethical justification was developed with the use of the rule of double effect. We concluded that for patients who have mental retardation and who subsequently develop a psychiatric illness, ECT is delayed and left as a treatment of last choice. Although the literature is sparse and uncontrolled, a cogent clinical and ethical justification may help negotiate these and other delays.

ECT: use in individuals with mental retardation

Electroconvulsive therapy (ECT) is an effective treatment of a variety of serious psychiatric and neurologic disorders. There are infrequent case reports of its use in individuals with mental retardation (MR). We describe 10 patients with MR and complex comorbid psychiatric disorder treated with ECT. Seven patients had an excellent response to treatment. Side effects of treatment were minimal and transitory.

Using thiamine to reduce post-ECT confusion

Cognitive side-effects are commonly seen following electroconvulsive therapy which convey no therapeutic benefit but are troublesome to both patient and clinician. Various efforts have been made in the past to minimize these symptoms. Although modification of technical parameters related to ECT administration has led to some limited improvement in this regard, attention is now being increasingly focussed on pharmacological approaches. A number of agents have been explored in this context, however, as far as we are aware, the use of thiamine has not yet been investigated. We present three cases of elderly patients undergoing ECT for major depression in whom thiamine administration was associated with beneficial effects on post-ECT confusion. We review the evidence suggesting that thiamine deficiency may be implicated in the confusional state following ECT and recommend that consideration be given to its use in preventing and treating this problematic side-effect, especially in elderly patients.

Electroconvulsive therapy is associated with superior symptomatic and functional change in depressed patients after psychiatric hospitalization

BACKGROUND

Major depressive episode is associated with quality of life (QOL) deficits, and QOL improves following remission of depression. We conducted an observational study of the relationship between depressive symptoms and QOL for 1 year after psychiatric hospitalization, and compared QOL in patients who received ECT against those who did not.

METHODS

We examined 88 patients with major depressive disorder (53.4+/-15.4 years old; 69 women) upon admission, with repeated measurements at discharge, 1, 3, 6, and 12 months after discharge. Depression severity was measured with the Beck Depression Inventory. QOL measurements encompassed ADLs, IADLs, performance in major roles, and satisfaction with relationships. Treatment for depression was at the discretion of the respective physicians.

RESULTS

Depression severity dropped dramatically by discharge, and changed little thereafter. QOL measures showed improvement at the first month, with additional improvement at the third month. Improvement in QOL was closely tied to improvement in depression severity. ECT during the index hospitalization was associated with greater improvement in depressive symptoms and in most measures of QOL.

LIMITATIONS

The results of this study may not apply to the treatment of outpatients, and the large number of statistical comparisons may have resulted in some spurious associations.

CONCLUSIONS

Inpatient treatment of depression is followed by improvement in QOL. Novel findings in this study include evidence that maximum improvement in QOL does not occur until an average of 3 months after discharge, and that ECT-treated patients had superior outcomes.

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.

Mossy fiber sprouting induced by repeated electroconvulsive shock seizures

The elicitation of repeated focal seizures (kindling) induces mossy fiber sprouting in the hippocampus of the rat. The present study investigated whether repeated generalized seizures also induce mossy fiber sprouting. Human psychiatric patients receive repeated generalized seizures during electroconvulsive therapy (ECT). Male Long-Evans rats received a course of eight electroconvulsive shock (ECS) seizures administered on a 48-h schedule over a course of 2 1/2 weeks. Control subjects received matched handling, but no stimulation. Fourteen days after the last ECS trial, all subjects were sacrificed and their brains subjected to Timm staining. Cell counts and area measures were also taken in the hilus. Significant sprouting, but not significant cell loss, was seen in the fascia dentata of the subjects that had received ECS.

Alteration in gastrointestinal and neurological function after electrical injury: a review of four cases

OBJECTIVE

Individuals exposed to an electrical injury develop a variety of complications, several of which are recognized years after the initial electrical shock. Alteration in gastrointestinal and nervous system function has been described in these patients, yet the frequency and character of these abnormalities are poorly understood. We reviewed records of 40 individuals with a history of electrical injury to identify evidence of delayed onset of complications.

METHODS

Forty consecutive patients with electrical shock injuries were monitored for up to 5 yr after their traumatic event using a comprehensive systems review. Of the eight patients who described an alteration in their gastrointestinal and neurological functions, four agreed to undergo further testing. Investigations included a flexible sigmoidoscopy, anorectal manometry, stool evaluation, serological and biochemical serum analysis, and a psychological examination.

