776 PARALYSIS OF RADIAL NERVE. 



head of the triceps and the anconeus, and furnishes a few cutaneous branches, 

 which perforate the caput medium. In the fore-arm the nerve supplies 

 the extensor muscles of the knee, fetlock and pastern, and the flexor 

 metacarpi externus. 



Paralysis of this nerve used often to be seen, though not 

 accurately diagnosed. Harms states having recognised this paralysis 

 in a cow. In 1875 Moller saw the disease repeatedly in horses, and 

 then for the first time carefully described it ; it has since been 

 frequently diagnosed. During the last few years Moller has often 

 seen this lameness in horses, and in one case in the dog. 



Even at the present time little is known of the causes of radial 

 paralysis. Sometimes it appears in horses which have been cast 

 for a long time, especially if lying on sand or on the earth. But it 

 is doubtful whether such lameness is not principally myopathic and 

 produced by continued pressure on the triceps muscle, interfering 

 with circulation ; its rapid disappearance supports this view, which 

 seems in accord with similar observations in man. Frohner has 

 asserted that the condition in question is a myopathic paralysis of 

 the caput muscles, and supports his contention by the results of 

 examination of the muscles in two slaughtered horses suffering from 

 the disease. These changes, however, were probably secondary in 

 character. Lanzillotti-Buonsanti, who found similar lesions, pointed 

 out that they were strictly confined to muscles served by the radial 

 nerve. Moreover, the nerve itself was hyperasmic. There can be 

 little doubt that in cases of long duration the nerve, and not the 

 muscles, is the structure primarily affected. Lustig saw radial 

 paralysis lasting thirty-eight days after a tedious dental operation. 

 Since casting on soft mattresses has become common, such cases 

 have seldom occurred. 



As a rule, radial paralysis occurs suddenly during harness work, 

 clearly pointing to a traumatic origin, though in many cases there 

 is no history of an accident of any sort, and as a rule there is no mark 

 of injury. During a very short period in the summer of 1887 Moller 

 saw many horses with this disease, which is generally rare. It therefore 

 seemed as though a specific cause were at work, a view confirmed 

 by the peculiar clonic spasms of the triceps muscle seen in other 

 horses. These spasms ceased during work, but returned with rest, 

 and could be produced by flicking the muscles with the finger. 

 Bormann in horses twice diagnosed radial paralysis which set in in 

 the same sudden fashion. One case seen by Werner, and described 

 as paralysis of the extensor pedis, occurred after violent attempts 

 to free the foot, which had been caught in some obstruction. Brauer 



