Pediatric athyroid cretinism

Introduction

Introduction to thyroid-free cretinism in children Kocher-Debré-Sémélaignesyndrome is also known as Kocher-Debré-Sémélaigne syndrome, abbreviated as KDS syndrome, cretinism-muscle hypertrophy, Debré-Sémélaigne syndrome, etc. This disease refers to congenital thyroid development. Insufficient cretinism, often associated with muscle pseudohypertrophy. In 1892, Swiss physician Kocher first pointed out the rare case of hypertrophic cretinism with muscle hypertrophy. Debré and Sémélaigne described the disease in detail in 1935. It is also known as KDS syndrome. basic knowledge The proportion of illness: the incidence rate is about 0.002% - 0.005% Susceptible people: children Mode of infection: non-infectious Complications: Osteoporosis, Coma, Adrenal Crisis

Cause

The cause of thyroid-free cretinism in children

(1) Causes of the disease

This disease is a kind of hypothyroidism in congenital infants. Nell et al have classified congenital infant hypothyroidism into type 3; type I lacks thyroid tissue; type II has thyroid tissue, but cannot release sufficient amount of thyroid hormone; III The body tissue cells do not respond to thyroxine, and the symptoms are type I.

(two) pathogenesis

The disease may be an autosomal recessive hereditary disorder, some patients may find a positive family history, Cross et al reported a close relatives married couple, and their two children also suffered from the disease.

The production function of thyroid problastogenic epithelial cells is to synthesize and secrete thyroid hormones. The role of thyroid hormones is to regulate the basic physiological processes such as metabolism, growth and development, enhance the oxidative decomposition of sugar and fat in tissues, and promote the synthesis of proteins. Indispensable for maintaining normal growth and development, when there is no thyroid, the hypothyroidism affects infant growth and development, brain development disorders.

The influence of thyroid hormone on some other organs of the human body is also very important. For example, for the central nervous system, due to hypothyroidism, there may be sensation, slow speech, tired sleep, etc. Thyroid hormones also have cardiovascular and reproductive systems. More obvious effects, but its mechanism of action has not yet been fully elucidated.

When thyroid hormone is deficient, systemic metabolic activity declines, causing clinical syndrome. In the male reproductive system, sexual dysfunction may occur, sexual maturity may be delayed, parasympathy may be delayed, libido, impotence and testicular atrophy may occur in women. Menstrual disorders, excessive menstrual bleeding or amenorrhea, general infertility, regardless of the birth of both male and female patients will have an impact.

Prevention

Non-thyroid cretinism prevention in children

No method for prevention of primary hypothyroidism has been found; reference can be made to the prevention of hereditary diseases; the government should vigorously promote iodized salt to eliminate endemic goiter, and pregnant women can take potassium iodide 3 to 4 months after pregnancy (1% solution per day) 10 ~ 12 drops), or intramuscular injection of iodized oil 1 time 2ml, eat more iodine-containing foods, those with low performance should be diagnosed early and early, deaf-mute should be specially trained.

Precautionary measures refer to birth defects, and prevention should be carried out from pre-pregnancy to prenatal:

Pre-marital medical examination plays an active role in preventing birth defects. The size of the effect depends on the examination items and contents, including general physical examination (such as blood pressure, electrocardiogram) and family history of the disease, personal medical history, serological examination (such as hepatitis B virus, Treponema pallidum, HIV), reproductive system tests (such as screening for cervical inflammation).

Systemic birth defect screening is required during antenatal care during pregnancy, including regular ultrasound, serological screening, and, if necessary, chromosomal examination.

Pregnant women should avoid harmful factors as much as possible, including away from smoke, alcohol, drugs, radiation, pesticides, noise, volatile harmful gases, toxic and harmful heavy metals.

It is up to the government to vigorously promote iodized salt to eliminate endemic goiter. Pregnant women can take potassium iodide (10 to 12 drops per day for 1% solution) or 2 ml of intramuscular injection of iodized oil for 3 to 4 months. Eat more foods containing iodine. Those with low performance should be diagnosed early and treated early, and deaf should be specially trained.

The cause has not yet been fully elucidated, and genetic counseling should be done to do all the health care work during pregnancy. Once an abnormal result occurs, it is necessary to determine whether to terminate the pregnancy; the safety of the fetus in the uterus; whether there is sequelae after birth, whether it can be treated, and how the prognosis is. Take practical and feasible treatment measures.

Complication

Pediatric thyroid cretinism complications Complications osteoporosis coma adrenal crisis

With pseudo-hypertrophic muscles, the lower limbs and forearm muscles are particularly prominent in the gastrocnemius muscles. When the weather is cold, the muscles can be accompanied by myotonia, and the motor function is dysfunctional. Because the tongue can have a dysarthm, it can be complicated by mucous edema and coma. It is a complication of life-threatening and life-threatening; it is prone to infection; excessive treatment of hypothyroidism can lead to adrenal crisis; infertility can occur; long-term excess replacement therapy can lead to osteoporosis.

Symptom

Symptoms of thyroid-free cretinism in children Common symptoms Mucinous edema Growth slow Muscle hypertrophy Thyroid dysarthria Hypothyroidism Lower tongue hypertrophy

Symptoms appear earlier and heavier than ectopic and goiter. The clinical manifestations are characterized by the presence of cretinism and laboratory features, as well as pseudohypertrophy in the muscle group.

