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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neuropsychological assessment was carried out in 57 patients aged 3.0 to 17.5 years (mean 8.5) with thyroid dysgenesis under adequate long-term therapy. Starting age of hypothyroidism as estimated by bone age at diagnosis was prenatal in 32 cases, close to birth in 13 cases and postnatal of 1-12 months in 12 cases. Hypothyroidism of prenatal onset results in severe neuropsychological disorders and mental retardation if not treated early. Only some signs of "minimal brain dysfunction" which compensate with advancing age and normal IQ are found in these children if therapy is started before one month of age. Hypothyroidism starting at birth does not result in mental retardation but neuropsychological disorders are found. They are more frequent if treatment is started after 6 months of age. Children who become hypothyroid between 1 and 12 months of age are usually not mentally retarded and show minor neuropsychological disorders.
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PMID:Neuropsychological study in treated thyroid dysgenesis. 29 65

It has been reported that mental retardation due to congenital hypothyroidism can be prevented by early detection and early adequate replacement therapy. We have developed a radioimmunoassay for TSH using the dried blood spot and have started screening for newborn congenital hypothyroidism using a part of sample of the inborn metabolic error screening. (1) The dried blood spot TSH of 61,000 newborn infants was assayed in the first half of our screening and that of 74,505 newborn infants was assayed in the latter half of our screening. As a result, although we were not able to detect any cases in the first screening, we were able to detect 9 cases of congenital hypothyroidism in the latter screening. From the results obtained through our investigation of the thyroid function of these 9 infants, we confirmed that mild hypothyroidism can be better detected by the screening of TSH. (2) As to the program of the screening, we chose from the latter half of our screening all the samples in which TSH concentrations contained above 3 percent of each assay and were remeasured on the next assay. (3) As we confirmed that the sensitivity of measurement was increased at very low concentrations, when the volume of antibodies, radioisotopes and eluates used for each assay were decreased, we measured TSH successfully using two 3 mm discs. (4) As we can perform very simple screening by the 3 mm disc method, we are changing the screening method from that with 10 mm disc to one with two 3 mm discs. We intend to extend our screening, and will make every effort to prevent mental retardation due to congenital hypothyroidism.
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PMID:[Early detection of congenital hypothyroidism by TSH radioimmunoassay using filter paper blood samples (author's transl)]. 52 Jun 28

The basal ganglia are presently implicated in learning, and thyroid deficiency induced neonatally is known to affect mentation. The effects of such a deficiency on the developing causate nucleus might be used to provide insight into structure and function of the normal subcortical brain, as well as possible influences of these extrapyramidal structures on mental retardation. Propylthiouracil was added to the diet of lactating rat dams and observations of the developing caudate nuclei of normal hypothyroid rats were made at 8, 14, 20, 30 and 42 days by using various tissue stains and Golgi-Cox preparations. Seven different types of neurons were distinguished in the caudate nucleus. Differences in the size of cell somata and the varying morphology of axons and dendrites were criteria used to make distinctions. Normally, the nucleus acquires cytoarchitectural complexity during the first three postnatal weeks. Within this period, neuron incidence increases in the caudate neuropil with age while the germinal matrix density decreases. Neuron accumulation reaches a plateau after the third week and cell migration is essentially complete at the end of the first postnatal month as shown by computer analysis of Nissl stained cell counts. Branching of cellular processes, attainment of receptor spines and complexity of the fiber network also appeared during this period. Retardation of structural development with thyroid hormone deficiency was shown by decreased numbers of neurons, inhibition of dendritic arborization, decreased numbers of dendritic spines and a reduced complexity of axonal plexuses. Thyroid deficiency delays cell migration during the first three weeks when compared to age-matched normal controls. The lack of thyroid hormone does not appear to influence the size of neuron somata, and the extent of related dendritic fields, nor does hypothyroidism affect a specific cell type population. Generalized disturbances of caudate nuclear morphological maturation are caused by the deficiency. An apparent compensatory process, including a spurt of neural growth and differentiation, takes place in the period between days 14 and 30 in the deficient animals and a seemingly "normal" caudate cytoarchitecture is seen after the third postnatal week. Quantitative data, however, show that this rapid "catch up" process is inadequate. The developmental imperfection of the caudate nucleus which persists might be a part of the underlying substrate for the mental retardation, disturbed motor performance and perceptual handicaps which are found in the human patient.
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PMID:The developing caudate nucleus in the euthyroid and hypothyroid rat. 83 51

