Plate IX.
Click image to enlarge

Plate IX. Frommann's Original Explanations:
Figg. A,B. Cross-sections through the spinal cord's cervical (A) and lumbar (B) enlargements. The darkness of the shading reflects the intensity of the tissue degeneration. In its thoracic sections, the spinal cord was affected throughout, while the cervical and lumbar section were mainly affected in their flanks.

Figg. A and B show a roughly wedge-shaped damaging of the spinal cord's sides. In fig. A, most of the cervical grey matter appears involved as well. Fig. B pictures, in addition, a lance-shaped lesion extending along the lumbar spinal cord's posterior median septum.

Figg. C,D. The central (C) and posterior (D) parts of the lesion to the left side of Fig. A have been more strongly magnified. These microscopical findings seem most important for a proper understanding of the spinal patches' manner of growth. a, "cortical layer", covering up the cord's functional tissue; a', vessel-related tissue clefts; b, fibrosed lesion core; c, paravascular tissue cleft not yet seamed by a "cortical layer"; d,d', blood vessels.

Both figures show the sclerosed spinal patches' jagged, pointed and angulated extensions, also described as the lesion's fringe zone, gradually tapering off and fluidly inserting into prominent strands of the normal interstitial framework of the lesion's neighborhood -- sided by inconspicuous myelin sheaths.

Fig. E. a,a, sclerosing interstitial meshworks of the lesion's advancing edge (aggravation of the changes from above downwards); the fibrosis affects both torn meshworks, meshes with normal or dwindling nerve fibers, as well as meshes in which the nerve fiber's cross-sections can no longer be discerned; b, small blood vessel whose wall appears markedly thickened.

Fig. F. Surface segment of thoracic spinal cord cross-section (a, pia -- the organ's fibrous cover; b, clumps of homogenized tissue; c, emptied and variously altered intersitial fibrous meshworks; d, thickened axon, denuded of its myelin sheath (the other three axons invested by a very broad one).

The Lesion's Main Histological Peculiarities:
The very inhomogenous tissue affections are, despite the involved interstitial frame- and meshworks' tendency to primarily hypertrophy, occasionally marked by ruptured or fused fibrous structures, even in the presence of spared nerve fibers and myelin sheaths. The fibrous hyperplasy culminates in the formation of the spinal patch's dense sclerosed core in the direction of which different proportions of both myelin sheaths and axons dwindle, the former disappearing at a somewhat faster pace.

The vascular and vessel-related changes are again very diversified: The small blood vessels of the patches' fringe zone show mostly bizarre wall broadenings, while vessel stems inserting into the spinal cord's sides may extend through coarse perivascular clefts.

The Study's Informative Value:
Because of its intricate structure and many reiterations of meticulous microscopical observations, the text is not easily accessible. However, it appears to be the most thorough and comprehensive account on the histology of Carswell's "remarkable spinal cord lesion", i.e. spinal multiple sclerosis.

© Dr. F. Alfons Schelling, M.D.