794 Spasm of the Nerves of the Diaphragm. 



8. Spasm of the Nerves of the Diaphragm. 



{Spasui of the diaphragm, socalled ahdomiual piilsatiou; 

 choree du diaphragme [French].) 



Spasm of the nerves of the diaphragm consists in twitch- 

 ing of the muscles of the diaphragm. 



History. The condition which prodnecs convulsive jerking of the 

 body was for a long time attributed to palpitation of the heart or to in- 

 creased pulsation of the aorta, but recent observations have shown that 

 it is due to muscular spa.sms which are even at this time very often mis- 

 taken for spasms of the abdominal muscles. With the aid of a consider- 

 able number of available observations Thomassen made a careful study 

 of the illness, and more recently Ziirn has undertaken an analysis of 

 the symptoms in two cases. 



Occurrence. Spasm of the diaphragm is not uncommon in 



horses, but is observed exceptionally also in cattle (Paimans, 



Bach, Lucet) and also in dogs (Marek). The greater number 



cases described under this name belong without doubt to 



spasm of the abdominal muscles. 



Etiology. Rather often digestive disturbances, or acute 

 stomach ailments precede spasm of the diaphragm or it occurs 

 as an accompanying complaint to intestinal catarrh or stoppage 

 of the bowels. In these cases the spasm is probably a reflex 

 condition being produced by an irritation occurring in the 

 mucous membrane of the stomach and intestine being communi- 

 cated through the n. vagus to the medulla oblongata, and from 

 there to the diaphraginatic nerves, and possibly also to the 

 nerves of other muscles. The effect of chemical substances ab- 

 sorbed from the intestinal canal does not appear to be excluded, 

 in fact, it appears probable in many cases. 



In some cases the spasms are not dependent on digestive 

 disturbances, but may arise after excessively severe work or 

 after psychic excitement. In these cases Haubner & Siedam- 

 grotzky believed that the diaphragmatic nerve was irritated 

 by the agitation due to strong beating of the heart, or that for 

 some reason the nerve had become more irritable. Thomassen 

 and Langendorf on the contrary believe that the nerve w^hich 

 passes over the heart muscle is irritated l)y the electrical current 

 generated at every systole, the irritation being capable of caus- 

 ing a spasm only in a nerve that had become irritable. 



The connection between the heart movements and the 

 spasms of the diaphragm is indicated by the fact that the num- 

 ber of the two contractions in many cases coincide, or in cases 

 where the contractions of the diaphragm occur less frequently, 

 these immediately follow upon the heart beats. 



But even if such a connection exists, the spasm of the diaphragm cannot be 

 attributed without further evidence to the heart action, as is shown by a case of the 



