THE HISTOLOGY OF DISSEMINATED SCLEROSIS. 705 



different stages of development, but here, perhaps more than in any other case, these different 

 stages gave the impression of having been quite independent in time and not, as was so fre- 

 quently the case, an extension of an already-existing process or the addition of a new process 

 to one not already exhausted. Further, even in the densest areas of sclerosis, longitudinal 

 sections showed that even the finest capillaries were patent : such capillaries could be traced 

 over long stretches with a single or double row of red blood cells within their lumen. The 

 vessel walls were, therefore, not so condensed as was often the case. And still further, it 

 may be noted that in the lateral columns there were indications of a slowly-increasing glia 

 hyperplasia, and in the optic nerves, in keeping with this finding, there was a very marked 

 chronic interstitial change affecting both the connective tissue and the glia elements. Cajal 

 and Bielschowsky preparations allowed numerous axis cylinders to be recognised, and the 

 ganglion cells showed changes, mostly of an atrophic nature. The meninges were not 

 thickened, but in the lumbar cord there was found a slight cell infiltration. 



The medulla and pons were comparatively slightly affected in comparison with the 

 changes found in most of the cases, but the roof and angles of the IVth ventricle showed 

 a slightly greater degree of involvement than the floor and lateral walls. The brain in this 

 case was not examined in large sections. 



Topographical Distribution. 



Spinal Cord. — Cervical Region (figs. 148-149). — In sections at the level of the third cer- 

 vical segment, the sclerotic areas are very symmetrically placed : one occupies the posterior 

 region, and other two, almost triangular in outline, are in the antero -lateral columns, separated 

 from the posterior horns by fibres which stain faintly. On both sides these areas reach 

 almost to the periphery of the cord. The posterior area is large and oval and extends from 

 the base of the anterior fissure, across the commissures, almost to the posterior margin of 

 the cord. Two projections, which pass laterally from this area, almost map out the pos- 

 terior horns. In C4 this arrangement of the sclerosis is continued, but both the antero- 

 lateral areas have increased in size and reach to the periphery, and the posterior area is 

 subdivided into four — one around the central canal, one in each posterior horn, and one 

 V-shaped, with the apex of the V in the anterior third of the posterior columns. The tissue 

 between these areas stains faintly. At C5 the areas have greatly diminished in size : the 

 two antero-lateral ones are now small but still triangular in outline, and reach from the 

 grey matter of the anterior horn to the surface — on one side involving the greater part of 

 the postero-lateral group of nerve cells. The other, subdivided, areas are still present, 

 but smaller in size, the posterior one being an almost equilateral triangle bisected by the 

 posterior median fissure. At C6 the largest area occurs as a broad band stretching from 

 the central canal to the surface along the posterior median fissure. Narrow bands are 

 present along the two sides of the anterior fissure, and the glia border zone is considerably 

 widened along the anterior surface of the cord. Several minute areas are present, distributed 

 irregularly in the white matter and posterior horns. At C7 the symmetry of the sclerosis 

 is again very marked and corresponds closely to that found in C4. From a peri-central 

 sclerosis bands radiate posteriorly and laterally, widening considerably as they pass towards 

 the surface. These areas thus involve large portions of the anterior and posterior grey 

 matter on either side : they are separated from the surface of the cord by bands, varying 

 in width, of normally-staining fibres. Zones of diffusely and faintly-staining fibres occur 

 around all these areas. 



Dorsal Region (figs. 150-152). — In the first dorsal segment the arrangement is a modifica- 

 tion of C7, but the patches are much more defined in shape, involve more of the grey matter, 

 and the symmetry is not quite so striking, for the posterior sclerosis extends on one side to 

 involve the whole of the posterior horn, and it is united by a narrow band to the sclerosis 



