海馬硬化を伴う内側側頭葉てんかん

BACKGROUND: Mesial temporal lobe epilepsy (MTLE), commonly associated with mesial temporal sclerosis (MTS), is a major cause of drug-resistant epilepsy in children. Conventional magnetic resonance imaging (MRI) may fail to detect subtle hippocampal abnormalities, particularly in MRI-negative epilepsy. Quantitative MRI volumetric assessment has emerged as a promising method for identifying structural changes not evident on routine imaging. OBJECTIVE: To evaluate the clinical value of MRI volumetric assessment of the hippocampus and its subfields for the early diagnosis of MTLE in children with epilepsy. METHODS: This case-control study was conducted at the MRI Unit, Ain Shams University Hospitals, Cairo, Egypt, between January 2024 and July 2025. A total of 100 children (50 with epilepsy and 50 age- and sex-matched healthy controls) underwent high-resolution brain MRI with three-dimensional T1-weighted imaging. Hippocampal and hippocampal subfield volumes were automatically quantified using VolBrain software. Group comparisons were performed using SPSS version 27, with statistical significance set at p < 0.05. RESULTS: The epilepsy and control groups were comparable in age and sex. Children with epilepsy had significantly lower total hippocampal volume (4.10 ± 0.66 vs. 4.42 ± 0.87 cm³; p = 0.045) and left hippocampal volume (2.03 ± 0.34 vs. 2.20 ± 0.41 cm³; p = 0.034). The SR-SL-SM subfield demonstrated the greatest volumetric reduction (0.75 ± 0.16 vs. 0.84 ± 0.17 cm³; p = 0.006), while the subiculum was also significantly smaller in the epilepsy group (0.48 ± 0.09 vs. 0.52 ± 0.11 cm³; p = 0.044). Among 38 children with normal conventional MRI findings, quantitative volumetric analysis identified hippocampal abnormalities in 34 cases, corresponding to a detection rate of approximately 89% for MRI-negative epilepsy. CONCLUSION: MRI volumetric assessment is a valuable adjunct to conventional MRI for detecting subtle hippocampal and hippocampal subfield volume loss in children with epilepsy, including those with normal conventional MRI findings. Quantitative volumetric analysis may improve the detection of structural abnormalities associated with MTLE and supports its use as a complementary imaging tool in the diagnostic evaluation of pediatric epilepsy.

Surgical failure in temporal lobe epilepsy with hippocampal sclerosis (TLE-HS) may reflect insufficient disruption of epileptogenic networks. We investigated whether integrating quantitative spatial patterns of regional atrophy and hypometabolism, along with clinical features, could provide complementary prognostic information for postoperative seizure freedom. T1-weighted MRI, 18F-FDG-PET, and postoperative CT scans of patients with TLE-HS were retrospectively analyzed against a validated healthy control cohort to compute age- and gender-adjusted W-score maps. Regional relationships of atrophy and hypometabolism were assessed using bivariate correlations and multiple regression analyses. Machine learning models integrating laterality of seizure onset, preoperative (extra-)temporal atrophy/hypometabolism extent, seizure frequency, focal to bilateral tonic-clonic seizures during the preceding year, and resection volume were developed to predict seizure freedom 1 year after surgery. Model interpretability was assessed via permutation-based variable importance analysis. The cohort comprised 101 patients with TLE-HS (48 left, LHS; 53 right, RHS), including 72 patients who underwent anterior temporal lobectomy. Distinct modality-specific patterns emerged: hypometabolism was significantly greater than local atrophy in left temporo-limbic cortex in TLE-LHS, while atrophy exceeded hypometabolism in bilateral occipital regions in TLE-RHS. Positive correlations between local atrophy and hypometabolism were more robust in ipsilateral temporo-limbic cortex in TLE-LHS. The combined model integrating preoperative atrophy and hypometabolism features (AUC: 0.56-0.64) significantly outperformed single-modality models (pfdr < 0.05). Notably, incorporating clinical factors further enhanced predictive performance (AUC: 0.63-0.70) and model calibration. This comprehensive preoperative clinical-imaging model achieved robust prognostic efficacy that was not significantly improved by the addition of actual postoperative resection volumes. Structural MRI and 18F-FDG-PET reveal complementary facets of the epileptogenic network in TLE-HS. While integrating multimodal imaging with clinical metrics demonstrates significant synergistic potential for predicting surgical outcomes, our models remain exploratory. External validation in independent multi-center cohorts is required before translating these findings into precise clinical tools for surgical planning.

