Epilepsy. Falling Sickness. 51 



5th. Morbid States of the Circulating Blood. Certain 

 poisons, when brought in contact with encephalic nerve centres 

 produce epileptic seizures. Gallerani and Lussana applied 

 creatinin directl}' to the cerebral cortex and quickly induced 

 epileptiform convulsions and choreiform movements. Injected 

 subcutaneously it failed to produce the same effect. Cinchonoidin 

 acted on the basal ganglia of the brain producing convulsions 

 but no choreiform movement. Poisoning with lead, ergot, nitro- 

 pentan, nitro-benzol and a number of other poisons brings about 

 intermittent convulsive seizures. The same may be inferred of 

 ptomaines and toxins, in the convulsions that appear in the ad- 

 vanced stages of infectious diseases (canine distemper, hog 

 cholera, etc.). 



6th. Reflex Irritation. Perhaps no peripheral irritation 

 more frequently causes epilepsj-, than parasites. In young dogs 

 worms in the intestines (taenia coenurus, taenia tenuicollis, taenia 

 serrata, taenia echinococcus, and ascarides) have been especially 

 incriminated. Also linguatula taenioides in the nasal sinuses. In 

 young pigs the echinorrhy nchus gigas, ascarides and trichocepha- 

 lus. In horses ascarides have been principall}^ blamed. 



Wounds implicating nerves, and tumors pressing on nerves, have 

 served as sources of nervous excitement which accumulates in 

 the cerebral ganglia and bursts forth as an epileptic explo.sion. 

 Bourgelat mentions the case of a horse which fell in a fit the 

 moment he was touched on his tender withers, also a case in 

 which a siezure coincided with an attack of recurrent ophthalmia. 

 Gerlach saw a horse which had an epileptic fit the instant he was 

 touched on his sensitive withers. In kittens and puppies the 

 irritation attendant on dentition is a common cau.se of attacks. In 

 nervous dogs and pigs indigestion or con.stipation may serve as 

 the occasion of an explosion. In the experimental ca.ses of 

 Brown-Sequard, not only did the injury to the sciatic nerve de- 

 velop in the brain a latent tendency to epilepsy, but the sub.se- 

 quent pinching of the .skin in certain areas (epileptigenous zones) 

 promptly brought about a siezure. 



Causes. Most of the causes of epilepsy have been given 

 above under the head of pathology and morbid anatomy. The 

 nervous predisposition may, like any other peculiarity or function, 

 become hereditary. In the human race nothing is more certain 



