Intellectual Functioning In Children Research Articles

Post-treatment intellectual functioning in children treated for acute lymphoblastic leukaemia (ALL) with chemotherapy-only: A prospective, sibling-controlled study

Intellectual functioning (verbal, performance and full-scale IQ) in 43 children treated for acute lymphoblastic leukaemia (ALL) with chemotherapy-only was evaluated in a nationwide, prospective, sibling-controlled study. Intellectual assessment was performed at diagnosis and repeated shortly after cessation of 2 years treatment, including intrathecal and systemic chemotherapy. Using hierarchical regression analysis, patients’ and siblings’ ( n = 27) scores were longitudinally analysed and compared to assess possible changes and differences over time. At both assessments, before and after treatment, the patients showed average scores on intelligence tests compared to population norms. Longitudinal analysis and cross-sectional comparisons revealed no significant differences between patients and controls. Young patients showed a small relative decline, albeit not significant, on performance-IQ compared to healthy siblings. Despite intensive and potentially neurotoxic treatment, no evident negative effects on intelligence were found. However, it cannot be precluded that younger patients are at risk for a small decline in PIQ.

Physiological correlates of intellectual function in children with sickle cell disease: hypoxaemia, hyperaemia and brain infarction

Lowered intelligence relative to controls is evident by mid-childhood in children with sickle cell disease. There is consensus that brain infarct contributes to this deficit, but the subtle lowering of IQ in children with normal MRI scans might be accounted for by chronic systemic complications leading to insufficient oxygen delivery to the brain. We investigated the relationship between daytime oxyhaemoglobin saturation (SpO2), cerebral blood flow velocity (CBFV) and intellectual function (IQ) using path-analysis in 30 adolescents with sickle cell disease (mean age 17.4 years, SD 4.2). Initial analyses revealed that the association between SpO2 and Full Scale IQ (FSIQ) was fully mediated by increased CBFV, whereby SpO2 was negatively correlated with CBFV and CBFV was negatively correlated with FSIQ, i.e. decreases in oxygen saturation are associated with increases in velocity, and increased velocity is associated with lowered IQ scores. The mediated relationship suggests that lowered IQ may be a function of abnormal oxygen delivery to the brain. Further analyses showed that the association between CBFV and IQ was significant for verbal but not for performance IQ. The pathophysiology characteristic of SCD can interfere with brain function and constrain intellectual development, even in the absence of an infarct. This supports the hypothesis that lowered intellectual function is partly explained by chronic hypoxia, and has wider implications for our understanding of SCD pathophysiology.

