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.

Morphology of tracheal scar after resection with CO2-laser and high-frequency cutting loop. A study in normal pigs

In 6 pigs a bronchoscopical resection of the tracheal mucosa was performed using CO2-laser on one side, and an electric high-frequency cutting loop (ECL) on the other. The pigs were sacrificed 3 months later. On macroscopic examination the tracheal mucosa appeared almost normal on the laser-resected side, while severe deformation was seen after ECL treatment. Microscopically the respiratory epithelium had regenerated irrespective of the instrument used. After laser resection the subepithelial tissue had a normal width and consisted of collagen fibrils with few vessels and sparse fragmented elastic tissue. The cartilage showed necrosis and pericellular fibrosis. The scar tissue after ECL was a broad cellular and richly vascularized connective tissue. The content of elastic fibres was markedly greater than after laser resection. The cartilage showed small irregular necroses lined by pyknotic nuclei. In neither case had the gland regenerated. Both CO2-laser and ECL caused severe (but not identical) damage to the tissue, clearly visible after 3 months. However, the deformation caused by ECL was not seen at the laser-resected sites, which makes the laser technique seem preferable--where economy permits.

Postanaesthetic arousal time in elderly patients. A double-blind study of glycopyrrolate and atropine

Postanaesthetic arousal time was studied in elderly patients given either glycopyrrolate 0.01 mg kg-1 or atropine 0.02 mg kg-1 before antagonism of neuromuscular blockade. Forty patients (age greater than or equal to 65 yr) undergoing elective hip replacement were included in a double-blind study. Arousal was scored for 2 h after recovery using a modified scoring system. No difference in arousal time was found between the two groups.