Changing disease identities: cretinism, politics and surgery (1844-1892).

In 1883 the Swiss surgeon and later Nobel laureate Theodor Kocher (1841-1917) made a journey to the Valais and Bernese Oberland. The purpose of the expedition was to see cases of cretinism which occurred in this area. Earlier in the same year Kocher had noticed that he had inadvertently created "artificial cretins" by total ablation of the thyroid gland. His objective now was to see whether there were any pathological changes of the thyroid gland in "naturally" occurring cretinism too. Kocher made the local authorities show him all known cases of cretinism at the localities he visited. He was not, however, very happy with what they presented to him as cretinism. Out of thirty-two alleged cretins he accepted only six as being genuine cases. Kocher was confronted with the same problem when he checked the literature: admittedly many of his predecessors had been excellent observers, but they all had mixed up cretinism with other, different diseases. Therefore, there was a need to redefine the disorder. The criteria for this redefinition must be the true cause of the disease discovered by Kocher: the affection of the thyroid gland which is the conditio sine qua non of the development of genuine cretinism, its specific cause.' So ifwe follow this account, in 1883 Kocher found out the cause of cretinism, a discovery officially sealed by his Nobel Prize of 1909. But, as we have seen, cretinism was a different disease after its cause had been discovered. So what did Kocher mean when he called a disease "cretinism"? What had his predecessors meant when they used the term? And what do we today mean when we speak about the history of cretinism? Writers on the history of medicine often assume a simple continuity of the identity of diseases, conceiving them as unproblematic natural entities which have a manifestly obvious character. Thus the historian's task is to indicate how diseases were described wrongly or partially until a significant individual discovered the truth about them and