76 INTERNAL SECRETION 



an etiological relationship between the symptoms of senile 

 cachexia and the retrograde changes which, in this condition, take 

 place in the internal secretory organs. The possibility suggests 

 itself that these changes are not the cause, but the consequence, 

 of the general nutritional disturbance which occurs in old age. 

 As Ewald rightly points out, the atrophy of the intestinal tract, 

 which is an invariable and characteristic feature of senile cachexia, 

 is absent in myxoedema. 



We have not sufficient grounds for the assumption that senile 

 decay results from the suppression of function of internal secretory 

 organs other than the thyroid gland. The pathogenesis of this 

 condition offers a wide field for investigation. 



We are very much better informed in regard to the patho- 

 logical consequences of thyroid insufficiency in youth. 



In addition to myxcedema, conditions occur in young growing 

 individuals as a result of suppression of the thyroid function, 

 which, like those which follow operative athyrosis, are charac- 

 terized by derangement of the processes of growth and serious 

 mental deficiency. Owing to the similarity which these cases 

 bear to those of endemic cretinism, they are generally included 

 under the heading of sporadic cretinism. Out of the medley of 

 these cases, Pineles, with considerable penetration, distinguished 

 two distinct clinical entities, namely, congenital myxoedema, 

 which he calls thyroplasia, and infantile myxcedema. In addition 

 to myxcedematous signs, both conditions present symptoms of 

 derangement of the processes of growth, though these are not as 

 severe in the latter condition as in the former. 



Infantile myxcedema appears at or after the fifth year; it 

 resembles adult myxcedema in its distribution and in its clinical 

 course, but more particularly in the fact that it is never congenital, 

 but always acquired. In both cases the condition is due to patho- 

 logical changes leading to atrophy of an already completely 

 formed thyroid gland. 



But in congenital myxcedema the case is otherwise, and we 

 have to do with a congenital thyroid deformity, a thyroidaplasia, 

 in fact. From evidence afforded by the literature of the subject, 

 Pineles drew the conclusion that the complete absence of the 

 thyroid, the parathyroids being present intact, is not the secondary 

 result of a previous pathological condition, but is a congenital 

 defect of development; it is, in fact, true spontaneous thyroid 

 suppression. The clinical picture, as in operative athyrosis, is 

 one of extreme severity ; there are pronounced dwarfism, extreme 

 idiocy, and marked symptoms of myxcedema, all of which are 

 present from earliest childhood. 



Congenital myxcedema, the symptoms of which closely re- 

 semble those of endemic cretinism, differs from the latter condition 

 in the sporadic nature of its occurrence. Moreover, endemic 

 cretinism is never, and goitre very rarely, found in the antecedents 



