MYXEDEMA IOQ 



in addition to alterations in the permeability of the endothelium of the blood- 

 vessels, also the pressing out of plasma on account of the long-continued 

 contracted condition of the vessels, this manifestation was absolutely lacking 

 or was essentially weaker in the thyroidless dogs. In this respect, individuals 

 without thyroids show similarity to individuals with cachexia, who, as is 

 known, do not react with hyperglobulia to the use of the lung suction-mask, 

 or to sudden transference to great heights. 



The autonomous nerves too show a diminution of their tonus and their 

 excitability, v. Cyan observed, as already mentioned, a diminution of the 

 electrical excitability of the vagi. The miotic action of pilocarpine in thy- 

 roidless dogs lasts for a shorter time (Eppinger, Falta, and Rudinger). The 

 observations of Asher have already shown that in dogs with thyroid insuffi- , 

 ciency the mydriatic action of atropine lasts for an abnormally long time. 

 Hence the autonomous nerves are more readily paralyzed than under nor- 

 mal relations. Also in blood-pressure investigations on thyroidless dogs 

 Rudinger and / observed that ruling out of the vagi through atropine lasts 

 extraordinarily long. Finally, in some cases of myxedema I could estab- 

 lish an abnormally long mydriatic action on the instillation of homatropine 

 into the eye (confer the analogous experiments in sporadic cretinism). 

 Fleischmann observed that the blood of normal animals destroys the activ- 

 ity of added atropine more rapidly than the blood of strumous animals. 



The previously mentioned alteration in the reaction of the vascular endo- 

 thelium to adrenalin depends perhaps on the disturbances in nutrition, and 

 these could be the cause of the premature arteriosclerosis of thyroidless 

 animals, such as Eiselsberg, Pick, Pineles, and others have described. Also in 

 myxedema patients we frequently find striking grades of arteriosclerosis 

 and depositions of lime salts, the latter even in other organs, such as the 

 kidney, liver, etc. (Abrikosojf) . Finally also in thyroaplasia has high- 

 grade atheroma been found in the aorta and other vascular territories 

 (Bournemlle, Maresch, Machand, Heyn, and others). The occurrence of arlerio- 

 sclerotic alterations in thyroid-gland insufficiency has been brought forward 

 as the explanation of the senile degeneration. Horsley first pointed out that 

 the thyroid gland in old age becomes atrophic, Vermehren compares old age 

 with a chronic myxedema, while in more recent times Lorand has elaborated 

 on this view. In opposition to this, Ewald has already shown that in maras- 

 mus senilis there is initiated not only an atrophy of the thyroid (and the 

 other ductless glands) but also a degenerative atrophy of the other organs, 

 especially the gastrointestinal tract. At all events, we should not use thy- 

 roid medication in old age uncritically (v. Noorden). 



The diminution of the tonus or the excitability of the vegetative nerves 

 is spoken for also by the failure of the sweat secretion in myxedema patients. 

 The secretion of sweat may fail entirely on bodily movements, or even when 

 there exists high external temperature. Mann observed that in myx- 



