428 



ditions of dementia, as with dementia paralytica and dementia senilis, 

 in whicli a general diminution oecnrs of the degree of conscionsness, 

 tlie position-reflexes are affecleci prior to ihe associated movements. 

 It is obvious, therefore, that the associated movenients will recur. 

 Associated movements manifest themselves niosl distinctly with an 

 affection of the pyramidal tract, because then the conduction of the 

 centrifugal impulse, which acts inhibilively, is lacking. This is easy 

 to demonstrate in patients with cerebral hemiplegia, because in these 

 cases the associated movement of Ihe paretic leg can be directly 

 compared with the movement of the healthy leg. In my investigation 

 I availed myself of the following associated movement. When a 

 subject, in dorsal position, is instructed to raise the right leg, the 

 left leg will be pressed down, of which fact the experimenter may 

 readily convince himself by putting his hand under the left heel. 

 A distinct pressure will then be |)erceived, which will increase with 

 a greater effort of the right leg. The associated movement of the 

 left leg may be reinforced by opposing a resistance to the movement 

 of the right leg. The registration of the associated movement happens 

 in the following way. The left leg is suspended in a loop a little 

 way above the heel. The loop is attached to a steel-yard by means 

 of a cord that passes over a pulley. When the leg is pressed down 

 the force of the effort can be read accurately from the steel-yard. 

 To the cord is fastened a stylus, which records the movement directly 

 on a rotating kymograph. In patients with ceiebral hemiplegia the 

 associated movement on the paretic side appears to be much more 

 pronounced than on the healthy side. In the subjoined curves A', 

 A" and A'" repiesent the associated movements of the normal leg; 



A' Associated movement 

 of the normal leg. 

 Xy \_f V_^^""" B' Associated movement 



of the paretic leg. 



A" Associated movement 

 of the normal leg. 



B" Associated movement 

 of the paretic leg. 



I. 



'^J- 



V 



u 



A'" Associated movement 

 of the normal leg. 



B'" Associated movement 

 of the paretic leg. 



III. 



