CHANGES IN HUMAN CEREBELLUM WITH AGE 



27 



If this is true, we should expect to find some anatomical basis 

 for the tendency to use one hand rather than the other. 



The relation of the cerebellar hemispheres to the body is not 

 entirely clear, but the weight of the evidence indicates that each 

 cerebellar hemisphere controls the muscular coordinations of its 

 own half of the body instead of being crossed, as is the case with 

 the cerebrum. It is consequently interesting to find that when 

 an excessive number of Purkinje cells is lost as a result of ad- 

 vancing age or as a result of disease, the right hemisphere in most 



30 



Chart 7 Showing the loss of Purkinje cells on age in the right and left hemi- 

 spheres of the human cerebellum. , right hemisphere; , left 



hemisphere. 



cases is found to have suffered the greater loss — when compared 

 with what is found in more nearly normal cerebeUa. To demon- 

 strate this, I have selected from my records the eighteen cases 

 which had suffered the greatest losses of cells, and I have shown 

 in chart 7 the numbers of cells in area 3 of the two hemispheres of 

 this group. Whether the greater loss in the right hemisphere is 

 due to use or to some difference in the vascular system, or to 

 both of these factors, cannot at present be determined. In less 

 extreme cases, as shown in tables 11 and 12, the difference be- 

 tween the hemispheres is not marked in old age. 



