Learning From Our Failures: When Anterior Temporal Lobectomies Fail.

Optimized stereoelectroencephalography-guided thermocoagulation versus anterior temporal lobectomy in mesial temporal epilepsy: A pilot randomized controlled study.

Insular involvement in temporal lobe epilepsy (TLE) has gradually been recognized since the widespread use of stereoelectroencephalography (SEEG). However, the correlation between insular involvement and failed temporal lobe surgery remains unclear. In this study, we analyzed the surgical outcomes of TLE patients who underwent temporal and insular SEEG recordings and explored the predictors of failed anterior temporal lobectomy (ATL) in these patients with temporal seizures.Forty-one patients who underwent ATL for drug-resistant TLE were examined using temporal and insular SEEG recordings. The clinical characteristics, SEEG data, and postoperative seizure outcomes of these patients were analyzed, and multivariate analysis was used to identify the predictors of surgical outcome.In this series, the ictal temporal discharges invaded the insula in 39 (95.1%) patients. Twenty-three (56.1%) patients were seizure-free (Engel class I) after ATL with at least 1 year follow-up. Only temporal-insular spreading time (TIST) was an independent predictor of postoperative seizure-free outcomes (P = .035). By creating receiver operating characteristic curves for TIST, 400 milliseconds was identified as the cutoff for classification. All patients were classified into 2 groups (TIST ≤ 400 milliseconds and TIST > 400 milliseconds) based on the cutoff value; the difference in seizure-free rates between the 2 groups was significant (P = .001).The very early insular involvement in TLE may be associated with poorer seizure outcomes after ATL. Our findings may be helpful for estimating the appropriate operative procedures and will be valuable for evaluating the prognosis of TLE patients with temporal-insular SEEG recordings and temporal lobectomy.

The Effect of Stereoelectroencephalography on the Long-Term Outcomes of Different Side Anterior Temporal Lobectomy: A Single-Center Retrospective Study

Background Epilepsy is a neurological disorder affecting approximately 70 million people worldwide, characterized by seizures. Around one-third of patients do not respond to medical treatment. Resective surgery is an established treatment for drug-resistant epilepsy, with success depending on a comprehensive presurgical evaluation. This evaluation ensures the appropriate selection of candidates and accurate identification of the epileptogenic zone for safe resection. The assessment includes clinical history, interictal EEG, high-resolution MRI, neuropsychological evaluation, and additional techniques like functional imaging and intracranial monitoring. The alignment of these methods is crucial for a successful outcome; this study aims to assess the outcome of resective surgery in patients with drug-resistant focal epilepsy. It was conducted between October 2021 and October 2023; 35 patients with drug-resistant focal epilepsy underwent resective surgical intervention, including lesionectomy, anterior temporal lobectomy, and selective amygdalohippocampectomy. Preoperative evaluations involved seizure semiology, interictal EEG, and MRI. Postoperative outcome was evaluated using the ENGEL classification (Class I: Free of disabling seizures, Class II: Rare disabling seizures (almost seizure-free), Class III: Worthwhile improvement, Class IV: No worthwhile improvement) and changes in anti-seizure medications (ASMs). Results The study included 35 patients for whom resective surgery was done as follows: 24 underwent lesionectomy, 4 had anterior temporal lobectomy, and 7 had selective amygdalohippocampectomy. According to the ENGEL classification, 25 patients achieved Class I, and 10 achieved Class II. A significant reduction in the number of anti-seizure medications was observed in the follow-up period following surgery compared to preoperative use. Conclusion Resective surgery in drug-resistant focal epilepsy is effective and results in improved outcomes as regards epileptic seizure freedom.

The American Epilepsy Society Annual Meeting is the largest gathering on epilepsy in the world. The 2018 meeting, which was held in New Orleans, Louisiana, from November 30–December 4, 2018, featured symposia, workshops, and lectures aimed at healthcare practitioners involved in all aspects of the care of patients with epilepsy. In a number of expert interviews conducted at the meeting, authors of key presentations shared their expertise and provided insights into some of the hottest topics in the field.

