The contribution of white and gray matter differences to developmental dyslexia: Insights from DTI and VBM at 3.0 T
The contribution of white and gray matter differences to developmental dyslexia: Insights from DTI and VBM at 3.0 T
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DOI：
10.1016/j.neuropsychologia.2008.07.015
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发表时间：
2008-11-01
期刊：
影响因子：
2.6
通讯作者：
Riecker, A.
中科院分区：
文献类型：
--
作者：
Steinbrink, C.;Vogt, K.;Riecker, A.
发展性阅读障碍是儿童和成人中最常见的神经心理障碍之一。关于这种特殊功能障碍的病理机制只有很少的数据可获得，其中假设-阅读障碍可能是涉及阅读过程的语音和正字法方面以及音素和石墨烯整合的大脑前后部区域的脱节综合征。因此，我们使用弥散张量成像（DTI）和基于体素的形态测量（VBM）来验证德语阅读障碍成人白质和灰质结构改变的假设。DTI显示双侧额颞和左侧颞顶叶白质区（上、下纵束）分数各向异性（FA）降低。脑白质各向异性与假词阅读速度之间存在显著相关。在失读症患者中，两个半球颞上回的灰质体积（通过VBM测量）减少。到目前为止，基于对白质和灰质异常的综合分析，我们的结果提供了极其有力的证据，证明与阅读和拼写相关的皮质区域存在断开综合征或功能障碍。因此，我们认为不同脑区之间神经元交流的不平衡可能是导致阅读障碍的关键因素。(c) 2008 Elsevier Ltd.版权所有。
Developmental dyslexia is one of the most common neuropsychological disorders in children and adults. Only few data are available on the pathomechanisms of this specific dysfunction, assuming - among others - that dyslexia might be a disconnection syndrome of anterior and posterior brain regions involved in phonological and orthographic aspects of the reading process, as well as in the integration of phonemes and graphenes. Therefore, diffusion tensor imaging(DTI)and voxel-based morphometry (VBM) were used to verify the hypothesis of altered white and gray matter structure in German dyslexic adults. DTI revealed decreased fractional anisotropy (FA) in bilateral fronto-temporal and left temporo-parietal white matter regions (inferior and superior longitudinal fasciculus). Significant correlations between white matter anisotropy and speed of pseudoword reading were found. In dyslexics, gray matter volumes (as measured by VBM) were reduced in the superior temporal gyrus of both hemispheres. So far, our results, based on a combined analysis of white and gray matter abnormalities, provide exceedingly strong evidence for a disconnection syndrome or dysfunction of cortical areas relevant for reading and spelling. Thus, we suggest that this imbalance of neuronal communication between the respective brain areas might be the crucial point for the development of dyslexia. (c) 2008 Elsevier Ltd. All rights reserved.