NEURALGIA OF THE TRIGEMINUS. : 327 



cutting out part of the nerve, since it readily heals up if simply di- 

 vided. The want of success in this operation is chiefly due to a di- 

 vision of the wrong nerve, or to its being divided at the wrong place, 

 that is, to the distal side of the point whence the pain orginates 

 (Bruns). Unfortunately, the division at " the right spot " is in most 

 cases entirely impossible, because the pain originates from a point 

 above which the nerve cannot be reached. Cauterization of the nerve, 

 for the purpose of disconnecting it from the brain, should be given up; 

 compression is only to be used as a palliative. The least benefit is 

 obtained from the specifics recommended in neuralgia, such as arsenic 

 in the shape of Fowler's solution, the preparations of zinc, particularly 

 the valerianate and hydrocyanide, nitrate of silver, and other metallic 

 and vegetable nervines. There are cases recorded where each of these 

 remedies is said to have produced brilliant results, but these examples 

 are few, and are far outweighed in number by those where they have 

 had no effect. Up to the present time it is absolutely impossible to 

 determine exactly in what cases these remedies are useful. 



OHAPTEK IV. 



NEURALGIA OF THE TRIGEMINUS PROSOPALGIA TIG DOULOUREUX 

 FOTHERGILL'S FACEACHE. 



ETIOLOGY. Next to the sciatic, no nerve is so often the seat of 

 pain as the trigeminus. This is partly because many branches of the 

 trigeminus pass through narrow canals and openings, where they may 

 readily be compressed, partly from the distribution of the nerves to 

 portions of the skin where they are more exposed to cold than other 

 nerves are. Hyrtl is doubtless correct in supposing that the passage 

 of the branches of the trigeminus through narrow openings of the 

 bones has much to do with the occurrence of facial neuralgia ; for see 

 the great immunity to the disease of those branches which pass 

 through the wide sphenopalatine foramen to the nose, compared with 

 its frequent occurrence in the infraorbital, zygomaticus malse, and su- 

 perior and inferior dental branches. 



Only in a few cases have foreign bodies under the skin (in one 

 celebrated case of Jeffreys there was a piece of porcelain) and tumors 

 pressing on the branches of the trigeminus been found as causes of 

 prosopalgia. Somewhat more frequently changes in the bony canals 

 can be found to explain the morbid excitement of the nerves traversing 

 them ; among these are exfoliations of a bony wall in neuralgia of the 

 infraorbital, exostosis of the root of a tooth in neuralgia of the in- 

 framaxillary. general thickening of the bones of the skull witli con- 

 71 



