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• Amino acid PET imaging in suspected LEAT provide a high diagnostic sensitivity for gangliogliomas. • ECoG and neuronavigation in extratemporal GG resections provide excellent seizure outcome. • In temporal GG an AMTLR (antero-mesial TLR) gave highest postoperative seizure freedom. Imaging and resection strategies for pediatric gangliogliomas (GG) and dysembryoplastic neuroepitheliomas (DNET) presenting with epilepsy were retrospectively analyzed in a consecutive institutional series of surgically treated patients. Twenty-two children (median 8 years, 3–18 years) presented with seizures for 30 months median (14–55.2 months) due to a histologically verified GG/DNET. There were 20 GG and 2 DNT, 68 % located temporal, 32 % extra-temporal. Seizure history was significantly longer in temporal cases (38 versus 14 months median, p < 0.01). MRI contrast enhancement was present in 50 % and methionine (MET) positron emission tomography (PET) uptake in 70 % (standard uptake values (SUVs) 2.92 mean, from 1.6 to 6.4). 27 % had glucose PET hypometabolism. Primarily, in temporal GG, ECoG (electrocorticography) -guided lesionectomies were performed in 87 % and antero-mesial temporal lobe resections (AMTLR) in 13 %, whereas in extra-temporal GG/DNETs, lesionectomies were performed in 100 %. ILAE Class 1 seizure outcome was primarily achieved in 73 % of the temporal cases, and was increased to 93 % by performing six repeat surgeries using AMTLR. Extratemporal patients experienced ILAE Class 1 seizure outcomes in 86 % without additional surgeries, although harboring significantly more residual tumor (p < 0.005, mean follow-up 28 months). In children, MET PET imaging for suspected GG is proposed preoperatively showing a high diagnostic sensitivity and an option to delineate the lesions for navigated resection, whereas MRI contrast behavior was of no differential diagnostic use. As a surgical strategy we propose primarily lesionectomies for extratemporal but AMTLR for temporal GG respecting eloquent brain areas. [ABSTRACT FROM AUTHOR]

• high efficacy of SEEG-guided RFTC: we observed a significant proportion of patients (46 %) achieving seizure freedom (ILAE class 1) with a median follow-up of 39.5 months and an overall responder rate of 71 %. This underscores the potential of SEEG-guided RFTC as a viable potential curative treatment option for patients with PVNH-related DRE. • complex epileptogenic networks: our findings reveal the heterogeneity of seizure onset patterns, with EEG onset localized exclusively within PVNH in some patients while involving both PVNH and adjacent cortical regions in others. This nuanced understanding of epileptogenic networks is crucial for tailored treatment approaches. • safety profile of RFTC: while SEEG-guided RFTC demonstrates promising efficacy, we also document adverse events, emphasizing the importance of balancing therapeutic benefits with potential risks. Notably, we observed a relative low rate of (expected) permanent visual impairment, highlighting the overall safety of the procedure. Periventricular nodular heterotopias (PVNH) are developmental abnormalities with neurons abnormally clustered around the cerebral ventricles. Patients frequently present with focal drug-resistant epilepsy (DRE). However, the relationship between PVNH and the seizure onset zone (SOZ) is complex. Stereo-electroencephalography (SEEG) is an invasive diagnostic procedure for patients with DRE. In selected patients, the SEEG may be converted into a therapeutic procedure, lesioning the probable (SOZ) with pulsed radiofrequency thermocoagulation (RFTC). The aim of our study was to evaluate the efficacy and safety of SEEG-RFTC in a series of DRE patients with PVNH. Twenty-four patients with focal DRE related to PVNH and treated with SEEG-guided-RFTC restricted to nodules were prospectively collected between 2016 and 2023 and retrospectively analyzed after a follow-up of at least 12 months. Seventeen patients (71 %) responded (ILAE class 1–4) after SEEG-guided RFTC of whom eleven (46 %) became seizure-free (class 1) at last follow up, nine (45 %) despite residual PVNH tissue on MRI. SEEG seizure onset was restricted to PVNH in eleven patients (class 1 in 45 %) and simultaneously in PVNH and other cortical areas in thirteen patients (class 1 in 46 %). Out of 31 SEEG-RFTC procedures in twenty-four patients, adverse events, related to RFTC, were recorded in eight (26 %), of which two patients (8 %) had predicted permanent visual complaints whilst the other five had transient complaints. This study demonstrates that a considerable percentage of patients, even with bilateral, multiple PVNH and involvement of adjacent cortical regions can be rendered seizure-free with SEEG-guided-RFTC restricted to the nodules. Furthermore, this study delivers evidence that the complete destruction of the entire nodule is not necessary to render a patient seizure free. This justifies the use of SEEG in patients with single, multiple or bilateral PVNHs to provide insight into the epileptogenic organization in and around these lesions. [ABSTRACT FROM AUTHOR]

