SPASM OF THE FACIAL NERVE. 351 



CHAPTER XV. 



SPASM OP THE FACIAL NERVE MIMIC SPASM OF THE FACE TIC 



CONVULSIF. 



ETIOLOGY. A morbid irritability involving the twigs of the facial 

 nerve which go to the muscles of the face, but which does not involve 

 the fibres running to the stylohyoid and digastric muscles, is called 

 tic convulsif whenever it is not combined with general convulsions. 

 The cause of this affection of the facial is obscure. Probably the cases 

 of isolated irritation to which alone we refer at present are never de- 

 pendent upon lesions of the brain. Nor does the cause of tic convul- 

 sif seem ever to be an irritation of the facial within the skull, or during 

 its passage through the canal of Fallopius. Whenever the morbid 

 excitement of this nerve is due to the action of some noxious influence 

 upon the face itself, such as cold, a contusion, or the pressure of a 

 tumor, it becomes a matter of doubt whether these influences act 

 directly upon the fibres of the facial nerve, or whether their immediate 

 effect is not upon the filaments of the trigeminus, the facial merely 

 becoming irritated by reflex action. Sometimes, too, tic convulsif has 

 been viewed as a reflex neurosis, arising from the irritation of remote 

 organs, such as the rectum in helminthiasis, or the uterus in hysteria. 

 Finally, mental emotion and the imitative instinct are set down among 

 the causes of tic convulsif. The affection seems to be somewhat more 

 common among men than among women. 



SYMPTOMS AND COURSE. In almost all cases of tic convulsif, but 

 one side of the face is affected ; sometimes the spasm is clonic, some- 

 times tonic. Romberg, in a few brief but graphic lines, gives the fol- 

 lowing description of the mimic spasm : " Grimaces occur, either inter- 

 mittent or constant, involving one side of the face, and, more rarely, 

 both sides. In the former case they consist chiefly of elevation or de- 

 pression of the occipito-frontal muscle, corrugation of the eyebrows, 

 blinking and closure of the eyelids, twitching and snuffling of the alae 

 nasi, and drawing up and down of the corners of the mouth. These 

 attacks set in suddenly, and as suddenly subside, to recur, with equal 

 suddenness, at short intervals. In permanent tonic contraction of the 

 facial muscles, the furrows and hollows in the affected side of the face 

 are deeper ; the tip of the nose, the commissure of the lips, and the 

 chin are drawn toward the convulsed side. The muscles feel hard and 

 tense, and so impede motion that the one eye cannot be as completely 

 closed as the other." The patient is unable to prevent or to control 

 these motions at will. As a rule, any individual motion, made volun- 

 tarily, is accompanied by involuntary contractions of other muscles. 



