Kronbichler Martin, Wimmer Heinz, Staffen Wolfgang, Hutzler Florian, Mair Alois, Ladurner Gunther
Department of Neurology, Christian Doppler Clinic and Center for Neurocognitive Research, Paracelsus Private Medical University, Salzburg, Austria.
Hum Brain Mapp. 2008 May;29(5):613-25. doi: 10.1002/hbm.20425.
Functional neuroimaging studies have consistently demonstrated less activation of the left occipitotemporal cortex in dyslexic readers. This region is considered critical for skilled reading and damage to it in adult readers leads to severe deficits in reading ability. In contrast to these findings, structural abnormalities in the occipitotemporal cortex were not consistently found to date. We used optimized Voxel Based Morphometry with T1 weighted MR images to investigate gray matter volume in 13 dyslexic and 15 nonimpaired reading adolescents (age 14-16). Less gray matter volume for dyslexic readers was found in the left and right fusiform gyrus, the bilateral anterior cerebellum and in the right supramarginal gyrus. Decreased gray matter volume in the left and right fusiform gyrus of dyslexic readers highlights the importance of this brain region for developmental dyslexia. The structural abnormalities in the right occipitotemporal cortex suggest that dyslexia may be such a persistent disorder because an occipitotemporal reading area, critical for skilled reading, cannot develop in any hemisphere. The extended areas of reduced gray matter volume in dyslexic readers in the cerebellum suggest that structural abnormalities in the cerebellum are also strongly associated with dyslexia and warrant further investigation.
功能性神经影像学研究一直表明，阅读障碍者的左侧枕颞叶皮质激活较少。该区域被认为对熟练阅读至关重要，成年读者该区域受损会导致阅读能力严重缺陷。与这些发现相反，迄今为止尚未一致发现枕颞叶皮质存在结构异常。我们使用基于体素的形态测量法结合T1加权磁共振图像，对13名阅读障碍青少年和15名阅读正常的青少年（年龄14 - 16岁）的灰质体积进行了研究。阅读障碍者在左右梭状回、双侧小脑前叶和右侧缘上回的灰质体积较少。阅读障碍者左右梭状回灰质体积减少，凸显了该脑区对发育性阅读障碍的重要性。右侧枕颞叶皮质的结构异常表明，阅读障碍可能是一种持续性疾病，因为对熟练阅读至关重要的枕颞叶阅读区域在任何半球都无法发育。阅读障碍者小脑灰质体积减少的区域扩大，表明小脑的结构异常也与阅读障碍密切相关，值得进一步研究。
