Evidence neuro-anatomique de l'hypothèse d'un retard de maturation chez les enfants atteints de TDAH


Petit résumé :Cette étude tend à démontrer que les comportements "enfantins" des enfants atteints de TDAH (se comportant comme des enfants plus jeunes) est dû à un retard de développement des structures cortico-striatales et une moindre activation du cerveau et de ses macanismes inhibiteurs par rapport aux enfants sans problèmes de déficit d'attention.

Attention deficit hyperactivity disorder (ADHD) has been hypothesized to be related to a delay rather than a deviance of normal brain development before it was first defined by the DSM-III (1). The hypothesis was initially based on the behavioral observation that children with ADHD behave like younger children who are naturally more active, more impulsive, and have a shorter attention span than older children. This is well expressed in the definition of the disorder in the DSM-IV, where ADHD is characterized by an age-inappropriate display of inattention, hyperactivity, and impulsiveness. The behavioral observation is further supported by the cognitive profile of ADHD children: They show deficits in late developing higher cognitive functions of inhibitory self-control, attention, and temporal foresight (2, 3). The fact that ADHD symptoms tend to improve with age and up to 80% of children (depending on the follow-up length and definition of persistence) grow out of ADHD in adulthood (4) further supports the theory of a maturational lag that eventually normalizes in a considerable proportion of children. Indirect neurobiological support comes from cross-sectional structural imaging studies finding reduced size in cortico-striatal brain regions that are known to develop late in adolescence (5) and functional imaging studies showing reduced brain activation in ADHD compared with their age-matched peers in precisely those brain areas whose functions develop progressively with age between childhood and adulthood (6–10). Cross-sectional studies, however, are confounded by cohort effects; direct testing of the maturational delay hypothesis requires longitudinal imaging studies that map the developmental trajectories of brain maturation in healthy and ADHD children. In a recent issue of PNAS, Shaw et al. (11) study largely longitudinal data to provide direct neurobiological evidence for the maturational delay hypothesis of ADHD.

Proc Natl Acad Sci U S A. 2007 Dec 11;104(50):19663-4. Epub 2007 Dec 6. Neuro-anatomic evidence for the maturational delay hypothesis of ADHD.


Programme CerebroStim :

Le programme cerebrostim est destiné aux enfants et adultes souffrant d'un spectre large de troubles y compris les troubles envahissants de développement, troubles de déficit d'attention, hyperactivité, dyslexie, troubles de comportements, etc. L'objectif est d'analyser les déficits de fonctionnement des parties du cerveau et planifier un programme de rééducation pour stimuler et renforcer les endroits ou hémisphères faibles.

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