小脳の変性病変に関する病理組織学的研究

抄録

1. Histopathological investigation were performed on the cerebellum of 54 autopsy cases in order to elucidate the pattern of degenerative lesion and its destribution in the cerebellum and 35 control cases of vavious age without any gross lesion in the central nervous system.
2. In cases with atrophy of the afferent cerebellar systems, the change in the cerebellum appeared as degeneration of the cerebellar white matter. In 3 cases of olivo-ponto-cerebellar atrophy, the pallor in myelinstaing was observed in the white matter of cerebellar hemisphers. In the vermis cerebelli, the change was confined to the medullary lamina of the monticulus. The degeneration was therefore pronounced in phylogenetieally newer part of the cerebellum. In some cases with degeneration of the spinocerebellar tracts in the medulla and spinal cord on the other hand, the degenerative lesion could be traced even in the medullary lamina of the anterior lobe of the cerebellar vermis.
3. There were 9 cases which showed extensive foci in the unilateral cerebral hemisphere and degenerations in the ipsilatereal corticospinal and corticopontile tracts on the level of the brainstem. Five of these 9 cases showed atrophic or degenerative lesion in the cerebellar hemisphere, contralateral of the cerebral hemisphere with foci, There was, however, no regularity in the distribution of foci in the cerebellum and histological features of the lesion were not identical in their nature, No sufficient findings were, therefore, obtained to support the presence of the so-called crossed cerebro-cerebellar atrophy, resulting from combination of the two degenerations through a definite fiber system.
4. In cases of patients who had clinically manifested epileptic fits, was observed characteristic lesion loss of Purkinie cells associated with glial shrub formation in the molecular layer of the cerebellum, These cases were also characterized by particular distribution of foci, being remarkable in deeper folia and in the depth of sulci.
5. Fusiform swelling of the Pnrkinje cells axon, which is known by the name of “torpedo”, was observed in a case of cerebello-olivary atrophy and in aged cases with abundant senile plaque and marked Alzheimer'stype of neurofibrillary change of nerve cells in the cerebral cortex, but more frequently it was observed in those cases which showed, such degeneration of the myelinated fibers in the cerebellar white matter as olivo-ponto-cerebellar atrophy, Implication of this lesion as an alteration of Purkinje cells, which is transneurally induced in association with white matter lesion, is worth to notice.
6. In 7 of the 54 investigated cases, the so-called acute selective necrosis of the cerebellar granular layer was observed, This lesion is characterized by reduced stainability of nerve cells of the granular layer, and is found extensively and irregularlly distributed in the deeper folia. It is little significant as a process, since it lacks glial cell reaction.
7. As the lesions of the cerebellar parenchyma associated with aging, there were decrease in number of Purkinje cells, increase of dark stained and atrophied Purkinje cells, proliferation of Bergmanns glial cells, formation of torpedo of Purkinje cell axon, dendritic expansion of Purkinje cells and waste pigment accumulation in nerve cells of the dentate nucleus, Purkinje cell lesion tended to be pronounced in the superior vermis and in the summits of convolution of the superior cerebellar hemisphere. Purkinje cells which occurred heterotopically in the molecular layer had no relation with aging, Almost all the cases showed focal lobular sclerosis or dysplasia in the nodulus, uvula and pyramis of the vermis cerebelli, and in the biventral lobule of the cerebellar hemisphere.