• The most prevalent seizure-onset patterns (SOPs) are low frequency periodic spikes (LFPS) and low-voltage fast activity (LVFA). • LFPS had the most divergent terminology, whereas LVFA had the most reproducible terminology. • Some SOP terms were inconsistent with standard EEG terminology. Increasing evidence suggests that the seizure-onset pattern (SOP) in stereo-electroencephalography (SEEG) is important for localizing the "true" seizure onset. Specifically, SOPs with low-voltage fast activity (LVFA) are associated with seizure-free outcome (Engel I). However, several classifications and various terms corresponding to the same pattern have been reported, challenging its use in clinical practice. Following the Preferred Reporting Items of Systematic reviews and Meta-Analyses (PRISMA) guideline, we performed a systematic review of studies describing SOPs along with accompanying figures depicting the reported SOP in SEEG. Of 1799 studies, 22 met the selection criteria. Among the various SOPs, we observed that the terminology for low frequency periodic spikes exhibited the most variability, whereas LVFA is the most frequently used term of this pattern. Some SOP terms were inconsistent with standard EEG terminology. Finally, there was a significant but weak association between presence of LVFA and seizure-free outcome. Divergent terms were used to describe the same SOPs and some of these terms showed inconsistencies with the standard EEG terminology. Additionally, our results confirmed the link between patterns with LVFA and seizure-free outcomes. However, this association was not strong. These results underline the need for standardization of SEEG terminology. [ABSTRACT FROM AUTHOR]

• Long-term follow-up of 84 treatment-naïve patients with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). • ASM provided encouraging treatment outcomes in drug-naïve MTLE-HS patients, with 64 % achieving seizure freedom (SF) and 41 % achieving complete SF in the last year of follow-up. • Remission and relapse were common in MTLE-HS, with 46 % and 51 % of patients experiencing a fluctuating course with periods of SF and complete SF, respectively. • Patients with MTLE-HS may require more ASMs for seizure control. This study aimed to describe long-term treatment outcomes of treatment-naïve patients with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). A retrospective review was conducted of treatment-naïve patients with MTLE-HS who visited the Yonsei Epilepsy Clinic from April 2000 to April 2022 and were followed up for at least 2 years. Seizure freedom (SF) was defined as no seizures or auras only for >1 year, and complete SF was defined as no seizures including auras for >1 year. Eighty-four treatment-naïve patients with MTLE-HS with a median follow-up of 122 months were included. Except for one patient who underwent early surgical treatment, of the remaining 83 patients, 31 (37.3 %) achieved SF and remained in remission, 38 (45.8 %) had fluctuations in seizure control, and 14 (16.9 %) never achieved SF. Additionally, 18 (21.7 %) patients achieved complete SF and remained in remission, 42 (50.6 %) showed fluctuations, and 23 (27.7 %) never achieved complete SF. Fifty-three (63.9 %) patients achieved SF and 34 (41.0 %) achieved complete SF at their last visit. Older age at epilepsy onset, male sex, low pretreatment seizure density, history of central nervous system infection before age 5, absence of aura, and fewer antiseizure medications in the final regimen were associated with favorable outcome. Of the 84 patients, 11 (13.1 %) underwent temporal lobectomy. Medical treatment outcomes in treatment-naïve MTLE-HS were relatively better than previously reported outcomes in MTLE-HS, although frequent fluctuations in seizure control were observed. [ABSTRACT FROM AUTHOR]