1. Family history: The onset of the disease has a family tendency and may be an autosomal recessive hereditary disease.

2. More common in children: Individual adults can also suffer.

3. cretin-like manifestations: thyroid dysfunction, cretin-like manifestations, most of which are congenital thyroid deficiency, stunting, mental retardation, mucous edema of the skin.

4. Muscle hypertrophy: more common in the limbs, tongue muscle, hypertrophy, normal muscle tension, muscles have a strong sense, the appearance is very strong, there is a baby Hercules, it is also called mucinous edema Hercules syndrome, but The movement is slow, the activity is not flexible, the reflex is slow, and the cold is aggravated.

The lower limbs and forearm muscles are particularly prominent in the gastrocnemius muscles, and the muscles are tight, giving a strong and developed feeling. Some movements have pain, and the muscle tension is normal, the motor function is coordinated, the muscle contraction is slow, and the gait is clumsy. When the weather is cold, the movement can be stagnant (muscle stiffness), due to the big tongue and the dysarthria, the muscles are still normal. From the clinical observation, it can be confirmed that the muscle hypertrophy is related to the hypothyroidism itself, because the thyroxine tablets are replaced. After that, muscle hypertrophy can gradually disappear.

Examine

Examination of thyroid-free cretinism in children

1. Thyroid function test: Thyroid hormone is reduced, 131I function is low, blood TSH is elevated, serum T3 and T4 are low or bounded, such as the first to lower the thyroid itself caused by TSH, generally at 100U/ml Above, neonatal A low screening with T4, but the diagnosis of TSH to determine primary hypothyroidism, due to low hereditary thyroglobulin and normal thyroid function, T4 is low, but TSH is normal.

2. TRH stimulation test: patients with low TSH in patients with hypothyroidism may be caused by pituitary or hypothalamic defects. Therefore, TRH stimulation test must be performed, TRH 510g/kg, after intravenous injection, respectively, at 15, 30, 60 At 90 and 120 min, the serum TSH value was measured. At 15 to 30 minutes after intravenous injection, the peak value exceeded 30-40 U/ml for excessive reaction, 10 U/ml for low reaction, and pituitary defect for low response, while hypothalamic defect was Excessive reaction.

3. Thyroglobulin: Determination of plasma thyroglobulin is also valuable, can not be measured as no thyroid tissue, can be measured or low value of thyroid tissue.

4. Increased blood cholesterol: Blood cholesterol increased above two years old.

5. Muscle biopsy: visible muscle fiber hypertrophy and increased mucin.

6. Electrocardiogram examination: P-wave and T-wave are low on the electrocardiogram, and the QRS wave is low.

7. X-ray inspection

(1) bone examination: 60% of patients with hypothyroidism have bone development on the X-ray film, and suggest that some thyroid hormone deficiency in the fetus, normal femur distal epiphysis has appeared at birth, and the first one is low Then, the bone age of the untreated patients is delayed, the osteophytes often have most punctate calcifications, the 12th thoracic vertebrae, the first and second lumbar vertebrae common variants (bird's beak type).

(2) Skull slice examination: The gap between the anterior humerus and the skull is wide, the saddle is often enlarged and round, and a few can be eroded and thinned.

(3) Chest X-ray examination: the heart is enlarged or there is pericardial effusion.

8. EEG: It is a slow wave.

9. Thyroid scan: No thyroid tissue can be found.

Diagnosis

Diagnosis and differential diagnosis of thyroid-free cretinism in children

diagnosis

According to the following characteristics can be diagnosed, muscle tension is often low, body muscle hypertrophy, due to muscle pseudohypertrophy may have an athlete-like appearance, especially the gastrocnemius muscle, the pathogenesis is unknown, non-specific histochemical and ultrastructural changes of muscle biopsy after treatment return to normal The boy is prone to this syndrome. He has been seen in the bloody marriage of the compatriots. The affected people have a long time and are serious.

1. Clinical features: The clinical manifestations of thyroid loss and laboratory findings, 24h thyroid 131I iodine absorption rate does not exceed 10%.

2. The thyroid gland can not be touched: 131I thyroid scan can not find thyroid tissue, and no obvious thyroid tissue can be found during surgery or autopsy.

Differential diagnosis

Pay attention to the growth and growth curve of infants and children, and the deceleration of growth rate can often provide the first diagnostic clue. Once the disease is suspected, the diagnosis is not difficult. Generally, thyroid function test can be used for diagnosis.

In the neonatal period, all the symptoms that should be identified from the first low, there are various causes of jaundice, heart disease, respiratory diseases, as long as the thyroid function test (first low T4 reduction and TSH increase) is easy to identify.

In preterm infants with respiratory distress, TSH in cord blood increases, T4 and T3 decrease, and this change disappears within a few weeks after birth.

It has been reported that there may be temporary hypothyroidism in term infants, that is, blood filter paper and serum TSH are high at 2nd and 6th week after birth, T4 is low, and T4 is reviewed at 8th week after birth. , TSH, thyroid scan and growth and development were normal, and the examination was normal after 8 months.

According to the information of the Second Affiliated Hospital of China Medical University, the first A low fever is often misdiagnosed as the following diseases in the field:

1. Rickets: It is a kind of skeletal developmental disorder caused by vitamin D deficiency. It is sweaty and often excited. It has no special disease capacity, and the skin is not dry but moist.

2. Brain hypoplasia: Although the disease has mental retardation, it has a balanced development, no high-grade tongue, constipation, dry skin and other clinical manifestations.

3. Hirschsprung's disease: Although this disease has symptoms such as constipation and bloating, it has no special face, dry skin, less sweat and lower body temperature.

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