Ibone Saralegui MD, Presenter: Nothing to Disclose

Begona Garcia-Zapirain MD, Abstract Co-Author: Nothing to Disclose

Begona Fernandez-Ruanova, Abstract Co-Author: Nothing to Disclose

Alejandro Basterra, Abstract Co-Author: Nothing to Disclose

Jose Maria Ontanon MD, Abstract Co-Author: Nothing to Disclose

Ricardo Martinez MD, Abstract Co-Author: Nothing to Disclose

To analyze the neural network while reading in a group of dyslexic children and to compare it that in two other groups, one of children with normal development and the other of children with monocular vision secondary to ocular motility disorders, to assess whether dyslexic readers share neuronal patterns with children with ocular motility disorders; if, in contrast, there are differences in their language networks, ocular motility disorders should not be considered a cause of dyslexia

We conducted a comprehensive fMRI study including three different cognitive tasks, two lexical decision tasks and a semantic categorization task, in order to explore the two main routes of reading, phonological and orthographic. We studied the brain activation pattern while reading in the most eloquent cortical areas from the two reading routes, and the strength of their association with reading scores in 66 Spanish children aged 9-12 years divided into three groups: typically developing readers (controls) (TDR), dyslexic readers (DXR) and readers with monocular vision due to ocular motility disorders (MVR) We used a non-parametric K Test for comparisons between the three groups, followed by a post hoc MW test for comparisons between pairs of groups

For the three paradigms, the pattern of activation while reading in MVRs seems differ from that in DXRs but be similar to that in TDRs. In relation to the two paradigms designed to explore the phonological route, DXR tended to hypoactivate the posterior region of the VWFA (Visual Word Form Area): (p = .001, K-W test), DXRs vs TDRs (p = .001, M-W test) and vs MVRs (p = .002, M-W test); as well as the left Wernicke´s area, and both the Broca´s areas. In the paradigm linked to the orthographic route, the semantic categorization task, DXR hypoactivated the left Wernicke´s area: MVRs vs DXRs (p = .016, M-W test); and both triangular regions of both Broca´s areas, and they seemed to compensate by activating the Wernicke´s area of the contralateral hemisphere: (p = .006, K-W test), DXR vs TDRs (p = .002, M-W test)  

According to our results, Spanish DXR do not have the same brain network for reading as MVR. Ocular motility disorders would not be a causal factor for dyslexia

fMRI might help to distinguish the underlying mechanisms of dyslexia and its relation with visual impairment, with beneficial consequences for its diagnosis and treatment

Saralegui, I, Garcia-Zapirain, B, Fernandez-Ruanova, B, Basterra, A, Ontanon, J, Martinez, R, Reading Networks in Children with Dyslexia Compared to Children with Ocular Motility Disturbances Revealed by fMRI.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14007042.html