Hypothalamic hamartomas are benign lesions associated with drug resistant epilepsy. Surgical treatment has become an increasingly utilised approach with promising results. This study aims to evaluate seizure outcome and complications after surgery in a population-based series of patients with intractable epilepsy and hypothalamic hamartoma. All patients with hypothalamic hamartoma treated with epilepsy surgery in Sweden since 1995 with at least two years of follow-up were included. Preoperative, two-, five- and ten-year prospective longitudinal data were collected from The Swedish National Epilepsy Surgery Register. Data included seizure types and frequency, duration of epilepsy, clinical characteristics, neurological deficits, cognitive level and complications. In a subgroup from Gothenburg, we also analysed data not included in the register such as classification of hamartomas, surgical procedures and gelastic seizures. Eighteen patients were operated on during the period 1995–2020. The median age at epilepsy onset was 6 months and age at surgery 13 years. Four were seizure free and another four had ≥75% reduction in seizure frequency at the two-year follow-up. Two of the 13 patients with a long-term follow-up (five or ten years) were seizure-free and four had ≥75% reduction in seizure frequency. Three had an increased seizure frequency. No major complications were seen. Five had minor complications. In the Gothenburg subgroup all had open pterional disconnection or intraventricular endoscopic disconnection. Six of 12 were free from gelastic seizures at the two-year follow-up and six of eight at the long-term follow-up. This study supports surgical treatment of hypothalamic hamartomas as a safe method with a low risk of permanent complications. The seizure reduction seems to be persistent over time. • Surgical treatment of hypothalamic hamartomas can be safe and without major complications. • Surgical treatment led to a substantial reduction in seizure frequency in most patients. • Reduction in seizure frequency seems to be persistent over time. [ABSTRACT FROM AUTHOR]

Hemispherectomy is an optimal treatment for patients with Sturge-Weber syndrome (SWS) affecting the whole hemisphere; however, a consensus has not been reached regarding therapeutic choices for those with involvement of two to three lobes. In this study, we compared seizure and cognitive outcomes between medical and surgical treatment groups in patients with multilobar involvement. We evaluated 50 patients with multilobar involvement. Surgical indications included (1) antiepileptic drug (AED)-resistant seizures; (2) developmental delay; and (3) cortical atrophy. Twenty-nine patients were classified in the medical treatment group (MTG), and 21 patients were in the surgical treatment group (STG). Seizure type and frequency, SWS electroencephalography score (SWS-EEGS), and pretherapeutic and posttherapeutic SWS neurological scores (SWS-NS) were compared between groups. Median ages at the initial evaluation of the MTG and STG were 4 and 2 years, and at the final evaluation were 13 and 17 years, respectively. The STG had a higher incidence (76.2%) of focal to bilateral tonic-clonic seizures and status epilepticus, although no difference in SWS-EEGS. Seizure and cognitive subcategories of SWS-NS at initial evaluation were worse in the STG (P = 0.025 and P = 0.007). The seizure subcategory in MTG and STG improved after therapy (P = 0.002 and P = 0.001). Cognition was maintained in MTG and improved in STG (P = 0.002). The seizure-free rates in MTG and STG were 58.6% and 85.7%, respectively. Appropriate therapeutic choices improved seizure outcomes. Although patients who required surgery had more severe epilepsy and cognitive impairment, surgery improved both. [ABSTRACT FROM AUTHOR]