Manganese in Drinking Water: Higher Doses May Hamper Intellectual Function

Vol. 114, No. 1 EnvironewsOpen AccessManganese in Drinking Water: Higher Doses May Hamper Intellectual Functionis accompanied byWater Manganese Exposure and Children’s Intellectual Function in Araihazar, Bangladesh Dinesh C. Sharma Dinesh C. Sharma Search for more papers by this author Published:1 January 2006https://doi.org/10.1289/ehp.114-a50Cited by:4AboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit Manganese is an essential nutrient for humans, but its excessive consumption can cause adverse health impacts. Past studies have linked inhalation of excessive manganese to neurotoxicity in adults. Now a group of U.S. researchers suggests that ingesting high doses of manganese in drinking water can hamper intellectual function in children [ EHP 114:124–129]. These effects were seen most strongly on scales that measure performance aspects of intellectual function.The same group had earlier observed a negative impact of water arsenic on intellectual function among children in Araihazar, Bangladesh. Though the manganese concentration in the water these children drank was much higher than its arsenic content, the independent impact of manganese on intellectual function could not be verified. The present study included 142 10-year-old children (including 54 children from the earlier study) who consumed well water with average concentrations of 793 micrograms per liter (μg/L) manganese and 3 μg/L arsenic.The children’s intellectual function was assessed on six tests (similarities, digit span, picture completion, coding, block design, and mazes) drawn from the Wechsler Intelligence Scale for Children, Version III. Results were summed to create Verbal, Performance, and Full-Scale raw scores. These tests were chosen as they could be applied to Bangladesh’s rural context with minimal alteration. The results showed that manganese concentration had a significant negative dose–response association with all three raw scores.The researchers found that children in exposure groups 1 (manganese lower than 200 μg/L) and 4 (manganese higher than 1,000 μg/L) differed significantly from one another for Verbal, Performance, and Full-Scale raw scores. Compared to group 1, children in exposure groups 2 (manganese between 200 μg/L and 500 μg/L) and 3 (manganese between 500 μg/L and 1,000 μg/L) had lower Full-Scale and Performance scores, but the differences were not statistically significant. Verbal scores of the children in groups 2 and 3 also did not differ significantly from those in group 1. Due to the lack of measures of intelligence standardized for use in Bangladesh, the team could not calculate IQ points lost.Though the children’s waterborne manganese intake was lower than the highest safe daily dose (6 milligrams per day) estimated by the U.S. Institute of Medicine, the authors write that additional dietary exposure could have pushed the total daily dose above this value. Moreover, bioavailability of manganese from food is very low, while it is high from drinking water. This could have contributed to neurotoxicity seen in children drinking water with higher amounts of manganese.The authors point out that their findings are relevant in the United States as well. Data collected by the U.S. Geological Survey have shown that about 6% of domestic wells contain manganese concentrations higher than 300 μg/L. Based on these data and their study results in Bangladesh, the researchers suggest that some U.S. children may be at risk for manganese-induced neurotoxicity.Toxics, toxics everywhere . . .Many studies have looked at the health effects of arsenic in Bangladeshi well water. New data now show that manganese in the water may also cause adverse effects.FiguresReferencesRelatedDetailsCited by Godefroy S (2023) Exposure-driven risk management strategies for chemicals in food Present Knowledge in Food Safety, 10.1016/B978-0-12-819470-6.00043-3, (673-685), . Hess C, Smith M, Trueman C and Schutkowski H (2015) Longitudinal and contemporaneous manganese exposure in apartheid-era South Africa: Implications for the past and future, International Journal of Paleopathology, 10.1016/j.ijpp.2014.09.005, 8, (1-9), Online publication date: 1-Mar-2015. (2013) Additional links between mental status and nutritional status Nutrition and Mental Health, 10.1201/b13745-12, (197-214), Online publication date: 29-Jan-2013. Jiménez-Cedillo M, Olguín M, Fall C and Colín A (2011) Adsorption capacity of iron- or iron–manganese-modified zeolite-rich tuffs for As(III) and As(V) water pollutants, Applied Clay Science, 10.1016/j.clay.2011.09.004, 54:3-4, (206-216), Online publication date: 1-Dec-2011. Related articlesWater Manganese Exposure and Children’s Intellectual Function in Araihazar, Bangladesh9 August 2005Environmental Health Perspectives Vol. 114, No. 1 January 2006Metrics About Article Metrics Publication History Originally published1 January 2006Published in print1 January 2006 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. 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Disparity of Verbal and Performance IQ Following Early Bilateral Brain Damage

To examine the effects of early bilateral brain damage on Full Scale IQ (FSIQ), Verbal IQ (VIQ) and Performance IQ (PIQ). Early unilateral brain damage typically results in relatively spared intellectual function, with IQ in the normal range and no significant differences between VIQ and PIQ, regardless of the side of the lesion. However, little is known about intellectual function in children after bilateral damage. FSIQ, VIQ, and PIQ scores of 10 children, ages 6-12 years, with early-onset bilateral focal lesions (BFL), were compared with those of age- and sex-matched controls. FSIQ was in the average range for BFL and control children. A bimodal distribution of VIQ was identified, resulting in 2 distinct groups, one performing above the average range and the other below. The unimpaired group displayed a significant discrepancy between VIQ and PIQ, with VIQ in the superior range and PIQ in the low average range. The impaired group did not demonstrate disparate VIQ and PIQ: both were in the borderline range. The 2 groups were differentiated by greater degree of cortical brain damage in the impaired than in the unimpaired group. The striking difference between the outcome of the unimpaired and impaired groups may reflect different processes of reorganization that are associated with the extent of cortical involvement.

