A structural basis for reading fluency - White matter defects in a genetic brain malformation
A structural basis for reading fluency - White matter defects in a genetic brain malformation
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DOI：
10.1212/01.wnl.0000286365.41070.54
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发表时间：
2007-12-04
期刊：
影响因子：
9.9
通讯作者：
Walsh, C. A.
中科院分区：
文献类型：
--
作者：
Chang, B. S.;Katzir, T.;Walsh, C. A.
背景：多条证据表明，发育性阅读障碍可能与神经元迁移或轴突连接异常有关。脑室周围结节异位症是一种罕见的遗传性脑畸形，其特征是侧脑室周围灰质结节错位。尽管智力正常，但患者存在特殊的、意想不到的阅读障碍。我们试图研究这一现象的认知和结构基础。方法：使用一系列神经心理测量方法对10名患有异位、10名阅读障碍的成人受试者和10名正常对照进行评估。应用扩散张量成像方法对6例异位受试者的白质完整性和纤维束组织进行了检测。结果：异位症受试者和发育性阅读障碍受试者具有共同的行为特征，在阅读流畅性方面存在特殊缺陷。阅读障碍的个体似乎比异位受试者有更显著的语音障碍。脑室周围结节异位与灰质结节附近白质微结构和组织的特定局灶性破坏有关。白质完整性程度与阅读流利性相关。结论：灰质异位症的遗传性障碍与发育性阅读障碍具有相同的行为特征，这种疾病的局灶性白质缺陷可能是这种现象的脑结构基础。我们的发现代表了一种潜在的模型，可以利用发育性脑畸形来研究异常的认知功能。
Background: Multiple lines of evidence have suggested that developmental dyslexia may be associated with abnormalities of neuronal migration or axonal connectivity. In patients with periventricular nodular heterotopia - a rare genetic brain malformation characterized by misplaced nodules of gray matter along the lateral ventricles - a specific and unexpected reading disability is present, despite normal intelligence. We sought to investigate the cognitive and structural brain bases of this phenomenon.Methods: Ten adult subjects with heterotopia, 10 with dyslexia, and 10 normal controls were evaluated, using a battery of neuropsychometric measures. White matter integrity and fiber tract organization were examined in six heterotopia subjects, using diffusion tensor imaging methods.Results: Subjects with heterotopia and those with developmental dyslexia shared a common behavioral profile, with specific deficits in reading fluency. Individuals with dyslexia seemed to have a more prominent phonological impairment than heterotopia subjects. Periventricular nodular heterotopia was associated with specific, focal disruptions in white matter microstructure and organization in the vicinity of gray matter nodules. The degree of white matter integrity correlated with reading fluency in this population.Conclusions: We demonstrate that a genetic disorder of gray matter heterotopia shares behavioral characteristics with developmental dyslexia, and that focal white matter defects in this disorder may serve as the structural brain basis of this phenomenon. Our findings represent a potential model for the use of developmental brain malformations in the investigation of abnormal cognitive function.