RESULTS

Each of the four patients described an increase in stool frequency and urgency. Anorectal manometry detected a reduction in threshold to rectal balloon distention and an abnormal anal sphincter control. Bowel function improved with meselamine. Psychiatric symptoms involving memory and concentration were observed in varying degrees.

CONCLUSIONS

To our knowledge, these induced physiological and psychological changes after exposure to electrical shock injury have not yet previously been described. Our findings should encourage further clinical investigations to better anticipate, diagnose, and manage these and other as yet unrecognized delayed complications of electrical shock injury.

Psychiatry in the geriatric neurology practice

This article provides a brief overview of the psychiatric syndromes most common in the elderly patient, as well as those most frequently accompanying neurologic disease. Diagnosis, work up, and treatment of depressive, psychotic, and anxiety disorders are also reviewed. This article is directed toward the practicing neurologist, with an emphasis on detection and treatment. Special attention is paid to psychiatric syndromes that accompany Parkinson's disease, stroke, and dementia. A brief review of the most common psychopharmacological agents is included as well.

The effects of electroconvulsive shock on the short-latency somatosensory evoked potential in the rat

The effects of electroconvulsive shock (ECS) were examined on the short-latency somatosensory evoked potential (SEP) in the awake rat. Immediately after the induction of generalized seizure activity (GSA), the primary cortical response was lost although the preceding far field thalamic component appeared to be preserved basically intact. Within 1 minute the cortical potential had begun to reemerge, albeit with an attenuated amplitude and a prolonged latency. Recordings made at 2 and 3 minutes revealed evidence of a slight postictal enhancement of the cortical potential. Within 6 minutes, a near normal waveform had been restored. It is concluded that the principal site of impact of ECS resides at the cortical level and that the somatosensory impulse is, therefore, able to traverse the central pathways unimpeded by GSA until it is finally blocked at the primary sensory cortex. The present findings are compared to previous attempts to record cortical SEPs from patients undergoing electroconvulsive therapy (ECT). It is presumed that the failure of ECT to abolish the SEP in these circumstances was due either to the protective role played by concurrent medication or because of a post-ECS delay in restarting the recordings. The relevance of the findings to an understanding of the physiology of electrical stunning is discussed.

Long-term enhancement of entorhinal-dentate evoked potentials following 'modified' ECS in the rat

Electroconvulsive therapy (ECT) is widely used as a treatment for drug-resistant depression. The animal analogue of ECT is electroconvulsive shock (ECS) seizures. We have recently shown that repeated ECS seizures cause a long-lasting, perhaps permanent, enhancement in entorhinal-dentate evoked potentials in the rat. Our study, however, involved 'unmodified' ECS, whereas in clinical practice ECT is now usually given in its 'modified' form (with near-threshold currents, a short-acting barbiturate, muscle relaxant and oxygen). We have therefore repeated our experiments using modified ECS. Entorhinal-dentate evoked potentials were measured in Long-Evans rats before and after: (1) eight modified ECS seizures; or (2) eight sham modified ECS trials. Despite the use of the modified procedure, a significant and long-lasting enhancement in population spike amplitude was seen in the ECS group. We conclude that the modified procedure does not protect rats against the long-lasting enhancement of evoked potentials. Similar changes may be occurring in the brains of patients subjected to modified ECT.

Hippocampal neurons are damaged by caffeine-augmented electroshock seizures

Caffeine-augmented electroconvulsive therapy has been introduced into medical practice without experimental confirmation that such seizure modification does not result in neuronal injury. In this report rats pretreated with caffeine prior to a series of nine electrically induced convulsions showed neuronal injury confined to hippocampal sectors and striatum. Electrically induced convulsions without caffeine pretreatment did not result in injury. The potential deleterious effects of caffeine augmentation of human electroconvulsive therapy require rigorous clinical assessment.

