284 MANUAL OF EQUINE MEDICINE. 



The term ' paresis ' is often used of the slighter forms of 

 this condition. 



Paralysis of the voluntary movements, which we now 

 propose to consider, may be complete or incomplete. 



Motor paralysis has special designations, in accordance 

 with the parts invaded : 



1. General Paralysis. — Is very rare in the horse, occur- 

 ring only as a temporary condition in certain diseases of 

 the cerebral structure, in cerebral congestion, in effusion 

 into the basal ganglia, and in injuries and diseases of the 

 anterior part of the cord and medulla oblongata. 



2. Hemiplegia. — Hemiplegia strictly implies a paralysis 

 of all the muscles of one half of the body ; but in this 

 perfect form it is never met with in man or animals. 



Hemiplegia is very rarely observed in horses. It is usually 

 the result of hsemorrhage or tumours affecting one half of 

 the brain. 



As a result of such changes, the angle of the mouth may 

 become relaxed and the facial expression on the same side 

 as the pathological lesion may be changed. The tongue 

 may be protruded, and there is difficulty in drinking and 

 in mastication. Deglutition is not impaired. 



The animal may not lose the power of standing, but the 

 power of progression is much affected. 



The paralysis of the body is on the opposite side to that 

 on which the cerebral lesion occurs. This is owing to the 

 decussation of the motor fibres in the medulla oblongata. 



The horse may regain power in a few days, but recovery 

 is rare. 



Those cases which end in recovery probably depend upon 

 temporary inflammatory action, or other causes. 



3. Paraplegia. — Paraplegia commonly depends on disease 

 of the spinal cord, and denotes a defect or loss of power in 

 all parts below the level of the lesion. 



