308 LEWIS J. POLLOCK 



nerve would have no effect on the appearance of this sensibiHty. 

 What are the facts? 



Although in isolated lesions of the ulnar nerve sensibility to 

 pain is frequently seen on the ulnar half of the ring finger, this 

 is never observed when a median nerve is divided at the same 

 time (figs. 2, D, E, F, G, H, I). When the ulnar, radial and 

 median nerves are divided, a year may follow their division and 

 no shrinkage of analgesia be found on the palmar or dorsal 

 surface of the hand, except on the proximal portion of the anal- 

 gesia where the musculocutaneous and the antibrachii posterior 

 areas adjoin the analgesic area (fig. 5, A, B, C). When a radial 

 lesion is combined with a median analgesia is always present on 

 the radial part of the palm (fig. 5, D, E, F, G). When a median 

 lesion or a radial lesion alone is present, this part of the palm is 

 usually sensitive to pin prick. Isolated lesions of the external 

 popliteal nerve may show only a small area of analgesia, but 

 when the internal popliteal as well as the external popliteal is 

 severed, there is never found any shrinkage of analgesia or reap- 

 pearance of sensibility to prick pain in the zone where the supply 

 of the external popliteal meets that of the internal popliteal 

 (fig. 6) 



I think it can be definitely stated that when nerves supplying 

 adjoining areas are severed, sensation to pain is at no time 

 present in the border areas, where it is uniformly observed when 

 either nerve is divided alone (fig. 7). 



Inasmuch as a large number of my cases have had resections 

 and sutures performed at least three months prior to the last 

 examination, it may be stated likewise that no sensation to 

 pain returned in such areas in the time given for the beginning 

 of regeneration of protopathic sensibility. 



3. EFFECT OF SUBSEQUENT SECTION OF AN ADJACENT NERVE 

 UPON SENSIBILITY TO PAIN IN THE AREA OF A SEVERED 



NERVE 



When return to sensibility to pain or presence of sensibility 

 to pain is found in the area of overlap of an adjacent nerve, 

 analgesia will result if this nerve is severed. 



