Intelligence Quotient at the Age of Six years of Iranian Children with Congenital Hypothyroidism

Objective

To evaluate the success rate of the National newborn screening program in maintenance of intelligent quotient (IQ) of children with congenital hypothyroidism in Iran.

Design

Retrospective cohort study.

Methods

The IQ scores, in three subsets of verbal, non verbal (Performance) and full scale IQ, of 240 children diagnosed with Transient congenital hypothyroidism (TCH) and Permanent congenital hypothyroidism (PCH), from 5 provinces in 5 different geographical areas of Iran, were measured at the age of 6 years using revised Wechsler pre school and primary scale of intelligence and compared with 240 healthy children. We used independent sample t test and two-way ANOVA for data analysis.

Results

Mean of verbal, performance, and full scale IQ scores were lower in the CH cases (permanent and transient) than the control group. Most of the IQ differences in two studied groups related to the PCH cases (P=0.005). Mean difference of IQs between children in the two groups in Yazd province (center of Iran) was higher than other provinces, and they also had significantly lower IQ than their control (healthy) children (P=0.001). No treated child had IQ<70.

Conclusion

Although mean IQs of CH children was lower than their controls, IQ of all treated CH cases were close to the healthy children.

     

Nonsignificance of sleep relative to IQ and neuropsychological scores in predicting academic achievement

OBJECTIVE: The goal of the study was to determine the relative importance of sleep, IQ, neuropsychological, and attention-deficit/hyperactivity disorder (ADHD) scores in predicting academic achievement. METHOD: Objective overnight polysomnograph sleep scores, parent ratings of sleep problems, IQ, neuropsychological test scores, and parent ratings of ADHD were used to predict academic achievement in a general population sample of 412 elementary schoolchildren, 6 to 12 years of age with IQs of 71 to 147. RESULTS: Using stepwise linear regression analysis, IQ was the best single predictor of reading and math achievement test scores. The most powerful combined predictors of achievement were IQ and some of the neuropsychological test scores. Subjective parent-reported sleep problems and objective polysomnograph scores (apnea-hypopnea index, mean oxygen saturation and lowest saturation percentage during sleep, snoring frequency and severity, sleep latency, minutes to rapid eye movement (REM) sleep, arousal index, number of awakenings, sleep efficiency, and percentage of stage 1, 2, 3, 4, and REM sleep) did not contribute significantly more to the prediction of achievement. Children with and without sleep problems did not differ from each other in achievement. IQ, neuropsychological test scores, and ADHD ratings were all significantly related to achievement, but correlations between achievement and objective and subjective sleep scores were all nonsignificant. CONCLUSIONS: There may be individual children for whom sleep problems affect achievement, but for a large group of community children, sleep was not significantly related to academic functioning. In contrast, IQ and neuropsychological test scores were powerful predictors of achievement.     

Giftedness. Can it be predicted in infancy?

A cohort of 200 children, who were followed from birth and periodically evaluated as part of a longitudinal study of child development, was used to determine the ability of the Bayley Scales of Infant Development (BSID) to predict children who would be considered intellectually gifted at 7.5 years. The cohort was predominantly white (91%), upper middle class (70% in Hollingshead class 1 or 2), and had preschool educational experiences (94%). At outcome, 36 children had WISC-R verbal, performance, or full scale IQs greater than 135 and were called gifted. On average, gifted children walked 0.7 months earlier and spoke two-word sentences 2.2 months earlier than the non-gifted group. As a group, gifted children showed statistically significant, but clinically small, advantages for age of walking, age of speaking two-word sentences, BSID, and Stanford Binet IQ. Of the 36 children who later proved to be gifted, only two had BSID IQs greater than 134. Of the four children who had BSID IQs greater than 134, two maintained their superior function but 2 did not. A discriminant function analysis was used to predict giftedness for individual children based on BSID performance. The resulting classification achieved sensitivity = 0.69 and specificity = 0.39. Although groups of infants who will be gifted have higher BSID scores, the BSID cannot be endorsed as a method of identifying individual infants who will later demonstrate superior cognitive function.     

