PARATHYROID GLANDS 647 



try. Idiopathic tetany seems to be relatively uncommon in the United 

 States, in England, in Scandinavian countries, and also in Russia. 



Familial Occurrence. Familial idiopathic tetany has been frequently 

 observed both in Europe and in this country. Thus Vaughan, in 1893, saw 

 five children affected by the disease in one Italian family in New York. 

 Chronic idiopathic tetany of the familial type has been described by 

 Schiffer (1911). 



Laureati (1916) advised the use of thyroid treatment to ward off or 

 to cure the syndrome in families subject to tetany. 



Recurrences. Patients who have suffered from idiopathic tetany in 

 one year are liable to recurrences in later years, especially in the spring. 



Formes frustes. At times of tetany epidemics, many persons who 

 are apparently quite healthy and who suffer from no spontaneous tetany at- 

 tacks, may exhibit, when carefully tested, a positive reaction to some 

 single tetany sign & ( Trousseau's, Erb's, or Chvostek's sign). 



Etiological Hypotheses. ?uchs believes that idiopathic tetany is, in 

 reality, a mild form of chronic ergotism, due to the use of rye bread, and 

 tries to correlate the geographic distribution of tetany with the areas in 

 which rye is much used instead of wheat. He points out, too, that the 

 patients attacked by idiopathic tetany are persons who are more likely to 

 use rye bread than the more expensive wheat bread. They are, in Vienna, 

 often people who work at home, who do not during the whole week leave 

 their workshops, and who always get the same cereals, apparently from 

 the same small bakeries. Fuchs even goes so far as to ascribe the tetany of 

 children and maternity tetany to the use of rye bread. He has further sup- 

 ported his doctrine by animal experiments, in which ergot was fed. The 

 hypothesis, though interesting, has not as yet been verified. 



In criticism of this view advanced by Fuchs, one may ask the question, 

 Why is tetany so prevalent in Vienna and Heidelberg and so rare in other 

 parts of Austria and in Germany, in which rye bread is fully as much 

 used? 



A second hypothesis associates idiopathic tetany in one way or another 

 with goiter, which, as is well known, is distributed in certain definite 

 geographic areas. From his studies of tetany and of goiter in India,- es- 

 pecially in the Gilgit Valley, R. MacCarrison has advanced this view. 



Certain exciting causes of the spontaneous attacks of idiopathic tetany 

 have been mooted. In tetany epidemics, the patients, before the onset of 

 the contractures, usually complain of paresthesias in the extremities, the 

 actual spasms appearing only under the influence of some accident, such as 

 a bad cold, sore throat, or other mild infection, some gastro-intestinal dis- 

 turbance, or a mechanical or psychic trauma. In many cases, however, no 

 such special precipitating cause is recognizable. 



Many of the young workmen affected by seasonal tetany are found, on 

 inquiry, to have suffered in early childhood from laryngospasm or from 



