610 LEWELLYS F. BARKER 



drome. Many of these were mentioned in the early collective reviews of 

 Oddo (1896} and of von Frankl-Hochwart (1897) and still more of them 

 in the compilation of Biedl (1913). Two systematic researches upon 

 the subject are, perhaps, worthy of especial mention: (1) that of J. 

 Ibrahim (a) (1911) on tetany of the sphincters, of the smooth muscula- 

 ture, and of the heart in sucklings; and (2) that of Falta and Kami (a) 

 (1911), who made clinical studies on tetany with especial regard to the 

 vegetative nervous system. 



Increased Mechanical Excitability of Autonomic Nerves 



Two symptoms referable to increased mechanical excitability of the 

 vasomotor nerves observable in tetany are: (1) dermographismus, out- 

 spoken in most patients in whom the syndrome occurs and (2) marked 

 anemia of the digits in the distribution of the nervus ulnaris on applica- 

 tion of a ligature to the upper arm, a symptom met with in at least one 

 instance by Falta and Kahn. 



Increased Chemical Excitability of the Autonomic Nerves 



Epinephrin Hypersensitiveness. It has been shown by Falta and 

 Riidinger that, in acute tetany, the effect of epinephrin on the blood 

 pressure, the heart's action, and the constriction of the cutaneous ves- 

 sels, is very marked. In normal individuals, alter the injection of one 

 milligram of epinephrin, the blood pressure and the pulse rate usually 

 rise gradually, whereas in acute tetany there is a very quick rise of both 

 blood pressure and pulse rate, the acme being reached within two minutes, 

 and, at the same time, marked pallor of the face and of the skin of the 

 whole body is observable. The accelerated heart's action is sometimes ac- 

 companied by premature beats or by subjective feelings of palpitation. 



In almost all eases of tetany, an acute exacerbation of the common 

 symptoms of tlie syndrome follow the injection of epinephrin. Thus, 

 Falta and Kahn observed in their cases a return of the paresthesias, an 

 aggravation of the Chvostek and of the Trousseau phenomena, the re- 

 currence of spasms in the muscles of the extremities, of the trunk, of the 

 glottis, and of the respiratory apparatus, including the diaphragm. As 

 the tetany dies down, the effects of epinephrin injections become less 

 pronounced. In single cases of acute tetany the augmenting effect of 

 epinephrin upon the symptoms is less marked, or may not be observable 

 at all. 



Elliot (r.K):>) pointed out that the vasodilators respond earlier to 

 minimal sympathicotropic stimuli than do the vasoconstrictors; hence, 

 vasodilatation is an especially delicate reagent for testing the excitability 

 of the vasomotor nerves. Falta and Kahn's experiments indicate, they 



