296 THE DUCTLESS GLANDS 



raised till the arterial flow is interrupted, in cases of tetany 

 the " obstetrical hand " attitude will be assumed. 



Much reliance is placed upon V Chvostek's sign " in tetany. 

 The region of the pes anserinus of the facial nerve is tapped 

 and one notes contraction of the muscles of the face. In 

 marked hyperexcitability there may be a contraction of all 

 the muscles of the side of the face stimulated (Chvostek I). 

 When the excitability is somewhat less great, there may be 

 only a movement of the nostrils and a drawing of the angle 

 of the mouth to the side (Chvostek II), while, when there is 

 only slight increase of excitability, there may be only a slight 

 twitch at the angle of the mouth (Chvostek III). 



The so-called arm and leg phenomena (Poole) are stated to be 

 useful in diagnosis. In tetany there is a constant response of 

 contracture of the muscles of the upper extremity upon 

 forcible abduction of the arm, and of contracture of the muscles 

 of the lower extremity extended at the knee. 



In chronic tetany certain trophic disturbances may occur. 

 Children who have suffered from tetany often show transverse 

 furrows and other defects of the teeth due to faulty develop- 

 ment of the enamel. As will be seen below, similar defects are 

 found after parathyroidectomy in animals. In the eye peri- 

 nuclear cataract has been described. 



Many different forms of tetany have been described. Among 

 these may be mentioned the idiopathic tetany of workmen, 

 maternity tetany, gastric tetany, tetany in infection and 

 intoxications, post-operative tetany, and tetany after pro- 

 longed forced respiration. It is not to be assumed that all 

 these forms are due to disease of the parathyroids. 



Parathyroid treatment does not appear to be of much 

 use, but calcium often does good. Transplantation is almost 

 always impracticable. 



It seems reasonable to suppose that a great many different 

 conditions may give rise to the phenomena of ' ' tetany." It has 

 recently been shown that administration of thyroid substance to 

 animals will frequently produce this condition. 



Parathyroid insufficiency has also been suspected to be the 

 essential pathological condition in paralysis agitans. But 

 hyperfunction has also been alleged to occur in this disease, 

 and the majority of observers fail to find any connection 

 between the parathyroid glandules and the disease in question. 



