Japanese Journal of Veterinary Research;Volume 2, Number 1

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ON A CASE OF EPILEPSY IN A LION

OHBAYASHI, Masashi;FUJIMOTO, Yutaka

Permalink : http://hdl.handle.net/2115/1651
JaLCDOI : 10.14943/jjvr.2.1.11

Abstract

As for the changes of viscera except the central nervous system, there were observed congestion of parenchymatous organs, anthracosis of the lungs and pulmonary hilus lymph nodes, dirofilariosis of the heart and formation of parasitic nodular foci in the walls of digestive tracts and lymph nodes in abdominal cavity. Same changes macroscopically demonstrated were identified by micrscopical examinations of abdominal and thoracic viscera. The brain, on the contrary, showed marked macroscopical changes. At the time of autopsy, the lateral ventricles were dilated with increased fluid. Multiple focal small lesions could be found through careful examination after formalin fixation. It was clarified by microscopy that macroscopical focal colouration, which was presumable as the persisting hemorrhagic focus, was due to the accumulation of macrophages with hemosiderin pigments. The focus manifested a scarred change ; blood vessels, adventitial fibrous elements and macrophages, which are the mesodermal element, and the CAJAL'S glial cells, which are the ectodermal element, proliferated and formed a sclerotic focus or glio-mesodermal scar. In most of the foci, blood vessels, collagen fibers and argyrophile fibers proliferated reticulately accompanied by numerous siderocytes. Large glial cells with light nucleus, abundant protoplasm and marked projections were increased in the mesh, and formed the foci of anisomorphic gliosis. CAJAL'S impregnation method revealed abundant glial fibers in the foci. Demyelination was also remarkable in the foci. In and out of the focus, perivascular lymphocytic cell accumulations were observed, and blood vessels leading to the focus were often infiltrated by some siderocytes. Through the more detailed investigation it was, as expectable, proved that there were some foci of different histological stages among the foci. In the more scarred focus, glial tissue became a more homogeneous and stratified cluster in the central limited area. The focus became more clearly demarcated than in the usual state and the regional cerebral cortex showed atrophy also. The focus, finally, progressed until a cystic structure was constructed by the glial wall and vascular cluster with siderocytes in the center. In the more fresh focus it was less clearly demarcated and HORTEGA glial cells and gitter cells were scattered in the meshes of reticulately proliferated vascular fibrous structures together with CAJAL'S glial cells. Fat granules were also confirmed in mesodermal pigment cells. A small number of nerve cells, myelin sheaths and axis cylinders were demonstrated in such focus. In the meninges which were edematous and thickened, slight lymphocyte infiltration was observed and perivascular lymphocytic cell accumulation was often present in sulci. Wall of blood vessels in the nervous tissue and also in the meninges frequently showed thickening. Fibrous thickenings were confirmable in the adventitia of blood vessels which were occasionally attacked with hyaline changes of the wall ; lymphocytes and macrophages with fat and pigment granules were demonstrated in the adventitia. The VIRCHOW-ROBIN'S spaces were cially worthy of attention in these circumstances. Among them the vascular lesions are incomprehensible as senile changes ; the authors consider that chronic lymphatic congestion, so as to bring about dilatation of the lateral ventricles, had played a main role. The authors critically compared the case, for the purpose of differential dianogsis, with the diseases characterized by hemorrhages or degeneration of the nervous tissues, such as "mouldy corn disease" of horse in U.S.A. by SCHWARTE et al.(1937), "encephalomalacia" in various domestic animals, especially with that of sheep and horses reported by YAMAGIWA and TAJIMA (1952), and human "multiple sclerosis". However, the lesions observed in these diseases were absolutely different from the authors' case in the character, distribution and extent of the lesions."Epilepsy" is a clinical term and quite various pathological changes can be found in various diseases clinically manifesting the epileptic symptoms. Epilepsy is usually, in human medicine, divided into two groups "genuine or idiopathic epilepsy" and "symptomatic epilepsy". As to the pathological findings of the former, sclerotic foci of hippocampus and marginal gliosis of cerebral cortex, as the chronic changes, and focal necrosis of the nervous tissue due to local functional disturbances of blood circulation, as the acute changes, are chiefly mentioned. Pertaining to the histopathology of the latter, on the other hand, various neurological lesions are demonstrated in the cases of infectious disease, intoxication, tumour, parasitosis, trauma, senile changes, embryonal or infantile encephalitis etc. The authors, therefore, are able to conclude that the case described in this report should be categoried to symptomatic epilepsy.

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