Intellectual performance after presymptomatic cranial radiotherapy for leukaemia: effects of age and sex

Cognitive outcome, as measured by verbal and performance IQs, was compared in 35 girls and 47 boys who were in first remission for acute lymphoblastic leukaemia. All children had received presymptomatic cranial radiotherapy and intrathecal methotrexate. The mean age at diagnosis was 4.2 years and the mean elapsed time from initial diagnosis to intellectual assessment was 7.1 years. Results showed that children irradiated before the age of 4 years were impaired in certain aspects of non-verbal ability, as well as in measures of short term memory and attention, calculated by factor scores derived from selected subtests of the IQ test. Subtests requiring verbal and non-verbal reasoning showed the greatest impairment after early diagnosis and treatment. In addition girls were selectively impaired in verbal IQ and other aspects of verbal ability, with the degree of impairment exacerbated by early treatment. No relationship was found between degree of impairment and either time since treatment or number of methotrexate injections. It is concluded that early age at irradiation increases the risk of impaired intellectual outcome, particularly in girls.     

Intellectual performance after presymptomatic cranial radiotherapy for leukaemia: effects of age and sex.

Cognitive outcome, as measured by verbal and performance IQs, was compared in 35 girls and 47 boys who were in first remission for acute lymphoblastic leukaemia. All children had received presymptomatic cranial radiotherapy and intrathecal methotrexate. The mean age at diagnosis was 4.2 years and the mean elapsed time from initial diagnosis to intellectual assessment was 7.1 years. Results showed that children irradiated before the age of 4 years were impaired in certain aspects of non-verbal ability, as well as in measures of short term memory and attention, calculated by factor scores derived from selected subtests of the IQ test. Subtests requiring verbal and non-verbal reasoning showed the greatest impairment after early diagnosis and treatment. In addition girls were selectively impaired in verbal IQ and other aspects of verbal ability, with the degree of impairment exacerbated by early treatment. No relationship was found between degree of impairment and either time since treatment or number of methotrexate injections. It is concluded that early age at irradiation increases the risk of impaired intellectual outcome, particularly in girls.     

Children of Alcoholic Mothers: Developmental, Perceptual and Behavioural Characteristics as Compared to Matched Controls

ABSTRACT. From a retrospective material including all the 103 children of 30 alcoholic women, the 21 youngest born 1970-76, were paired to controls matched for sex, age, birth weight, gestational age and living area. IQ scores were measured with Griffiths and WISC scales. Controls tested within the normal range for Swedish children, while the study group scored 15-19 IQ points below controls ( p <0.01), the means of the study group corresponding to -1.6 SD below means of the controls. Significant differences between the groups were found in all subscales. Visual perception was measured with Frostig's test. Perceptual age was generally equal to mental age except in the most severely affected cases where perceptional age was lower than mental age. A marked perceptual delay exceeding 1 year was found in 8/17 tested cases in the study group, while all controls were normal. Developmental levels evaluated from Human Figure Drawings according to Koppitz was in accordance with IQ testresults. Indicators of emotional instability were found significantly more often in the study group than in controls. Hyperactivity, distractability and short attention span were found in 12/21 cases and perseveration in 6/21 cases but not among controls. Members of the study group with traits of the fetal alcohol syndrome (10/21) had significantly lower IQ and perceptual delay was more pronouned than in members without such signs. No significant IQ difference was found between subjects reared in foster homes and in biological homes.     

