442 NEUROSES OF THE LARYNX. 



when the animal is not under the eye of the operator. Serious oedema 

 of the mucous membrane and dyspnoea occasionally occur, but are 

 rare. In dealing with new growths removal must be complete ; 

 Paquelin's cautery, in certain circumstances, does good service, and 

 also checks bleeding. Where marked dyspnoea exists, or occurs 

 periodically, tracheotomy must either be performed before casting 

 the horse, and a cannula inserted ; or the instruments must be in 

 readiness, so that, in case of need, a tube can be inserted. In the 

 treatment of perilaryngitis chronica fibrosa, or of new growths with 

 broad bases in the larynx, tracheotomy below the growth is the 

 only means of removing dyspnoea. 



(2.) NEUROSES OF THE LARYNX— SPASM OF THE RIMA- 

 GLOTTIDIS— LARYNGISMUS STRIDULUS— HEMIPLEGIA 

 AND DIPLEGIA LARYNGIS. 



These terms are applied to attacks of difficult breathing, occurring 

 periodically, and apparently caused by spasmodic closure of the 

 rima-glottidis. As a rule, the dyspnoea is inspiratory, and may 

 occasionally be so severe as to constitute apnoea, — that is, temporary 

 cessation of respiration. 



The causes consist in either direct irritation of the mucous membrane 

 or in reflex irritation of the nerves supplying the muscles of the larynx. 

 Records of many such cases have been published, but are seldom 

 sufficient to determine the exact cause of the attack. Acute 

 inflammatory changes, catarrh, oedema of the glottis, food materials, 

 or foreign bodies in the upper air passages, have all been assigned as 

 causes. Post-mortem examination has discovered tumours in the 

 pharynx, larynx, or trachea, but true neuroses of the larynx are 

 occasionally met with. 



Ebinger describes a horse suddenly attacked by severe dyspnoea, 

 threatening suffocation, and accompanied by roaring. When at rest the 

 breathing was normal and the health undisturbed, but the slightest work 

 or pressure on the larynx, or indeed on any point of the neck above the 

 jugular furrow, caused immediately severe dyspnoea and marked roaring, 

 which continued during the next 8-10 respirations. Light pressure sufficed 

 again to produce the attack. The symptoms disappeared after eight 

 days' treatment with subcutaneous injections of acetate of morphine. 

 Ebinger, not without justification, believes this to have been a neurosis 

 of the recurrent nerve. The cases described by Holzendorf and Neumann 

 as spasm of the larynx, or cramp of the muscles of the glottis, may have 

 been due to other causes. In that recorded by Holzendorf, inflammatory 

 disease of the larynx was clearly present; while the obstinate dyspnoea 

 treated by Neumann does not appear to have been neuropathic. 