Arsenic Reduces Children’s Intellectual Function

Arsenic Reduces Children’s Intellectual Function

Arsenic and Intellectual Function: Bangladeshi Children at Risk

In Bangladesh, naturally occurring arsenic contaminates some 10 million tube wells that about 30–40 million people depend on for drinking water. Scientists have already established that adults with heavy exposure to arsenic can suffer adverse impacts on cognitive functions such as learning and memory. However, there have been no well-controlled studies of the neurological consequences of arsenic exposure in children. This month, a group of U.S. and Bangladeshi researchers led by Gail Wasserman of Columbia University provides evidence that even modest exposure to arsenic in drinking water is associated with reduced intellectual function in children in Araihazar, Bangladesh [EHP 112:1329–1333]. The investigators studied a group of 201 10-year-old children. The children’s parents were participating in an ongoing study of arsenic exposure among residents in a 25-square-kilometer region located about 30 kilometers east of Dhaka. The study site, Araihazar, was chosen because of its wide range of arsenic concentrations in drinking water. The research team’s earlier survey of 6,000 contiguous tube wells in the region showed concentrations in individual wells ranging from less than 1 microgram per liter (μg/L) to 900 μg/L. Of the wells surveyed, 75% exceeded the World Health Organization (WHO) arsenic standard of 10 μg/L, and 53% exceeded the Bangladeshi standard of 50 μg/L. In the current study, children and their mothers came to the research team’s field clinic for examination by a physician. The children provided urine specimens for the measurement of urinary arsenic and creatinine; about half also agreed to provide blood samples for measurement of blood lead and hemoglobin. Each child’s mother provided information about the family’s primary source of drinking water, and these sources were matched to the previously surveyed wells. In an effort to control for sociodemographic variables, the research team asked parents about parental age, education, and occupation, among other questions. The team also controlled for drinking water exposure to manganese, another known neurotoxicant (in their earlier survey, they had found that 82% of wells surveyed for manganese exceeded the WHO standard of 500 μg/L). In addition to the medical evaluation, the children were assessed using an adaptation of the Wechsler Intelligence Scale for Children, version III (WISC-III). Because of the lack of standardized IQ measures in Bangladesh, Wasserman, a child psychologist, adapted the WISC-III for this cultural context. The WISC-III is a comprehensive series of tests that measures intellectual abilities such as comprehension and problem solving. Verbal subtests together provide a Verbal IQ, and a number of performance subtests (such as Picture Completion, Coding, Block Design, and Mazes) together provide a Performance IQ. The researchers found that consumption of water contaminated by arsenic was associated with reduced intellectual function in a dose–response fashion. Children with exposures above 50 μg/L had significantly lower Performance and Full Scale scores than children with exposures under 5.5 μg/L. The children with the highest quartile of water arsenic also had marginally reduced Verbal scores. Lead and manganese exposures were not conclusively associated with impaired intellectual function, likely due to the low number of blood samples and confounding between arsenic and manganese, respectively. The research team is working to curb exposure to arsenic in the study region. Since arriving in 2000, U.S. researchers, along with Bangladeshi colleagues, have overseen the installation of low-arsenic private and community wells and implemented a village education program that has successfully reduced some exposure. The authors note that the associations between arsenic and intellectual function were stronger for well-water concentrations than for urinary concentrations, which reflect recent exposure. The urinary concentrations at the time of testing may not reflect the full magnitude of the children’s earlier exposure, and the authors write that recently reduced exposure may explain the weaker associations between intellectual function and urine arsenic, compared to well-water arsenic.

Surgical versus medical treatment for severe epilepsy: consequences for intellectual functioning in children and adults. A follow-up study

We compared the effects of medical and combined surgical and medical treatment of refractory epilepsy on intellectual functioning in a group of children ( n=13) and a group of adults ( n=15). The patients were tested with the age-appropriate versions of Wechsler’s intelligence scales twice prior to and once after epilepsy surgery. There were no significant differences between the groups in preoperative epilepsy-related variables, including age at onset. The IQ scores were submitted to two-way analyses of variance (ANOVA). We also evaluated individual changes in IQ scores. Adult patients maintained stable levels of performance after drug treatment as well as following surgery, while children declined in Full Scale IQ after both kinds of treatment. Children also declined in Performance IQ, but not in Verbal IQ after drug treatment, and in Verbal IQ, but not in Performance IQ after surgery. Three of six children who underwent a significant decline in Full Scale IQ before surgery did not show any further decline postoperatively. We have proposed a developmental model to account for the different findings in children and adults, and conclude tentatively that refractory, long-standing epilepsy may interfere with intellectual development both during drug treatment and following combined surgical and medical treatment in children, while the impact of long-standing refractory epilepsy of similar severity as in children is not strong enough to reduce intellectual performance in adults, irrespective of treatment modality.

