104 



Mr. J. S. R. Russell. The Abductor and [Mar. 31, 



the arrangement of the fibres in the trunk of the recurrent laryngeal 

 nerve, either by anatomical observation or direct experimental in- 

 vestigation. 



Historical Account of Previous Experimental Researches. 



Hooper,* wishing to decide, by experimental investigation, whether 

 it is the abductor or the adductor fibres that are really the more 

 prone to succumb in affection of the recurrent laryngeal nerve, 

 passed a thread through the middle of one recurrent nerve, and left it 

 in situ in the hope that it would act as a foreign body and excite 

 inflammation of the nerve. At the end of a week, on inspecting the 

 larynx, the vocal cord on the side corresponding to the injured nerve 

 was observed not to come up to the middle line with the same " snap " 

 on expiration as did the cord of the opposite side. 



The nerve was found imbedded in a mass of inflammatory tissue, 

 and electrical stimulation of its trunk below this point resulted in 

 abduction of the corresponding vocal cord. When a strong current 

 was used, stimulation of the nerve resulted in abduction of the 

 vocal cord of the same side, and adduction of that of the opposite 

 side. The opposite uninjured nerve was next divided, and adduction 

 of the vocal cord on this side followed stimulation of its peripheral 

 end. Division of the injured nerve below the point at which the 

 thread had been inserted, and stimulation of its peripheral end, 

 resulted in distinct outward rotation of the arytenoid cartilage of that 

 side and an approximation of both arytenoid cartilages at the 

 same time. All attempts to verify these results have failed, so that 

 the experiment stands alone. Proneness of the adductors to suffer 

 before the abductors is what this experiment seemed to point to, but 

 the observer was unable to lay very great stress on this single experi- 

 ment, positive as it seemed. 



The possibility of direct injury to the adductor fibres during the 

 process of inserting the thread into the nerve does not seem to have 

 occurred to this observer, a possibility which is more than likely. 

 Further, it is quite evident that the effects he obtained on the opposite 

 cord, by stimulating the injured nerve, were due to diffusion of the 

 electrical current to the nerve of the other side by diffusion to the 

 vagal trunk, and so reflexly to the opposite nerve. 



Onodif exposed the muscles of the larynx in dogs, and found that 

 at the point where the recurrent laryngeal nerve crosses the crico- 

 arytenoideus lateralis muscle it splits into three bundles, the first of 

 which supplies the crico-arytenoideus posticus, the second the aryte- 

 noideus transversus and crico-arytenoideus lateralis, and the third 



* Hooper, ' New York Med. Journ.,' July 4, 1885. 

 t Onodi, ' Berliner Klin. Wochenschr.,' 1889, No. 18. 



