Impact of intervention: can we affect typical and atypical development of the human brain?

Abstract

Society becomes increasingly complex. Changes involve altered ways of communication and information exchange, changes in food consumption, changes in motor activities, and in the age at which women have their first child. Postponement of motherhood is associated with an increase in fertility problems and the application of assisted reproductive technology, factors that in turn are associated with an increased risk of preterm birth and low birthweight. Preterm birth and low birthweight are well-known risk factors for developmental disorders, such as CP, developmental coordination disorder, and attention-deficit–hyperactivity disorder. In April 2010, when the Islandic volcano Eijafjällajökull was spitting ash clouds into the air, a workshop was organized in Groningen, the Netherlands, which dealt with vulnerability and plasticity of the developing human nervous system. Leading experts discussed their recent research findings. The aim of the workshop was to address vulnerability and plasticity from neurobiological, neurobehavioural, and clinical perspectives, the last particularly including the consequences for guidance of children with developmental motor disorders. This special issue of Developmental Medicine & Child Neurology is the product of that venture. The first paper by Bryan Kolb et al. reviews cortical plasticity during early development. It highlights the age- and region-specific nature of developmental plasticity and stresses the complexity of early plasticity: many factors may have a positive or negative effect on developmental outcome after a lesion of the brain at early age. The paper by John Martin et al. also deals with plasticity of the young brain. It summarizes a neat series of experiments on activity-dependent plasticity of the young feline brain, which provide challenging insights into possibilities and limitations of early intervention in infants with a unilateral lesion of the brain (see also the commentary in this issue by Gordon and Hadders-Algra). The next two papers, written by Katharina Braun et al. and Bea van den Bergh, deal with the effect of stress during prenatal and early postnatal life. Evidence is accumulating that early stress may programme the brain through complex epigenetic cascades in such a way that it carries an increased risk for the development of psychopathology. The next section addresses two neonatal problems associated with deviant neurodevelopment: hyperbilirubinaemia and preterm birth. Thor Hansen reviews the state of the art in prevention of kernicterus. Gerda van Wezel-Meijler et al., and Arend Bos and Elise Roze discuss the nature and effect of lesions and/or altered neural wiring associated with preterm birth. Kirsten Heineman et al. evaluate the use of the recently developed Infant Motor Profile in the early detection of cerebral palsy (CP) in a high-risk population. The last section deals with the effect of intervention in children with or at high risk for CP. The first three papers, written by Andrea Guzzetta et al., Mijna Hadders-Algra, and Andrew Gordon, address general aspects and the effect of specific activities on developmental outcome. Guzetta et al. present promising results on the effect of massage during the preterm period. Hadders-Algra discusses possibilities but also limitations of early intervention. Gordon elegantly reviews the effects of two types of intervention in children with unilateral spastic CP: constraint-induced movement therapy and bimanual training. He concludes that each method has advantages and disadvantages and that – most importantly – presumably intensity of intervention matters more than the exact nature of the intervention. The last two papers deal with the role of the family in intervention in children with developmental motor disorders. Tineke Dirks et al. review the nature of family involvement in various early intervention programmes, and Peter Rosenbaum stresses that the themes we address in services for children with developmental disorders, and the way we do that, can have important effects on families, and by extension, their children. The papers in this special issue indicate the keen interest of neuroscientists and clinicians in vulnerability and plasticity of the young brain, in particular on the impact of intervention in developmental disorders. They demonstrate that our knowledge of the consequences has increased impressively over the past few years. Nevertheless, there is still much to discover before we understand all of the contributing factors so that we can facilitate functional recovery after a lesion of the young human brain. To achieve this ultimate goal, interdisciplinary translational research is needed, where results from animal models are paired with studies in humans, and studies that use brain imaging techniques are matched with those in which interventions in children are examined to compare functional outcome.