Secondary degenerations of the spinal cord : The Gulstonian Lectures delivered at the Royal College of Physicians, March 1889.

  • Tooth, Howard Henry.
Date:
1889
Catalogue details

Licence: Public Domain Mark

Credit: Secondary degenerations of the spinal cord : The Gulstonian Lectures delivered at the Royal College of Physicians, March 1889. Source: Wellcome Collection.

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

    98/120 (page 70)
    7° from it, according to the level of the section, in what appears to be a rounded tubercle. This is the substantia gelatinosa Rolandi, and is probably not nervous at all. What appears as the tip of the horn is in reality the posterior root fibres passing to pierce the substantia gelatinosa. The zone which lies between the substantia gelatinosa and the edge of the section is called by Lissauer the Randzone, or border zone. This zone in the lumbar and sacral region is broad because the substantia gela- tinosa is broad, and short because the substantia gelatinosa comes close to the surface. In the lower dorsal region the substantia gelatinosa is a long way from the surface, and therefore the border zone is long and narrow, lying on each side of the fibres passing to enter the horn. Now, this zone after staining by Weigert's haematoxyHn has a fine stippled appearance, which is due to the great number of fine fibres seen in transverse section. This zone in the upper dorsal region recedes from the surface more and more, till it becomes, as it were, applied in the sub- stantia gelatinosa. It is small in the cervical region, but in the vicinity of the entering fibres of the posterior roots there are always grouped a number of small fibres, and therefore this border zone cannot be said to be absent anywhere in the cord. Its significance is that it marks the entry of the fine fibres from the posterior roots. It is very consistently sclerosed, as Lissauer has pointed out, in tabes, a circumstance which will, as our knowledge grows, no doubt account for many of the obscure visceral symptoms of that disease. It is, of course, degenerated secondarily to section or disease of posterior roots of that side, but the degeneration rarely extends far up, and therefore it is most likely that its fibres pass sooner or later into the posterior vesicular column or into the posterior median. The border zone then bears the same relation to the fine fibres as the postero-lateral does to the large. Bechterew,* in 1885, had anticipated Lissauer somewhat by showing that this zone develops in the embryo at a time distinct from the rest of the posterior region.f * Bechterew., Neurol. Centralbl., 1885, p. 369. j- See also Sherrington, Brain, vol. ix„ p. 342.