The occurrence, in the formative period of infancy and childhood, of a disease which attacks fundamentally nutrition, development, and growth, has much more disastrous effects than when its appearance is delayed until the organism has reached maturity.
And while it is possible that the removal of causes inhibitory to growth may result in a gradual return of developmental processes, the thyroid treatment of infantile myxœdema has in no case been carried out for a sufficient length of time to permit the assertion that such will be the case. In no case is treatment reported to have lasted more than three years, and in few cases is it said that the patient is in all respects cured; but from the fact that in nearly all of the cases treatment was not instituted until the child was several years of age and had developed but little or not at all for a considerable length of time, several years would be necessary, by the natural processes of development, for the complete re-establishment of normal growth.
Although data sufficient to justify positive assertions are lacking, it seems entirely in the range of possibility that if the treatment of sporadic cretinism were begun at the outset of the disease, before growth was seriously interfered with, it would permit the proper development of the child without myxœdematous symptoms as long as the thyroid was administered.
From the consideration of the history of myxœdematous conditions it will have been seen that all this treatment promised to do was to supply to the body the necessary substance which the thyroid gland was no longer able to produce. It never undertook to supply a new thyroid gland; and the disappearance of the symptoms of myxœdema under the thyroid treatment means that the necessary secretion is being artificially supplied, and not that the function of the gland has been restored.
Consequently, any one in whom the activity of the thyroid gland has been lost, whether it be by myxœdema, or operation which has induced the condition of cachexia thyreopriva, must continue the use of the thyroid glands of animals for the remainder of life. Dr. Murray's original case is still taking thyroid, and after five years remains well.
The therapeutic use of the thyroid has now been tried in many other conditions with varying success. From its efficacy in reducing the size of ordinary goiters it has to a great extent supplanted the knife in the treatment of that condition. Recent reports from Germany would seem to indicate that it exerts a beneficial influence upon the development of children who are physically or mentally backward, although they have none of the characteristic symptoms of cretinism. Its power to reduce excessive fat is becoming very widely known, and when properly
