30 research outputs found

    Atypical Balance between Occipital and Fronto-Parietal Activation for Visual Shape Extraction in Dyslexia

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    Reading requires the extraction of letter shapes from a complex background of text, and an impairment in visual shape extraction would cause difficulty in reading. To investigate the neural mechanisms of visual shape extraction in dyslexia, we used functional magnetic resonance imaging (fMRI) to examine brain activation while adults with or without dyslexia responded to the change of an arrow’s direction in a complex, relative to a simple, visual background. In comparison to adults with typical reading ability, adults with dyslexia exhibited opposite patterns of atypical activation: decreased activation in occipital visual areas associated with visual perception, and increased activation in frontal and parietal regions associated with visual attention. These findings indicate that dyslexia involves atypical brain organization for fundamental processes of visual shape extraction even when reading is not involved. Overengagement in higher-order association cortices, required to compensate for underengagment in lower-order visual cortices, may result in competition for top-down attentional resources helpful for fluent reading.Ellison Medical FoundationMartin Richmond Memorial FundNational Institutes of Health (U.S.). (Grant UL1RR025758)National Institutes of Health (U.S.). (Grant F32EY014750-01)MIT Class of 1976 (Funds for Dyslexia Research

    Combined immunosuppression and radiotherapy in thyroid eye disease (CIRTED): a multicentre, 2 x 2 factorial, double-blind, randomised controlled trial

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    BACKGROUND: Standard treatment for thyroid eye disease is with systemic corticosteroids. We aimed to establish whether orbital radiotherapy or antiproliferative immunosuppression would confer any additional benefit. METHODS: CIRTED was a multicentre, double-blind, randomised controlled trial with a 2 × 2 factorial design done at six centres in the UK. Adults with active moderate-to-severe thyroid eye disease associated with proptosis or ocular motility restriction were recruited to the trial. Patients all received a 24 week course of oral prednisolone (80 mg per day, reduced to 20 mg per day by 6 weeks, 10 mg per day by 15 weeks, and 5 mg per day by 21 weeks) and were randomly assigned via remote computerised randomisation to receive either radiotherapy or sham radiotherapy and azathioprine or placebo in a 2 × 2 factorial design. Randomisation included minimisation to reduce baseline disparities in potential confounding variables between trial interventions. Patients and data analysts were masked to assignment, whereas trial coordinators (who monitored blood results), pharmacists, and radiographers were not. The radiotherapy dose was 20 Gy administered to the retrobulbar orbit in ten to 12 fractions over 2 to 3 weeks. Azathioprine treatment was provided for 48 weeks at 100–200 mg per day (dispensed as 50 mg tablets), depending on bodyweight (100 mg for <50 kg, 150 mg 50–79 kg, 200 mg for ≥80 kg). The primary outcomes were a binary composite clinical outcome score and an ophthalmopathy index at 48 weeks, and a clinical activity score at 12 weeks. The primary analysis was based on the intention-to-treat allocation and safety was assessed in all participants. This study is registered with ISRCTN, number 22471573. FINDINGS: Between Feb 15, 2006, and Oct 3, 2013, 126 patients were recruited and randomly assigned to groups: 31 patients to radiotherapy plus azathioprine, 31 to sham radiotherapy and azathioprine, 32 to radiotherapy and placebo, and 32 to sham radiotherapy and placebo. Outcome data were available for 103 patients (54 for sham radiotherapy vs 49 for radiotherapy and 53 for placebo vs 50 for azathioprine), of whom 84 completed their allocated treatment of radiotherapy or sham radiotherapy and 57 continued to take azathioprine or placebo up to 48 weeks. There was no interaction betweeen azathioprine and radiotherapy (pinteraction=0·86). The adjusted odds ratio (ORadj) for improvement in the binary clinical composite outcome measure was 2·56 (95% CI 0·98–6·66, p=0·054) for azathioprine and 0·89 (0·36–2·23, p=0·80) for radiotherapy. In a post-hoc analysis of patients who completed their allocated therapy the ORadj for improvement was 6·83 (1·66–28·1, p=0·008) for azathioprine and 1·32 (0·30–4·84, p=0·67) for radiotherapy. The ophthalmopathy index, clinical activity score, and numbers of adverse events (161 with azathioprine and 156 with radiotherapy) did not differ between treatment groups. In both groups, the most common adverse events were mild infections. No patients died during the study. INTERPRETATION: In patients receiving oral prednisolone for 24 weeks, radiotherapy did not have added benefit. We also did not find added benefit for addition of azathioprine in the primary analysis; however, our conclusions are limited by the high number of patients who withdrew from treatment. Results of post-hoc analysis of those who completed the assigned treatment suggest improved clinical outcome at 48 weeks with azathioprine treatment

