Epilepsiecentrum Kempenhaeghe, KNF, Sterkselseweg 65, 5590AB Heeze, Netherlands.
Epilepsy Res. 2010 Mar;89(1):148-53. doi: 10.1016/j.eplepsyres.2009.11.007. Epub 2009 Dec 21.
To evaluate if single voxel proton magnetic resonance spectroscopy (SV-MRS) can help in lateralising and sometimes in localizing an epileptogenic focus. The assumption is that in MRI negative patients the underlying pathology most often is focal cortical dysplasia (FCD). Several studies have shown that in the presence of FCD there are also (1)H-MRS abnormalities on the contralateral side. However, in most cases the studied group was not homogeneous and included different forms of dysplasias, including band heterotopias and polymicrogyria, and the studies used different spectroscopy protocols. In the present study, using bilateral SV-MRS we investigated the presence of a lateralisation index in two groups of patients with localisation related epilepsy: patients with focal cortical dysplasia on MRI and patients without MRI abnormalities with a focus identified by MEG. Aim of the study was to show that in both groups the expected epileptogenic side shows more pronounced metabolic alterations, making MRS a possible screening tool for clarifying lateralisation questions in patients with cryptogenic localisation related epilepsy.
In ten patients a single voxel was placed over the FCD and in nine patients over the region of interest (ROI) as indicated by MEG. In all patients a voxel was also placed in the contralateral homologus location. We used metabolite concentrations as peak ratios relative to the creatine (Cr) peak to calculate a lateralisation index.
In both groups NAA/Cr was significantly lower on the affected side whereas the results for Cho/Cr were more diverse. There were no significant differences between the two groups. The limitations of the used methods and the implications of the findings are discussed.
评估单体素质子磁共振波谱（SV-MRS）是否有助于定位和有时定位致痫灶。假设在 MRI 阴性患者中，潜在的病理通常是局灶性皮质发育不良（FCD）。多项研究表明，在存在 FCD 的情况下，对侧也存在（1）H-MRS 异常。然而，在大多数情况下，研究组并不均匀，包括不同形式的发育不良，包括带异位和多微小脑回，并且研究使用了不同的波谱协议。在本研究中，我们使用双侧 SV-MRS 研究了两组局灶性相关癫痫患者的侧化指数：MRI 上有局灶性皮质发育不良的患者和 MEG 确定有焦点但 MRI 无异常的患者。该研究的目的是表明，在这两组患者中，预期的致痫侧显示出更明显的代谢改变，使 MRS 成为澄清隐源性局灶性相关癫痫患者侧化问题的一种可能的筛选工具。
在 10 例患者中，单个体素置于 FCD 上，在 9 例患者中置于 MEG 指示的 ROI 上。在所有患者中，还在对侧同源位置放置了一个体素。我们使用代谢物浓度作为相对于肌酸（Cr）峰的峰比来计算侧化指数。
在两组患者中，NAA/Cr 在受影响侧显著降低，而 Cho/Cr 的结果则更加多样化。两组之间无显著差异。讨论了所使用方法的局限性和发现的意义。
