698 FACIAL NERVE. 



"as behind a mask." 2. In the presence of paralysis of the palate, the uvula 

 is deflected toward the unaffected side, and the paralyzed half of the palate is 

 depressed and relaxed and cannot be elevated (greater superficial petrosal nerve). 

 It has not as yet been determined whether and to what extent it affects the move- 

 ments of swallowing and the formation of consonants. 3. Impairment of the 

 sense of taste (either absence" upon the anterior two-thirds of the tongue or delay 

 and alteration in the sensation) results in accordance with what has been stated 

 concerning the chorda tympani. 4. Diminution in the secretion of saliva upon 

 the paralyzed side was first described by Arnold, although it will have to be 

 determined to what extent any impairment of taste that may be present at the 

 same time may give rise to interference with the reflex secretion of saliva, or 

 whether, possibly, increased evaporation of saliva from the separated lips and the 

 angle of the mouth may result in greater dryness of the affected side of the mouth. 

 5. Since the time of Roux increased attention has been called to acuity of hearing 

 (oxyakoia or hyperacusis of Willis). The paralysis of the stapedius muscle 

 causes oscillation of the stapes in the oval window, so that impulses from the 

 tympanic membrane are strongly transmitted to this bone, which in turn gives 

 rise to marked oscillations in the labyrinthine fluid. Less commonly, in conse- 

 quence of paralysis of the stapedius muscle, it is observed that deeper notes are 

 heard at a greater distance than upon the unaffected side. 6. As the facial 

 nerve in man appears to contain sweat-fibers, it is clear that with the occurrence 

 of atrophy of this nerve loss of sweating in the face must result. 7. Derangement 

 of sensibility naturally cannot occur in connection with pure central affections of 

 the facial nerve. As, however, numerous sensory fibers enter the peripheral por- 

 tion of the nerve, peripheral paralysis will be attended with a certain limited 

 impairment of sensibility (principally affecting the muscle-sense) in the face. 



Division of the facial nerve in young animals causes atrophy of the related 

 muscles. Therefore, the bones of the face are retarded in their growth. They 

 remain smaller and the bones of the opposite side finally extend beyond the 

 middle line toward the affected side. Also the salivary glands remain smaller. 



Irritation of the facial nerve gives rise to circumscribed or diffuse, direct or 

 reflex, tonic or clonic spasm. The diffuse form of spasm is designated mimetic 

 facial spasm. Among the forms of circumscribed spasm tonic spasm of the eyelids, 

 blepharospasm, is the most frequent, being caused by stimulation of the sensory 

 nerve of the eye, principally in connection with scrofulous inflammation of the 

 eye or in consequence of excessive irritability of the retina (photophobia) . Less 

 commonly the irritation is transmitted from a remote point, for example in one 

 case in consequence of inflammatory irritation of the anterior palatine arch. 

 The center for reflex stimulation is the facial nucleus. The clonic form of spasm, 

 abnormal winking (spasmus nictitans) , is generally of reflex origin through irrita- 

 tion of the eyes, the dental nerves or even remotely situated nerves. In marked 

 cases the disorder is bilateral, and the spasm may extend to the muscles of the 

 neck, the trunk and the upper extremities. Twitching of the muscles of the lips 

 is caused in part by emotional influences, in part by reflex influences. Fibrillary 

 twitching appears also in the sequence of paralysis of the facial nerve as a de- 

 generative phenomenon. In dogs Schiff observed for years fascicular twitching 

 in the paralyzed facial area, which in contradistinction to fibrillary twitchings, 

 could be excited reflexly, and to which Schiff attributes the oblique position of 

 the face in man. Intracranial irritation of the most varied form, affecting the 

 cortical center or the nucleus of the nerve, may likewise cause spasm. Finally, 

 facial spasm may occur as part of general convulsions, such as attend epilepsy, 

 eclampsia, chorea, hysteria, and tetanus. Aretasus (81 A. D.) made the interesting 

 observation that the muscles of the auricle take part in the convulsions of tetanus. 

 With respect to the influence of irritation of the facial nerve upon the sense of 

 taste information must be derived from future careful investigations. Rarely, 

 spasmodic elevation of the palate and increased salivation have been described 

 in connection with irritation of the facial nerve. Moos observed profuse secretion 

 of saliva on irritation of the chorda in consequence of an operation in the tympanic 

 cavity. Aristotle had already observed transitory impairment of hearing during 

 the act of yawning and this has been attributed by Landois to spasm of the stape- 

 dius. This is the antithesis of the hyperacusis of Willis. In conjunction with 

 this there occurs a feeble droning sound, due to the vibrations of the labyrinth 

 induced by the contraction of the muscle named. Gottstein observed in one case 

 this stapedius droning to occur paroxysmally in addition to blepharospasm. 



