16 PHYSIOLOGY CHAP. 



particularly iii the flexor muscles of the hand and forearm; soon, 

 however, the spasms invade other muscular groups, inducing 

 lock -jaw, blepharospasm, cramp of the tongue, trachelismus, 

 opisthotonus. 



The tetanic spasms are preceded, accompanied, or followed by 

 tachypnea and tachycardia, with a concomitant rise of tempera- 

 ture of '2-'.l C. Sometimes the neuro-niuscular super-excitation 

 assumes the form of clouic-tonic epileptoid convulsions, conscious- 

 ness being retained. This is generally the most serious symptom 

 of tetania thyreopriva, and sets in shortly before death. 



Unlike simple cachexia, post-operative tetauy seldom exhibits 

 sugar or even albumin in the urine. 



The course and outcome of tetany varies. It may consist in 

 one or more severe attacks, leading rapidly to the death of the 

 patient. In other cases it may be protracted for many days and 

 even mouths, when less acute attacks are observed from time 

 to time, which may be followed by the slowly developing pheno- 

 mena of cachexia thyreopriva. In other cases, again, tetany in a 

 more or less intense form may appear much later, 3-4 years after 

 thyroidectomy, when the phenomena of cachexia thyreopriva are 

 already fully developed. 



VI. These grave effects of thyroidectomy in man were the 

 subject of much discussion and controversy at the Congress of 

 German surgeons which took place in 1883. The observations of 

 Keverdin, Kocher, Wolfler, and Bardeleben were confronted with 

 not a few cases of goitre in which no subsequent morbid symptoms 

 were apparent. We shall return later to the cause of this 

 phenomenon. Meantime, experimental confirmation of the great 

 physiological importance of the thyro- parathyroid system was 

 not long wanting. The merit of its discovery is due to M. Schiff, 

 who in 1884 published two Memoirs on the effects of removing 

 the thyroid bodies in the dog, which indicated the true solution of 

 this crucial question. Schiff was followed by a host of experi- 

 menters in Italy, Germany, and France, whose work threw much 

 light on the subject, though it is still obscure. 



Let us first consider the phenomena consequent on total 

 thyroidectomy in the dog, on which many experiments have been 

 carried out. 



The total extirpation of both thyroid bodies in these animals 

 produces effects no less complex and variable than in man : usually 

 they present a combination of the phenomena of tetany and of 

 cachexia thyreopriva. The operation is almost invariably fatal, 

 after a period varying from 3-4 days to a month. Death more 

 often occurs between the sixth and tenth days. The fatal issue 

 is more rapid when acute symptoms of tetany prevail ; it is 

 retarded when the depressing and dystrophic symptoms of 

 cachexia predominate. The phenomena of the first and second 



