. The elements of pathological histology with special reference to practical methods . dother cranial nerves. It must also be mentioned that so-calledcorpora amylacea are often found in the degenerated posteriorcolumns of the spinal cord, especially in their peripheral parts,though the presence of these bodies seems to be connected muchless with the atrophy of the nerve-fibres than with the more orless advanced age at which tabes usually comes on (see p. 56).Less common is a second form of primary tract-degeneration, Y S38 THE CENTRAL NERVOUS SYSTEM viz., amyotrophic lateral sclerosis. This be
. The elements of pathological histology with special reference to practical methods . dother cranial nerves. It must also be mentioned that so-calledcorpora amylacea are often found in the degenerated posteriorcolumns of the spinal cord, especially in their peripheral parts,though the presence of these bodies seems to be connected muchless with the atrophy of the nerve-fibres than with the more orless advanced age at which tabes usually comes on (see p. 56).Less common is a second form of primary tract-degeneration, Y S38 THE CENTRAL NERVOUS SYSTEM viz., amyotrophic lateral sclerosis. This begins in the lateral columnsand then extends to the anterior horns, especially in the cervicalregion, and to the motor nuclei of the fourth ventricle, notablythose of the hypoglossal, facial, and spinal accessory nerves. Inmany cases the lateral columns are not affected in their entirethickness, but merely the crossed pyramidal tracts (Fig. 164, a)\and, in case the cord still contains undecussated anterior pyramidaltracts, these are also affected (Fig, 164, h). In the anterior horns. Fig. 104.—Amyotrophic Lateral ScLh;Rosis. About x 5. (Ammonia carmine.)a, Degenerated crossed pyramidal tracts ; h, Degenerated direct pyramidal tracts;c, Anterior horns, with atrophy of the ganglion ceUs. it is the ganglion cells of the most anterior parts that are chieflydestroyed. It need hardly be said that the atrophy also involvesthe nerves springing from the nuclei, as well as the whichthese nerves supply. Under certain circumstances the degenerationmay even ascend as high as the pons and crura cerebri. 3. Haemorrhage and (Edema, etc.—The hcenionhages are either punc-tiform (capillary apoplexies) or larger effusions (haemorrhagic foci).The former take place in inflammations, in embolism or atheroma ofthe smallest cerebral arteries, in acute infective diseases (diphtheria,anthrax, etc.), in morbus maculosus Werlhoffii, in phosphorus poison-ing, and so forth ; whilst the latter onl
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectpatholo, bookyear1895
