Profiles of aberrant white matter microstructure in fragile X syndrome.
Profiles of aberrant white matter microstructure in fragile X syndrome.
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DOI：
10.1016/j.nicl.2016.01.013
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Reiss AL
中科院分区：
文献类型：
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作者：
Hall SS;Dougherty RF;Reiss AL
以前试图量化脆性X综合征(FXS)患者脑白质(WM)微结构的研究结果不一致，很可能是因为采用了不同的对照组，分析方法不同，以及未能检查潜在的运动伪影。此外，到目前为止，分析缺乏足够的特异性来提供地区性信息。在这项研究中，我们使用自动化纤维束量化(AFQ)来识别FXS患者WM束上WM微结构异常的特定区域，这些患者在年龄、智商和自闭症症状程度上与匹配的对照组不同。参与者是20名FXS患者，年龄在10岁到23岁之间，以及20名匹配的对照组。使用自动纤维束量化(AFQ)，我们创建了沿18个主要的WM束的分数各向异性和平均弥散率的束轮廓。我们发现，与对照组相比，FXS患者左侧和右侧下纵束(ILF)、右侧钩状束和左侧扣带回的各向异性分数显著增加。相反，与对照组相比，FXS患者右侧ILF的平均弥散率显著降低。年龄与两组11个区域的MD值呈显著负相关。综上所述，这些发现表明，FXS导致ILF和钩状束特定区域的WM微观结构异常，很可能是由于脆性X智力低下蛋白(FMRP)减少或缺失导致突触修剪效率低下所致。需要进行纵向研究来证实这些发现。我们对脆性X综合征患者的WM微结构异常区域进行了量化。将FXS患者与年龄和症状特征匹配的对照组进行比较。FXS患者右侧钩状区各向异性分数增加。FXS患者右侧ILF的平均弥散率显著降低。FXS导致ILF和钩状束特定区域的WM显微结构异常。
Previous studies attempting to quantify white matter (WM) microstructure in individuals with fragile X syndrome (FXS) have produced inconsistent findings, most likely due to the various control groups employed, differing analysis methods, and failure to examine for potential motion artifact. In addition, analyses have heretofore lacked sufficient specificity to provide regional information. In this study, we used Automated Fiber-tract Quantification (AFQ) to identify specific regions of aberrant WM microstructure along WM tracts in patients with FXS that differed from controls who were matched on age, IQ and degree of autistic symptoms. Participants were 20 patients with FXS, aged 10 to 23 years, and 20 matched controls. Using Automated Fiber-tract Quantification (AFQ), we created Tract Profiles of fractional anisotropy and mean diffusivity along 18 major WM fascicles. We found that fractional anisotropy was significantly increased in the left and right inferior longitudinal fasciculus (ILF), right uncinate fasciculus, and left cingulum hippocampus in individuals with FXS compared to controls. Conversely, mean diffusivity was significantly decreased in the right ILF in patients with FXS compared to controls. Age was significantly negatively associated with MD values across both groups in 11 tracts. Taken together, these findings indicate that FXS results in abnormal WM microstructure in specific regions of the ILF and uncinate fasciculus, most likely caused by inefficient synaptic pruning as a result of decreased or absent Fragile X Mental Retardation Protein (FMRP). Longitudinal studies are needed to confirm these findings. We quantified regions of aberrant WM microstructure in patients with fragile X syndrome. FXS patients were compared to controls matched on age and symptom characteristics. Fractional anisotropy was increased in sections of the right uncinate in patients with FXS. Mean diffusivity was significantly decreased in sections of the right ILF in patients with FXS. FXS results in abnormal WM microstructure in specific regions of the ILF and uncinate fasciculus.