A textbook of mental diseases.

  • Lewis, W. Bevan.
Date:
1899
Catalogue details

Licence: Public Domain Mark

Credit: A textbook of mental diseases. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

    646/749 (page 566)
    naked-eye examination, however, may indicate its existence by the altered contour of the cord, the column implicated being often shrunken, contracted, and the normal symmetry distorted. Again, section of the fresh cord in the former afiection (descending lateral sclerosis) exhibits the degeneration to the naked eye as a greyish, brownish, or fawn tint, and a translucency due to the diminution of meduUated sheaths of the nerve-fibres, as also to the preponderance of enlarged blood-vessels and connective elements. In the lesions of these columns in general paralysis these appearances are observed only where the process has been unusually active ; in the great majority of cases they require microscopic examination of specially-hardened chrome-specimens to reveal the degenerative condition. What is observed in such sections prepared and stained by the usu.d means is the deep tint taken up by the diseased tract; the vessels and trabecular tissue and intervening connective being so far predominant as to take up much more of the staining reagent than the healthy tracts, where the axis-cylinder is ensheathed by its normal amount of myeli'ne; if, before staining, such sections are cleared up and examined by transmitted light, the peculiar translucent aspect of the diseased tracts also suffices to map them out accurately to the naked eye. The intimate nature of the process is revealed by histological examination. It is thus found that, in the posterior half of the lateral column, reach- in- back to the posterior cornu, but bounded externally by a tract of hellthy nerve-tissue-^Ae dWect cerebellar tract-theve is a dark-stamed area in which the nerve-elements are in a state of inflammatory disintegration. The medullated fibres have lost a great part of their myeline, and are notably diminished in size-their axis-cyhnders, however, still remaining; here and there the nerve-fibres appear larger than usual, the medulla swoUen-faintly tinted with the dye (an indication (^f its necrotic stage)-and the axis-cylinder either displaced laterally or entirely absent. These enlarged fibres, seen in transverse sections, are but the swollen moniliform portions of the egra -g nerve-fibre divided at its largest diameter. To indicate this fact Tonc^itudinal sections through the column should be made, and examxned in tfetesh and in the mounted state. The nerve-fibres will then be ZL to be undergoing marked inflammatory change; a large proporUon Zy exhibit almost empty medullated sheaths, enclosmg a still- may exnio ^^^^^ axis-cylinder is itself :::e::;Td^ '^^^^^^^^^^ -d severed along its course; the : s d tne ate fibres show irregular enlargements along the. course often presenting a notably-moniliform aspect due to proliieration of rriucle — ^^^^^^^ ---^ - cellular element of