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XVIII. — The Histology of Disseminated Sclerosis. By James W. Dawson, M.D., 



Neurological Histologist to the Royal College of Physicians' Laboratory ; 

 formerly Carnegie Research Fellow. To which is prefaced a Preliminary 

 Communication on the subject made to the Pathological Society of Great 

 Britain and Ireland by the late Alexander Bruce, M.D., LL.D., and James W. 

 Dawson, M.D. Communicated by A. Ninian Bruce, M.D., D.Sc. 



(MS. received July 7, 1914. Read February 1, 1915. Issued separately March 10, 1916.) 



[Plates XLV-LXXVIIL] 



PREFACE. 



The research of which this paper gives an account was originated by the late 

 Dr Alexander Bruce and undertaken in conjunction with him ; most of the material 

 used had been accumulated by him during the later years of his life. The following 

 preliminary communication made to the Pathological Society of Great Britain and 

 Ireland in July 1910 represents in brief outline the position which had been reached 

 at the time of Dr Bruce's lamented death : — 



Preliminary Communication on the Pathology of Disseminated Sclerosis. By A. Bruce 

 and J. W. Dawson. (Reprinted from Journ. Path, and Bacteriol., Cambridge, 1911, 

 vol. xv, p. 126.) 



The plaques in disseminated sclerosis, wherever they are situated, are distributed evidently 

 without any relation to nerve tracts. Their character and appearance suggest a gradual infiltra- 

 tion from some central source into the surrounding or neighbouring tissues. In the cord their 

 tendency is to pass inwards from the meninges in a more or less wedge-shaped form, their 

 relationship to blood-vessels being often difficult or impossible to trace except in the earlier 

 stages. The cerebrum and cerebellum are better adapted to give an idea as to their mode of 

 formation because of the independence of the arterial and venous paths. Within the cerebrum 

 the veins pass towards the wall of the ventricles and the choroid plexus towards the veins of 

 Galen, and have in this way a distribution altogether different from that of the arteries. The 

 same is true of the cerebellum. A study of a series of sections shows that the plaques are 

 deposited in relation to the distribution of the veins and to the walls of the ventricles. An 

 examination of sections of the cerebral hemispheres strongly suggests that the infiltration is 

 along the lymphatic channels surrounding the veins. Similar conclusions are suggested by 

 study of the sections of the pons, cerebellum, and medulla. 



For some years Dr Bruce's attention had been concentrated on the important 

 part played by the lymphatics in disease processes in the central nervous system, 

 and I had the honour of being associated with him in the investigations which he 

 hoped would throw light on the subject. The earlier results obtained were recorded 

 in the paper " On the Relations of the Lymphatics of the Spinal Cord," and more 

 especially in that entitled " Multiple Neuromata of the Central Nervous System." As 



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