Late appearance of bone nucleus, small development

Introduction Physical retardation and dysplasia are characteristic of endemic cretinism. The patient's body is short and uneven, the lower part of the body is shorter than the upper part, and the bone development is slow, showing the late appearance of the bone nucleus and small development.

Cause

(1) Causes of the disease

The etiology of endemic cretinism has been relatively clear and is the result of severe iodine deficiency during embryonic and neonatal periods. In addition to the iodine deficiency theory, there are also people who raise genetic problems, autoimmune problems and goiter problems.

Iodine deficiency

(1) Endemic goiter and Dick disease are prevalent in areas with severe iodine deficiency. Iodine deficiency is not serious or there is no Dick disease in new wards and light wards. In the non-thyroid epidemic area, no one has reported typical Dick disease. In the epidemic area of Dick disease, the iodine content of drinking water is often <1g/L. The local residents including the nail disease and the patient's 24h urine iodine are often <25g, even close to zero. The incidence of goiter in this ward is >40%, the prevalence of men and women is close, and there are more adult nodular goiters. The above indicates that areas with severe iodine deficiency have a long epidemic time and disease in the old ward. There are individual serious areas of endemic disease, no or little gram, and the reasons are pending.

(2) Dick disease often has varying degrees of goiter. Foreign statistics account for about 50% to 85%. Domestic patients in Heba Township, Guizhou Province, have thyroid enlargement, accounting for 30%, Chengde City, Hebei Province, 40%, and Xujiawopu Village, Chifeng County, Inner Mongolia, 29%. In addition, the mothers of patients with Dick disease have many goiters. The results of the suburban survey in Chengde City, the mother has a goiter rate of 71%, which can explain the close relationship between Dick disease and endemic goiter.

(3) The iodine metabolism of patients with gram disease is basically the same as that of patients with thyroid disease, but the degree of the former is more serious. For example, the urinary iodine is low, the 131I rate of thyroid is "iodine starvation curve", and the thyroid rate of 131I is increased. And serum T4 can be maintained or reduced (the decline in Dick disease is more pronounced). TSH is normal or elevated (the increase in Dick disease is more pronounced), while T3 maintains normal or compensatory elevation.

(4) Animal experiments have shown that pregnant animals are fed with iodine-deficient diet, and young animals after birth may have similar manifestations of human growth and stagnation.

In 1976, in the experimental study of rats, he observed the effect of maternal iodine deficiency on brain development in intrauterine rats. The brain of iodine-deficient animals has low brain weight, brain cells are significantly reduced, serum T3 content is also low, and thyroid function is low. which performed.

In recent years, many scholars in China have been engaged in animal experiment research. They have successfully replicated animal models of low iodine gram disease in rats and mice, and observed that brain development is lagging, animal learning ability is low, and growth and development are obviously hindered. The pituitary gland, the thyroid system also has a significant change in hypothyroidism.

(5) In the endemic area of endemic goiter, the iodized salt is used for prevention and treatment, and the disease is also disappeared, that is, there will be no new disease. For example, Switzerland, Germany, Austria, etc. in the European Alps have been seriously ill-affected areas for decades. After decades of prevention and treatment of iodized salt, no new patients with Dick disease have occurred. Before the supply of iodized salt in the suburbs of Chengde City, the prevalence of Dick disease in several villages was 2%. Since the supply of iodized salt in 1962, no new Dick disease patients were found in the 1975 review. Before the prevention and control of Heba Township in Guizhou Province (1979), the infant's low detection was 40.5%. After the prevention and treatment with 1:5000 iodized salt, it decreased to 7.8% in the first year (1980) and decreased to 1.4% in the second year. In the 5th year, no baby was born.

The above explanation shows that the basic cause of Dick disease is iodine deficiency in the environment.

2. Genetic factors

Dick disease has a tendency to have multiple families, and there are a lot of reports at home and abroad. A history of 208 cases of cretin patients with cretinism was investigated in a ward of Ningwu County, Shanxi Province. Among the family members, 127 (59.9%) had no cretinism, and 3 (1.5%) had cretins. There were 23 cases (10.9%) of mothers with cretinism, 1 case (0.5%) of parents with cretinism, 59 cases (27.6%) of brothers and sisters with cretinism, and a total of cretins among family members. 40.5%. One of the six mothers in the village had mental retardation, and each child had 2 to 3 children with cretinism. However, the above situation cannot be considered that the disease is a hereditary disease, because the congenital factors other than heredity also have similar phenomena in a family. In 1938, Wagner-Jaurig observed 20 young couples in Switzerland, and gave birth to 6 normal children before moving into the ward. After moving into the ward, they gave birth to 4 typical cretin children. The last time they were pregnant, A healthy boy was born because of the preventive treatment of thyroid tablets. There is a family in a certain ward in Xinjiang. In 1964 (that is, before the prevention of iodized salt), all three children were all cretinism. After prevention with iodized salt, four children were born and developed normally. It is indicated that genetic factors are not the main factors in the above two families.

