A long-term study of the effects of electro-convulsions on the structure of the cerebral cortex

Does electroconvulsive therapy cause brain damage?

Although the use of ECT has declined dramatically from its inception, this decrease has recently shown signs of leveling out because of ECT's powerful therapeutic effect in severely ill depressed individuals who either do not respond to pharmacologic alternatives or are too ill to tolerate a relatively lengthy drug trial. Notwithstanding its therapeutic benefits, ECT has also remained a controversial treatment modality, particularly in the eye of the public. Given the unsavory qualities associated with the word “electroconvulsive,” claims of possible, probable, or even certain brain damage with ECT have easily found listeners. A careful, nonselective assessment of data covering the areas of pathology, radiology, electrophysiology, biochemistry, and neuropsychology leads both to certain conclusions and to certain unanswered questions. ECT is not the devastating purveyor of wholesale brain damage that some of its detractors claim. For the typical individual receiving ECT, no detectable correlates of irreversible brain damage appear to occur. Still, there remains the possibility that either subtle, objectively undetectable persistent deficits, particularly in the area of autobiographic memory function, occur, or that a rarely occurring syndrome of more pervasive persistent deficits related to ECT use may be present. Clearly, more research directed toward answering these questions needs to be carried out so that the role of ECT can be more rigorously defined. While such research is pending, however, we cannot expect that the conditions that predispose to clinical referrals for ECT will disappear. Given the misery, anguish, and risk of death by suicide, starvation, or debilitation associated with severe depressive illness, for example, it still appears that ECT, at least for the present, must continue to be available.

Unaltered neuronal and glial counts in animal models of magnetic seizure therapy and electroconvulsive therapy

Anatomical evidence of brain damage from electroconvulsive therapy (ECT) is lacking; but there are no modern stereological studies in primates documenting its safety. Magnetic seizure therapy (MST) is under development as a less invasive form of convulsive therapy, and there is only one prior report on its anatomical effects. We discerned no histological lesions in the brains of higher mammals subjected to electroconvulsive shock (ECS) or MST, under conditions that model closely those used in humans. We sought to extend these findings by determining whether these interventions affected the number of neurons or glia in the frontal cortex or hippocampus. Twenty-four animals received 6 weeks of ECS, MST, or anesthesia alone, 4 days per week. After perfusion fixation, numbers of neurons and glia in frontal cortex and hippocampus were determined by unbiased stereological methods. We found no effect of either intervention on volumes or total number or numerical density of neurons or glia in hippocampus, frontal cortex, or subregions of these structures. Induction of seizures in a rigorous model of human ECT and MST therapy does not cause a change in the number of neurons or glia in potentially vulnerable regions of brain. This study, while limited to young, healthy, adult subjects, provides further evidence that ECT and MST, when appropriately applied, do not cause structural damage to the brain.

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.

Hippocampal neuron density and seizures in the Mongolian gerbil

Mongolian gerbils of the seizure-sensitive strain exhibit epileptic seizures in relation to changes in the environment, a characteristic which has been increased to about 100% by inbreeding. The seizures vary from animal to animal but are rather stable in the individual animal, which makes it possible to study the neuron densities in the hippocampus of the gerbil in relation to seizure type and seizure intensity. Five groups of gerbils with seizures ranging from minor movements and motor arrest to intense generalized convulsions were investigated with a quantitative method including cell counting by light microscope and estimation of possible brain shrinkage, as well as determination of nucleoli and nuclei diameters. The cell densities were determined in different areas of the pyramidal cells of the hippocampus (H-fields). The study discloses a reduction of cell densities in fields H2 and H3 in relation to intense generalized convulsions. It is suggested that the reduction in cell density in field H2 is a result of seizure activity, whereas the field H3 cell loss can be the result of both the hypoxia and the seizure activity.