PARATHYROID GLANDS 



645 



IV. The Etiology and Pathogenesis of Tetany 

 with Comments Upon Its Different Forms 



When considering the etiology and pathogenesis of tetany, it is helpful 

 to consider the various forms of the syndrome that are met with in children 

 and in adults. Cases of human tetany in adults were, from the etiological 

 viewpoint, divided by von Frankl-Hochwart into several groups. Tetany 

 presents certain peculiarities in each of these groups, and to these special 

 features we shall immediately refer. 



1, Idiopathic Tetany 



(Tetany of Workmen; Epidemic-Endemic Tetany) 



Idiopathic Character. This group is characterized by its idiopathy. 

 Spontaneous attacks of tetany appear in young, apparently healthy per- 

 sons, and without any ascertainable cause. 



Fig. 11. Table giving the incidence of tetany by months and years. (After L. 

 von Frankl-Hochwart.) 



Seasonal Influences. The attacks occur at certain times of the year, 

 particularly in the early spring. Residents of cities in which tetany is 

 endemic are prone to the attacks, and when the cases are numerous, owing 

 to seasonal influences, "tetany epidemics" are spoken of. In Figs. 11 and 

 12 graphic representations of the numbers of tetany patients admitted to 

 the General Hospital in Vienna from the year 1880 to 1895 (inclusive) 

 are exhibited according to months. It will be noticed how few cases 

 occurred in the months of August, September, and October, and what a 