Clinical Neurophysiology: EEG–Video Monitoring

The study was performed to investigate the relation between seizure outcome after surgical treatment of mesial temporal lobe epilepsy (MTLE) and pathological findings, classified according to the recently proposed classifications of mesial temporal sclerosis (MTS), granule cell pathology (GCP), focal cortical dysplasia (FCD) and epilepsy-associated low-grade tumors (ELGT). The authors analyzed data obtained in 120 consecutive cases involving patients presenting with drug-resistant MTLE, who underwent tailored anteromesial temporal lobe resection, and correlated seizure outcome with pathological findings. They identified 5 histopathological groups: Group 1-ELGT, alone or associated with other lesions (30 cases); Group 2-isolated FCD (17 cases); Group 3-MTS, with or without GCP (28 cases); Group 4-MTS associated with FCD, with or without GCP (37 cases); Group 5-other lesions (8 cases). Engel Class I outcome was observed in 83% of patients with ELGT (Class IA in 63%); in 59% of patients with isolated FCD, with FCD Type II showing a better prognosis than FCD Type I; in 82% of patients with isolated MTS (Class IA in 50%), with MTS Type 1a and MTS Type 1b showing a better prognosis than MTS Type 2 and patients with MTS and GCP having better postsurgical results than those with MTS without GCP. Engel Class I outcome was also achieved in 84% of patients with FCD associated with MTS (Engel Class IA in 62%); also in this group MTS 1a and MTS 1b associated with FCD showed a better prognosis than FCD associated with MTS 2. Finally, Engel Class I was also achieved in 2 patients with vascular malformation and in 1 with a temporal pole encephalocele. Patients with MTLE and ELGT, MTS, or MTS associated with FCD showed the best postsurgical seizure outcome (Engel Class I in more than 80% of cases), whereas only 63% of patients with isolated FCD achieved the same type of outcome. Interestingly, the analysis of seizure outcome in histopathological subtypes of FCD and of MTS showed different prognoses in the different pathological subgroups, with worse outcomes for atypical MTS, absence of GCP, and isolated FCD Type I.

Postoperative interictal epileptiform discharge within 1 month is associated with seizure recurrence after anterior temporal lobectomy

Peri-ictal water drinking and other ictal vegetative symptoms: Localizing and lateralizing the epileptogenic zone in temporal lobe epilepsy? Two case reports and review of the literature

The default-mode network (DMN) is a major resting-state network. It can be divided in two distinct networks: one is composed of dorsal and anterior regions [referred to as the dorsal DMN (dDMN)], while the other involves the more posterior regions [referred to as the ventral DMN (vDMN)]. To date, no studies have investigated the potentially distinct impact of temporal lobe epilepsy (TLE) on these networks. In this context, we explored the effect of TLE and anterior temporal lobectomy (ATL) on the dDMN and vDMN. We utilized two resting-state fMRI sessions from left, right TLE patients (pre-/post-surgery) and normal controls (sessions 1/2). Using independent component analysis, we identified the two networks. We then evaluated for differences in spatial extent for each network between the groups, and across the scanning sessions. The results revealed that, pre-surgery, the dDMN showed larger differences between the three groups than the vDMN, and more particularly between right and left TLE than between the TLE patients and controls. In terms of change post-surgery, in both TLE groups, the dDMN also demonstrated larger changes than the vDMN. For the vDMN, the only changes involved the resected temporal lobe for each ATL group. For the dDMN, the left ATL group showed post-surgical increases in several regions outside the ictal temporal lobe. In contrast, the right ATL group displayed a large reduction in the frontal cortex. The results highlight that the two DMNs are not impacted by TLE and ATL in an equivalent fashion. Importantly, the dDMN was the more affected, with right ATL having a more deleterious effects than left ATL. We are the first to highlight that the dDMN more strongly bears the negative impact of TLE than the vDMN, suggesting there is an interaction between the side of pathology and DM sub-network activity. Our findings have implications for understanding the impact TLE and subsequent ATL on the functions implemented by the distinct DMNs.

Low-grade epilepsy-associated tumors (LEATs) are common in the temporal lobe and can cause drug-resistant epilepsy. Complete resection of LEATs is sufficient for seizure relief. However, hippocampal resection might result in postoperative cognitive impairment. This study aimed to clarify the necessity of hippocampal resection for seizure and cognitive outcomes in patients with temporal lobe LEATs and a normal hippocampus. The study included 32 patients with temporal lobe LEATs and without hippocampal abnormalities. All patients underwent gross total resection as treatment for drug-resistant epilepsy at our tertiary epilepsy center from 2005 to 2020, followed by at least a 12-month follow-up period. Seizure and cognitive outcomes were compared between patients who underwent additional hippocampal resection (Resected group) and those who did not (Preserved group). Among the participants, 14 underwent additional hippocampal resection and 28 (87.5%) achieved seizure freedom irrespective of hippocampal resection. The seizure-free periods were not different between the two groups. Additional hippocampal resection resulted in a significantly negative impact on the postoperative verbal index. In conclusion, additional hippocampal resection in patients with temporal lobe LEATs without hippocampal abnormalities is unnecessary because lesionectomy alone results in good seizure control. Additional hippocampal resection may instead adversely affect the postoperative language function.