When magnetic resonance imaging (MRI) fails to detect an underlying epileptogenic lesion, the odds of a good outcome after epilepsy surgery are significantly lower (20%–65% compared with 60%–90% if a lesion is detected). We investigated the possible effects of introducing hybrid 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET)/MRI into the decision algorithm for patients with lesioned and nonlesioned drug-resistant epilepsy. Three databases were searched from January 1990 to October 2022. We registered the protocol with International Platform of Registered Systematic Review and Meta-analysis Protocols. Studies in which 18F-FDG PET/MRI was conducted with ≥12 months of postsurgical follow-up in patients with refractory epilepsy. Random-effects meta-analysis was used to calculate the proportion of patients with good outcomes. Metaregression was used to investigate sources of heterogeneity. We identified 8105 studies, of which 23 (1292 patients in total) were included. The overall good postoperative outcome rate was 71% (95% confidence interval 63.6–74.9). Good outcome was associated with the location of the refractory epileptic lesion (temporal lobe or extratemporal; risk ratio 1.27 [95% confidence interval 1.01–1.52], P = 0.009); Length of postoperative follow-up ≥40 months included in the same study accounted for 0.6% of the observed heterogeneity. Seventy-one percent of patients with refractory epilepsy and 18F-FDG PET/MRI epileptogenic lesion features had a good outcome of epilepsy after surgery. Our findings can be incorporated into routine preoperative consultations and emphasize the importance of the complete resection of the temporal lobe epileptogenic zone for 18F-FDG PET/MRI detection when safe and feasible. [ABSTRACT FROM AUTHOR]

• Epilepsy surgeries have decreased despite increases in pre-surgical evaluations. • Cases with failure to localize seizures increased in the most recent time period. • Increasing proportion of surgery patients are reporting seizure freedom over time. A recent U.S. study reported that the number of epilepsy surgeries has remained stable or declined in recent years despite an increase in pre-surgical evaluation. This study aimed to evaluate trends in pre-surgical evaluation and epilepsy surgery from 2001 to 2019 and to determine whether these trends have changed in the later period (2014–2019) compared to earlier period (2001–2013). This study evaluated trends in pre-surgical evaluation and epilepsy surgery at a tertiary pediatric epilepsy center. Children with drug resistant epilepsy who were evaluated for surgery were included. Clinical data, reasons for not undergoing surgery, and surgical characteristics of surgery patients were collected. Overall trends and trends in later period compared to earlier period for pre-surgical evaluation and epilepsy surgery were assessed. There were 1151 children who were evaluated for epilepsy surgery and 546 underwent surgery. There was an upward trend in pre-surgical evaluation in the earlier period (rate ratio [RR]=1.04 (95%CI:1.02–1.07), p <0.001) and the trajectory of presurgical evaluation in the later period was not significantly different to the earlier period (RR=1.00 [95%CI:0.95–1.06], p = 0.88). Among the reasons for not undergoing surgery, failure to localize the seizures occurred more frequently in later period than earlier period (22.6% vs. 17.1% respectively, p = 0.024). For number of surgeries, there was an upward trend between 2001 and 2013 (RR=1.08 [95%CI:1.05–1.11], p <0.001), and a decreasing trend in the later period compared to earlier period (RR=0.91 [95%CI:0.84–0.99], p = 0.029). Despite an increasing trend in pre-surgical evaluation, there was a decreasing trend in the number of epilepsy surgery in the later period as there was a larger proportion of patients in whom the seizures could not be localized. Trends in presurgical evaluation and epilepsy surgery will continue to evolve with introduction of technologies such as stereo-EEG and minimally invasive laser therapy. [ABSTRACT FROM AUTHOR]

