FACIAL PARALYSIS. 251 



also be produced, as in man, by severe chills. Utz saw the condition 

 after an animal had been struck by lightning. 



The paralysis is mostly confined to the facial muscles. The lips 

 are distorted, the nostrils narrowed, the upper lip, and sometimes 

 the under, are drawn towards the sound side. The condition is 

 best recognised by looking at the lips from in front. So long as one 

 side alone is affected, feeding is little interfered with ; but in double- 

 sided paralysis the lips hang flaccid, a condition best seen in the 

 under lip, and feeding now becomes slow or extremely difficult. The 

 food can only be grasped with the teeth, and, in drinking, the corners 

 of the mouth must be immersed in order to prevent the water 

 flowing back. Even when carefully tended, animals rapidly 

 lose condition, for they have difficulty not only in grasping food, 

 but, owing to the paralysis of the cheeks, also in masticating it. The 

 food cannot be brought between the opposing rows of teeth and 

 so accumulates between the cheeks and molars. These are the 

 appearances when injury has occurred at the point where the nerve 

 passes round the under jaw ; but where in addition the subzygomatic 

 nerves are involved, sensation is lost in the skin of the affected side. 



Facial paralysis due to central injury or disease is different both 

 in its symptoms and consequences. Should the lesion be sufficiently 

 near the brain to involve the zygomatico-temporalis nerve, then, 

 in addition to the above appearances, paralysis affects the levator 

 palpebrarum, as well as various muscles of the ear. The upper eyelid 

 droops (ptosis) whilst the orbicularis palpebrarum is unable properly 

 to close the eye, and the external ear on the affected side hangs 

 limply (Fig. 270). Zahn found the eye of the affected side smaller, 

 and the cornea cloudy. Disturbance of hearing could also be 

 detected. Not infrequently paralysis of other portions of the body 

 accompanies paralysis of the facial nerve ; thus Jewtichilew saw 

 hemiplegia, Tempel paralysis of the trigemina lnerve, and Fuchs of 

 the hypoglossal and glossopharyngeal. 



The causes are various. Tumours, developing in the parotid, 

 as well as disease of the Fallopian canal, may cause pressure 

 on the nerve. Occasionally the origin is central. Thus the post- 

 mortem of a horse suffering from double-sided paralysis, disclosed 

 sarcoma of the pons. Gotze noted paralysis of the lips and ears 

 in a horse after influenza, and found on section an abscess in the 

 cerebellum. In another case, Lydtin saw sarcoma of the petrous 

 temporal bone, the growth extending from the posterior convolutions 

 of the cerebrum to the point of origin of the twelfth nerve. Thomassen 

 and Hamburger found haemorrhage in the facial nerve centre. In 



