60 STUDIES ON THE CENTRAL NERVOUS SYSTEM 



terior longitudinal fasciculus. We must consider that the 

 sidewards movement of both eyes alike in the horizontal 

 level, is a function, only present in higher mammals, where 

 the eyes are placed more frontal in the head and where the 

 structure of the face makes it possible that such a function 

 has acquired a great significance. In this connection I 

 may note that experiences in the Great War have shown, that 

 it is hardly possible to use the horizontal nystagmus for 

 topographic diagnosis, since this symptom appears without 

 any regularity in so many different injuries of the brain. 



Spastic paresis in disseminated sclerosis is caused by in- 

 jury being done to the pyramidal tracts, as mentioned above. 

 These are phylogenetically and ontogenetically young, 

 especially the part for the legs and hence we can understand 

 that this function suffers frequently and early. The 

 spasmus is caused through the influence of the older, sub- 

 cortical motor tracts predominating. The above mentioned 

 disturbances of coordination, accompanying the paresis, 

 are often found in cases, where the strength of the move- 

 ments is still normal. Meijer published, some years ago, a 

 valuable paper on this matter. He showed after accu- 

 rately investigating a great clinical material, that a slight 

 tremor, some disturbance of the equilibrium and a slight 

 disorder in the right cooperation of the muscles of the trunk 

 and extremities, are very frequent at early periods in this 

 illness. 



Several authors are inclined to ascribe these disturbances 

 to the cerebellum being injured. This, in my opinion, is not 

 justified. For, although recent researches have shown, 

 that the cerebellum is more frequently affected than 

 Charcot believed, yet this is too rare to explain such a 

 frequent S3^mptom as this disturbance of coordination. In 

 my opinion these disturbances are caused by lesions of the 

 pathways between the neopallium and the cerebellum. 

 These cerebro-cerebellar tracts, passing through the pons 

 Varoli, are very young and have a late myelinization, still 