No loss of hippocampal hilar somatostatinergic neurons after repeated electroconvulsive shock: a combined stereological and in situ hybridization study

Electrically induced seizures with anesthesia and muscle relaxation (ECT) is commonly used in the therapy of psychotic depression in humans. Unmodified electroshock (ECS) is used as a model for epilepsy in the rat. In several seizure models of epilepsy, in particular the dentate hilar somatostatin-containing (SSergic) neurons have been found to undergo degeneration. To assess the potential loss of SSergic hilar neurons after repeated ECS, 10 rats were given 110 ECS, one per day, 5 days a week. One day after the last ECS the rats were anesthesized, perfused, the brains cut on a vibratome and prepared for nonradioactive in situ hybridization for somatostatin along with five control rats. Like rats given 10-36 ECS in earlier studies, the ECS-treated rats displayed a markedly increased neuronal hybridization labeling when compared with control rats. The total number of dentate hilar SSergic neurons of each rat was estimated using the optical disector technique. The mean number of hilar SSergic neurons in the ECS-treated rats was 12,785, compared to 12,392 in the control rats. The total number of hilar SSergic neurons in ECS-treated versus control rats was not significantly different (Student's t test; t value = .35; p = .74). We conclude that repeated ECS treatment does not cause loss of hilar SSergic neurons.

Subjective memory complaints prior to and following electroconvulsive therapy

Using the Squire Subjective Memory Questionnaire (SSMQ), depressed patients rated their memory functioning prior to a course of brief pulse, electroconvulsive therapy (ECT) within the 1 week following the course and 2 months later. Normal controls made similar ratings at comparable intervals. Prior to ECT, patients reported poorer memory functioning than controls. There was marked improvements in the patients' self-reports shortly following ECT, and at 2-month follow-up SSMQ scores were generally comparable in patients and controls. At all time points, the severity of depressive symptoms was strongly associated with patients' reports of memory dysfunction. SSMQ subscales ("depression" and "ECT" items) were not differentially sensitive to effects of ECT or depression. Relations between ECT treatment parameters and changes in patients' self-evaluations only emerged after controlling for clinical state change. Shortly following ECT, there were no relations between SSMQ scores and objective measures of cognitive functioning. However, 2 months following ECT, there was a suggestion that greater retrograde amnesia for autobiographical memories was associated with self-rating of greater memory impairment.

Long-term changes in entorhinal-dentate evoked potentials induced by electroconvulsive shock seizures in rats

Entorhinal-dentate evoked potentials were measured in rats before and after: (1) eight electroconvulsive shock (ECS) seizures, or (2) matched handling. In animals that received ECS, evoked potentials were significantly enhanced, as evidenced by a long-lasting increase in the amplitude of the population spike. This increase in population-spike amplitude lasted for at least 3 months after the last ECS trial. No evoked-potential changes were observed in the subjects that received matched handling. These data suggest that ECS seizures produce long-lasting, perhaps permanent, changes in the brain.

Electroconvulsive shock increases interstitial concentrations of uric acid in the rat brain

This study examined the effects of electroconvulsive shock (ECS) on striatal interstitial concentrations of the purine metabolite uric acid (UA) using microdialysis in freely moving rats. UA increased to about 200% of baseline following ECS. Intense seizure activity induced by the convulsant agent flurothyl also resulted in a two-fold increase of UA concentrations suggesting that the ECS-induced UA increase is related to the seizure activity per se. Local administration of tetrodotoxin or perfusion with a Ca(2+)-free solution failed to affect the basal or the ECS-induced increase in UA concentrations. These data indicate that both the basal and the stimulated interstitial concentrations of uric acid are not dependent upon neuronal activity and exocytotic release. The UA response to ECS appears to be refractory to a second ECS delivered 2 but not 24 h after the first. Intrastriatal infusion of allopurinol (1 mM), an inhibitor of UA synthesis, decreased basal UA concentrations to 26% but did not influence the ECS-induced UA increase. Systemic injection of allopurinol (20 mg/kg, i.p.) decreased basal UA concentrations to 25% and prevented the ECS-induced UA elevation. ECS also increased serum concentrations of UA to almost 200% of baseline. Allopurinol (20 mg/kg, i.p.) markedly decreased serum UA concentrations to non-detectable levels and completely abolished the ECS-induced increase. The estimated concentration difference between blood and brain interstitial UA strongly suggests that ECS-induced increase in brain interstitial UA concentrations is of peripheral origin possibly due to disruption of the blood brain barrier during seizure activity.

