236 DISEASES OF THE BRAIN 



mer season thousands of animals are killed or injured 

 annually by lightning on the farms of this country. 



Symptoms. — Usually a lightning stroke kills the animal 

 either instantly or in a few minutes. In other cases the 

 animal appears stunned from the stroke, but soon regains 

 consciousness and normal condition. In a few instances, 

 however, the patient is left for a time with irregular gait, 

 weakness of the hind parts, may show forced movements, 

 and appear stupid and dull. Usually they recover after a 

 few days or weeks. In rare cases topical symptoms are 

 retained, such as monoplegia, paraplegia, paralysis of indi- 

 vidual nerves, from which the animal usually recovers in 

 one or two months. Horses are sometimes left permanently 

 blind. 



Occasionally lightning stroke produces peculiar markings 

 or figures on the hair or skin. These figures are often 

 branched and forked, and may involve pigmented as well 

 as unpigmented skin. On the unpigmented skin they are 

 dark-colored and sometimes resemble a tree or forked shrub. 



Treatment. — If the patients remain down good bedding 

 should be provided. To assist the return to consciousness 

 excitants (alcohol, ether, camphor, caffein, skin rubbing) 

 may be tried. Usually treatment is unnecessary. 



HEMORRHAGE IN THE BRAIN AND ITS MEMBRANES. 

 APOPLEXY. 



Definition. — By apoplexy in a narrow sense is understood 

 a hemorrhage of the brain or its membranes which is due 

 neither to traumatism nor inflammation. 



Etiology. — The causes are very varied. In many of the 

 acute infectious diseases (anthrax, purpura hemorrhagica, 

 hemorrhagic septicemia), blood diseases (anemia, leukemia), 

 and in chronic inflammation of the liver and kidneys the 

 walls of the bloodvessels in the brain become weakened, a 

 condition conducive to hemorrhage. In rarer instances 

 parasites (larvse of sclerostomes) form a cause. Arterio- 

 sclerosis, a common cause of apoplexy in man, probably 

 does not occur in animals. 



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