Children of alcoholic mothers. Developmental, perceptual and behavioural characteristics as compared to matched controls

From a retrospective material including all the 103 children of 30 alcoholic women, the 21 youngest born 1970-76, were paired to controls matched for sex, age, birth weight, gestational age and living area. IQ scores were measured with Griffiths and WISC scales. Controls tested within the normal range for Swedish children, while the study group scored 15-19 IQ points below controls (p less than 0.01), the means of the study group corresponding to -1.6 SD below means of the controls. Significant differences between the groups were found in all subscales. Visual perception was measured with Frostig's test. Perceptual age was generally equal to mental age except in the most severely affected cases where perceptional age was lower than mental age. A marked perceptual delay exceeding 1 year was found in 8/17 tested cases in the study group, while all controls were normal. Developmental levels evaluated from Human Figure Drawings according to Koppitz was in accordance with IQ test results. Indicators of emotional instability were found significantly more often in the study group than in controls. Hyperactivity, distractability and short attention span were found in 12/21 cases and perseveration in 6/21 cases but not among controls. Members of the study group with traits of the fetal alcohol syndrome (10/21) had significantly lower IQ and perceptual delay was more pronounced than in members without such signs. No significant IQ difference was found between subjects reared in foster homes and in biological homes.     

EFFECT OF INTRAUTERINE GROWTH RETARDATION (IUGR) ON THE PSYCHOLOGICAL PERFORMANCE OF PRETERM CHILDREN AT PRESCHOOL AGE

The present paper forms part of a larger prospective study and reports on the psychological performance of preterm children (n = 68) and fullterm control children (n = 36) at preschool age. Intelligence quotients (IQs) of intrauterine growth retarded (IUGR) preterm children were lower than those of appropriate-for-gestational-age (AGA) preterm children or fullterm controls at preschool age. Specific deficiencies (visuomotor, language) were found in 30% of the IUGR group and in 9% of the AGA group. When measuring general intellectual capacity, specific areas of intellectual function should be included by means of appropriate psychological tests, because a child may have a normal IQ but still show specific deficiencies.     

SIX WEEKS TO TWENTY-ONE YEARS OLD: A LONGITUDINAL STUDY OF CHILDREN WITH DOWN''S SYNDROME AND THEIR FAMILIES

A cohort of children with Down's syndrome, and their families, have been seen at intervals from six weeks old. Some follow-up data to 21 yrs are reported here. Until 21 yrs when one mother withdrew her son there have been no losses to the study apart from those caused by death. Mean IQs rose slightly from 11 to 21; scores on language and academic tests favoured the home-reared, females, and middle-class young people even when IQ was allowed for. Some of the effects on the family of having a handicapped member were explored; although adverse effects are fewer than might have been expected many parents, especially mothers, carry significant burdens.     

Influence of Age, Sex, and Concurrent Intrathecal Methotrexate Therapy on Intellectual Function after Cranial Irradiation During Childhood: A Report from the Children's Cancer Study Group

Standard IQ tests were performed in 70 children and adolescents 3.5-10 years (median 5 yrs) after 24 Gy cranial irradiation, with or without concurrent intrathecal methotrexate, for central nervous system prophylaxis of acute lymphoblastic leukemia. Lower IQ scores correlated with younger age, female gender, and concomitant intrathecal methotrexate therapy. Multivariate analysis identified age as the most important determinant of the three factors. The lowest IQ scores were observed in girls who were less than 5 years old at the time of irradiation and who received concurrent intrathecal methotrexate. The observed adverse contribution of simultaneous intrathecal methotrexate therapy on IQ outcome may have significant implications for school performance, peer relationships, and occupational expectations.     

Cognitive development at 5.5 years of children with chronic lung disease of prematurity

BACKGROUND: Preterm infants with chronic lung disease (CLD) had impaired cognitive development and poorer eye-hand coordination at 10 months of age. AIMS: To study whether this effect of CLD persisted until school age and whether the severity of CLD affected outcome. METHOD: Cognition and visual-motor skills were examined (Wechsler preschool and primary scale of intelligence, and tests from the Nepsy scale) in 60 very preterm children, without intraventricular haemorrhage or periventricular leucomalacia, at 5.5 years of age. Thirty two children suffered from CLD and 28 were controls. RESULTS: The groups did not differ significantly in cognitive outcome. Children with CLD and controls attained a full scale intelligence quotient (IQ) of 94.4 and 99.1, a verbal IQ of 99.6 and 101.5, and a performance IQ of 90.9 and 96.7 respectively. Similarly, no difference was found in tests of eye-hand control. However, the children with the most severe form of CLD had significantly lower performance (84.8) and full scale(87.6) IQs and worse visual-motor performance than the controls. CLD grade III, together with the need for glasses or lenses, had a significant impact on the explained variance. CONCLUSIONS: At school age, children born very preterm and who experienced severe CLD had deficits in cognition, visual-motor perception, and performance. The findings suggest a need to consider intervention programmes for such infants.     

