THE HISTOLOGY OF DISSEMINATED SCLEROSIS. 625 



(6) Conclusion. 



1. General Features and Distribution of Areas in Case I. 



The number of areas was very large and their distribution throughout the central 

 nervous system was very extensive. The parts most involved were the cervical 

 enlargement of the spinal cord, the medulla oblongata, the pons, and the peri- 

 ventricular tissue. The most striking histological feature was that almost every 

 area showed evidence of an advancing process (figs. 64-69). The areas were thus 

 wholly in an " early" stage or showed a peripheral advancing zone around a central 

 condensed zone, and the impression the latter areas left was that the primary 

 affection had never died down, but had gradually extended peripherally, while the 

 central sclerosis had also extended eccentrically. A further striking feature was the 

 presence of very extensive areas of "shadow" sclerosis, which united the areas of 

 demyelinated tissue. It is unnecessary to enter into the structure of the areas, as 

 this has been fully given in the earlier part of the study : the great majority were 

 at the height of the fat granule formation and had not reached the stage of 

 commencing glia fibril formation. 



In the spinal cord the cervical enlargement was very markedly affected : the 

 dorsal cord much less so, except at the level of D 10, which showed a complete 

 transection (fig. 58) : the lumbar cord was also comparatively slightly affected, but 

 almost the whole sacral cord showed a demyelination (fig. 63). The most striking 

 feature of the cord affection was that with one or two exceptions no isolated areas 

 could be traced. The exceptions were in the dorsal cord, and one of these (fig. 66), 

 cut in serial sections, extended about one-third centimetre in longitudinal extent, 

 and at each end gradually passed into normally staining fibres. The central portions 

 of the posterior and lateral columns were the most densely sclerosed, but round the 

 periphery of even these parts there was a zone more or less wide of fat granule cells ; 

 and radiating vessels, with their lymphatic sheaths filled with similar cells, passed 

 from this zone to the circumference of the cord. The frequent symmetry is well 

 brought out in figs. 49 and 59. Bielschowsky preparations showed a marked 

 diminution in the number of axis cylinders, and those persisting were swollen and 

 stained faintly. The ganglion cells showed all stages of degeneration and at no level 

 were they normal : numerous atrophic forms with central chromatolysis and absence 

 of processes could be found in the demyelinated tissue at almost every level, where 

 the grey matter was affected (fig. 410). The membranes of the lumbo-sacral cord 

 were slightly thickened and infiltrated with cell elements. 



The areas in the medulla oblongata and pons were much more sharply defined, 

 as a rule, than those in the cord. Their most striking feature was the large number 

 that showed a zone of " shadow" sclerosis around them. This was specially evident 

 in the areas occurring amongst the transverse fibres of the pons and grey nuclei, and 

 such shadow sclerosis had here the same defined outline as the central area. The 



