THE HISTOLOGY OF DISSEMINATED SCLEROSIS. 541 



The blood-vessels of the cortex and of the membranes and the membranes themselves 

 were normal. 



A further peculiarity was the presence of numerous tumour-like swellings on the 

 anterior and posterior roots close to the cord. Microscopically these showed degenera- 

 tion of the myelin sheath, marked proliferation of the Schwann nuclei, and persistence 

 of the axis cylinders. Later, the axis cylinder disappeared and the central part of 

 the nucleated hyperplastic zone became hyaline and structureless. The spinal ganglia 

 and peripheral nerves were not preserved. 



In correlating the clinical and anatomical appearances two points of importance 

 stand out : (l) the considerable diffusion of the ganglion cell changes in the cortex 

 and the apparently normal intellectual and psychical functions ; (2) the appearance 

 of posterior root changes without any sensory disturbances. 



Spiller and Camp (1904) give an account of two cases, one of which was of the 

 type of a multiple myelitis. They regard it as exceedingly difficult to determine 

 the relation of disseminated sclerosis to multiple myelitis. In the latter disease the 

 areas of sclerosis are much less sharply denned, and in some cases the peri- vascular 

 cellular infiltration is marked without any close relation to sclerotic areas. The 

 authors emphasise the frequent implication of the visual tracts in disseminated 

 sclerosis, the most frequent seat being the optic chiasma. The disturbance of vision 

 may be slight compared with the anatomical alterations. Ophthalmoscopic 

 examination is of great importance, in every case presenting symptoms that can be 

 attributed to disseminated sclerosis, and pallor or even atrophy of the discs may 

 exist even when the vision is not complained of. 



Dercum and Gordon (1905) describe the anatomical findings in a case of 

 disseminated sclerosis and briefly discuss its pathogenesis. They think it is unlikely 

 that the relation of the blood-vessel changes to the sclerosed areas is that of cause 

 and effect. They conclude that the origin of the process may be in the glia, but 

 that at present it is impossible to go further than to infer that neither nerve cells, 

 nor axis cylinders, nor blood-vessels are primarily involved. 



Ceni and Besta (1905), in the course of a series of experimental researches upon 

 the pathogenicity of aspergillus spores, observed a dog, which presented symptoms 

 closely resembling disseminated sclerosis. Ceni's previous researches had led him 

 to the conclusion that aspergillus infection is the essential cause of the pellagra, and 

 that this condition is dependent upon the presence of the parasite in the spore form, 

 in which it elaborates very virulent toxins. Animals inoculated intraperitoneally, 

 frequently developed spastic paraplegia with tremors, and the spinal cords of such 

 animals showed primary degeneration of the crossed pyramidal tracts and posterior 

 columns. In this dog, the spastic paraplegia and tremors disappeared at the end of 

 the second month, and the animal showed symptoms characteristic of both locomotor 

 ataxia and disseminated sclerosis. The animal was killed three months after 

 infection with the aspergillus fumigatus and, at the autopsy, the spinal cord, 



TRANS. ROY. SOC. EDIN., VOL. L, PART III (NO. 18). 77 