Electroconvulsive seizures upregulate astroglial gene expression selectively in the dentate gyrus

Previous studies have revealed that kindled seizures induced via chronically implanted electrodes up-regulate the expression of glial fibrillary acidic protein (GFAP), the protein constituent of intermediate filaments in astrocytes. The present study evaluates the consequences of a single electroconvulsive seizure (ECS) on glial gene expression. ECS were induced in mice via externally-placed electrodes. GFAP mRNA levels were evaluated 1, 2, 4, and 6 days post-seizure by in situ hybridization. GFA immunocytostaining was evaluated in a separate series of animals. Following a single ECS, the levels of mRNA for GFAP increased several fold by 1 day and were still substantially elevated at 4 days. The increases occurred primarily in the dentate gyrus despite the fact that the seizures involved widespread brain regions. GFAP mRNA levels were also increased in areas bordering the ventricles, especially in areas immediately adjacent to the dentate gyrus. These results indicate that ECS up-regulates the mRNA for a key structural protein of astrocytes in a manner that is similar to the response that occurs following injury, that this response occurs selectively in a part of the brain that plays a key role in memory function, and that the increase may be due in part to a diffusible substance that also affects glial gene expression in nearby structures.

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.

Can ECT-induced cognitive effects be altered pharmacologically?

1. A systematic review of the literature revealed twelve clinical trials that evaluated nine different drugs, and used three different conceptual models to prevent, restore or treat ECT-induced cognitive deficits. 2. This review indicated inconclusive results regarding clinical utility of any of the drugs. 3. Major factors discussed include the complexities involved in the evaluation of ECT-induced cognitive deficits, and the techniques of evaluating changes in cognitive functions. 4. Our conclusion is that future research should emphasize understanding the neural mechanisms related to ECT-induced cognitive deficits. We suggest several areas for future exploration.

Long-term changes in regional brain cytochrome oxidase activity induced by electroconvulsive treatment in rats

Quantitative cytochrome oxidase (CO) histochemistry was used to examine brain regional metabolic effects of electroconvulsive shock-induced seizures (ECS). Rats receive a course of either eight ECS or control treatments and were sacrificed either 24 h or 28 days after the last session. Regional CO activity (mumol/gT/min) was quantitated throughout the brain using internally calibrated standards. Twenty-four hours after the last ECS session there was no significant difference between ECS- and sham-treated brains in any of the 99 brain regions examined. In contrast, 28 days after the last session, ECS brains showed significant increases in CO activity in the interpeduncular nucleus (+20%), bed nucleus of the stria terminalis (+25%), dorsomedial hypothalamus (+20%), ventromedial hypothalamus (+12%), mammillary nucleus (+14%), pontine nucleus (+16%), basolateral amygdala (+14%), medial amygdala (+12%), piriform cortex (+12%) and ventromedial thalamus (+9%). These results suggest that ECS induces localized increases in brain CO activity which are long-lasting and may develop independently of additional stimulation. The fact that CO changes were predominantly in limbic areas suggests that they may be relevant to the antidepressant effects of ECS.

Electroconvulsive therapy

The following position paper was approved by the Board of Directors of the Canadian Psychiatric Association on September 15,1992.

Learning disabilities in epilepsy: neurophysiological aspects

Subclinical generalized spike-wave discharges are often accompanied by transitory cognitive impairment, demonstrable by psychological testing during EEG recording. Transitory cognitive impairment is demonstrated most readily by difficult tasks and during generalized regular spike-wave bursts lasting for more than 3 s, but can also be found during briefer and even focal discharges. That this is not simply a consequence of global inattention is shown by the fact that focal discharges exhibit some specificity: left-sided focal spiking is more likely to produce errors on verbal tasks, for instance, whereas right-sided discharges are more often accompanied by impairment in handling nonverbal material. Both learning difficulties in general and specific abnormal patterns of cognitive functioning are well documented in children with epilepsy and are most pronounced in those with frequent interictal discharges. However, there is now evidence that intermittent cognitive impairment due to the discharges themselves contributes significantly to such neurophysiological abnormalities. The significance of transitory cognitive impairment accompanying subclinical EEG discharges for everyday functioning is uncertain, but there is experimental evidence that subclinical discharges may be accompanied by disruption of educational skills in children or by impairment of driving performance in motorists. In some individuals, suppression of discharges by antiepileptic drugs has demonstrably improved psychological function, but further work is required to determine the indications for such treatment.

