| Objective: 1 Investigate the functional changes of the cat's motor cortex following MST or cortex thermocoagulation, compare the changes of pathology and ultrastructure in the damaged cortex in different time after transections or thermocoagulations. 2 Establish acute epileptic models in the cats' motor cortex by penicillin injection, then observe and compare the changes of epileptic seizures following MST or thermocoagulation.Evaluate the difference of therapeutic efficacy between MST and cortex thermocoagulation. 3 Discuss the advantages and disadvantages of the two kinds of operations by comparing the safety and effectiveness of MST with that of thermocoagulation in seizure control.Materials and methods: 1 Expose the motor cortex of the dominant hemisphere in cats,then perform transections or thermocoagulations in them.During postoperation, the changes of the activities of behavior were observed. Put those cats into death and then obtain the damaged cortex for analysis of pathology and ultrastructure in different time of postoperation. 2 Establish focal epileptic models induced by penicillin in the motor cortex of cats. Then applied transections or thermocoagulations in those epileptic foci. Postoperations, the changes of eletrophysiology and muscular spasms were observed.Results: 1 Behavior changes:Following cortex thermocoagulations, weak muscle strength of right limb and unstable gait were found in one cat,and then recovered little by little in a week.Postoperations, hemiplegias and other abnormal- 4 -behaviors were not found in other cats.2 Microscopic findings: The major morphological change after transection was an irregular crevice which was vertical or obliquitous with the surface of the cortex.and there was a fresh or obsolete bleeding in it. The depth of those crevices were unaltered with the change of time. Extensive acute pyknosis and tissue edema were also evident adjacent to the transactions.One month later, diffuse gliosis, minimal cystic alterations were all found around the transections, and the crevices were still existed.Postoperations, the major morphological change of thermocoagulation was an arc destroied band between the apexes of the two forcipes. In the acute period,evident acidophilic degeneration and necrosis could be observed in the upper area of the lesion, and also pyknotic neurons were found.Below the necrotic region there was an obviously edematous region. Gradually, the neurocytes within the injuried region decreased and the nerve tissue collapsed.Thus it finally resulted in a lesion looked like a necrotic cavum.Consequently, the depth of the lesion deepened as time went by.Synchronicly, mild gliosis and obviously collagenous fibers hyperplasia were found around the former edematous region.3 Changes of ultrastructure: The changes of ultrastructure following thermocoagulations or transections were not showing no difference. The neuronal necorsis was obviously their common ground. But in difference, the necrosises after thermocoagulations seemed more serious than that of transections, while transections could lead to more reliable damages on the dendrites, BBBs, myelinated and unmyelinated nerve fibers than thermocoagulations.4 Seizures controliafter the acute focal epileptic models induced by penicillin were established successfully, sporadic or multiple spike waves, sharp waves and then spike and wave complexes appeared in EcoG. These individuals showed muscular spasms on the opposite lateral face and limbs.Exceptionally, the EcoG showed a rhythmic activity, in which continuous spike waves were found (frequency: 20-30times per second), and these individuals showed GTCS.Without operational control, the epileptic seizures would spontaneously controlled in four and a half hours on average. While treated with transections or thermocoagulations, the majority of the experimental seizures could be completely controlled in several minutes. In the other minorities treated with operations,although not as satisfactory as those interfered... |
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