Plasma MHPG: within- and across-day stability in children and adults with Tourette's syndrome

Within- and across-day stability of unconjugated plasma 3-methoxy-4-hydroxyphenethyleneglycol (pMHPG, the major metabolite of norepinephrine) levels were assessed in several subgroups of 47 primarily child and adolescent subjects with Tourette's syndrome (TS). Mean morning pMHPG levels remained stable over a 20-min period from 8:30 to 8:50 AM at 3.5 +/- 0.8 ng/ml. However, the mean intraindividual fluctuation in pMHPG levels over 20 min was +/- 12%. Mean pMHPG levels remained stable in the morning from 8:00-8:30 AM to noon. However, an 11% decrease (p less than 0.01) in mean pMHPG levels was observed in the afternoon between noon and 3:00-4:00 PM. Monitored on consecutive days, mean morning pMHPG levels fell 12% (p less than 0.002). The afternoon and across-day falls in pMHPG levels observed in this study of primarily children and adolescents with TS have not been observed in studies of adult control subjects. The results suggest that the design of research protocols involving children and adolescents that use pMHPG should take into consideration the effects of time, both within- and across-day, in pMHPG levels.

[Rett's syndrome: study of 15 cases]

A multicentric study of 15 cases of Rett syndrome selected with the diagnostic criteria according HAG-BERG et al: female sex, normal pre and perinatal period, normal psychomotor development through the first months of life, early dementia between 1-3 years of age with autistic behaviour, loss of acquired purposeful hand skill, "washing hands" stereotypies, normal head circumference at birth with later deceleration of head growth and truncal ataxia with gait apraxia. Waking EEG showed unspecific abnormalities while sleep recording demonstrated extremely frequent multifocal spike and sharp waves mainly over the rolandic region and generalized, and also pseudo-periodic suppression of background activity. In 3 cases the EMG showed a peripheral axonal neuropathy. Only in one case we found hyperammonemia. Karyotypic studies performed in 12 cases demonstrated non specific fragile sites. CT scan was normal in almost all cases. The QD was extremely low.

Low-level fetal lead exposure effect on neurobehavioral development in early infancy

A prospective method was used in this study to assess the effects of fetal lead exposure on neurodevelopmental status in 3- and 6-month old infants. At their first prenatal medical appointments, 305 lower socioeconomic status women residing in predesignated lead-hazardous areas of Cincinnati were recruited. Lead was measured in whole blood in both the mother and fetal-placental unit (prenatal and cord) and the neonate (ten days and 3 months). All blood lead levels were less than 30 micrograms/dL. Infant development was assessed with the Bayley scales at 3 and 6 months of age. Multiple regression analyses which treated perinatal health factors such as birth weight and gestation as confounders indicated an independent, inverse relationship between both prenatal and neonatal blood lead levels and performance on the Bayley Mental Developmental Index at both ages. Male infants and infants from the poorest families appeared to be especially sensitive to these psychoteratogenic influences. Further study using a structural equations approach indicated that neurobehavioral deficits were partly mediated by lead-related reductions in birth weight and gestation.

Anticonvulsant medication use and circulating levels of total thyroxine, retinol binding protein, and vitamin A in children with delayed cognitive development

Circulating thyroxine (T4), retinol binding protein (RBP), and vitamin A were measured in conjunction with nutritional status assessment of 707 cognitively delayed children, ages 3.0-9.0 y. Twenty percent were receiving anticonvulsant (AC) medication. T4 was lower and RBP and vitamin A were higher (p less than 0.0001) among AC than non-AC subjects. Molar ratios of vitamin A:RBP did not differ between the two groups nor did intakes of protein or vitamin A. Lower T4 and higher RBP were found among children who received diphenylhydantoin (DPH), phenobarbital, or AC combinations, but vitamin A was higher only among those who received DPH. RBP and vitamin A were lower (p less than 0.05) among children with infections and vitamin A was lower (p less than 0.05) among those with serum zinc less than 70 micrograms/dL (less than 10.7 mumol/L); differences between AC and non-AC subjects remained when other variables were considered.

Elevated lead levels in children with nonorganic failure to thrive

Every child with failure to thrive has at least one organic medical disease: malnutrition. It is well documented that lead and other heavy metals are absorbed more readily in the presence of both malnutrition and iron deficiency anemia. Malnutrition and lead exposure tend to be found in the same population groups. Furthermore, lead poisoning is correlated with many of the identical intellectual and behavioral deficits demonstrated in children suffering from nonorganic failure to thrive. Because of these facts, whole blood lead levels were determined for 45 children with nonorganic failure to thrive and 45 age-, race-, and socioeconomically matched comparison subjects. Children with failure to thrive had a lead level of 22.67 +/- 10.29 (micrograms/dL (mean +/- SD); for control children, it was 14.33 +/- 5.42 (P less than .001). Children with failure to thrive were more frequently anemic (P less than .0001), a possible lead effect, and had higher free erythrocyte protoporphyrin levels. Children with failure to thrive were developmentally delayed on the Denver Developmental Screening Test (unblinded observation) with high failure rates in both language (P less than .001) and gross motor skills (P less than .02). Although failure on the Denver Developmental Screening Test within the failure to thrive group was not linearly correlated with lead level, any such effects may have been masked by the effects of malnutrition and failure to thrive per se. A number of authors have suggested that lead levels formerly thought to be inconsequential are clinically toxic.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum levels of radioreceptor-assayable somatomedins in children with minor neurodevelopmental disorders

The somatomedins are a family of multitarget, growth-promoting hormones suggested to play a regulatory role in the central nervous system. Serum concentrations of somatomedins were determined by a radioreceptor assay in 26 patients (19 boys and 7 girls) with minor neurodevelopmental disorders. Five of these 26 patients showed high serum levels (greater than 2 S.D.) of somatomedins. It is concluded that patients with elevated concentrations of somatomedins might represent a pathogenetic subgroup.

Thyroid function in developmental disorders

The relationships between catecholamines and thyroid state are considered from clinical and molecular perspectives. The effects of thyroid hormone on adrenergic systems are mediated by altered receptor and post-receptor function. Clinical symptoms of major childhood neuropsychiatric disorders, as well as related biological measures, may be influenced by thyroid hormone regulation.

Evaluation and management of the child with delayed pubertal development

The physical and hormonal changes of puberty are presented and the wide range of ages at which the pubertal process may begin is emphasized. The great variability in the timing of onset of adolescence, its rate of progression, and the age of completion are detailed. The causes of delayed adolescence in males and females are considered. The most common form of delayed adolescent development is termed constitutional delay in growth and development, which may occur sporadically, or may be the familial pattern of growth and development or may reflect a suboptimal nutritional environment. The evaluation of such children, including appropriate historical review, physical examination, and laboratory assessment, is outlined. In most patients with constitutional delay in growth and development, strong reassurance is sufficient therapy. In other subjects, treatment with androgens (boys) or estrogens (girls) may be indicated. In patients with primary systemic diseases accociated with delayed maturation, specific treatment which eradicates the illness will often be followed by resumption of growth and development. In subjects with primary disorders of the hypothalamus, pituitary, or gonads, replacement therapy with androgens or estrogens is indicated. If gonadal function is intact, these patients may eventually become fertile with appropriate use of hypothalamic and/or pituitary hormones.