EXOPHTHALMIC GOITER 495 



There can be no doubt that the thyroid secretion is capable 

 of causing serious intoxication, for patients who have overused 

 thyroid preparations in the treatment of obesity, skin diseases, 

 etc., have often suffered severely from the symptoms mentioned 

 previously, and, in at least one such case, a diagnosis of ex- 

 ophthalmic goiter was made before the cause of the disturbance 

 was detected. Not infrequently evidences of acute intoxication, 

 sometimes resembling tetany, have followed immediately after 

 operations upon the thyroid, and these have been considered as 

 due to intoxication with the large quantities of thyroid secretion 

 that have escaped from the gland during the operative manipu- 

 lation. The fact that amblyopia, resembling that produced by 

 tobacco, etc., may follow overuse of thyroid preparations 1 is 

 also indicative of their toxicity, as also is the glycosuria that 

 may result from thyroid administration. 



Even if the hypothesis that exophthalmic goiter is due to intox- 

 ication with thyroid secretion is correct, we have no satisfactory 

 explanation of the cause of the hyperactivity of the thyroid. In 

 some cases degenerative changes have been observed in the 

 superior cervical sympathetic ganglia, and cure or improvement 

 of exophthalmic goiter is said to have followed resection of these 

 ganglia ; however, this relation has not been observed at all 

 constantly. In other cases there has been evidence that sug- 

 gested a primary intoxication with the products of intestinal 

 putrefaction, leading to a secondary hyperplasia of the thyroid, 

 but this also seems to be an exceptional observation. All things 

 considered, it seems most probable that the hyperactivity of the 

 thyroid is due to some exciting condition, and is not of itself 

 primary, although the resulting hyper secretion of the thyroid may 

 cause the dominant features of the disease. The frequent associa- 

 tion of exophthalmic goiter with puberty and pregnancy suggests 

 that some abnormality in the function of the generative organs 

 may be a frequent starting-point of the thyroid derangement. 



The Relation of the Parathyroids to Exophthalmic 

 Goiter. This has not yet been definitely established. As 

 nervous manifestations are very prominent after parathyroid- 

 ectomy, so that many experimenters attribute all the acute 

 nervous and muscular symptoms of total thyroidectomy to 

 simultaneous removal of the parathyroids, it has seemed very 

 probable that these organs may be more closely associated with 

 exophthalmic goiter than is the thyroid itself. 2 Against the 



1 Birch-Hirschfeld and Inouye, Graefe's Arch., 1905 (61), 499. 



2 This subject is thoroughly reviewed by MacCallum, Med. News, 1903 

 (83), 820. 



