Neuroanatomical markers for dyslexia: a review of dyslexia structural imaging studies

A neuroanatomical description of dyslexia has been elusive, due in part to the complex cognitive nature of dyslexia. People with dyslexia have varying degrees of impairment in reading skills that engage oral and written language (reading) neural networks. Although findings for the inferior parietal lobule, inferior frontal gyrus, and cerebellum have been relatively consistent across studies, these studies also demonstrate that anatomical patterns of results vary according to the reading skills that characterize dyslexia. The number and likelihood of atypical anatomical findings in oral and/or written language systems appears to be related to the pattern of impairments in measures of phonology, orthography, and fluency. A comprehensive neurobiological understanding of dyslexia will depend on studies of dyslexic individuals with homogeneous perceptual, cognitive, and genetic backgrounds.