John Libbey Eurotext




Looking for brain anomalies in autism
Revue de neuropsychologie. Volume 4, Number 1, 36-42, Mars 2012, Article de synthèse
Résumé Texte intégral
Author(s) : Céline Cavézian, Sylvie Chokron
Summary : In the current review, physiological, structural, and functional data are summarized in an attempt to present the common cerebral anomalies in autistic spectrum disorder (ASD). Physiologically and structurally, a decreased number of cells (Purkinje cells in the cerebellum), global electrical dysfunction (epileptiform EEGs) and increased white matter are frequently reported, particularly in temporal and parietal regions. Functionally, a redistribution of brain activity is almost always observed. ASD patients exhibited lower recruitment of classical networks typically in associative areas (temporal and parietal regions) and in the frontal lobe. Conjointly, increased activation is observed in areas which typically are not recruited in healthy individuals. In particular, increased activation is seen in homologous regions of the other hemisphere, mainly in the occipital regions. Atypical pattern of activation was reported for language, social cognition, and executive functions. Finally, studies investigating brain connectivity (using fcMRI, DTI, or tractography) compete for the hypothesis of abnormal functional and structural connectivity with decreased long-distance connectivity. Overall, there is a growing body of evidence suggesting that ASD is associated with defective brain connectivity and defective modulation of cerebral networks with a redistribution of activation.
Keywords : Pervasive Developmental Disorder, brain anatomy, DTI, fcMRI, fMRI

Looking for brain anomalies in autism