I Tl'i - TS OP l XP1 i;i Ml \T\I. LESION'S 



- 17 



extremities it is nol al firsl sighl so clear, although it ••an !»<• accurately 

 worked out, as is indicated in the accompanying diagram Pig 218 



In attempting to determine the level of a lesion from the sensory paraly- 

 sis, some confusion often arises mi account of the oblique course of the 

 decussation of the sensor} fibers in the spin,!] cord, fibers for the differenl 

 sensations qoI crossing al the same levels. For example, the appreciation 

 of moderate temperature is often lost Blightly higher than thai of pain. 

 The appreciation <>!* the vibrations caused by drawing the base of a 



Pig 218 Diagram showing • I "t th 



Stew 



ln-a\\ tuning fork over the skin is often very useful in locating the 

 Lesion, particularly in the abdomen. When this method is used on the 

 thorax, however, the skin Bhould be pulled up in folds before the fork 

 is applied, since otherwise the thorax will act as ;i resonator and spread 

 the sensation. Section of two or more sensor} a very 



definite area <>i" anesthesia, involving all the skin sensations as well 

 several of those of deep sensat ion. 



If ■• ■ tevered roots includi all of thost going to 

 there is nol onlj an entire absence of sensation, Imt a marked int ace 



