Section IV. 



FUNCTIONAL DISEASES OF THE NERVES. 



{Neuroses ivltho'iit Known A)iatoniical Basis.) 



In contradistinction to the ori>anic diseases of the nervons 

 system the nenroses may be classified with those aihnents which 

 are not associated with any visible anatomical changes in the 

 nervous system and which, besides, arise as independent clinical 

 forms of illness. 



Owing to lack of research in nervous diseases, a proper 

 division cannot yet be made in veterinary medicine between ac- 

 tual neuroses and those affections causing- similar swiptoms, but 

 which are due to organic diseases of the nerves or to other dis- 

 orders of an organ of the body. 



1, Megrims. Vertigo. 



By megrims one understands a conflict arising between 

 the sensations of movement and position causing a loss of 

 equilibrium and a sense of dizziness. This sensation causes in 

 man a feeling as if his own body or, on the contrary, the neigh- 

 boring ground moved in a certain direction; immediately the 

 sense of equilibrium becomes uncertain and finally the conscious- 

 ness is affected and swooning occurs. The subjective sensa- 

 tions of animals under such circumstances are withheld from our 

 innnediate notice, but animals are sensible to these disturbances 

 of movement and, the nature and manner of innervation in 

 them being similar to those in man, it may with justice be as- 

 sumed that attacks of vertigo in animals mil be accompanied 

 by similar false sensations. 



Since the wliole of the or^^aiis of sense are more or less concerned in the sensa- 

 tions of movenient and position, certain functional disturbances of one particular 

 organ of sense can cause vertigo, yet the vestibular or the apparatus of vision includ- 

 ing their central areas are chiefly concerned because they especially enable one to see 

 and find one's way about. 



Since one only has knowledge of the final sequel of vertigo, in animals, that is 

 of the disturbance of equilibrium, he is comiielled at i)resent to ascribe the vertigo 

 to a transitory derangement of consciousness and not to consider it a real vertigo 

 due to disturbance of equilibrium. 



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