THE SYMPATHETIC SYSTEM 125 



PATHOGENESIS. 



Several theories have been brought out to explain the 

 sudden death. 



(a) According to Paltauf, the patients, the children in 

 particular, have a peculiar appearance. They are fat and 

 anemic, having small genital organs. The tonsils, the 

 glands of the neck and axilla are swollen; the spleen is 

 increased in size. The cardio-aortic system shows aplasia. 

 The examination of the blood shows an appreciable 

 lymphocytosis. In other words, these subjects show a 

 status lymphaticus characterized by hyperplasia of the 

 lymphoid tissue and hypoplasia of the cardio arterial 

 system. This diatheses shows a peculiar vulnerability 

 of the heart as evidenced by the vagotonia; the sudden 

 accidents are the result of an inhibition of the heart by the 

 rupture of the equilibrium between the tonus of the vagus 

 and of ^the sympathetic. 



(6) According to Svehla, the syncope is due to a 

 toxemia. The thymus secretes an abnormal secretion 

 (quantity or quality) which results in a hyperexcitability 

 of the cardiac nerve centers. All stimuli, which normally 

 would be without effect, in healthy individuals, will cause 

 in these susceptible cases a fatal syncope. This theory 

 would help to explain the cases in which the gland is 

 not hypertrophied. 



(c) Others finally believe that the fatal syncope is due 

 to a pressure on the vagus or the phrenic or even the right 

 inferior cardiac nerves. 



None of these theories, however, ingenious they may be, 

 have ever been demonstrated and the pathogenesis of 

 sudden thymic death is still hypothetical. 



