240 PHYSIOLOGY CHAP. 



functional recovery of a cut and sutured nerve, Purpura made 

 some interesting clinical applications of his conclusions on nerve 

 regeneration. He demonstrated the possibility of recovery of 

 function on crossing two different nerves. In a patient affected 

 with facial paralysis, which resisted medical treatment (Fig. 153), 

 he made a crossing of the outer branch of the spinal accessory 

 nerve with the facial (May 1909). Forty days after the operation 

 a slight correction of the facial asymmetry was perceptible ; after 

 two and a half months it was practically cured (Fig. 154). At the 

 close of 1909 the invalid began to exhibit associated movements 



FIG. 153. Complete paralysis of left facial nerve previous to operation. (Purpura.) 



of the shoulder and the muscles innervated by the facial. In the 

 early months of 1910 the movements were associated when they 

 were sharp and sudden, but the patient was able to dissociate 

 them when she fixed her attention on them. By the second half 

 of that year she was always able to dissociate them. 



More recently (1910) Modena instituted histological investiga- 

 tions with Donaggio's method upon the regenerative phenomena 

 in divided nerve, and his results agree fundamentally with those 

 of Purpura and Perroncito. 



VII. Special interest, from both the theoretical and the 

 practical standpoint, attaches to the study of the changes which 

 the nerve undergoes when any part of it is exposed to the action 

 of a constant current. These changes appear as physical electro- 

 motive and physiological phenomena, and consist in profound 

 alterations of the excitability and conductivity of the nerve. 