Repeated electroconvulsive shock increases glial fibrillary acidic protein, ornithine decarboxylase, somatostatin and cholecystokinin immunoreactivities in the hippocampal formation of the rat

Rats were submitted to single or repeated (7 days, one session for each day) sessions of electroconvulsive shock. A computer-assisted morphometric and microdensitometric analysis of glial fibrillary acidic protein-, ornithine decarboxylase-, somatostatin- and cholecystokinin-like immunoreactivities was performed in the hippocampal formation and other brain areas. The results of the study showed a significant increase of the intensity of the immunostaining for glial fibrillary acidic protein, ornithine decarboxylase, somatostatin and cholecystokinin in the hippocampal formation and distinctively in the dentate gyrus following repeated, but not single, electroconvulsive shock. No significant change was found in the number of somatostatin- and cholecystokinin-like immunoreactive cell bodies in any hippocampal subregion and in the number of glial cells in the hilus of dentate gyrus in rats treated with single or repeated electroconvulsive shock. It is a distinct possibility that the observed increase in the content of the neuropeptides in the hippocampal formation reflects a compensatory response of the brain to seizure-inducing stimuli and that such an increase may play a role in the therapeutic effect of electroconvulsive shock.

Neuroimaging and affective disorder in late life: a review

Within the past two decades brain imaging techniques have given the clinician access to new anatomical and functional findings for dealing with affective disorder in the older age group. Despite the proliferation of such technology, the significance of findings on computerized axial tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) remains unclear in this patient group. The literature covering old age depression and imaging techniques is reviewed, and problems related to methodology, sample selection, and implications for the direction of future research are discussed. Current evidence particularly suggests that subcortical atrophy may be an important factor in the genesis of affective disorder in old age. The question of cognitive decline in the setting of affective disorder is examined. The use of brain imaging techniques may have particular bearing upon identification of etiology of affective disorder, prediction of treatment response, or risk of relapse.

Time course of cerebra; magnetic resonance changes after electroconvulsive therapy

Nuclear magnetic resonance images of the non-dominant cerebral hemisphere were obtained in 20 unipolar depressed patients immediately before and 25 minutes after electroconvulsive therapy (ECT). T1 values rose about 1%. Repeated scanning up to 24 hours after ECT was carried out in 13 of these patients. The greatest change in magnetic resonance images was two hours after ECT, and thereafter images gradually returned to baseline values. There was no correlation between magnetic resonance changes and the time taken to become reorientated after ECT.

Electroconvulsive therapy in depression

Electroconvulsive therapy (ECT) has been in use for over 50 years and remains one of the most effective treatments in psychiatry. Effectiveness rates for ECT in depression range between 80% and 90%; no comparative study has shown any other intervention to be superior to ECT. ECT is also recommended for mania, schizophrenia and as a safe treatment for the elderly or medically ill depressed patient. This paper will deal with the use of ECT in depression. The areas to be covered are the clinical indications, the factors predictive of response, the evidence for the efficacy of ECT, as well as theories of the mechanism of its action, side effects and guidelines for prescribing the procedure. Notwithstanding the efficacy, the safety and perhaps an improved public acceptance, some observers have noted that there is a decline in the use of ECT. Others have suggested that such a decline may be evident only in the public sectors such as state and provincial psychiatric hospitals. Ongoing research is necessary to achieve further refinement of ECT, as well as enhance our understanding of this important treatment procedure.

Electroconvulsive therapy and cerebral computed tomography. A prospective study

Cerebral computed tomography (CT) was performed before and after right-sided electroconvulsive therapy (ECT) in 40 patients aged 26-87 years with major affective disorders. Nine patients with a concomitant definite or possible non-acute organic brain disorder were included. Several patients had long seizure durations, maximum 6.5 min, caused by hyperventilation-induced hypocapnia. Twenty-nine patients received at least 16 treatments (maximum 46). No CT changes occurred following ECT. A questionable dilatation of the left temporal horn in a 69-year-old hypertensive man who recovered completely without side effects after 3 ECT sessions was probably unrelated to the ECT. Provided sufficient oxygenation, even relatively long ECT series and seizures lasting several minutes do not cause any brain damage visible on CT.

Status epilepticus after electroconvulsive therapy

Status epilepticus is a rare complication of ECT. We describe a patient who suffered a prolonged seizure which required termination with intravenous diazepam. The status epilepticus was not accompanied by motor movements, and the diagnosis was made only because of simultaneous EEG monitoring. The incidence of status epilepticus after ECT may be underestimated.