Background: Interictal [18F]FDG-PET is commonly used for temporal lateralization in mesial temporal lobe epilepsy (mTLE). Whether atlas-based quantitative PET measures differ according to surgical outcome among otherwise concordant unilateral MRI-positive mTLE patients remains uncertain. This study compared preoperative FDG-PET ROI measures between 2-year Engel outcome groups using SPM-assisted spatial normalization followed by AAL atlas-based ROI analysis. Methods: Among 319 screened temporal lobe epilepsy surgery patients, 94 had evaluable preoperative FDG-PET images, and 62 patients with at least 2 years of postoperative follow-up were included in the total cohort. The primary quantitative analysis was restricted to 54 unilateral MRI-positive patients with hippocampal atrophy and mesial temporal sclerosis on MRI (Engel I, n = 45; Engel II-IV, n = 9). Cerebellum-normalized AAL ROI uptake ratios were compared using Mann-Whitney U tests in conventional left/right and ipsilateral/contralateral analyses. FDR-adjusted q values, effect sizes, and Hodges-Lehmann median differences with 95% confidence intervals were calculated. Reference-region and global mean normalization sensitivity analyses were also performed. Results: In the unilateral MRI-positive subgroup, 10 of 80 conventional left/right ROIs showed unadjusted differences between Engel I and Engel II-IV patients, predominantly involving left frontal-orbitofrontal, medial frontal, middle cingulate, and inferior parietal regions. After ipsilateral/contralateral transformation, eight ROIs showed unadjusted group differences, mainly in contralateral frontal-orbitofrontal regions, with additional cingulate and inferior parietal involvement. Uptake ratios were lower in Engel II-IV patients in all candidate ROIs. However, none of the ROI findings survived FDR correction. Raw cerebellar uptake did not differ between outcome groups, and global mean normalization did not yield FDR-corrected ROI findings. Conclusions: Quantitative ROI analysis identified several extratemporal metabolic differences between postoperative outcome groups; however, none remained significant after correction for multiple comparisons. These findings should therefore be considered exploratory and hypothesis-generating rather than evidence that quantitative FDG-PET can discriminate surgical outcomes. Larger, adequately powered cohorts are needed before the potential clinical utility of quantitative FDG-PET analysis in presurgical evaluation can be determined.

BACKGROUND: Pathological subtypes are key determinants of surgical strategy and prognosis in refractory mesial temporal lobe epilepsy (MTLE), with hippocampal sclerosis (HS) associated with better outcomes than gliosis only. Subtype-specific patterns of cerebral metabolism and neuroinflammation, which may inform lesion localization and subtype differentiation, remain poorly defined. This study aimed to delineate these patterns using ¹⁸F-FDG PET and translocator protein (TSPO) PET with ¹⁸F-DPA-714 for precise localization, with emphasis on the added value of quantitative analysis. METHODS: Patients with unilateral refractory MTLE undergoing surgery were retrospectively included, and pathological subtypes were classified according to histological profiles (HS, n = 43; gliosis only, n = 41). Patients underwent sequential integrated dual-tracer PET/MR imaging within one week. Age- and sex-matched healthy controls (HC) were recruited. Whole-brain voxel-wise and temporal lobe subregional analyses were performed. Localization performance was assessed by visual inspection and quantitative analysis employing an asymmetry index (AI) derived from standardized uptake value ratios. Sensitivity and accuracy were calculated, with false discovery rate correction applied for multiple comparisons. RESULTS: In total, 43 MTLE-HS and 41 MTLE-gliosis only were included. Compared with HC, both HS and gliosis exhibited significant 18F-FDG hypometabolism alongside increased 18F-DPA-714 uptake, more pronounced in HS. Whole-brain 18F-DPA-714 abnormalities were more confined to temporal regions, affording clearer lateralization and localization than 18F-FDG. In temporal-lobe subregional analysis, 18F-FDG outperformed 18F-DPA-714 for subtype discrimination, and hippocampal AI value achieved the best performance (35/43 [81.4%] vs. 22/41 [53.7%], p = 0.007). Quantitative analysis enhanced localization accuracy for both tracers, yielding the greatest improvement for TSPO in gliosis (from 10/41 [24.4%] to 19/41 [46.3%], p = 0.038). CONCLUSION: Dual-tracer PET/MR combined with quantitative analysis may improve subtype-specific presurgical localization in refractory MTLE. TSPO-PET precisely localized the epileptogenic lesion, whereas FDG-PET facilitated differentiation of pathological subtypes.

OBJECTIVE: Resective surgery is a significant therapeutic option for patients with drug-resistant mesial temporal lobe epilepsy (MTLE) due to hippocampal sclerosis (HS). Numerous studies have demonstrated the efficacy of epilepsy surgery in the short to median term. However, studies on long-term outcomes are limited in number. The objective of this study was to document the long-term prognosis and associated factors of patients undergoing resective surgery for MTLE. METHODS: A retrospective analysis was conducted on the data of patients with drug-resistant MTLE due to HS who underwent resective surgery between 2001 and 2013 at our epilepsy centre. The demographics and clinical variables of the patients were documented and analysed in order to ascertain their long-term prognosis. The postoperative outcomes were evaluated in accordance with the Engel classification system. RESULTS: Of the 45 patients (mean age: 44.64 ± 8.96, range: 31-67), 31 (68.89%) were male. The age at onset of epilepsy, age at surgery, and the duration of epilepsy at the time of surgery ranged from 0.25 to 26 years (11.51 ± 7.07), from 12 to 47 years (26.82 ± 8.14), and from 2 to 33 years (16.03 ± 7.85), respectively. The patients were followed up for 10-23 years (17.73 ± 2.96). HS was identified in 23 (51.11%) of the patients on the right side and 22 (48.89%) on the left. The pre-operative EEG recordings revealed temporal discharges in 40 (88.89%) patients unilaterally. 22 patients (48.89%) underwent amygdalohippocampectomy with a temporal lobectomy (AH+ATL), while 23 patients (51.11%) underwent selective amygdalohippocampectomy (SAH). 28 (62.22%) patients were classified as Engel I. The patients did not have any statistically significant difference in terms of gender, age at epilepsy onset, age at surgery, duration of epilepsy at surgery, side of HS, and surgical procedure according to Engel classification (p = 0.64, 0.08, 0.60, 0.25, 0.67, 0.10, respectively). Executive and memory functions were improved after surgery at 5th year. CONCLUSION: 62% of the patients were classified as Engel I. Although previous studies have suggested that certain factors may influence prognosis, our findings did not yield any statistically significant results in this regard. It is crucial that patients undergo surgical evaluation without delay to achieve seizure control and improve cognitive function.