332 DISEASES OF THE NERVOUS SYSTEM. 



Although many of the symptoms supposed to be associated 

 with this portion of the cranial nervous matter are probably 

 indirectly induced, it would appear that motor paralysis is not 

 a feature of disease of this part, but rather that it is attended 

 with a peculiar disorder of equilibrium. The animal, on 

 making attempts at movement, staggers, with a disposition to 

 fall, and probably also to move in a circle, pressing with its body 

 to any resisting object. Sensation does not seem aftected, but 

 there is squinting and spasmodic movements of the eyeball. 



In lesions of a sudden nature connected with the 2^ons 

 varolii and medulla oblongata, there is rarely a distinct train 

 of symptoms, a fatal termination being rapid from inter- 

 ference with the functions of respiration and circulation. 

 When of a slow or gradually developing character, the indica- 

 cations are often confusing and difficult to decipher, seeing we 

 have here motor and sensory tracts meeting, and the nuclei of 

 origin of several nerves of importance. 



h. Kegarding the spinal cord itself, we know if destroyed in 

 its entirety that both motion and sensation are lost posterior 

 to the lesion. Commonly in our patients the disturbance or 

 paralysis includes only the posterior extremities, the lesion 

 being in the lumbar region. When in the cervical region, the 

 anterior extremities are also affected ; while should the injury 

 sustained be situated in the anterior portion, the probabilities 

 are that death will result from interference with respiration 

 and other functions essential to life. Retention of urine or 

 difficulty of micturition may follow a lesion in the anterior 

 portion of the cord, from spasm of the sphincter ; while in- 

 continence will follow injury of the same structure in the 

 loins. 



In some instances we find that motor-power is interfered 

 with long before sensory, from the fact that the sensory tracts 

 are confined to the superior cornua and the grey matter about 

 the central canal, the outer structure suffering from injury 

 earlier than the deep-seated, which may escape for some 

 time. 



As regards special tracts of the cord, we find that if one 

 lateral half is completely destroyed, there Avill be motor par- 

 alysis of the same side of the body, posterior to the lesion and 

 sensory of the opposite side ; such, however, in a perfect 



