THE NERVOUS SYSTEM 167 



Cerebral Hyperemia 



Hyperemia no doubt occurs in the brain and meninges 

 of swine, but such cases have received meager clinical 

 investigation. A few cases of purulent cerebritis, or 

 staggers, have been observed. Some of these cases were 

 caused by wormeaten, moldy corn, or at least no new 

 cases appeared after changing the feed. The cerebral 

 tissue was affected and the lesion consisted of a liquefying 

 necrosis, the necrotic area usually occurring in relation 

 to the lateral ventricle and being unilateral in the cases 

 investigated. The liquefied necrotic tissue was grayish 

 red in color and usually represented an area about the 

 size of an English walnut. The affected swine were 

 generally dull in the beginning, but in one case observed 

 the animal was excitable and delirious. Swine affected 

 with cerebral hyperemia usually evidence an unsteady 

 gait and may fall to the ground and show symptoms of 

 convulsions. One case was observed that turned in a 

 circle, jumped up from the ground, and performed other 

 antics. 



Treatment. Treatment is of little value after the 

 brain substance has become necrotic. In the very early 

 stages drastic purgatives may be of value, particularly if 

 the cause lay in the provender. 



Parasites 



Rarely does the Cysticercus cellulosae develop in the 

 brain of swine. The cyst does not develop as readily in 

 the brain as in a muscle, and it is the exception to find 

 a matured cyst in the nervous tissue. The symptoms 

 produced will depend upon the location of the cyst in the 

 brain. 