The effects of refractory epilepsy on intellectual functioning in children and adults. A longitudinal study

The aim of this study was to compare the long-term consequences of refractory epileptic seizures for intellectual functioning in pediatric and adult patients , taking the severity of the epilepsy into consideration. Thirty-four patients , 17 children (mean age 10.2 years) and 17 adults (mean age 24.4 years) were tested twice with the age-appropriate version of Wechsler’s Intelligence Scales. The mean test–retest interval in the two groups was 3.5 and 6.0 years, respectively. There were no statistically significant differences between the groups with respect to severity of the epilepsy at Test 1, as indicated by retrospective assessments of seizure severity, interictal EEG pathology, and number of antiepileptic drugs received per patient . Assessments of changes in these variables during the test–retest interval did not indicate different courses of the disease in the two groups. Despite these similarities, a statistically significant difference was found between the children and the adults regarding changes in intellectual functioning. In the children, there was a decline in mean intelligence quotient (IQ) scores during the test–retest interval, while the IQ scores increased in the adult group. It is concluded that recurrent seizures may represent a considerable risk for intellectual decline in children, while intellectual functioning seem to be less vulnerable in adults with early onset of epilepsy.

Heavy prenatal alcohol exposure with or without physical features of fetal alcohol syndrome leads to IQ deficits

Objective: To assess general intellectual functioning in children with histories of heavy prenatal alcohol exposure, with or without the facial features and growth deficiencies characteristic of fetal alcohol syndrome (FAS).Design: Forty-seven alcohol-exposed children were recruited on evaluation at a dysmorphology clinic and evaluated as part of a university research project using standard tests of IQ. Thirty-four of the alcohol-exposed patients met the traditional diagnostic criteria for FAS. The other 13 alcohol-exposed children lacked both the pattern of facial features and prenatal or postnatal growth deficiency characteristic of the diagnosis.Results: Compared with normal control subjects matched for age, sex, and ethnicity, both groups of alcohol-exposed children displayed significant deficits in overall IQ measures and deficits on most of the subtest scores. Although those in the nondysmorphic group usually obtained marginally higher IQ scores than those in the FAS group, few significant differences were found between the two alcohol-exposed groups.Conclusions: These results indicate that high levels of prenatal alcohol exposure are related to an increased risk for deficits in intellectual functioning and that these can occur in children without all of the physical features required for a diagnosis of FAS. They also emphasize the need for conducting a thorough history of prenatal alcohol exposure in children with intellectual deficits. (J Pediatr 1997;131:718-21)

Increased intellectual functioning in children with Neuroblastoma

Abstract Neuroblastoma, a catecholamine-producing childhood peripheral tumor derived from the neural crest, is intriguing because of its genetic aberrations and its expression of neurotrophins, neuropeptides, and their receptors. The hypothesis that this tumor would be associated with alterations in cognitive functioning in children was tested. Depending on the age of the child, the Wechsler Intelligence Scale for Children (either WISC-R or WISC-III) or the Stanford-Binet Intelligence Scale: Fourth Edition (SB-IV) was administered. The Neuroblastoma group (n = 23) had a significantly higher (p = .001) mean global IQ (M = 112.8, SD = 13.9) than a gender-matched cancer comparison group (n = 20; M = 98.9, SD = 17.0), after the effects of socio-economic status, age, and amount of schooling missed due to illness were statistically controlled by covariance. For the children who completed the Wechsler scales (n = 33), 7 with neuroblastoma obtained a maximum subtest scaled score of 19 whereas only 1 comparison child obtained this value (p = .01). We speculate that neuroblastoma may exert distant beneficial effects on the developing brain or there may be a genetic linkage between predisposition to the disease and amplified intellectual development.

Relationship between cerebellar appearance and function in children with Dandy-Walker syndrome.

