Center for Imaging of Neurodegenerative Diseases and Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA.
J Neurol. 2011 Apr;258(4):603-12. doi: 10.1007/s00415-010-5799-6. Epub 2010 Oct 26.
MR spectroscopy has demonstrated extrahippocampal NAA/(Cr+Cho) reductions in medial temporal lobe epilepsy with (TLE-MTS) and without (TLE-no) mesial temporal sclerosis. Because of the limited brain coverage of those previous studies, it was, however, not possible to assess differences in the distribution and extent of these abnormalities between TLE-MTS and TLE-no. This study used a 3D whole brain echoplanar spectroscopic imaging (EPSI) sequence to address the following questions: (1) Do TLE-MTS and TLE-no differ regarding severity and distribution of extrahippocampal NAA/(Cr+Cho) reductions? (2) Do extrahippocampal NAA/(Cr+Cho) reductions provide additional information for focus lateralization? Forty-three subjects (12 TLE-MTS, 13 TLE-no, 18 controls) were studied with 3D EPSI. Statistical parametric mapping (SPM2) was used to identify regions of significantly decreased NAA/(Cr+Cho) in TLE groups and in individual patients. TLE-MTS and TLE-no had widespread extrahippocampal NAA/(Cr+Cho) reductions. NAA/(Cr+Cho) reductions had a bilateral fronto-temporal distribution in TLE-MTS and a more diffuse, less well defined distribution in TLE-no. Extrahippocampal NAA/(Cr+Cho) decreases in the single subject analysis showed a large inter-individual variability and did not provide additional focus lateralizing information. Extrahippocampal NAA/(Cr+Cho) reductions in TLE-MTS and TLE-no are neither focal nor homogeneous. This reduces their value for focus lateralization and suggests a heterogeneous etiology of extrahippocampal spectroscopic metabolic abnormalities in TLE.
磁共振波谱已经证明，内侧颞叶癫痫伴（TLE-MTS）和不伴（TLE-no）内侧颞叶硬化的海马外 NAA/（Cr+Cho）降低。由于之前的研究脑覆盖范围有限，因此不可能评估 TLE-MTS 和 TLE-no 之间这些异常的分布和程度的差异。本研究使用 3D 全脑单次激发磁共振波谱成像（EPSI）序列来解决以下问题：（1）TLE-MTS 和 TLE-no 在海马外 NAA/（Cr+Cho）降低的严重程度和分布上是否存在差异？（2）海马外 NAA/（Cr+Cho）降低是否为侧化焦点提供了额外信息？43 名受试者（12 名 TLE-MTS，13 名 TLE-no，18 名对照）接受了 3D EPSI 研究。统计参数映射（SPM2）用于识别 TLE 组和个别患者中 NAA/（Cr+Cho）显著降低的区域。TLE-MTS 和 TLE-no 均存在广泛的海马外 NAA/（Cr+Cho）降低。TLE-MTS 的 NAA/（Cr+Cho）降低呈双侧额颞分布，而 TLE-no 的分布则更为弥散，边界不太明确。在单例分析中，海马外 NAA/（Cr+Cho）降低显示出较大的个体间变异性，且未提供额外的侧化焦点信息。TLE-MTS 和 TLE-no 的海马外 NAA/（Cr+Cho）降低既不是局灶性的，也不是均匀的。这降低了它们用于侧化焦点的价值，并提示 TLE 中海马外波谱代谢异常的异质性病因。
