NERVOUS SYSTEM. 205 



plcgia, of both sides (both hind legs) paraplegia; paralysis of 

 a single organ or part is known as monoplegia. Hemiplegia 

 has its origin in the brain, paraplegia in the spinal cord, 

 monoplegia in the motor centers of the brain or, and as a 

 rule, in peripheral nerves.' 



In cerebral paralyses the cranial nerves are 

 frequently also affected and psychic disturbances are present; 

 we observe cerebral paralysis in 



1. Brain diseases: acute cerebritis, cerebro-spinal menin- 

 gitis, abscesses, hemorrhages (apoplexies), tumors, parasites. 



2. Infectious diseases: rabies, mal du coit (always), ex- 

 ceptionally in horse distemper, and in contagious pleuro-pneu- 

 monia of the horse. 



3. In intoxication diseases: parturient fever, mycotic 

 intoxications, brine poisoning. 



Spinal paralyses are usually cases of paraplegia 

 which aft"ect all nerves beyond the point of injury or dis- 

 ease and are always attended with sensory paralysis. 

 Psychic disturbances are wanting. They are caused by : 



1. Spinal fractures; 



2. Diseases of the cord: inflammation, hemorrhage, tu- 

 mors, parasites ; 



3. Infectious diseases: dog distemper, rabies, rarely in 

 contagious pleuro-pneumonia of the horse. 



Spinal paralyses also affect the veg- 

 etative branch of the nervous s }- s t e m , 

 since the lumbar cord is the center for the production of the 

 contractions that produce defecation and urination. Hence 

 paralysis of the rectum and bladder with the inevitable results 

 (impaction of rectum and distention of bladder with urine) 

 occurs. See pp. 137 and 148. 



Peripheral paralyses are for the most part of 

 surgical interest. In internal medicine paralysis of the fa- 

 cial nerve, because it interrupts normal feeding, and paralysis 

 of the recurrent nerve, because it disturbs respiration, are of 



