320 



MR. BELL ON THE NERVES OF THE FACE. 



has been divided in the extirpation of a tumour from before the ear, and the 

 immediate effect has been horrible distortion of the face by the prevalence of 

 the muscles of the opposite side, but without the loss of sensibility ; and that 

 distortion is unhappily increased when a pleasurable emotion should be re- 

 flected in the countenance. 



These facts are so distinct, that I cannot presume to detain the Society with 

 the instances of the lesser defects which I have witnessed from the more partial 

 injuries or temporary diseases of the nerve ; — such as distortion of the features 

 produced by glands pressing on this nerve, paralysis from suppurations in the 

 ear affecting the nerve in its passage, or temporary derangement disturbing 

 one or more of its functions. 



As to the fifth nei-ve, the facts are equally impressive, and correspond with 

 our former experiments and opinions. By a small sacculated tumour affecting 

 the roots of this nerve, the sensibility was destroyed in all the parts supplied 

 by its widely extended branches ; that is, in all the side of the head and face 

 and the side of the tongue, whilst the motion of the face remained. Two cir- 

 cumstances affecting this nerve have occurred with most curious coincidence 

 in the symptoms. By the drawing of a tooth from the lower jaw, the nerve 

 which comes out upon the chin to supply one half of the lip was injured, and 

 exactly this half of the lip was rendered insensible. When the patient put 

 his mouth to a tumbler he thought they had given him a broken glass! 

 Precisely the same thing occurred from the division of that branch of the fifth 

 nerve, which goes to one half of the upper lip. A gentleman falling, a sharp 

 point entered his cheek and divided the infra orbitary nerve : the effect was 

 loss of sensation without loss of motion, in that half of the upper lip to which 

 the nerve is distributed. The remarkable circumstance was, that this indivi- 

 dual made the same remark when the cup was put to his lip : — that they had 

 given him a broken one ! The part of the cup which was placed in contact 

 with the insensible portion of the lip appeared to him to be broken off. 



I have had two or three instances before me of disease affecting the 

 ophthalmic branch of the fifth nerve, and producing total insensibility of the 

 eye and eyelids, without loss of vision ; whilst the eyelids continued to be 

 closed and the eyebrow to be moved by the influence of the portio dura of the 

 seventh nerve. 



