NERVE OVERLAP — PAIN SENSE — PERIPHERAL NERVES 361 



cases showing return to pin prick over a larger area in less than 

 thirty days were predominately cases of radial and musculo- 

 spiral lesions. 



The material of peri]:)heral nerve lesions studied later may be 

 divided into two groups: the first, a group of 391 cases of peri- 

 pheral nerve lesions uncontrolled by operation and in the major- 

 ity of instances recovering spontaneously; the second a group of 

 132 cases controlled by operation. 



Cases controlled hy operation 



Nervt lesions Number 



Ulnar 20 



Radial 31 



Median 9 



Ulnar and median 15 



Median and radial 2 



Musculocutaneous, ulnar and median 2 



Brachial plexus 2 



Ulnar and radial 3 



Great sciatic 20 



External popliteal 25 



Anterior tibial 2 



Ulnar, median and internal cutaneous 1 



Total 132 



My general impressions relative to the sensory changes in 

 l)eripheral nerve lesions were deri\'ed from the whole material. 

 The areas of overlap were obtained only from cases certified by 

 operation. The cases which have been used in the study of 

 regeneration of nerves likewise were certified by operation. 

 Therefore, although the whole 1023 cases contributed to my 

 general conclusions concerning these problems, only one group, 

 consisting of the cases coming to operation, was employed in 

 obtaining the data which serve as the basis for the special con* 

 elusions contained in this article. 



METHODS OF INVESTIGATION 



The problems under investigation were studied from a clinical 

 and not from a psycho-physical standpoint. The areas of over- 

 lap were found in the course of clinical examinations in a large 

 group of cases. The methods of examination, therefore, were 