• This research is the first meta-analysis to focus on differences on postoperative seizure control between tuberectomy and tuberectomy plus in patients with TSC. • Proportion of seizure freedom in patients after tuberectomy plus is significantly higher than after tuberectomy. • Perituberal cortex, combined with the tuber itself, may play an important role in origin of seizures in TSC-related epilepsy. To perform a systematic review and meta-analysis to identify whether tuberectomy and tuberectomy plus are associated with different postoperative seizure outcomes in patients with tuberous sclerosis complex (TSC) -related epilepsy. Electronic databases (PubMed, Embase, Cochrane, Proquest, Web of Science, Scopus, Biosis Previews) were searched without date restriction. Retrospective cohort studies of participants with TSC-associated epilepsy undergoing resective surgery that reported demographics, presurgical evaluation, extent of resection and postoperative seizure outcomes were included. Title, abstract and the full text were checked independently and in duplicate by two reviewers. Disagreements were resolved through discussion. One author extracted data which was verified by a second author using identified common standard in advance, including using a risk of bias tool we agreed on to evaluate study quality. Five studies, with a total of 327 participants, were included. One hundred and sixty patients received tuberectomy, and 93 of them (58.1%) achieved postoperative seizure freedom, while the other 167 patients underwent tuberectomy plus, and 128 of them (76.6%) achieved seizure freedom after adequate follow-ups (RR=0.72, 95% CI [0.60, 0.87], P <0.05). Subgroup analysis found that 40 of 63 (63.5%) patients after tuberectomy and 66 of 78 (84.6%) patients after tuberectomy plus of a single tuber achieved seizure freedom (RR = 0.71, 95% CI [0.56,0.91], P <0.05). In the multituber subrgroup, 16 of 42 (38.1%) and 21 of 31 (67.7%) patients achieved seizure freedom, after tuberectomy and tuberectomy plus, respectively (RR = 0.57, 95% CI [0.32,1.03], P = 0.06). Tuberectomy plus is a more effective treatment than tuberectomy for patients with TSC-related intractable epilepsy. [ABSTRACT FROM AUTHOR]

• Resection should include ictal single equivalent current dipole (SECD), interictal SECD and MRI lesion localization, when feasible. • Concordant ictal and interictal SECDs can be a favorable predictor of seizure freedom if the areas can be safely resected. • Among SECD, dynamic statistical parametric mapping, and linearly constrained minimum variance, SECD should be considered the first line of analysis for ictal MEG when the data is amenable to SECD source localization. The significance of ictal magnetoencephalography (MEG) is not well appreciated. We evaluated the relationships between ictal MEG, MRI, intracranial electroencephalography (ICEEG), surgery and postoperative seizure outcome. A total of 45 patients (46 cases) with ictal MEG who underwent epilepsy surgery was included. We examined the localization of each modality, surgical resection area and seizure freedom after surgery. Twenty-one (45.7%) out of 46 cases were seizure-free at more than 6 months follow-up. Median duration of postoperative follow-up was 16.5 months. The patients in whom ictal, interictal single equivalent current dipole (SECD) and MRI lesion localization were completely included in the resection had a higher chance of being seizure-free significantly (p < 0.05). Concordance between ictal and interictal SECD localizations was significantly associated with seizure-freedom. Concordance between MRI lesion and ictal SECD, concordance between ictal ICEEG and ictal and interictal SECD, as well as concordance between ictal ICEEG and MRI lesion were significantly associated with seizure freedom. Ictal MEG can contribute useful information for delineating the resection area in epilepsy surgery. Resection should include ictal, interictal SECDs and MRI lesion localization, when feasible. Concordant ictal and interictal SECDs on MEG can be a favorable predictor of seizure freedom. [ABSTRACT FROM AUTHOR]

