Cretinism

Cretinism, the term given to a chronic disease, either sporadic or endemic, arising in early childhood, and due to absence or deficiency of the normal secretion of the thyroid gland. It is characterized by imperfect development both of mind and body. The thyroid gland is either congenitally absent, imperfectly developed, or there is definite goitre. The origin of the word is doubtful. Its southern French form Chrestiaa suggested to Michel a derivation from cresta (crête), the goose foot of red cloth worn by the Cagots of the Pyrenees. The Cagots, however, were not cretins. The word is usually explained as derived from chrétien (Christian) in the sense of “innocent.” But Christianus (which appears in the Lombard cristanei; compare the Savoyard innocents and gens du bon dieu) is probably a translation of the older cretin, and the latter is probably connected with creta (craie)—a sallow or yellow-earthy complexion being a common mark of cretinism.

The endemic form of cretinism prevails in certain districts, as in the valleys of central Switzerland, Tirol and the Pyrenees. In the United Kingdom cretins have been found in England at Oldham, Sholver Moor, Crompton, Duffield, Cromford (near Matlock), and other points in Derbyshire; endemic goitre has been seen near Nottingham, Chesterfield, Pontefract, Ripon, and the mountainous parts of Staffordshire and Yorkshire, the east of Cumberland, certain parts of Worcester, Warwick, Cheshire, Monmouth, and Leicester, near Horsham in Hampshire, near Haslemere in Surrey, and near Beaconsfield in Buckingham. There are cretins at Chiselborough in Somerset. In Scotland cretins and cases of goitre have been seen in Perthshire, on the east coast of Fife, in Roxburgh, the upper portions of Peebles and Selkirk, near Lanark and Dumfries, in the east of Ayrshire, in the west of Berwick, the east of Wigtown, and in Kirkcudbright. The disease is not confined to Europe, but occurs in North and South America, Australia, Africa and Asia. Wherever endemic goitre is present, endemic cretinism is present also, and it has been constantly observed that when a new family moves into a goitrous district, goitre appears in the first generation, cretinism in the second. The causation of goitre has now been shown to be due to drinking certain waters, though the particular impurity in the water which gives rise to this condition has not been determined (see Goitre). The causation of the sporadic form of cretinism is, however, obscure.

Cretinism usually remains unrecognized until the child reaches some eighteen months or two years, when its lack of mental development and uncouth bodily form begin to attract attention. Occasionally the child appears to be normal in infancy, but the cretinoid condition develops later, any time up to puberty. The essential point in the morbid anatomy of these cases is the absence or abnormal condition of the thyroid gland (see Metabolic Diseases). It may be congenitally absent, atrophied, or the seat of a goitre, though this last condition is very rare in cases of sporadic cretinism. The skeleton shows arrested growth, most marked in the case of the long bones. The skull in the endemic form of cretinism is usually brachycephalic, but in the sporadic cases it is more commonly dolichocephalic. The pathology of cretinism and its allied condition myxoedema (q.v.) has now been conclusively worked out, and its essential cause has been shown to be loss of function of the thyroid gland.

The condition has existed and been described in far back ages, but mingled with so many other entirely different deformities and degenerations that it is now often almost impossible to classify them satisfactorily. The following is a vivid picture by Beaupré (Dissertation sur les crétins, translated in Blackie on Cretinism, Edin., 1855):—

When fully grown the height rarely exceeds 4 ft., and is often less than 3 ft. The skin feels doughy from thickening of the subcutaneous tissues, and it hangs in folds over the abdomen and the bends of the joints. Very frequently there is an umbilical hernia. The hair has a far greater resemblance to horse-hair than to that of a human being, and is usually absent on the body of an adult cretin. The temperature is subnormal, and the exposed parts tend to become blue in cold weather. The blood is usually deficient in haemoglobin, which is often only 40-50% of the normal. The mental capacity varies within narrow limits; an intelligent adult cretin may reach the intellectual development of a child 3-4 years of age, though more often the standard attained is even below this. The child cretin learns neither to walk nor talk at the usual time. Often it is unable even to sit without support. Some years later a certain power of movement is acquired, but the gait is waddling and clumsy. Speech is long delayed, or in bad cases may be almost entirely lacking. The voice is usually harsh and unpleasant. Of the senses smell and taste are but slightly developed, more or less deafness is generally present, and only the sight is fairly normal. In the adult the genital organs remain undeveloped. If the cretin is untreated he rarely has a long life, thirty years being an exceptional age. Death results from some intercurrent disease.

Cretinism has to be distinguished from the state of a Mongolian idiot, in whom there is no thickening of the subcutaneous tissues, and much greater alertness of mind; from achondroplasia, in which condition there is usually no mental impairment; and from infantilism, which covers a group of symptoms whose only common point is that the primary and secondary sexual characteristics fail to appear at the proper time.

Before 1891 there was no treatment for this disease. The patients lived in hopeless imbecility until their death. But in that year Dr George Murray published his discovery of the effect of hypodermic injections of thyroid gland extract in cases of myxoedema. In the following year Drs Hector Mackenzie, E. L. Fox of Plymouth, and Howitz of Copenhagen, each working independently, showed the equally potent effect of the gland administered by the mouth. The remedy was soon after applied to cretinism and its effects were found to be even more wonderful. It has to be used, however, with the greatest care and discrimination, since personal idiosyncrasy seems to be a very variable factor. Even small doses, if beyond the patient’s power, may produce fever, excitement, headache, insomnia and vomiting. The administration must be persisted in throughout life, otherwise myxoedematous symptoms appear. The first most apparent results are those of growth, and this may supervene even in patients up to 25-30 years of age. Once started, 4 to 6 in. may be gained in stature in the first year’s treatment, though this is usually in inverse ratio to the age of the patient, and also diminishes in later stages of treatment. In young adolescents it may be so rapid that the patient has to be kept lying down to prevent permanent bending of the long bones of the leg, softened by their rapid growth. A very typical case under Dr Hector Mackenzie, showing what can be expected from early treatment, is that of a cretin aged 11 years in 1893, when thyroid treatment was started. He grew very rapidly and became a normal child, passed through school, and in 1908 was at one of the universities.

---