Thyroid hormone exerts a powerful influence on CNS growth and maturation. Hypothyroidism early in life has long been known to cause disturbances in innate behavior, motor performance, severe and frequently irreversible mental retardation. In this deficiency, depressed caudate neurogenesis, cell migration and neuropil development during the rapid period of CNS growth may contribute to the clinical picture of perceptual handicaps often seen in cretins. Light microscopic and Golgi studies of the developing caudate nucleus in thyroid deficiency have been carried out to help attain insights into the mechanisms whereby the extrapyramidal system regulates motor function. The ultrastructural study of caudate nuclear cytogenesis and synaptogenesis in normal and hypothyroid states provides more detailed information for further analysis of the problem. Hypothyroidism was induced from birth by adding prophylthiouracil to the food and drinking water of lactating dams. Linear development of the caudate nucleus of both normal and hypothyroid rats at ages 8, 14, 20, 30 and 42 days was studied by electron microscopy. Thyroid glands were examined by light microscopy to assess the normal and deficient states. Immature cells, primitive processes and synapses were the characteristic features of the 8-day-old normal caudate nucleus. Distinctively wide cisternae of the rough endoplasmic reticulum, loosley packed Golgi apparatus and chromatin clumps throughout the nuclei of the neurons were significant early morphologic variations. The dramatic cytoarchitectural maturation in the 14- and 20-day normal caudate neuropil points to the rapidity of developmental rate. After the growth spurt of the first three weeks a maturational plateau occurs which is characterized by well-formed neuronal cytoplasmic organelles, myelinated and non-myelinated axons, axon terminals, dendrites and their spines, and synapses. Thyroid deficiency causes a marked maturational delay of approximately 7 days in caudate neuronal proliferation, the elaboration of neuronal networks and the attainment of mature synaptic contents and membranes. This delay is evidenced by comparison of the structural similarities between 8-day-old normal and 14-day-old deficient rats; and additional comparisons between the 14-day-old normal and 20-day-old hypothyroid rats. A rapid "catch up" process in fine structural morphogenesis takes place in the period between days 14 and 30 in the deficient animals. Repression of thyroid function does not entirely prevent development of the caudate nucleus but allows a fairly extensive, though critically incomplete degree of maturation. This imperfection is manifested by a decrease in the number of synaptic contacts that persists even after the rapid "catch up" phenomenon of caudate synaptogenesis.
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PMID:An electron microscopic study of the developing caudate nucleus in euthyroid and hypothyroid states. 86 26

A sensitive, specific, rapid radioimmunoassay is described for the determination of thyrotropin (TSH) in eluates from two 3 mm discs punched from dried blood filter-paper specimens. This method is sufficiently sensitive to easily discriminate between normal infants and infants with primary hypothyroidism. The use of two 3 mm discs enables screening laboratories to easily incorporate this methodology into the currently available, fully automated systems to screen for several metabolic disorders. Since mental retardation occurs in untreated infants with primary hypothyroidism, our TSH method as the primary screening test alone, or in association with a thyroxine (T4) screening test, should detect all infants with primary hypothyroidism with a very acceptable low false-positive recall rate.
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PMID:Adaptation of TSH filter paper method for regionalized screening for congenital hypothyroidism. 87 62

Primary thyroidal hypothyroidism, growth hormone deficiency, congenital malformations and mental retardation occurred in a child with an interstitial deletion of one of the No. 1 chromosomes. Two bands were missing, so that the karyotype could be written: del(1)(pter leads to q25::q32 leads to qter). The possible relationship between the clinical features and chromosomal deletion are discussed.
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PMID:Primary hypothyroidism, growth hormone deficiency and congenital malformations in a child with the karyotype 46,XY,del(1)(q25q32). 93 3