In recent years, domestic studies on the genetics of Dick disease have been studied in many aspects. Most scholars believe that the disease does not conform to the dominant or recessive inheritance of single genes, nor does it find abnormalities in the number or morphology of chromosomes. In short, this issue remains to be seen. further research.

3. Autoimmune problems

Whether there is autoimmune factor in the disease, the current research data is no. Brazil (26 cases), Uele region (11 cases) in Congo (Golden), New Guinea (10 cases) mothers of children with cretinism, etc., were tested for thyroglobulin antibodies in patients with citrate hemagglutination and a few families. . The results of serum globulin examination in 11 patients in Ningxia, Gansu Province were normal. In addition, patients with severe cretinism often have thyroid atrophic lesions, and uneven punctate distribution can be seen during thyroid scan. Some people mention whether it is related to autoimmunity. Anti-thyroid home immune antibodies are now known. In addition to TGAb and TMAb, there are TSAbs (thyroid stimulating hormone antibodies) that induce Graves' disease. TSAbs can be divided into thyroid growth stimulating antibodies and thyroid stimulating antibodies, which can cause simple goiter or simple hyperthyroidism, respectively. . In recent years, Doniach has proposed a thyroid growth inhibitory antibody, which may be caused by this antibody in some patients with thyroid atrophy. In particular, whether thyroid atrophy of visceral dysplasia is related to this is worth studying.

4. Thyroid-producing substances

There are many thyroid-causing substances, but the obvious one is cassava. Delange et al. surveyed 9,993 residents in three rural areas in the Congo (Golden) and found that one of the villages, Ubangi, and the other two villages had similar 24-hour urinary iodine values. It is 16.15g, 20g), but the rate of goiter in this village is 77% higher (13% and 2% in the other two villages), and there is cretinism, the prevalence is 4.7% (the other two villages are No), the reason for this is because the cassava eaten in the village of Ubangi contains glucosides, which can form thiocyanate compounds under the action of enzymes in the body.

an examination

Related inspection

Children's orthopedic examination of the bones and joints of the extremities: plain bone and soft tissue CT examination

Mental retardation caused by the disease is more severe with mental retardation. There are data showing that the moderate and severe are above 60%. Most of the clinical manifestations are quiet, dull, wilting, and reduced activity. A small number of temperament is violent, and laughter is impermanent. Both speech and hearing impairments are common. A county in Hubei Province had observed 936 patients and found that there were different levels of speech disorders, including 545 cases (58.4%) with total dumbness, 737 cases (78.8%) with hearing impairment, and 252 cases (accounting for total). 26.9%).

Physical retardation and dysplasia are another feature of the disease. The patient's body is short and uneven, the lower part of the body is shorter than the upper part, and the bone development is slow. It is characterized by late development of the bone nucleus, small development, and small metacarpophalangeal bone. Many patients have poor motor function and severe sputum. Sexual stunting, mild patient development and fertility. Weighing less than the same age.

Differential diagnosis

Need to be identified with the following symptoms:

Meningitis: Meningitis is a disease in which a delicate meninges or meninges (a membrane between the skull and the brain) are infected. The disease is usually accompanied by a bacterium or virus that infects any part of the body, such as an ear, sinus or upper respiratory tract infection. Bacterial meningitis is a particularly serious disease that requires timely treatment. If the treatment is not timely, it may die within a few hours or cause permanent brain damage. Viral meningitis is more serious but most people can recover completely, with a few legacy sequelae.

Mental retardation caused by the disease is more severe with mental retardation. There are data showing that the moderate and severe are above 60%. Most of the clinical manifestations are quiet, dull, wilting, and reduced activity. A small number of temperament is violent, and laughter is impermanent. Both speech and hearing impairments are common. A county in Hubei Province had observed 936 patients and found that there were different levels of speech disorders, including 545 cases (58.4%) with total dumbness, 737 cases (78.8%) with hearing impairment, and 252 cases (accounting for total). 26.9%).

Physical retardation and dysplasia are another feature of the disease. The patient's body is short and uneven, the lower part of the body is shorter than the upper part, and the bone development is slow. It is characterized by late development of the bone nucleus, small development, and small metacarpophalangeal bone. Many patients have poor motor function and severe sputum. Sexual stunting, mild patient development and fertility. Weighing less than the same age.

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