    Developmental malformation of the corpus callosum: a review of typical callosal development and examples of developmental disorders with callosal involvement

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    This review provides an overview of the involvement of the corpus callosum (CC) in a variety of developmental disorders that are currently defined exclusively by genetics, developmental insult, and/or behavior. I begin with a general review of CC development, connectivity, and function, followed by discussion of the research methods typically utilized to study the callosum. The bulk of the review concentrates on specific developmental disorders, beginning with agenesis of the corpus callosum (AgCC)—the only condition diagnosed exclusively by callosal anatomy. This is followed by a review of several genetic disorders that commonly result in social impairments and/or psychopathology similar to AgCC (neurofibromatosis-1, Turner syndrome, 22q11.2 deletion syndrome, Williams yndrome, and fragile X) and two forms of prenatal injury (premature birth, fetal alcohol syndrome) known to impact callosal development. Finally, I examine callosal involvement in several common developmental disorders defined exclusively by behavioral patterns (developmental language delay, dyslexia, attention-deficit hyperactive disorder, autism spectrum disorders, and Tourette syndrome)

    Consensus-driven conceptual development of a standardized whole body-MRI scoring system for assessment of disease activity in juvenile idiopathic arthritis : MRI in JIA OMERACT working group

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    Objectives Whole body-MRI is helpful in directing diagnostic and treatment approaches, and as a research outcome measure. We describe our initial consensus-driven phase towards developing a whole body-MRI scoring system for juvenile idiopathic arthritis. Methods An iterative approach using three rounds of anonymous Delphi surveys followed by a consensus meeting was used to draft the structure of the whole body-MRI scoring system, including the relevant anatomic joints and entheses for assessment, diagnostic item selection, definition and grading, and selection of appropriate MRI planes and sequences. The surveys were completed independently by an international expert group consisting of pediatric radiologists and rheumatologists. Results Twenty-two experts participated in at least one of three rounds of Delphi surveys and a concluding consensus meeting. A first iteration scoring system was developed which ultimately included the assessment of 100 peripheral, 23 chest, and 76 axial joints, and 64 entheses, with 2–4 diagnostic items graded in each of the items, using binary (presence/absence) and 2-3-level ordinal scores. Recommendations on anatomic MRI planes and sequences were specified as the minimally necessary imaging protocol for the scoring system. Conclusion A novel whole body-MRI scoring system for juvenile idiopathic arthritis was developed by consensus among members of MRI in JIA OMERACT working group. Further iterative refinements, reliability testing, and responsiveness are warranted in upcoming studies

    Proton magnetic resonance spectroscopy in developmentally delayed young boys with or without autism.

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    Contains fulltext : 53082.pdf (publisher's version ) (Closed access)OBJECTIVE: The aim of the present study is to investigate whether brain metabolism of boys with autism spectrum disorder (ASD) is altered compared to boys with a developmental delay without autism if corrected for patient age and developmental level. STUDY DESIGN: 25 boys with ASD (with or without concurrent mental retardation) and 12 boys without ASD with mental retardation or language disorder underwent proton magnetic resonance spectroscopy. All analyses were performed with chronological age and developmental level as independent variables. RESULTS: No metabolic differences were found between boys with ASD and without ASD. CONCLUSIONS: Our findings do not replicate previous reports of differences in NAA, Cho and Cr levels in ASD
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