Are Frontal Lobe Size and Executive Dysfunction Contributors to ADHD AND Dyslexia

描述（由申请人提供）：患有阅读障碍的儿童经常表现出语音处理能力差。然而，人们逐渐接受的是，神经发育障碍可能是最好的解释，包括其他常见的缺陷以及多因素模型。其中一个缺陷是执行功能障碍。在20世纪80年代，人们认识到许多有阅读障碍的儿童有执行功能障碍;然而，当研究人员开始更一致地检查语音处理时，对这一领域的研究基本上被搁置了。因此，对于阅读障碍患者的执行功能障碍，尤其是它与额叶结构的关系，仍有许多未知之处。阅读障碍和ADHD有很高的共患病率，ADHD儿童中常见执行功能障碍。因此，它是感兴趣的，以确定执行功能障碍和非典型的前额叶结构可能是共享的贡献者之间的两种疾病。该项目将包括100名8-12岁的儿童：25名患有阅读障碍，25名患有ADHD，25名患有阅读障碍/ADHD共病，25名通常发展对照。所有受试者都将参与对其执行功能的神经心理学评价沿着结构MRI扫描。因子分析将用于确定执行功能的潜在变量。将追踪以下额叶区域：前扣带回和后扣带回、中央前回、眶额回、内侧额叶皮质以及上级、中间和下额回。使用MANCOVA它是假设，儿童阅读障碍和多动症将共享赤字的流畅性，转移，和口头工作记忆。ADHD也会有抑制和视觉工作记忆的缺陷。此外，假设两组的右额下回和左眶额回均小于对照组。与此相反，ADHD患者的右上级额回、内侧额叶皮质和右前扣带回比阅读障碍患者和对照组小。当前额叶区域崩溃时，阅读障碍和多动症患者的双侧灰质会减少，特别是在右半球。此外，ADHD患者左前额叶白色物质体积减少。这项研究将通过提供可能有助于诊断和干预的知识使患有阅读障碍和ADHD的儿童受益。例如，通过更好地了解阅读障碍和ADHD的生物学相关性，可以比传统的行为技术提供更快速的诊断。此外，早期诊断将允许更早地进行干预，并且早期干预与较晚开始的治疗相比具有更好的结果。 公共卫生相关性：发育性阅读障碍和多动症是两种最常见的儿童疾病。它们也有很高的共现率。这个项目将检查执行功能（有助于目标导向行为的各种技能/能力）和大脑前部的结构，看看它们是否与阅读障碍和ADHD有关。

DESCRIPTION (provided by applicant): Children with dyslexia frequently present with poor phonological processing. However, it is becoming accepted that neurodevelopmental disorders may be best explained by a poly-factorial model which includes other common deficits as well. One such deficit is executive dysfunction. In the 1980s it was recognized that many children with dyslexia have executive dysfunction; however, research into this area largely fell by the wayside when researchers began examining phonological processing more consistently. As a result, much remains unknown about executive dysfunction in dyslexia, especially in terms of how it relates to frontal lobe structure. Dyslexia and ADHD share a high comorbidity, and executive dysfunction is common in children with ADHD. Thus, it is of interest to determine if executive dysfunction and atypical prefrontal structure may be shared contributors between the two disorders. This project will include 100 children, ages 8-12 years: 25 with dyslexia, 25 with ADHD, 25 with comorbid dyslexia/ADHD, and 25 typically developing controls. All subjects will participate in a neuropsychological evaluation of their executive functioning along with a structural MRI scan. Factor analysis will be used to determine latent variables of executive functions. The following frontal regions will be traced: anterior and posterior cingulate, precentral gyrus, orbitofrontal gyrus, mesial frontal cortex, and the superior, middle, and inferior frontal gyri. Using MANCOVA It is hypothesized that children with dyslexia and ADHD will share deficits in fluency, shift, and verbal working memory. ADHD will also have deficits in inhibition and visual working memory. Moreover, it is hypothesized that the right inferior frontal and left orbitofrontal gyri will be smaller in both groups compared to controls. In contrast, the right superior frontal gyrus, mesial frontal cortex, and right anterior cingulate will be smaller in ADHD than dyslexia and controls. When collapsing across prefrontal regions, gray matter will be reduced bilaterally in dyslexia and ADHD, particularly in the right hemisphere. In addition, left prefrontal white matter volume will be reduced in ADHD. This study will benefit children with dyslexia and ADHD by providing knowledge that may aid diagnosis and intervention. For example, by having a better knowledge of the biological correlates of dyslexia and ADHD, a more rapid diagnosis may be possible than is provided by traditional behavioral techniques. Furthermore, earlier diagnosis will allow for earlier placement in intervention, and early intervention is linked with better outcome than treatment started later. PUBLIC HEALTH RELEVANCE: Developmental dyslexia and ADHD are two of the most prevalent childhood disorders. They also have a high rate of co-occurrence. This project will examine executive functioning (various skills/abilities which contribute to goal-directed behavior) and structure of the front aspect of the brain to see if they may be related to both dyslexia and ADHD.