Imaging normal and abnormal brain development: new perspectives for child psychiatry.

Child Psychiatry Branch, National Institute of Mental Health, Bethesda, Maryland 20892-1600, USA.
Australian and New Zealand Journal of Psychiatry (Impact Factor: 3.77). 07/2001; 35(3):272-81.
Source: PubMed

ABSTRACT The availability of non-invasive brain imaging permits the study of normal and abnormal brain development in childhood and adolescence. This paper summarizes current knowledge of brain abnormalities of two conditions, attention deficit hyperactivity disorder (ADHD) and childhood onset schizophrenia (COS), and illustrates how such findings are bringing clinical and preclinical perspectives closer together.
A selected review is presented of the pattern and temporal characteristics of anatomic brain magnetic resonance imaging (MRI) studies in ADHD and COS. These results are discussed in terms of candidate mechanisms suggested by studies in developmental neuroscience.
There are consistent, diagnostically specific patterns of brain abnormality for ADHD and COS. Attention deficit hyperactivity disorder is characterized by a slightly smaller (4%) total brain volume (both white and grey matter), less-consistent abnormalities of the basal ganglia and a striking (15%) decrease in posterior inferior cerebellar vermal volume. These changes do not progress with age. In contrast, patients with COS have smaller brain volume due to a 10% decrease in cortical grey volume. Moreover, in COS there is a progressive loss of regional grey volume particularly in frontal and temporal regions during adolescence.
In ADHD, the developmental pattern suggests an early non-progressive 'lesion' involving neurotrophic factors controlling overall brain growth and selected dopamine circuits. In contrast, in COS, which shows progressive grey matter loss, various candidate processes influencing later synaptic and dendritic pruning are suggested by human post-mortem and developmental animal studies.

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    ABSTRACT: mones have been intensely studied in the animal model and in humans. High and sustained levels of cortisol and corticotrophin releasing hormone (CRH) during gestation , are associated with modifications in the foetus HPA Axis response and in the normal brain asymmetry. It seems that some behaviours, as attention deficit disorders, hyperactivity, aggressiveness, sexual dysfunction, or even schizophrenia, might have their origin during life in uterus. There is some evidence of a connection between maternal stress and anxiety and the offspring neu-rophysiology and behaviour. Other problems, like fetal growth restriction and preterm birth, might also be associated with antenatal stress, and some pathologies, like hypertension and diabetes, have been related with a programming process during this period of life. INTRODUÇÃO Em todas as sociedades conhecidas, antigas e actuais, é manifesta a ideia de que o estado emocional da mãe pode ter repercussões no filho que vai nascer, como se pode veri-ficar em citações do Antigo Testamento, de Hipócrates e de Leonardo da Vinci (The same soul governs the two bodies and the desires and fears and sorrows are common...) 1. Foi, no entanto, Sontag 2 , em 1941, o primeiro cientista a escre-ver sobre o assunto. O termo " stress " foi publicado pela pri-meira vez em 1936 por Hans Selye na revista Nature 3 , a propósito de um estudo em ratos, e nas últimas décadas sur-giu extensa investigação sobre os seus efeitos no feto. Pode ser definido como a resposta global do organismo a qual-quer exigência ou pressão externa, tendo o indivíduo a per-cepção que lhe é exigido mais do que as suas capacidades adaptativas para a situação em causa, podendo sentir o seu bem-estar ameaçado 4. O processo biológico que envolve as hormonas do stress durante a gestação, um estado de hipercortisolismo
  • Australian and New Zealand Journal of Psychiatry 08/2002; 36(4). DOI:10.1046/j.1440-1614.2002.t01-1-01066.x · 3.77 Impact Factor


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