Faculty of Medicine, University of Sydney, Sydney, New South Wales, Australia.
Epilepsia. 2012 Aug;53(8):1333-40. doi: 10.1111/j.1528-1167.2012.03547.x. Epub 2012 Jun 18.
Fluorine-18-fluorodeoxyglucose-positron emission tomography (FDG-PET) hypometabolism has been used to localize the epileptogenic zone. However, glucose hypometabolism remote to the ictal focus is common and its relationship to surgical outcome has not been considered in many studies. We investigated the relationship between surgical outcome and FDG-PET hypometabolism topography in a large cohort of patients with neocortical epilepsy.
We identified all patients (n = 68) who had interictal FDG-PET between 1994 and 2004 and who underwent resective epilepsy surgery with follow up for more than 2 years. The volumes of significant FDG-PET hypometabolism involving the resected epileptic focus and its surrounding regions (perifocal hypometabolism) and those distant to and not contiguous with the perifocal hypometabolism (remote hypometabolism) were determined statistically using Statistical Parametric Mapping (voxel threshold p = 0.01, extent threshold ≥ 250 voxels, uncorrected cluster-level significance p < 0.05) and were compared with magnetic resonance imaging (MRI) and clinical and demographic variables using a multiple logistic regression model to identify independent predictors of seizure outcome.
Remote hypometabolism was present in 39 patients. Seizure freedom was 49% (19 of 39 patients) in patients with glucose hypometabolism remote from the epileptogenic zone compared to 90% (26 of 29 patients) in patients without remote hypometabolism. In 43 patients with an MRI-identified lesion, seizure freedom was 79% (34 of 43 patients). In patients with normal MRI, cortical dysplasia was the predominant pathologic substrate. Multiple logistic regression analysis identified a larger volume of significant remote hypometabolism (p < 0.005) and absence of a MRI-localized lesion (p = 0.006) as independent predictors of continued seizures after surgery.
In patients with widespread glucose hypometabolism that is statistically significant when compared to controls, epilepsy surgery may not result in complete seizure freedom despite complete removal of the MRI-identified lesion. The volume of significant glucose hypometabolism remote to the ictal-onset zone may be an independent predictor of the success of epilepsy surgery.
氟-18-氟代脱氧葡萄糖正电子发射断层扫描（FDG-PET）代谢低下已被用于定位致痫区。然而，在许多研究中，发作焦点远处的葡萄糖代谢低下是常见的，并且其与手术结果的关系尚未被考虑。我们在一大群新皮质癫痫患者中研究了 FDG-PET 代谢低下的形态与手术结果之间的关系。
我们确定了 1994 年至 2004 年间进行了发作间期 FDG-PET 检查且术后随访时间超过 2 年的所有患者（n=68）。使用统计参数映射（体素阈值 p=0.01，范围阈值≥250 体素，未校正的簇水平显著 p<0.05）统计确定与切除的癫痫灶及其周围区域（灶周代谢低下）和远离且不与灶周代谢低下连续的区域（远处代谢低下）相关的显著 FDG-PET 代谢低下的体积，并使用多元逻辑回归模型将其与磁共振成像（MRI）和临床及人口统计学变量进行比较，以确定手术结果的独立预测因素。
39 例患者存在远处代谢低下。在有葡萄糖代谢低下的患者中，发作频率为 49%（39 例患者中的 19 例），而在无远处代谢低下的患者中，发作频率为 90%（29 例患者中的 26 例）。在 43 例有 MRI 确定的病变的患者中，发作频率为 79%（43 例患者中的 34 例）。在 MRI 正常的患者中，皮质发育不良是主要的病理基础。多元逻辑回归分析确定了更大体积的显著远处代谢低下（p<0.005）和缺乏 MRI 定位的病变（p=0.006）是手术后持续发作的独立预测因素。
在与对照组相比具有统计学意义的广泛葡萄糖代谢低下的患者中，尽管切除了 MRI 确定的病变，癫痫手术可能无法导致完全的发作自由。发作起始区以外的显著葡萄糖代谢低下的体积可能是癫痫手术成功的独立预测因素。