Executive functioning in high-functioning children with autism

Executive functioning was investigated in 34 children (24 boys and 10 girls) with developmental language disorder (DLD) and 21 children (18 boys and 3 girls) with high-functioning autistic disorder (HAD) matched on Full Scale IQ, Nonverbal IQ, age (mean age 9 year, 1 month), and SES. The DLD group had a Verbal IQ that was 10 points higher than the HAD group. These children were given the Wisconsin Card Sorting Test (WCST), the Mazes subtest from the WISC-R, the Underlining test, and the Rapid Automatized Naming test. In addition, these children were given the Vineland Scales of Adaptive Functioning and the Wing Diagnostic Symptom Checklist in order to assess severity of autistic symptomatology. Results indicated that the only significant difference between the two groups on the cognitive tasks was perseverative errors on the WCST; there was no significant difference on total number of categories achieved or total number of errors on the WCST or on the other executive function measures. There was also significant overlap in the scores between the two groups and the difference in perseverative errors was no longer significant when Verbal IQ was partialled out. Executive functioning was strongly related to all IQ variables in the DLD group and particularly related to Verbal IQ in the HAD group. Although there was a relationship in the HAD group between executive functioning and adaptive functioning, as well as between executive functioning and autistic symptomatology, these relationships were generally no longer significant in the HAD group after the variance due to Verbal IQ was accounted for. The results are interpreted to indicate that although impaired executive functioning is a commonly associated feature of autism, it is not universal in autism and is unlikely to cause autistic behaviors or deficits in adaptive function.     

Intellectual and perceptual-motor characteristics of treated myelomeningocele children.

We studied 173 children with myelomeningocele, 133 of whom developed hydrocephalus (and had shunt procedures) and 40 of whom did not. Eighty siblings were tested as a control group. Sixty-three percent of children with hydrocephalus had IQs above 80; 87% of those without hydrocephalus had IQs above 80. Children who had associated hydrocephalus were significantly less intelligent than their siblings, whereas those without hydrocephalus were not. When patients and siblings were not. When patients and siblings were matched by age and IQ, the former scored significantly lower on a perceptual-motor functioning test. When patients with and without hydrocephalus were similarly matched, those with hydrocephalus scored lower. Inverse relationships between sac location and IQ, and sensory level and IQ, were found to be dependent on the association of higher sac levels and of sensory loss with hydrocephalus. Patient IQ was related to family income and education.     

Oral and written language abilities of XXY boys: implications for anticipatory guidance

Previous studies of XXY boys suggest that they are at risk for certain communication disorders involving oral and written language. In this study, the language, reading, and spelling skills of a group of 14 XXY boys identified during neonatal cytogenetic screening were compared with those of a group of 15 control children. The two groups were matched for age, grade, race, parity, birth weight, parental age and education, and socioeconomic status. The mean age of the XXY group was 9 years 7 months and that of the control group was 9 years 3 months. The mean academic grade level for both groups was at the transition between third and fourth grade. There was selective reduction in verbal IQ scores for the XXY group and no significant differences apparent between groups for performance IQ scores. The decrease in verbal IQ was associated with a reduced full-scale IQ and also with significant problems in expressive language, auditory processing abilities, and auditory memory. Word-finding difficulties and problems in the production of syntax were major components of the specific expressive language deficit. Except for difficulties in the understanding of complex sentence structures, the receptive language skills of XXY boys did not differ significantly from those of the control group. These reductions in speech and language abilities correlated with decreased achievement by the XXY group on a variety of reading and spelling tasks. These results suggest that difficulty learning how to read and spell may be due to a preexistent language disability. Early attention to such expressive language problems may be essential to ameliorate secondary maladaptive behaviors due to chronic language-related learning disabilities.     

