718 Paralysis of the Trigeminal Nerve. 



Treatment. In view of the fact that the origin of the dis- 

 ease is as a rule central, treatment should be along the lines 

 laid down for diseases of the brain or its membranes. 



Literature. Ballangee, A. f. Tk., 1906, XXXII, 103.— Clerehet, Fayet and 

 Nicolas, Bull., 1909, 490.— Zschokke, Sehw. A., 1885, XXVII, 174. 



2. Paralysis of the Trigeminal Nerve. 



Occurrence. This paralysis has up to the present been ob- 

 served in the horse and dog, and Reuschel claims to have 

 seen it in a cow. (Hintze found degenerative atrophy of the 

 infraorbital nerve in a pig aifected with rickets of the jaw.) 

 In the dog, the disease is not rarely observed, even if cases of 

 rabies, in which it is common, and cases of distemper, in which 

 it is infrequent, are excluded. 



Etiology. The principal causes of paralysis of the tri- 

 geminal nerve in the dog are rabies and distemper, but among 

 other causes may be mentioned inflammation of the brain in the 

 neighborhood of the pons (Mathis), concussion of the brain 

 (Hutyra & Marek), the development of a neoplasm around the 

 intracranial root (Gratia, and Cadeac & Roquet, a gliosarcoma 

 and an endothelioma) and, under certain circumstances, squeez- 

 ing of the motor branch through powerful contraction of the 

 muscles of mastication (laying hold of some heavy object, bit- 

 ing a hard bone, etc.). 



The crushing of the motor branch lietween the niasseter and temporal muscles 

 is explained by supposing that the nerves mentioned are pressed against the condy- 

 loid process during active contraction of the temporal muscle. This is particularly 

 the case when a dog forcibly closes its widely opened mouth or is holding a heavy 

 object in its mouth. A consideration of the anatomy of the part is sufficient to 

 convince one that a crushing of the motor branch only, and one that is as a rule 

 bilateral, is quite possible, and it is not necessary to suppose that the cause is 

 either rheumatism or some intoxication, as Cadiot and Almy assert. The sudden 

 onset of the disease contraindicates this. 



The disease is met with only very occasionally in the horse. 

 In a case recorded by Lydtin, the cause of the paralysis was 

 a fibrosarcoma in the immediate neighborhood of the Gasserian 

 ganglion, and a growth of the same nature close to the temporo- 

 maxillary joint is recorded as the cause by Tempel. Meyer, 

 in one case ascribes the paralysis to the presence of an angioma 

 in the cranium, and neuritis is said to be the cause in cases 

 mentioned by Roll, Liipke, Dexler and Marek. Sometimes tri- 

 geminal paralysis appears to be due to concussion of the brain 

 (Berton, Pr. Mil. Vb.). 



Symptoms. In cases of paralysis of all three branches of 

 the trigeminal nerve both, disturbance of mastication and loss 

 of sensibility are observed. If the first branch (ophthalmic 



