There is controversy over the nature of the disturbance in brain development that underpins attention-deficit/hyperactivity disorder (ADHD). In particular, it is unclear whether the disorder results from a delay in brain maturation or whether it represents a complete deviation from the template of typical development. Using computational neuroanatomic techniques, we estimated cortical thickness at >40,000 cerebral points from 824 magnetic resonance scans acquired prospectively on 223 children with ADHD and 223 typically developing controls. With this sample size, we could define the growth trajectory of each cortical point, delineating a phase of childhood increase followed by adolescent decrease in cortical thickness (a quadratic growth model). From these trajectories, the age of attaining peak cortical thickness was derived and used as an index of cortical maturation. We found maturation to progress in a similar manner regionally in both children with and without ADHD, with primary sensory areas attaining peak cortical thickness before polymodal, high-order association areas. However, there was a marked delay in ADHD in attaining peak thickness throughout most of the cerebrum: the median age by which 50% of the cortical points attained peak thickness for this group was 10.5 years (SE 0.01), which was significantly later than the median age of 7.5 years (SE 0.02) for typically developing controls (log rank test χ(1)2 = 5,609, P < 1.0 × 10−20). The delay was most prominent in prefrontal regions important for control of cognitive processes including attention and motor planning. Neuroanatomic documentation of a delay in regional cortical maturation in ADHD has not been previously reported.

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Attention-deficit/hyperactivity disorder is characterized by a delay in cortical maturation

Understanding the organization of the cerebral cortex remains a central focus of neuroscience. Cortical maps have relied almost exclusively on the examination of postmortem tissue to construct structural, architectonic maps. These maps have invariably distinguished between areas with fewer discernable layers, which have a less complex overall pattern of lamination and lack an internal granular layer, and those with more complex laminar architecture. The former includes several agranular limbic areas, and the latter includes the homotypical and granular areas of association and sensory cortex. Here, we relate these traditional maps to developmental data from noninvasive neuroimaging. Changes in cortical thickness were determined in vivo from 764 neuroanatomic magnetic resonance images acquired longitudinally from 375 typically developing children and young adults. We find differing levels of complexity of cortical growth across the cerebrum, which align closely with established architectonic maps. Cortical regions with simple laminar architecture, including most limbic areas, predominantly show simpler growth trajectories. These areas have clearly identified homologues in all mammalian brains and thus likely evolved in early mammals. In contrast, polysensory and high-order association areas of cortex, the most complex areas in terms of their laminar architecture, also have the most complex developmental trajectories. Some of these areas are unique to, or dramatically expanded in primates, lending an evolutionary significance to the findings. Furthermore, by mapping a key characteristic of these development trajectories (the age of attaining peak cortical thickness) we document the dynamic, heterochronous maturation of the cerebral cortex through time lapse sequences (“movies”).

https://www.jneurosci.org/content/jneuro/28/14/3586.full.pdf

Neurodevelopmental Trajectories of the Human Cerebral Cortex

Objective To trace growth charts for height, weight and body mass index (BMI) that apply to the whole Italian population. Different charts were drawn for central-north and south Italy since children in central-north regions are known to be taller and leaner. Design: Cross-sectional study. Setting: A sample of schoolchildren covering 16 of the 20 Italian regions, with data collected between 1994 and 2000. Subjects: A total of 27 421 girls and 27 374 boys, aged 6–20 y. Methods: Height and weight were measured using portable Harpenden stadiometers and properly calibrated scales, respectively. SIEDP references are presented both as centiles and as LMS curves for the calculation of standard deviation scores. According to International Obesity Task Force, SIEDP charts for BMI include the limits for overweight and obesity, ie the centiles having, at 18 y of age, the value of 25 and 30 kg/m2, respectively. Results: The comparison between SIEDP and Tanner et al's charts for height, still in use among most Italian paediatricians, shows that before puberty Italian children are 2–4 cm taller than their English peers. Because of these differences, Tanner's charts fail to detect, when applied to Italian children, 50–90% of short children aged 6–11 y, ie with stature below the 3rd centile of their reference population. Rolland-Cachera et al's centiles for BMI are lower than those of SIEDP standards, mainly during adolescence (up to 6.6 kg/m2 for the 97th centile), and apply poorly to Italian children. The prevalence of overweight is 27 (boys) and 19% (girls) in south Italy vs 17 (boys) and 10% (girls) in central-north Italy. Conclusions: These references intend to supply Italian paediatricians with a tool that avoids the use of outdated or inadequate charts, and thus should be suitable for monitoring their patients' growth. Sponsorship: Italian Society for Pediatric Endocrinology and Diabetes (SIEDP).