In children with Dandy-Walker syndrome (DWS), the relationship between cerebellar appearance on imaging and either cerebellar function or intellect is unknown. To evaluate those relationships, we retrospectively studied 20 patients with DWS treated in our institution between 1978 and 1994. The patients were treated with ventriculoperitoneal, cystoperitoneal, or ventriculocystoperitoneal shunts. Intellectual and cerebellar function were determined from neurological and developmental testing. Cerebellar development was evaluated by measuring cerebellar and posterior fossa volumes from computed tomography images; the ratio of cerebellar size to posterior fossa size was considered to reflect cerebellar development. The cerebellar function was normal in 50% and the intellectual function in 45% of the patients. There was no correlation between cerebellar size and intellectual development or cerebellar function. There was also no correlation between the type of shunt and the subsequent cerebellar size. We conclude that there is no relationship between the cerebellar development evident on computed tomography scans and the cerebellar or the intellectual function of children with DWS. We, therefore, infer that treatment of Dandy-Walker cysts with posterior fossa shunts is unlikely to enhance the cerebellar function.

Association of 1800 cGy cranial irradiation with intellectual function in children with acute lymphoblastic leukaemia

Summary Cranial radiation therapy in childhood acute lymphoblastic leukaemia has been associated with adverse neuropsychological effects, such as low intelligence. However, records show that these associations usually occur when the dose of radiation used is 2400 cGy. We investigated whether a lower dose of 1800 cGy had the same adverse effects on long-term survivors and whether high doses of methotrexate but no radiation therapy would have a more beneficial effect. We evaluated 203 children for six years in a multi-centre European study. The patients were divided into two groups: 129 children treated with 1800 cGy of cranial radiation therapy and 74 children who received high-dose methotrexate but no radiation therapy. We used full scale intelligence quotient, verbal, and performance IQ tests to assess the patient's intelligence. We found a significant decline in full scale intelligence quotient in the irradiated group that increased with the length of time from diagnosis. Younger age at diagnosis was associated with lower full scale intelligence quotient in the radiated group. Our results indicate that a radiation dose of 1800 cGy can have negative effects on neurocognitive function and we continue to question the benefit of low-dose cranial radiation therapy.

Verbal and performance IQ patterns in children after perinatal stroke

Studies of intellectual functioning in children with focal brain lesions have yielded inconsistent results. Some show a lateralizing pattern similar to that found in adults; others do not. We studied Wechsler IQ patterns in children with early onset focal brain lesions and matched controls. Subjects with left hemisphere (LH) and right hemisphere (RH) focal lesions exhibited a significant decrement in Full Scale IQ, Verbal IQ (VIQ), and Performance IQ (PIQ) compared to controls. VIQ and PIQ were similar within the LH group, whereas VIQ was significantly higher than PIQ within the RH group. The picture painted by our results is one of partial compensation and/or reorganization against a backdrop of global decrements in cognitive functioning.

Neuropsychological and psychosocial effects of childhood leukemia and its treatment.

Neuropsychological and psychosocial effects of childhood leukemia and its treatment.

Discontinuing the PKU Diet

In response to the article by Seashore et al, "Loss of Intellectual Function in Children With Phenylketonuria After Relaxation of Dietary Phenylalanine Restriction" (Pediatrics 1985;75:266-232): we have had a similar experience at the PKU Outpatient Clinic at the Bancroft School in Haddonfield, NJ. In a retrospective study of the effects of diet termination on the intellectual and social functioning of children with phenylketonuria (PKU), we found that a significant number of the children's IQ scores declined five or more points following termination of the restricted diet.

