REMOTE EFFECTS OF DIVISION OF THE TRIFACIAL 529 



sympathetic system, not occurring when these sympathetic filaments 

 escape division, are to be attributed to lesion of the sympathetic and not 

 to the division of the sensory nerve itself. 



The following explains, in a measure at least, the consecutive inflam- 

 matory effects of section of the fifth with its communicating sympathetic 

 filaments : By dividing the sympathetic, the eye and the mucous mem- 

 branes of the nose, mouth and ear are rendered hyperemic, the tempera- 

 ture is raised and the processes of nutrition are exaggerated. This 

 condition of the parts would seem to require a full supply of nutritive 

 material from the blood in order to maintain the condition of exagger- 

 ated nutrition ; but when the blood is impoverished probably as the 

 result of deficiency in the introduction of nutritive matter, from paralysis 

 of the muscles of mastication on one side the nutritive processes in 

 these delicate parts are seriously modified, so as to constitute inflam- 

 mation. It has been observed, however, that inflammation of the eye 

 does not follow section of the fifth when the part is protected from 

 external irritation, as by sewing together the eyelids. It must be, as it 

 seems, that the delicate structures of the organs of special sense, 

 especially vision, are rendered vulnerable by the loss of sensibility and 

 the hyperemia, the congestion following this operation readily passing 

 into inflammation. Under these conditions, when the eye is completely 

 protected from irritation, inflammation may not occur. 



Pathological facts in confirmation of experiments on the fifth pair 

 in the lower animals are not wanting ; but it must be remembered 

 that in cases of paralysis of the nerve in the human subject, it is not 

 always possible to locate exactly the seat of the lesion and to appreciate 

 fully its extent, as can be done when the nerve is divided by an opera- 

 tion. In these cases it sometimes occurs that the phenomena, particu- 

 larly those of modified nutrition, are more or less contradictory. 



Cases of paralysis of the fifth in the human subject in the main 

 confirm the results of experiments on the inferior animals. In cases in 

 which the fifth nerve alone is involved in the disease, without the facial, 

 there is simply loss of sensibility on one side, the movements of the 

 superficial muscles of the face being unaffected. When the small root 

 is involved, the muscles of mastication on one side are paralyzed ; but 

 in certain reported cases in which this root escaped, there was no 

 muscular paralysis. The senses of sight, hearing and smell, except as 

 they are affected by consecutive inflammation, are little if at all dis- 

 turbed in uncomplicated cases. The sense of taste in the anterior por- 

 tion of the tongue is perfect, except in those cases in which the facial, 

 the chorda tympani or the lingual branch of the fifth after it had been 

 joined by the chorda tympani is involved in the disease. In some cases 



2M 



