Zhao Xu, Zhou Zhi-Qiang, Xiong Ying, Chen Xu, Xu Ke, Li Juan, Hu Ying, Peng Xiao-Long, Zhu Wen-Zhen
Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Front Neurol. 2019 Apr 24;10:394. doi: 10.3389/fneur.2019.00394. eCollection 2019.
Mesial temporal lobe epilepsy (MTLE), one of the most common types of refractory focal epilepsy, has shown white matter abnormalities both within and beyond the temporal lobe. In particular, the white matter abnormalities in the ipsilateral hemisphere are more obvious than those in the contralateral hemisphere in MTLE, that is, the abnormalities present asymmetrical characteristics. However, very few studies have characterized the white matter microstructure asymmetry in MTLE patients specifically. Thus, we performed diffusion tensor imaging (DTI) to investigate the white matter microstructure asymmetries of patients with MTLE with unilateral hippocampal sclerosis (MTLE-HS). We enrolled 25 MTLE-HS (left MTLE-HS group, = 13; right MTLE-HS group, = 12) and 26 healthy controls (HC). DTI data were analyzed by tract-based spatial statistics (TBSS) to test the hemispheric differences across the entire white matter skeleton. We also conducted a two-sample paired -test for 21 paired region of interests (ROIs) parceled on the basis of the ICBM-DTI-81 white-matter label atlas of bilateral hemispheres to test the hemispheric differences. An asymmetry index (AI) was calculated to further quantify the differences between the left and right paired-ROIs. It was found that the asymmetries of white matter skeletons were significantly lower in the MTLE-HS groups than in the HC group. In particular, the asymmetry traits were moderately reduced in the RMTLE-HS group and obviously reduced in the LMTLE-HS group. In addition, AI was significantly different in the RMTLE-HS group from the LMTLE-HS or HC group in the limbic system and superior longitudinal fasciculus (SLF). The current study found that the interhemispheric white matter asymmetries were significantly reduced in the MTLE-HS groups than in the HC group. The interhemispheric white matter asymmetries are distinctly affected in left and right MTLE-HS groups. The differences in AI among RMTLE-HS, LMTLE-HS, and HC involved the limbic system and SLF, which may have some pragmatic implications for the diagnosis of MTLE and differentiating LMTLE-HS from RMTLE-HS.
内侧颞叶癫痫（MTLE）是最常见的难治性局灶性癫痫类型之一，其颞叶内外均出现了白质异常。特别是，MTLE患者同侧半球的白质异常比 contralateral半球更明显，即异常呈现不对称特征。然而，很少有研究专门对MTLE患者的白质微观结构不对称进行表征。因此，我们进行了扩散张量成像（DTI），以研究单侧海马硬化（MTLE-HS）的MTLE患者的白质微观结构不对称性。我们纳入了25例MTLE-HS患者（左MTLE-HS组，n = 13；右MTLE-HS组，n = 12）和26名健康对照者（HC）。通过基于纤维束的空间统计学（TBSS）分析DTI数据，以测试整个白质骨架的半球差异。我们还对基于双侧半球的ICBM-DTI-81白质标签图谱划分的21对感兴趣区域（ROI）进行了两样本配对t检验，以测试半球差异。计算不对称指数（AI）以进一步量化左右配对ROI之间的差异。结果发现，MTLE-HS组白质骨架的不对称性明显低于HC组。特别是，右MTLE-HS组的不对称特征中度降低，左MTLE-HS组明显降低。此外，右MTLE-HS组与左MTLE-HS组或HC组在边缘系统和上纵束（SLF）中的AI存在显著差异。当前研究发现，MTLE-HS组的半球间白质不对称性明显低于HC组。左右MTLE-HS组的半球间白质不对称性受到明显影响。右MTLE-HS、左MTLE-HS和HC之间AI的差异涉及边缘系统和SLF，这可能对MTLE的诊断以及区分左MTLE-HS和右MTLE-HS具有一定的实际意义。
