PATHOLOGICO-ANATOMICAL CHANGES OF THE NERVOUS SYSTEM 217 



and especially in the dorsal cord. The changes consist partly of hyperemia 

 and round cell accumulation, partly of sclerosis with thickening of the neu- 

 roglia and of the walls of the vessels, also atrophy of the ganglion cells and 

 neuritic processes in the spinal roots (particularly the posterior ones). 



It must also be mentioned that by some authors special stress is laid upon 

 disease of the small pericapsular adrenal ganglia which are frequently impli- 

 cated by the local process. 



Many of these reports have been met by the criticism that the importance - 

 of the pathologico-anatomical changes has been exaggerated, and that many 

 of them do not go beyond what we have learned to recognize by more recent 

 investigations as the consequence of general nutritive disturbances produced 

 by many forms of anemia, cachexia and the like in the elements of the nervous 

 system. This criticism can only refer to the mild degrees of such changes, 

 as the atrophy of the ganglion cells and nerve fibers, the pigmentation of 

 tissue elements, etc.; and I do not intimate that the importance of changes 

 such as these is to be denied. It is, however, different with the severer findings 

 reviewed above, in which, as a rule, advanced degenerative conditions of the 

 cellular elements are combined with conspicuous inflammatory processes of 

 the interstitial tissue. Such changes must be counted among the characteristic 

 findings of the disease in question, and must be considered in judging of its 

 pathogenesis. 



It" is true that our limited knowledge makes it difficult to estimate the 

 relative frequency of such pathologic nerve findings. Judging from the mate- 

 rial at hand, we cannot look upon them as constant. For quite a number of 

 reports are diametrically opposed to those just mentioned, and show that, 

 in the investigation of certain areas of the nervous system, no abnormality 

 had been found. It is true a large number of these communications are far 

 removed from being susceptible of general proof. First, there are some of 

 them, particularly dating from earlier periods, in which the anatomical inves- 

 tigation regarding the more minute relation of the nerve elements was insuffi- 

 cient. It need only be mentioned here that in many of the earlier cases it 

 was decided macroscopically whether, for example, the semilunar ganglia 

 were of normal size, color, consistence and the like. Then the majority of 

 these investigations refer only to small areas of the nervous system; few 

 among them follow completely the important central parts of the sympathetic 

 system, and investigate whether the neighboring areas of the central nervous 

 system are also implicated. In the overwhelming majority of cases only the 

 semilunar ganglion and solar plexus have been examined; much more rarely 

 the splanchnics and the boundary column between the dorsal ganglion and the 

 cervical ganglion of the sympathetic have been examined. The intervertebral 

 ganglia, upon which lately special stress has been laid, as well as upon the 

 spinal roots and the spinal cord, have been but very rarely investigated except 

 in the few cases mentioned above. It may be added that these negative 

 reports (as well as the positive nerve findings) occurred usually in cases in 

 which the adrenals showed no conspicuous change. 



Here, therefore, are flaws and doubts which can be removed only by con- 

 tinued and thorough histologic investigations of a large number of additional 