Description and evaluation of creative thinking in preterm low birth weight infants

AIM: Since the 1950s, the problem of how to evaluate creativity has been addressed in studies on the definition of measurement criteria and on the relationship between intelligence and creative thinking. Many revealed cognitive and relational disorders in preterm infants, particularly in preterm very low birth weight infants (birth weight <1500 g) and in infants with serious complications. This study describes the development of creative thinking in a group of children born preterm. METHODS: The study sample was 43 children (21 males, 22 females; age range 6-11 years), regularly attending school, born with low birth weight (1050-2450 g) at 29-32 weeks gestational age, and compared with a control group with birth weight >2500 g. The test battery included: Torrance Test of Creative Thinking (TCTT); WISC-R intelligence test; Goodenough Human Figure Drawing Test. RESULTS: Statistical analysis (Mann-Whitney U test) showed a statistically significant difference (P>0.05) between the 2 groups; scores for figure originality, figure fluidity and figure elaboration were consistently higher in the control group. Within the low birth weight group, there was a significant correlation (Spearman r) between verbal IQ and verbal fluidity and verbal flexibility subscale scores and between IQ performance and figure elaboration. Scores on the figure drawing tests showed higher creative ability in the control group. CONCLUSIONS: In children born preterm with low birth weight, emotive dynamics and flow of affection may influence the channels of communication between child and family. The low figure originality subscale scores support the hypothesis that psychodynamic and relational factors (worry about the preterm condition, overprotective behaviour by parents and others) could lead to diminished autonomy, flexibility and manipulatory interest in the child.     

Neonatal hyperviscosity association with lower achievement and IQ scores at school age

A longitudinal study was conducted to determine whether the early neurologic and motor impairment observed in children with neonatal polycythemia and hyperviscosity persisted into school age. Forty-nine children who had neonatal polycythemia and hyperviscosity were evaluated at a mean age of 7 years. Of these, 21 (group 1) received a partial plasma exchange transfusion, whereas 28 (group 2) received symptomatic care. Forty control children (group 3) with a normal neonatal hematocrit were also evaluated. Testing consisted of a battery of measures to evaluate IQ, achievement, neuromotor function, and gross and fine motor skills. Maternal education and IQ were also assessed to avoid potential confounding by differences in the home environment. The neonatal course of the children with polycythemia and hyperviscosity was characterized by an increased number of problems, including hypoglycemia and cyanosis. At 7 years of age, the 49 children who had hyperviscosity (groups 1 and 2) had significantly lower "spelling" and arithmetic achievement test results and gross motor skill scores. Scores for reading, visual motor integration, and neurologic signs did not differ significantly from group 3. Maternal IQ scores were similar for both groups. Left-hand preference was seen in 14% of group 1 and 2 children and 7% of group 3 children (not significant). The scores for IQ, achievement, neuromotor function, and visual motor integration were compared for the hyperviscosity group (groups 1 and 2) and the control group (group 3) by multivariate analysis of variance with sex and hyperviscous group as independent variables and maternal education and maternal IQ as covariates (P = .040).(ABSTRACT TRUNCATED AT 250 WORDS)     

A follow-up study of the effects of early malnutrition on subsequent development. II. Fine motor skills in adolescence

One hundred nine children, aged 8 through 15 yr, who suffered from malnutrition in the 1st yr of life and 107 well-nourished comparison children were tested for fine motor skills by the Purdue Pegboard test. The performance of index children was impaired on three of the four test measures. IQ measured concurrently showed a reduction in the index group; when the effects of IQ were eliminated, there was no longer any significant difference between index and comparison groups. The data suggest that the effects of early malnutrition on Pegboard performance are largely mediated by deficits in IQ. The presence of soft neurologic signs measured 4 yr earlier in the same children was highly correlated with reduced Pegboard performance, implying that early malnutrition has effects on nervous system function that are evident at least through 15 yr of age.     

