Objective

To characterise temporal lobe epilepsy (TLE) surgery-induced changes in brain network properties, as measured using diffusion weighted MRI, and investigate their association with postoperative seizure-freedom.

Methods

For 48 patients who underwent anterior temporal lobe resection, diffusion weighted MRI was acquired pre-operatively, 3–4 months post-operatively (N = 48), and again 12 months post-operatively (N = 13). Data for 17 controls were also acquired over the same period. After registering all subjects to a common space, we performed two complementary analyses of the subjects’ quantitative anisotropy (QA) maps. 1) A connectometry analysis which is sensitive to changes in subsections of fasciculi. 2) A graph theory approach which integrates connectivity information across the wider brain network.

Results

We found significant postoperative alterations in QA in patients relative to controls measured over the same period. Reductions were primarily located in the uncinate fasciculus and inferior fronto-occipital fasciculus ipsilaterally for all patients. Larger reductions were associated with postoperative seizure-freedom in left TLE. Increased QA was mainly located in corona radiata and corticopontine tracts. Graph theoretic analysis revealed widespread increases in nodal betweenness centrality, which were not associated with patient outcomes.

Conclusion

Substantial alterations in QA occur in the months after epilepsy surgery, suggesting Wallerian degeneration and strengthening of specific white matter tracts. Greater reductions in QA were related to postoperative seizure freedom in left TLE.

中文翻译：

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颞叶前切除术后的网络重组及其与术后癫痫发作复发的关系：一项纵向研究。

目的

为了表征颞叶癫痫（TLE）手术引起的脑网络特性的变化（使用弥散加权MRI进行测量），并研究它们与术后癫痫发作的相关性。

方法

对于48例行颞叶前切除术的患者，术前，术后3-4个月（N = 48）和术后12个月（N = 13）进行了弥散加权MRI检查。同期还获得了17个对照的数据。将所有受试者注册到一个公共空间后，我们对受试者的定量各向异性（QA）图进行了两次补充分析。1）连线法分析，对筋膜小节的变化敏感。2）一种图论方法，该方法整合了整个大脑网络中的连通性信息。

结果

我们发现，与同期测量的对照相比，患者术后QA发生了显着变化。对于所有患者，减少的部位主要位于同侧的束状筋膜和额枕下筋膜。更大的减少与左TLE术后无癫痫发作有关。QA增加主要位于电晕放射线和肾上腺皮质区。图理论分析显示，结节之间的中心性普遍增加，这与患者预后无关。

结论

癫痫手术后的几个月内，QA发生了实质性变化，这表明Wallerian变性并增强了特定的白质束。QA的更大降低与左TLE术后癫痫发作的自由度有关。