Distinct memory impairments following electroconvulsive therapy and imipramine

Memory functioning was assessed in 26 unmedicated patients with major depressive disorder (DSM-III) who were then administered either bilateral electroconvulsive therapy (ECT) (N = 16) or imipramine 200 mg per day (N = 10). The subjects were retested following seven ECT administrations or 21 days of imipramine treatment respectively. The retrograde memory tasks included recall of public and autobiographic events. The anterograde memory tasks included an immediate memory task, a verbal paired-associates recall task, and a non-verbal figure reproduction task. Depression was significantly improved in the ECT-treated subjects but not in those administered imipramine. Both ECT- and imipramine-treated patients showed a deficit in recent anterograde memory relative to their pretreatment performance, but no deficit in immediate memory. ECT-treated patients also had a significant and well-characterized impairment in retrograde remote memory. By contrast, imipramine-treated patients did not show a retrograde memory impairment which could be explained by treatment. The results suggest qualitatively different memory deficits produced by ECT and imipramine.

Seizures and recovery from experimental brain damage

The effects of the gamma-aminobutyric acid antagonist, pentylenetetrazol (PTZ), on recovery from somatosensory and motor asymmetries after unilateral sensorimotor cortex lesions were investigated. Behavior was assessed using a bilateral tactile stimulation test and a measure of forelimb motor coordination. Immediately after surgery, the PTZ-treated and saline (SAL) control groups both exhibited severe ipsilateral behavioral asymmetries. Rats receiving PTZ recovered significantly faster from somatosensory asymmetry than those receiving SAL. Recovery was complete in the PTZ group within 3 postoperative weeks, while the SAL group failed to reach a comparable level until 2 months after surgery. There was no difference between PTZ and SAL groups on recovery of forelimb motor coordination. No difference in lesion size between the SAL and the PTZ groups could be found. These data are consistent with the hypothesis that post-traumatic neuronal depression may contribute to the severity of sensorimotor deficits observed after brain damage.

Leukoencephalopathy in elderly depressed patients referred for ECT

Using brain magnetic resonance imaging (MRI) and high-resolution computed tomography (CT), we identified changes in the subcortical white matter in 44 of 67 elderly depressed inpatients (66%) referred for electroconvulsive therapy (ECT). This "leukoencephalopathy" was frequently associated with other structural brain changes, including cortical atrophy, lateral ventricular enlargement, and lacunar infarctions of the basal ganglia and thalamus. Many (58%) of the patients had developed late-onset depressive disorders, and the majority (86%) had been refractory to and/or intolerant of antidepressant drug therapy. Nevertheless, all but 1 of the 44 patients subsequently responded to a course of ECT, which in general was well tolerated. Although the precise etiology of the leukoencephalopathy remains unclear, clinical data suggest that it may result from arteriosclerotic disease of the medullary arteries that supply the subcortical brain regions. Several lines of evidence suggest that leukoencephalopathy may have implications for the pathophysiology of depressive illness, at least in some elderly patients.

Effects of single and repeated electroconvulsive shock on local cerebral glucose utilization in the conscious rat

Local rates of cerebral glucose utilization (LCGU) were determined in adult rats submitted to electroconvulsive shock (ECS) treatment. One group of rats (n = 5) received a single ECS, a second group (n = 5) was treated once daily for 7 days. A third group (n = 5) of unshocked rats served as control. LCGU measurements were performed one day after either the single or the last ECS. Following a single ECS, most of the 45 brain regions examined exhibited lower rates of LCGU than controls, in contrast after repeated ECS treatment the metabolic activity results increased in segments of the hippocampus. The results indicate that repeated ECS treatment selectively increases metabolic rates within the hippocampus, a structure of the limbic system thought to be related to affective disorders and memory.

Neuropsychological aspects of disorientation

Patients were asked twelve orientation questions before ECT and during the recovery period (the postictal confusional state) following ECT. Disorientation was more severe in the elderly. The different orientation items did not recover simultaneously; different recovery times may enable patients to give responses that are logical contradictions. While certain models (e.g., "person" versus "place" versus "time") may be useful in describing the differential recovery of orientation items, other models based on memory will probably prove more useful in delineating what causes this differential recovery. Patients gave responses to age and current year that were displaced backwards in years from the correct response. It is suggested that this displacement represents retrograde amnesia. As the postictal confusional state cleared, however, these backwardly displaced responses decreased in years of remoteness, thus showing a pattern of "shrinkage" that is similar to shrinking retrograde amnesia following head-injury. It is suggested that this result supports Ribot's law of regression.