[Morphologic image of structures of the limbic system in rats after prolonged administration of antiepileptics]

Morphological changes in the anatomical structures of the limbic system induced by phenytoin and ethosuximide administered in effective doses for 1, 3 and 6 months in rats were analyzed. The clinical symptoms consisted of some vegetative and behavioral disorders, mostly transitory. Differences in gain of body weight depending on the sex of the animal and the drug administered were observed. The morphological changes in the parenchymal and mesenchymal nervous tissue elements were not specific with regard to their topography or to the type of pathological process. Some morphological differences depending on the drug and its period of administration were observed only in rats treated for 1 and 3 months. The neuropathological picture in rats treated with both drugs for 6 months showed a great similarity. The pathological process in the ganglionic cells had the character of degeneration. Morphological changes in the myelin sheaths were due to edema which appeared to be vasculogenic and situated in the white matter. Focal and diffuse proliferation of cellular glia appeared after administration of both drugs for 1 and 3 months while in those treated for 6 months the degenerative changes were seen. The anatomo-comparative study of the neuropathological picture in the rats treated with both drugs and the morphological picture of the limbic system structures in patients with chronic epilepsy indicates that the drugs examined could play some role in the pathogenesis of the limbic system lesions encountered in epileptics.