58 



LECTURES ON THE CENTRAL NERVOUS SYSTEM. 



Injuries which involve the normal structure and function 

 of the cortex give rise in the human being to symptoms differ- 

 ing according to the part injured. Up to the present time there 

 have been several hundred carefully observed cases of disease 

 of the cortex, and by comparing them with one another we can 

 arrive at the following conclusions: 



FIG. 35. 

 The convolutions on the base of the brain (diagrammatic). (After Ecker.) 



Motor symptoms of irritation (from the twitching of single 

 muscles up to epilepsy) may arise from any part of the cortex, 

 but there exists a zone of the brain embracing both central 

 convolutions, injury to which is almost always accompanied by 

 motor disturbances on the opposite side of the body. The dis- 

 turbances may be divided into symptoms of irritation and symp- 



