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 I/Ussana applied 

 creatinin directly 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 epilepsy, than parasites. In young dogs 

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

 serrata, taenia echinococcus, and ascarides) have been especially 

 incriminated. Also linguatula taenioides in the nasal sinuses. In 

 young pigs the echinorrhynchus gigas, ascarides and trichocepha- 

 lus. In horses ascarides have been principally 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 explosion. 

 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 seizure coincided with an attack of recurrent ophthalmia. 

 Gerlach saw a horse which had an epileptic fit the instant hewas 

 touched on his sensitive withers. In kittens and puppies the 

 irritation attendant on dentition is a common cause of attacks. In 

 nervous dogs and pigs indigestion or constipation may serve as 

 the occasion of an explosion. In the experimental cases of 

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

 velop in the brain a latent tendency to epilepsy, but the subse- 

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

 promptly brought about a seizure. 



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 