Italian cross-sectional growth charts for height, weight and BMI (6-20 y).

The aim of this study is to extend to pre-school ages the Italian Society for Pediatric Endocrinology and Diabetes (SIEDP)-2002 growth charts for height, weight and body mass index (BMI), to obtain charts (SIEDP-2006) that apply to the Italian population from 2 to 20 yr of age, taken as a whole, or separately in two geographical areas (Central-North Italy and South Italy). The charts are based on a sample of about 70,000 subjects attending infant, primary and secondary schools, between 1994 and 2004. The distribution of the sample by gender, age and geographic area was roughly similar to that of Italian school population in the last decade of the 20th century. Height and weight were measured using portable Harpenden stadiometers and properly calibrated scales, respectively. SIEDP-2006 references are presented both as centiles and as LMS curves for the calculation of SD scores, and include the extra-centiles for overweight and obesity. Large differences in BMI growth pattern emerged between the SIEDP-2006, 2000 CDC and UK90 references: in Italy, BMI is higher and its distribution is more skewed during childhood and adolescence. At the end of growth, median values of the three references are similar, but the 97th centile of 2000 CDC charts is much higher and increases more steeply than that of SIEDP-2006 charts, which on the contrary reach a plateau. SIEDP-2006 references intend to supply pediatricians with a tool that avoids the use of charts that are outdated or that refer to other populations, and thus should be suitable for adequately monitoring the growth of their patients.

Italian cross-sectional growth charts for height, weight and BMI (2 to 20 yr).

The measurement of age, age structuring, and the life course has become more problematic as the study of human lives has moved toward more detailed analyses and explanations. As we seek to better understand the course of human lives in contemporary and changing societies, the effective empirical measurement of its key concepts simultaneously becomes more pressing and more complicated. We first review the critical concepts of, and measurement strategies associated with, age and age structuring—including a discussion of different types of age, subjective age identification, age norms and age expectations, critical life events, life phases, and life review. We then discuss state-of-the-art methods for measuring the life course, especially through life history and event matrices, and we close the chapter with some comments on the organization, analysis, and modeling of data.

https://www.jstor.org/stable/pdfplus/2952551.pdf

The Measurement of Age, Age Structuring, and the Life Course

A new seven-parameter asymptotic growth curve has been applied to longitudinal data on the height of 13 boys and 14 girls from 1 month to 19 years of age. The residual sums of squares with this new curve were 7.5 times lower on the average than with the currently-used five-parameter curve No. 1 of Preece and Baines (1978, Annals of Human Biology 5, 1-24) and 2.4 times lower than with the recent six-parameter curve of Shohoji and Sasaki (1987, Growth 51, 432-450). The new curve is expressed with respect to total age, passes through the origin, and fits infants as satisfactorily as older children.

A lifetime asymptotic growth curve for human height.

On explicite certaines proprietes liees aux sous-espaces propres associes aux valeurs propres nulles des matrices diagonalisees de l'analyse canonique et indique des possibilites d'utilisation de ces proprietes

Analyse canonique complète

Auxology, which is “la science metrique de la croissance” (the metric science of growth) according to Godin (1903), is, in human biometrics, a very important example of a field which requires a methodology adapted to the analysis of multivariate longitudinal data.

Solution Using “Longi”

Resume. — Les tests statistiques d'homogeneite entre groupes sont soumis a des conditions d'utilisation qu'il est tres souvent difficile ou impossible de satisfaire (par exemple : normalite des caracteres, effectifs importants d'observations). Ces conditions d'utilisation sont en fait imposees par une certaine facon de choisir l'ensemble de reference. Nous montrons ici comment un autre choix possible de l'ensemble de reference elimine ce type de contraintes. Nous introduisons ainsi le concept de tests d'autocomparaison, dont nous donnons quelques exemples d'applications en Anthropologie. Sont mises en discussion la justification de cet autre choix de l'ensemble de reference, les conditions de mise en pratique des tests d'autocomparaison, et leur comparaison avec des tests classiques.

Marie-Odile Pernin

Papers

A lifetime asymptotic growth curve for human height.

Analyse canonique complète

Solution Using “Longi”

Les tests d'autocomparaison: applications à l'anthropologie