506 



NERVOUS SYSTEM 



Certain pathological facts bearing on the question of decussation of 

 the filaments of origin of the facial have long been recognized. They 

 are in brief as follows : When there is lesion of the brain-substance 

 anterior to the pons Varolii, the phenomena due to paralysis of the 

 facial are observed on the same side as the hemiplegia, opposite the side 

 of injury to the brain. When the lesion is either in or below the pons, 



Fig. 122. Superficial branches of the facial and the fifth (Hirschfeld). 



I, trunk of the facial; 2, posterior auricular nerve ; 3, branch which it receives from the cervical 

 plexus ; 4, occipital branch ; 5, 6, branches to the muscles of the ear ; 7, digastric branches ; 8, branch 

 to the stylo-hyoid muscle; 9, superior terminal branch; 10, temporal branches; n, frontal branches; 

 12, branches to the orbicularis p alp ebr arum ; 13, nasal, or suborbital branches ; 14, buccal branches ; 

 15, inferior terminal branch; 16, mental branches ; 17, cervical branches; 18, superficial temporal 

 nerve (branch of the fifth) ; 19, 20, frontal nerves (branches of the fifth) ; 21, 22, 23, 24, 25, 26, 27, 

 (branches of the fifth) ; 28, 29, 30, 31, 32 (branches of the cervical nerves). 



the face is affected on the same side, and not on the side of the hemi- 

 plegia. This is called alternate paralysis. In view of these facts, the 

 phenomenon of hemiplegia of one side and facial paralysis on the other 

 is regarded as indicating, with tolerable certainty, that injury to the 

 brain has occurred on the same side as the facial paralysis, either 

 within or posterior to the pons Varolii. 



