514 
PARALYSIS OF RADIAL NERVE. 
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 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 suggested that the condition 
in question is a myopathic paralysis of the caput muscles, and supports 
his view by the results of examinations of the muscles in two slaughtered 
horses suffering from the disease. These changes, however, were prob¬ 
ably 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 hypersemic. 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 para¬ 
lysis 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 heavy draught, 
clearly pointing to a traumatic origin. 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 saw this lameness result from long exposure to rain during work. 
Liibke also saw double-sided partial radial paralysis caused by chill; the 
disease was accompanied by fever, and proved fatal. 
In the year 1890 Moller saw a case of diplegia of the radial nerve in 
the horse. The disease suddenly appeared in the left limb during a 
