ISSN:0749-8055    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The similarities and differences between electroconvulsive therapy (ECT) and antidepressant medications are reviewed with respect to their clinical indications. The implications of the overlap and divergence in their spectra of clinical efficacy are discussed in reference to mechanisms of action. The hypothesis is offered that ECT has multiple mechanisms of action, which differ depending on the clinical syndrome being treated. From this perspective, ECT may share similar mechanisms of action with other agents that are also effective in treating the specific syndrome. Thus, although ECT may result in a plethora of neurobiological effects, depending on the clinical syndrome, specific and differing subsets of neurobiological changes are relevant to therapeutic action.

ISSN:0749-8055    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The available evidence indicates that electroconvulsive therapy (ECT) has a marked and specific antimanic effect. Data on change in seizure threshold during ECT and acute effects of ECT on cerebral blood flow are presented in support of the view that the therapeutic effects of ECT are related to its anticonvulsant properties in manic patients. Specifically, an antimanic effect of ECT was associated with a significantly greater increase in seizure threshold during bilateral ECT and, across treatment conditions, with a significantly greater reduction in cerebral blood flow acutely following ECT. A low initial seizure threshold during bilateral ECT was found to be associated with a poor therapeutic response. This, along with earlier findings in depressed patients, suggests that heterogeneity of the disease processes underlying mood disorders may be critical for an understanding of the mechanisms of action of ECT.

ISSN:0749-8055    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

This article critically reviews the six controlled studies of the anti-depressant effects of right unilateral versus left unilateral ECT (R-ECT, L-ECT), contrasting them with results recently obtained in double-blind, random assignment comparison of the two methods, using a square-wave stimulus, widely spaced temporoparietal electrode placement, and markedly supra-threshold stimulus charge. The author challenges the prevalent belief in a therapeutic advantage of R-ECT versus L-ECT, proposing instead the contrary case for a therapeutic advantage of L-ECT, based on the interaction of a hypothesized interhemispheric seizure threshold difference and a maximally efficient method of stimulus delivery.

ISSN:0749-8055    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Since its first use in humans 50 years ago, electroconvulsive therapy has been a controversial topic. Nevertheless, a great many experimental and clinical data have been collected. Much of it strengthens the notion that ECT is a more specific therapy than it appears at first sight. The pharmacological effects of ECT seem to be directed toward changes in signal transduction chain processes in the synapse and on the postsynaptic cell membrane. Some aspects of this have been well investigated, especially the effects of ECT on membrane receptors, whereas others have only recently evolved. This article discusses some general principles and conclusions and focuses on some very recent data acquired with new laboratory techniques, such as in vivo dialysis and molecular biology. An attempt is made to interpret these new data and to integrate them in previous results.

ISSN:0749-8055    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Since the discovery of opioid peptides, the brain opioid system has been implicated in the pathophysiology of a spectrum of mental disorders, including depression and epilepsy. For example, a growing body of evidence demonstrates that these neuropeptides are activated by seizures. Specifically, using electroconvulsive shock, it has been possible to describe an array of antinociceptive, autonomie, behavioral, biochemical, and electroencephalographic responses that appear to be mediated by endogenously activated opioids. A primary role for opioid peptides as neuromodulators of postictal seizure arrest and refractoriness is now recognized, and the existence in the central nervous sytem (CNS) of an endogenous anticonvulsant substance activated by electroconvulsive shock (ECS) has been determined. This review focuses on the more recent developments regarding ECS-induced modulation of brain opioid systems. The ability of ECS to alter opioid receptors, to influence the release and biosynthesis of the various opioid peptides, and to activate endogenous anticonvulsant mechanisms will be addressed.

ISSN:0749-8055    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Although the mechanism of action of electroconvulsive therapy (ECT) in affective illness has remained elusive, it is hoped that the consideration of mechanisms underlying the anticonvulsant efficacy of ECT will provide new insights into its biochemical and neuroanatomical substrates. In the amygdala-kindling model, electroconvulsive seizures (ECS) inhibit both the development and completed phases of kindled seizure evolution, and therefore, ECS is a more potent anticonvulsant modality than carbamazepine, which inhibits only completed kindled seizures. Carbamazepine is increasingly recognized for its acute and prophylactic efficacy in bipolar affective illness. Thus, comparing and contrasting effects of ECS and carbamazepine may provide insights into overlapping mechanisms of anticonvulsant and psychotropic action. Anticonvulsant effects of ECS have been most closely linked to endogenous opiate substances, perhaps acting on delta-opiate receptors, but a wide variety of other neurotransmitter and peptidergic effects are also potential candidates. Electroconvulsive seizures in mice activate the proto-oncogene c-fosin many discrete areas of brain, including a variety of limbic sites, the ventromedial nucleus of the hypothalamus, and the cerebellum. As such, c-fosinduction may provide both an anatomical map of areas potentially activated by ECS and a potential mechanism for initiating a sequence of events that may be important to the mechanism of action of ECT. Although the anticonvulsant effects of ECT may ultimately prove to be separable from those mediating its therapeutic effects in affective illness, seizures and anticonvulsant effects provide easily measurable endpoints for preclinical and clinical studies. Given this clarity of effect, potential anticonvulsant mechanisms can rapidly be identified, enabling direct testing of whether or not these same mechanisms are also critical to the therapeutic effects of ECT in affective illness.

ISSN:0749-8055    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

A neuroendocrine hypothesis to explain the clinical activity of convulsive therapy is described. The hypothesis is based on the diabetes/insulin model and suggests that hypothalamic dysfunction with an insufficiency of a mood-maintaining peptide is the basis for affective disorders. Repeated seizures enhance the production and release of the hypothalamic peptideantidepressin-the active principle that relieves both neuroendocrine and behavioral abnormalities.

ISSN:0749-8055    

出版商:OVID    

年代:1989

数据来源: OVID

ISSN:0749-8055    

出版商:OVID    

年代:1989

数据来源: OVID