Persons with drug refractory TLE have the option of being managed by surgery. They may develop memory impairment with specific etiology of mesial temporal sclerosis and anterior temporal lobe resection (ATLR). The study evaluated the semantic verbal memory outcomes in pre- and post-surgery temporal lobe epilepsy (TLE) patients using functional MRI and voxel morphometric methods. Twenty consecutive persons with drug-resistant epilepsy (DRE) and 20 healthy controls were recruited after obtaining the institute ethics approval. The fMRI scans were performed on a 1.5 T MR Scanner using standardized semantic verbal memory tasks using a native Hindi paradigm, before and after an anterior temporal lobectomy (in cases). A task-based functional connectivity (FC) was estimated using a conn toolbox. Data analysis was carried out using the statistical parametric imaging (SPM12) and CAT12 toolbox. Post-surgery TLE group showed increased robust FC in the right middle and posterior temporal regions as compared to pre-surgery session. A significant reduction in grey matter volume was observed in the left temporal lobe post-operatively as compared to presurgery and healthy control groups. In the post-surgery TLE group, neuropsychological scores were reduced in specific PGI domains such as visuospatial, working memory, and executive functioning. Our results may help in understanding of memory reorganization in TLE post-operatively.

Usefulness of Wada test in predicting seizure outcome following anterior temporal lobectomy

Focal epilepsies have been described as a network disease. Noninvasive investigative techniques have been used to characterize epileptogenic networks. This study aimed to describe ictal and interictal cortical and subcortical perfusion patterns using single- photon emission computed tomography (SPECT) in patients with drug-resistant epilepsy (DRE). Thirty-five interictal-ictal SPECT scans were obtained from 15 patients with DRE. A methodology was developed to get a relative perfusion index (PI) of 74 cortical and sub-cortical brain structures. K-means algorithm, together with modified v-fold cross-validation, was used to identify the two regions of interest (ROIs) that represent hypoperfused and hyperperfused areas. In common with the individual analysis, the statistical analysis evidenced that the hyperperfusion ROIs resulting from group analysis during interictal and ictal involved mainly the cingulate gyrus, cuneus, lingual gyrus, and gyrus rectus as well as the putamen. ROIs hypoperfused included the red nucleus, the substantia nigra, and the medulla. The medians of the group analysis of the hypoperfusion and hyperperfusion ROIs were 0.601-0.565 and 1.133-1.119 for the ictal and interictal states, correspondingly. A group of mostly cortical structures involved in the hyperperfused ROIs in both interictal and ictal states showed no change or negative change in the transition from interictal to ictal state (mean change of -0.002). On the other hand, the brain stem, basal ganglia, red nucleus, and thalamus revealed a mean global change of 0.19, indicating a mild increase in the PI. However, some of these structures (red nucleus, substantia nigra, and medulla oblongata) remained hypoperfused during the interictal to ictal transition. The methodology employed made it possible to identify common cortical and subcortical perfusion patterns not directly linked to epileptogenicity, for a better epileptogenic network and sudden unexpected death (SUDEP) mechanism in DRE.

Objective: To evaluate the efficacy and safety of stereotactic electroencephalography (SEEG)-guided 3D radiofrequency thermocoagulation (RF-TC) in the treatment of drug-resistant mesial temporal lobe epilepsy with hippocampal sclerosis (mTLE-HS). Methods: This study was a randomized controlled trial. The patients with drug-resistant mTLE-HS recruited from Xuanwu Hospital, Capital Medical University between August 2019 and October 2022 were prospectively enrolled. The patients were randomly assigned to receive either anterior temporal lobectomy (ATL) or RF-TC treatment using a variable block randomization method. All patients were assessed both preoperatively and 1 year postoperatively. The postoperative outcomes in terms of epileptic seizure results, visual field defects, and surgery-related complications were compared between the two groups. Results: A total of 38 patients were included, 19 males and 19 females, with an average age of (28.3±6.9) years. There were 20 cases in the ATL group and 18 cases in the RF-TC group. There was no statistically significant difference in age [(28.5±5.7) vs (28.2±8.1), P=0.848] or gender distribution (7/20 vs 12/18, P=0.103) between the both groups. At the 1-year follow-up post-surgery, there was no statistically significant difference in the proportion of patients achieving Engel Class Ⅰfor epileptic seizure results between the ATL group and the RF-TC group (17/20 vs 13/18, P=0.438). The proportion of patients in the ATL group who developed visual field defects was higher than that in the RF-TC group (15/20 vs 3/18, P<0.010). No severe adverse events were observed in both groups. Conclusion: The epilepsy control efficacy of SEEG-guided 3D RF-TC is comparable to that of traditional surgery, while offering superior outcomes in visual field preservation.