Pediatric endemic cretinism
Introduction
Introduction to local cretinism in children Endemic cretinism is the result of developmental differentiation of the brain and central nervous system caused by iodine deficiency and hypothyroidism during the embryonic period and early postnatal period. The main clinical manifestations are mental retardation and hoarseness. The general prevalence rate is 1% to 5% of the population in the goiter area, and can be as high as 5% to 10% in severe areas. basic knowledge The proportion of illness: 0.002% Susceptible people: children Mode of infection: non-infectious Complications: mental retardation
Cause
Causes of endemic cretinism in children
Causes:
It is generally believed that due to iodine deficiency during embryonic period, thyroxine deficiency causes irreversible damage to the central nervous system and skeletal system. It is generally considered that the disease is purely nutritionally deficient, and there are individual differences in iodine tolerance in the body. Is there any inheritance that needs to be inherited in the future? Research.
Pathogenesis:
Maternal hypothyroidism during pregnancy is a major risk factor for the high incidence of endemic cretinism. Due to iodine deficiency, the maternal and fetal thyroids compete for limited intake of iodide, which in turn affects maternal and neonatal thyroid hormone synthesis. Some local cretinism with neurological manifestations is caused by severe intrauterine iodine deficiency in the early stage of embryo damage, and some mucinous edema-type endemic cretinism is in the existing nervous system defects. On the basis of the reduction of thyroid hormone synthesis ability, suggesting that the normal development of the thyroid itself depends on iodine, genetic, autoimmune and other factors have not been confirmed.
Pathological changes:
The pathological changes of endemic cretinism are diverse and non-specific. The main pathological changes are brain weight loss, atrophy, neuronal cells mostly degenerative changes, thyroid gland enlargement, normal or shrinking, and shrinkage is small follicles. Uneven distribution, fibrous tissue hyperplasia between follicles.
Prevention
Pediatric endemic cretinism prevention
The treatment of Dick disease is not effective. Once Dick disease is formed, especially after two years of age, the developmental disorders of the central nervous system are essentially irreversible. The key to this disease is not treatment, but prevention. The eradication of Dick disease is possible. As long as the iodine deficiency in the population is corrected, especially the iodine deficiency of women of childbearing age, pregnant women and lactating women is corrected, local cretinism will not be born. As long as the long-term supply of qualified iodized salt is adhered to, the disease and the swelling of the body will be eradicated together.
(1) Iodized salt is an easy and effective measure to prevent and treat iodine deficiency disorders. Salt iodization ratio of 1:50,000 can effectively prevent the disease of the nail; 1:2 million can prevent the disease. Potassium iodide added to the salt is easily oxidized and sublimated. Since 1993, it has been changed to potassium iodate with good stability. During the process of packaging, storage, transportation and consumption of iodized salt, it is necessary to keep the iodized salt dry, tightly packed, airtight, and stored in dark places. It is determined that the iodine loss rate of iodized salt after half a year of different storage methods is: 10% in the cylinder; 29.4% in the sack; 57.8% in the drawer; 1.9% loss in boiling for 2 hours; 66.1% loss in baking for 2 hours.
(2) Iodine oil injection or oral administration. Iodized oil is a long-acting, economical, convenient, and side-effect prevention and treatment drug. It is especially suitable for remote, inconvenient, and soil-drainage areas, especially for women of childbearing age. After iodized oil injection, the iodine efficiency can reach 3 to 5 years. The method of oral iodized oil is simple, the mass is easy to accept, the control effect is also obvious, and the iodine supply efficiency is generally about one and a half years.
(3) Guarantee the amount of iodine required by the human body:
1 group <4 years old normal range 30 ~ 105g / d; suitable amount 70ug / d;
2 4 years old and normal range of 75 ~ 225g / d; suitable amount of 150ug / d;
3 The normal range of pregnant women and lactating mothers is 150-300 g/d; the appropriate amount is 200 g/d.
(4) Women with childbearing age during pregnancy can prevent iodine deficiency in the embryonic period (cretinism, subclinical cretinism, neonatal hypothyroidism, neonatal hyperthyroidism, premature birth, stillbirth, congenital malformation).
Complication
Pediatric endemic cretinism complications Complications, mental retardation
Mental retardation, short stature, hoarseness, language barrier, may have neuromuscular dyskinesia.
Symptom
Symptoms of endemic cretinism in children Common symptoms Craniofacial malformation Language developmental gait instability cretinism facial deafness iodine dementia edema goiter
Its main clinical manifestations are mental retardation, hoarseness, and neuromuscular dyskinesia, which are classified into two types:
Neurological type
Mental retardation, expression is sluggish, classified according to mental retardation can have:
(1) Idiot: The development of nerve function is completely arrested in infancy.
(2) Stupid: There are some abilities and mechanical memory, self-care, simple labor, poor thinking activities, dementia between the two, short stature, normal, hoarseness, language barrier, neuromuscular movement Obstruction, gait instability, gait paralysis, knee reflexes, can also be weakened, pathological reflex positive, moderate thyroid enlargement, no significant thyroid function reduction.
2. Mucinous edema
There may be obvious symptoms of hypothyroidism, obvious growth retardation, and typical sporadic cretinism.
Examine
Examination of pediatric endemic cretinism
Umbilical cord blood T4 decreased, TSH increased, T3 increased, suitable for mucinous edema.
1. X-ray examination: distal femoral epiphysis: embryos should appear on average 38 weeks, cretinism and premature infants may not appear, pelvic femoral condyle: point color and deformity, more than half a year after birth.
2. EEG examination: abnormal brain waves are often found.
Diagnosis
Diagnosis and diagnosis of local cretinism in children
diagnosis
Local cretinism also emphasizes early diagnosis. Neurological types may lack clinically typical symptoms of hypothyroidism, and only manifest as neurological abnormalities. The early diagnosis methods mainly include the following four items:
Diagnose based on
1. Patients from prevalent areas must come from areas where iodine-deficient goiter is endemic.
2. Clinical features include mental and neurological disorders, dull expression, language development retardation, and hearing impairment.
3. Thyroid function test is applied to mucinous edema type, T4 is decreased, and TSH is increased.
4. Auxiliary examination of bone age is low, and the color of the skull is visible.
Differential diagnosis
1. Brain hypoplasia mental retardation, increased muscle tone, hyperreflexion of the knee; normal T4 and TSH levels in the blood, normal or slightly behind the bone.
2. Sporadic thyroid sporadic thyroid is a hyperthyroidism caused by non-localized hyperthyroidism, non-tumor or inflammation, and normal thyroid function.
3. Deafness - Goiter syndrome (Pendred syndrome) is an autosomal recessive disorder, with deafness and dumb after birth. Goiter can occur in childhood, thyroid function is basically normal or low, perchlorate excretion test is often Positive (usually more than 30%), the disease is a defect in the organicization of congenital iodine, increased iodine tyrosine in the blood, increased MIT/DIT and iodine tyrosine/iodolinine ratio, and no reduction in urinary iodine.
4. General deafness and no mental retardation, urine iodine is not reduced, the rate of 131I is not high, no iodine or iodine starvation.