Intellectual development after relaxing the diet at the age of 5 years in typical phenylketonuria]

BACKGROUND. No satisfactory controlled trial has yet been completed on typical phenylketonuria (PKU) patients whose treatment was relaxed at the age of 5 years. METHODS. 27 children having typical PKU were treated before the age of 3 months. The intake of phenylalanine and protein was carefully regulated during the first 5 years of life, after which the treatment was relaxed. All children were evaluated after at least 6 years on the relaxed diet. Their IQ scores and school performance were related to the degree of dietary control and plasma phenylalanine values. RESULTS. The IQ scores at 5 years of age were 100 +/- 10.8. Continued evaluation showed that IQ scores remained unchanged. Poor school performance was twice as frequent as in general population; the deficit in the IQ score of this group was 8 points below that of normal sibs. There was no correlation between plasma phenylalanine and the IQ score after the age of 5 years. The positive control decreased with aged. CONCLUSIONS. Children with typical PKU have an IQ deficit relative to their normal sibs just before relaxing treatment. Good dietary control until 5 years of age, maternal intelligence and continuing evaluation during relaxing diet are the best conditions for optimal intellectual progress. There is no evidence that continued treatment during adolescence is beneficial.     

Executive functions in school-age children born very prematurely

BACKGROUND: School-age preterm children are at risk for cognitive difficulties including Executive Dysfunction and low average IQ. AIM: The aim of this study was to determine the performance of very preterm, school-age children on three components of Executive Function (EF), two components of Executive Attention and a measure of IQ. STUDY DESIGN: Cross-sectional, independent samples comparison. METHODS: A UK sample of 40 very preterm (<32 weeks gestational age, Mean 28.43, SD 2.41) children and 41 term born control children aged between 6 and 12 years (mean ages 8 years 5 months in both groups) was assessed on IQ, EF (inhibition, working memory and set shifting) and attention (sustained and selective). Between group comparisons were made using multivariate analysis of variance and covariance. RESULTS: Multivariate analyses indicated that preterm children scored significantly lower than their term born peers across Executive Function and executive attention tasks. As expected, the preterm group achieved IQ scores at the low end of the average range. Univariate analyses indicated some difficulties with shifting and inhibition components of EF, although covariate analysis revealed that only shifting was independent of IQ. CONCLUSIONS: Preterm children showed mild executive function and executive attention difficulties in the context of average IQ scores. The findings highlight the benefit of using multivariate assessments of executive skills rather than general intellectual outcome alone, to obtain a better distinction of the specific cognitive weaknesses associated with preterm birth.     

Factors associated with IQ scores in long-term survivors of childhood acute lymphoblastic leukemia

To identify factors which might be associated with intellectual function following treatment for childhood acute lymphoblastic leukemia, 50 long-term survivors were studied using the Wechsler Intelligence Scale for Children-Revised. All patients were diagnosed between 1972 and 1974 and were treated on a single clinical trial protocol with identical induction and maintenance chemotherapy plus central nervous system prophylaxis that included cranial radiation. The mean full scale IQ score for the group was 95 (SEM 2.0), with mean verbal IQ of 94.4 and mean performance IQ of 96.9. Factors which were found to be closely associated with a lower IQ score included female sex (in both verbal IQ and full-scale IQ), longer duration of chemotherapy (in performance IQ), and younger age at the time of radiation (in both verbal IQ and full-scale IQ). The age at the time of radiation was found to be significantly correlated with discrepancy between verbal and performance IQ, with younger age being associated with verbal IQ scores higher than performance IQ scores. When analyses were performed within specific subgroups of patients defined by sex and age at the time of radiation, dose of cranial radiation, concomitant intrathecal methotrexate therapy, and duration of therapy were all found to be correlated with a lower level of intellectual function. These preliminary findings provide direction for future studies to help identify high-risk patients.