HYPOTIIYKOIDISM 391 



growth anomalies in cretinism have been well delineated by E. Wieland 

 and F. Siegert, 



Dwarfism in athyrosis is pronounced. Growth in other less affected 

 hypothyroid individuals is stunted in direct ratio to the amount of func- 

 tionating thyroid tissue remaining. Even when the other stigmata of the 

 subthyroid condition are very slightly marked, complete cessation of de- 

 velopment may occur. On the other hand it is surprising to find adult 

 subjects with hypothyroid disease dating from their early life but with 

 large robust frames of normal height, and yet showing severe signs and 

 symptoms of the disease. It is well in such instances to remember the 

 influence of the pituitary and probably still other endocrin organs upon 

 growth. 



In spite of statements in the literature to the contrary, it is probable 

 that the delayed ossification changes may set in at or before birth, the rea- 

 son being that young infants are seldom carefully examined rontgenologi- 

 cally. This seems likely from the knowledge gained in hypothyroid experi- 

 ments in animals in which young have been born with pronounced delay 

 in the degree of development of the osseous system usual at birth. There- 

 after the youngest case carefully studied seems that of Dieterle (c), who 

 described a four months old case of athyrosis with the skeletal development 

 of a newly born baby. 



Some of the severest cases of dwarfism known were formerly found 

 among cretins. Thus Telford-Smith's cases measured 30 inches in height 

 at the 16th year. Curling's but 26 inches at the 20th year. The general 

 nature of the bony changes include retardation of ossification and 

 epiphyseal union, osteoporosis, osteosclerosis and marrow changes. The 

 growth retardation is usually reported as proportional, in carefully ex- 

 amined cases such as those of Bourneville (a) and von Maresch. Clinical 

 observation, however, certainly suggests that the extremities are more 

 often affected than the trunk. The bones are of normal outline when once 

 formed but the lower extremity is occasionally slightly bowed from de- 

 fective ossification. Often the bones are apparently normal rontgeno- 

 logically, except that the appearance of the epiphyses and other distinguish- 

 ing characteristics are those of an age much younger than that of the sub- 

 thyroid individual under observation. There is no ground for confusing 

 hypothyroid osseous lesions with rachitic skeletal changes, into which error 

 certain of the older writers, even Virchow, have fallen. 



The delay in growth in cretinism is brought about by the late appear- 

 ance of the bone nuclei and extremely slow ossification of centers already 

 laid down. The epiphyses may be absent many years after they are due 

 to appear and their closure with the shafts of the long bones be indefinitely 

 delayed. It has been demonstrated that this phenomenon is one of the 

 earliest and most constant in hypothyroidism. Even mild cases clinically 

 may show very remarkable delay in bone development which is retarded 