847 THYROID DYSFUNCTION IN DOWN SYNDROME

We investigated the thyroid function of 151 children with Down syndrome. Compared with a control group of 89 siblings nearest in age to their brother or sister with Down syndrome the mean TSH value was significantly higher in children with Down syndrome than in the non-Down syndrome children (8.49 μU/ml vs. 3.55 μU/ml). However, the mean T4, levels in both groups were nearly the same (8.36 μg/dl and 8.60 μg/dl). In the Down syndrome group there was a trend for TSH values to increase and for T4 values to decrease with advancing age. Of the 151 patients with Down syndrome, 10 had both significantly elevated TSH levels ( > 9.5 μU/ml) and significantly decreased T4 levels (< 5.5 μg/dl) 21 had abnormally high TSH values (>9.5 μU/ml), 7 had markedly increased T4 levels (> 12.0 μg/dl), and 3 had significantly decreased T4 levels (< 5.5 μg/dl). The intellectual functioning of children with both abnormal TSH and T4 levels was significantly lower (mean IQ 41.7) than that of Down syndrome children with only increased TSH values (mean IQ 53.8) and that of Down syndrome children with normal thyroid function (mean IQ 55.3).This study provides evidence that there is an increased prevalence of thyroid dysfunction in children with Down syndrome. Therefore, children with Down syndrome should have thyroid function studies performed at regular intervals and prompt treatment should be instituted if thyroid dysfunction has been identified.

Factors Affecting Head Growth and Intellectual Function in Children of Drug Addicts

The effect of maternal heroin and methadone use on head growth and neurodevelopmental performance was studied in preschool children of untreated heroin addicts (n = 25), women receiving methadone therapy (n = 26), and a drug-free comparison group (n = 41) who had been followed from birth. The mean birth head circumference of both groups of drug-exposed infants was significantly below that of the comparison group; however, the only factors determined by multiple regression analysis as associated with head size at birth were maternal nutritional status and birth weight. By preschool age, head size did not differ significantly among groups. The factors associated with postnatal head growth were birth weight, intrapartum risk score, and race. Data show an increased incidence of low-average and mildly retarded intellectual performance in the drug-exposed children. Regression analyses demonstrated that amount of prenatal care, prenatal risk score, and home environment were most predictive of intellectual performance and that the degree of maternal narcotic use was not a significant factor.

Loss of Intellectual Function in Children with Phenylketonuria After Relaxation of Dietary Phenylalanine Restriction

Fourteen patients with classic phenylketonuria (PKU) were treated with a phenylalanine restricted diet from early infancy. All had satisfactory dietary control, with serum phenylalanine concentrations ranging between 2 to 5 mg/dL. Dietary restriction was discontinued in all these children between ages 5 and 6 years, and a free diet allowed. Developmental testing was performed using the Cattell Infant Intelligence Scales (1 to 2 years), Stanford-Binet Intelligence Scale (2 to 4 years), Wechsler Intelligence Scale for Children (WISC) and the revised version (WISC-R) (less than 5 years). Mean IQ for the group (Stanford-Binet and WISC) at termination of dietary therapy was 104 +/- 13. Four to 7 years after discontinuation of dietary therapy, mean IQ for the group was 90 +/- 13. The severity correlated, to some degree, with duration of unrestricted diet, but not with initial serum phenylalanine concentrations, age at initiation of therapy, or IQ at time diet was discontinued. Several children are experiencing difficulties, both attentional and academic, in school. Two children have had a change in the EEG from normal to abnormal. Neurologic testing performed after 4 to 7 years off diet demonstrated deficits in visual-motor integration or cognitive problem-solving in most children. The mean developmental age for the group for perceptual-motor integration was 1.2 years below the mean chronologic age of the group. This deterioration in intellectual function suggests that discontinuation of the phenylalanine-restricted diet is hazardous for some children with classic phenylketonuria.

Growth Development and Its Relationship to Intellectual Functioning of Children with Phenylketonuria

Growth measurements, including weight, height, and head circumference, of 67 early treated children with phenylketonuria (PKU) were compared to normal standards from infancy up to six years of age. Children with PKU, both girls and boys, achieved growth parameters that were similar to those of normals. Head circumference of the boys at six years of age and of the girls at three and four years of age correlated positively with IQ scores. Weight/height (W/H) ratios at one year of age correlated positively with IQ scores for boys. Similar correlations between IQs and weight/height ratios were found for girls at one, two, and three years of age.

The effects of prophylactic treatment of the central nervous system on the intellectual functioning of children with acute lymphocytic leukemia: Moss HA, Nannis ED, Poplack DG: Am J Med 1981; 71: 47–52

The effects of prophylactic treatment of the central nervous system on the intellectual functioning of children with acute lymphocytic leukemia: Moss HA, Nannis ED, Poplack DG: Am J Med 1981; 71: 47–52