THE HISTOLOGY OF DISSEMINATED SCLEROSIS. 545 



possible to recognise a few axis cylinders. Schob has recognised the importance 

 of examining the nerve roots in their longitudinal course. Several roots showed 

 disease in their whole length : the emergent root zone showing a glious sclerosis, 

 and the immediately adjoining tissue a connective-tissue sclerosis. On the other 

 hand, in a few roots it was recognised that the affection was strictly limited to 

 circumscribed areas, into which one could follow non-degenerated myelinated fibres, 

 distal to the glious root emergent zone. Only one peripheral nerve, the right 

 crural, was preserved, and in this similar degeneration was found. In criticising 

 such findings it is necessary to state, firstly, that as the spinal ganglia were not pre- 

 served the portion of nerve roots attached was short, and secondly, that the only 

 justification for asserting the non-glial content of the tissue seems to have been 

 that these changes affected root sections where the nerve fibres are normally sur- 

 rounded by Schwann sheath. It must be remembered that the glious zone reaches 

 for a very varying distance into both cranial and spinal nerve roots, and that one 

 can frequently recognise glia islets appearing in a part far into the connective- 

 tissue portion of the root. It is difficult, therefore, to exclude the possibility of the 

 glia-containing root emergent zone being primarily affected and the possibility of 

 secondary degeneration. 



Volsch (1908) describes very minutely the changes in a case of " acute multiple 

 sclerosis." His choice of this designation instead of acute disseminated myelitis 

 indicates, in his opinion, both the assumption of the influence of an exogenous factor, 

 and also the supposition that the process depends on a primary proliferative process 

 in the glia — this process depending only in part on the direct action of the 

 exogenous factor. The illness set in with a gradually increasing weakness of the 

 legs, which was followed by paralysis of the abdominal muscles, flaccid paralysis 

 of the legs, and severe decubitus : the patient died four months after the onset 

 of the illness. The characters of the sclerotic areas, which were very numerous 

 in both brain and spinal cord, are very similar to those previously described as 

 typical of disseminated sclerosis. In the centre of most areas was a compact glia 

 proliferation, surrounded by a looser glia structure, which gave an areolar appear- 

 ance to the periphery. In addition to these areas, the author describes diffuse 

 alterations in the cord, which consist of a lighter staining of the myelin, 

 together with a marked hyperplasia of the septal glia. The vessels in these 

 latter areas were almost normal. This diffuse septal glia hyperplasia often ex- 

 tended over the whole transverse section, and in Marchi-stained sections the 

 nerve fibres showed deeply stained granules of degeneration surrounding the 

 axis cylinder. 



Volsch looks upon the typical areas as the essential substratum of the disease : 

 they were mostly at a uniform stage of development, already far advanced, and 

 undoubtedly owed their origin to an unknown exogenous " noxa." On the other 

 hand, he thinks that the areas of a more diffuse gliosis are related more probably 