A clinical and cytogenetic investigation carried out in a special institution for mentally retarded patients revealed 82 cases of oligophrenia, amongst whom were found 56 normal karyotypes (68.3%). Out of 25 karyotypes with chromosome anomalies or variants there were 18 cases of trisomy 21 and 7 others: one case of mosaicism with balanced translocation, 46,XX/46,XX,6p+,17q-; one case of partial trisomy, 46,XX,11q+; one case of pericentric inversion, 46,XY,inv(1) (p13,q21); one case with 8% chromosome breaks; three cases of marker chromosomes, of which one was of karyotype 46,XX,1qh+, and two (oligophrenic sisters) 46,XX,21p+. Moreover, there was an interesting case of testicular feminisation in a 9-year-old girl with karyotype 46,XY. The authors' results corroborate those obtained in several important previous studies based on much larger numbers of patients. Amongst the 56 cases where the karyotype was shown to be normal, there were 15 for whom a probably exogenic cause of the oligophrenia could be established, occurring mainly during the perinatal period. The authors were also able to confirm that the genetic factor plays an important role in the incidence of mental retardation, since in 22 examined patients, i.e. 26.8% of all cases, the condition was of familial type. Some interesting observations of idiopathic oligophrenia are reported, as well as several cases with well-known syndromes (Crouzon's and Cornelia de Lange's syndromes, hypothyroidism). Two cases of incest between father and daughter, which had produced children with serious oligophrenia associated, in one case, with deaf-mutism, microphthalmia, microcephaly and sclerocornea, are also discussed. The data show that mental retardation can frequently have a genetic cause, either of mendelian, chromosomal or multifactorial origin.
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PMID:[A clinical and cytogenetic investigation carried out in a special institution for mentally retarded patients: preliminary results concerning 82 cases of oligophrenia (author's transl)]. 102 53

A woman in her 24th week of gestation was referred for treatment of hypothyroidism, after she underwent radioablation of the thyroid during the 13th week of gestation. Because of the high risk of hypothyroidism in the fetus, prenatal administration of intramuscular T-4 to the fetus was begun at 32 weeks. The last dose of T-4 was given 2 weeks before delivery; cord blood levels of T-4 and T-3 were undetectable and the TSH concentration was markedly elevated. The case illustrates several important physiological concepts regarding thyroid hormone and TSH metabolism in the fetal-placental unit, including the minimal placental permeability to iodothyronines and TSH, independent function (including feedback control) of the fetal hypothalamic-pituitary-thyroid axis, and the TSH response at parturition. In addition we suggest that administration of T-4 to the hypothyroid fetus in utero is an acceptable modality of treatment and may help to minimize irreversible mental retardation in known high risk infants. However, further studies are necessary to assess the effectiveness and safety of this approach.
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PMID:Intra-uterine treatment of a hypothyroid fetus. 111 55

Five cases of early-onset gouty arthritis are presented, with roentgenographic abnormalities evident in the first two decades of life. Three patients suffered from "primary" gout; classification of the other two patients was difficlut because of associated mental retardation, hypothyroidism and psoriasis. Radiographic alterations included soft-tissue masses and calcification, with typical erosive abnormalities and predilection for the hands and feet. The sacroiliac joints were abnormal in two patients.
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PMID:Early-onset gouty arthritis. 120 73

In a study of nine Klinefelter syndrome patients obtained from a military population, all were found to have normal electroencephalograms (EEGs), all were clinically euthyroid, and had normal thyroid function test results. All had normal verbal and nonverbal IQs and no evidence of neurologic dysfunction on psychological testing. There was a high incidence of personality maladjustment as indicated by both the Minnesota Multiphasic Personality inventory and individual psychiatric evaluation. No particular personality pattern appeared typical for the group as a whole. Neurologic dysfunction, as manifest by EEG abnormality, mental retardation, or neuropsychological test deficits, and hypothyroidism are not necessarily associated with Klinefelter syndrome. Likewise, although the incidence of personality disorders may be strongly associated with this disorder, no specific personality type appears especially characteristic of the syndrome.
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PMID:Klinefelter syndrome in a military population. Electroencephalographic, endocrine, and psychiatric status. 126 76


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