Neurological subtle signs and cognitive development a study in late childhood and adolescence

Introduction and aim—Neurological subtle signs (NSS) are often observed during the neurological examination of children and tend to disappear with age. Their persistence into late adolescence or young adulthood has been related to psychiatric and neurocognitive disorders. To provide a better understanding of their functional basis a longitudinal correlational study with neurocognitive measurements was performed. Methods—We conducted multiple regression and correlation analyses of NSS with demographic and cognitive measures on a subset of 341 healthy children (56% males), taking part in a longitudinal dental study. Participants, whose ages ranged between 11–15 years, at first evaluation, undertook yearly, during five years, a 6-item NSS exam (producing a total score ranging between 0–18) and a comprehensive battery of neurocognitive tests. Effects of age, gender, IQ and 7 neurocognitive factors on NSS were analysed. Results—Over the years, NSS scores correlated consistently with selective attention (Stroop test), motor speed (finger tapping), and visuo-motor speed (pegboard speed). Discussion—These results suggest that the disappearance of NSS in late childhood and adolescence occurs primarily in parallel with the development of motor and visuo-motor functions and secondarily in relation to higher order functions such as selective attention (Stroop) and executive control (B-A Trails difference).info:eu-repo/semantics/publishedVersio

Age group differences on neuropsychological battery performance in a neuropsychiatric population: An international descriptive study with replications

The relationship of age to performance on the Halstead-Reitan Neuropsychological Battery was examined in three samples drawn from neuropsychiatric populations: an initial sample of 217 subjects, a within-laboratory replication of 307 subjects, and a cross-national replication sample of 101 subjects. The results showed significant relationships of age to subtests of the Halstead-Reitan Battery involving problem-solving abilities and motor strength, which were replicated across the three samples. Verbal and perceptual subtests were not consistently related to age across samples. For those problem-solving and motor tests showing replicated correlations with age. mean scores are provided for three age groups (16-34, 35-54, and 55 and above), and group differences were tested with analysis of variance. These results help clarify for which measures age group differences are consistent in neuropsychiatric populations. Implications of these results for treatment program planning are discussed

A longitudinal factor analytic study of children’s neurocognitive abilities

The neurocognitive abilities of 503 Portuguese children aged 8–11.9 years at onset of the study were assessed annually for 8 years in 3 functional domains: memory,motor and visual motor functions, and attention. A series of exploratory principal axis factor analyses, with varimax rotation, revealed seven factors: Divided Attention, Selective Attention, Verbal Learning and Recall, Visual Learning and Recall, Motor Speed, Visual-Motor Speed, andWorkingMemory. The same factors emerged across the 8-year period, suggesting that children’s neurocognitive structures are articulated and stable throughout this period of development. From these exploratory analyses a small set of cost-effective neuropsychological tests were found to characterize children’s functioning consistently throughout the 8-year period.info:eu-repo/semantics/publishedVersio

Factor analysis of the Wechsler memory scale: Is the associate learning subtest an unclear measure?

A factor analysis of the Wechsler Memory Scale (WMS) with 30-minute delayed recall scores (percent retained) for the Logical Memory, Visual Reproduction, and Associate Learning subtests indicated that this variant of the WMS taps different types of learning and memory for new material. With regard to the verbal learning/recall subtests, Logical Memory appears to be related to attention/ concentration ability, while Associate Learning is relatively indepemdent. The results also showed that both the easy and hard items from Associate Learning tap the same ability, providing evidence that this subtest is a measure of rote verbal learning. These results support the clinical utility of the WMS with delayed recalls in neuropsychiatric populations

The serial use of child neurocognitive tests: development versus practice effects

When serial neurocognitive assessments are perfomed. 2 main factors are of importance: test—retest reliabílity and practice effects, With children. however. there is a third. developmental factor. which occurs as a result of maturation. Child tests recognise this factor through the provision of age.corrected scaled scores. Thus, a ready.mad method for estimating the relative contribution of developmentaI versus practice effects is the comparison of raw (developmental and practice) and scaled (practice only) scores. Data from a pool of 507 Portuguese children enrolled in a study of dental amalgams T. A. DeRouen, B. G. Leroux, et al, 2002; T. A- DeRouen., M. D. Martin, et aI., 2006) showed that practice effects over a 5-year period varied on 8 neurocognitive tests. Simple regression equations are provided for calculating individual retest scores from initial test scores.info:eu-repo/semantics/publishedVersio

Age and sex differences in neurobehavioral performance : a study of Portuguese elementary school children

Copyright © 2005 Taylor & Francis IncIn this study normative data were obtained on measures of IQ, visual/motor, motor and memory functions among Portuguese elementary school children. Subjects were 228 females and 275 males, 8.0 to 11.9 years of age, in grades 2 through 4, who participated in a dental study. Performance on all tests improved with increasing age. Females performed better in rote verbal learning, psychomotor speed, and speed of information processing. Males had higher scores on tests of visual learning, visual memory, and fine motor speed and coordination. Nonverbal IQ had a significant impact on all tests except motor speed and coordination. Results represent an initial attempt to evaluate Portuguese children in educational and medical settings.info:eu-repo/semantics/publishedVersio

The association of dental caries with blood lead in children when adjusted for IQ and neurobehavioral performance

Associations between childhood lead exposures and dental caries in children have been reported for over 30 years, with widely varying findings and conclusions, and using measures of lead exposure which ranged from food sources and water to tooth, hair or blood lead concentrations. Objectives: This study examined the relationship of lead exposure and dental caries in a population of normatively healthy children. Methods: This cross-sectional study used a population of 507 children aged 8–12 who were participating in a clinical trial of dental materials to examine the relationship between lead and caries. Blood lead concentrations and dental caries were examined for association in both primary and permanent teeth. Because it is possible that neurobehavioral status could be associated with both lead exposure and dental caries prevalence, we also examined neurobehavioral status of the subjects. Results: A gender-specific association (males only) between lead exposure and dental caries was found in primary teeth only. Neurobehavioral measures and IQ were not associated with caries status in this population. Conclusions: This study did not support neurobehavioral status as mediating any association between lead exposure and caries in a normatively healthy population. A gender-specific association between lead and caries not previously reported was found in primary teeth, and no biological explanation for this has been suggested. We conclude that this study provides only weak evidence, if any, for an association of low-level lead exposure with dental caries.info:eu-repo/semantics/publishedVersio