The seizure outcomes after hemispheric epilepsy surgery have been excellent, with 54%–90% of patients achieving long-term freedom from seizures. Similarly, the neuropsychological outcomes have been favorable. The prognostic value of pre- and postoperative electroencephalography (EEG) has not been well-studied. In the present study, we characterized the value of the pre- and postoperative EEG findings for predicting the seizure and neuropsychological outcomes for pediatric patients undergoing hemispherectomy. A total of 22 children who had undergone functional hemispherectomy at our institution from 2010 to 2020 were included. The ictal and interictal findings were categorized as ipsilateral to the operated hemisphere, independently arising from the contralateral hemisphere, and/or generalized. The seizure outcomes were classified using the Engel scale. All neuropsychological evaluations were performed in accordance with our institution's protocol. The relationship between the EEG findings and outcomes was analyzed. Of the 22 patients, 19 (86%) were seizure free (Engel class IA) at the latest follow-up (mean, 4.2 years). On the preoperative EEGs, 9 had had seizures, all had had ipsilateral interictal discharges, and 9 had had contralateral interictal discharges. On the postoperative EEGs, obtained a median of 1 year after surgery, 3 had had seizures, 16 had had ipsilateral interictal discharges, and 5 had had contralateral interictal discharges. Of the 3 patients with seizures found on the postoperative EEG, all were clinically free of seizures. The patients who had not achieved Engel class IA were not significantly more likely to have abnormalities found on the EEG. The neuropsychological scores were stable from before to after surgery, with no evidence of EEG abnormalities having predictive value. The seizure and neuropsychology outcomes after hemispherectomy were excellent in our study, with 86% of our cohort achieving freedom from seizures. The presence, lateralization, and evolution of pre- and postoperative EEG abnormalities were not predictive of the outcomes. [ABSTRACT FROM AUTHOR]

• Non-lesional late-onset epilepsy in the elderly has variable presenting features. • In this population, comorbid dementia has been diagnosed in 35% of cases. • Seizure-free status for ≥ 12 months has been attained in 72% of patients. • Seizure-free status is often attained with the low-dose antiseizure monotherapy. • Comorbid dementia is associated with worse response to antiseizure therapy. The objective of the present retrospective study was analysis of clinical, radiological, and electrophysiological characteristics of the non-lesional late-onset epilepsy (NLLOE) in the elderly Japanese patients, and comparison of the seizure outcomes in this population with regard to presence of comorbid dementia. The study cohort comprised 89 consecutive patients with NLLOE aged ≥ 65 years. In 49 cases (55%), NLLOE manifested with a single type of seizure. Focal impaired awareness seizures (FIAS) were encountered most often (in 69 patients; 78%). Ten patients (11%) had a history of the status epilepticus. Comorbid dementia was diagnosed in 31 patients (35%). Localized or diffuse white matter hyperintensity was the most common imaging finding (66 cases). Epileptiform discharges in the temporal area represented the most frequent abnormality on interictal EEG (24 cases). Seizure-free status for ≥ 12 months was attained in 46 out of 64 patients (72%), who were followed for ≥ 12 months (range, 12 – 110 months), and 42 of them received monotherapy, mainly with levetiracetam (21 patients), carbamazepine (10 patients), or lacosamide (8 patients). In comparison to their counterparts, the rate of seizure-free status for ≥ 12 months was significantly lower in patients with comorbid dementia (81% vs. 52%; P = 0.0205). In conclusion, the NLLOE among Japanese patients aged ≥ 65 years has variable presenting characteristics, and comorbid dementia is diagnosed in one-third of cases. Seizure-free status for ≥ 12 months may be attained in more than two-thirds of treated patients, but comorbid dementia is associated with significantly worse response to antiseizure therapy. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to identify risk factors of postoperative seizure outcome in a consecutive cohort of patients operated on for TSC-related focal epilepsy, by evaluating several presurgical and surgical variables, including also MRI-visible brain abnormalities other than cortical tubers.Methods: This retrospective study included 51 patients surgically treated for drug-resistant focal epilepsy with a histological diagnosis of cortical tuber and followed for at least 12 months postoperatively. We investigated the association between several potentially explanatory variables and seizure outcome by univariate and multivariate analysis in the whole cohort and in the subgroups of patients with single and multiple tubers, respectively.Results: The median postoperative follow-up was 115 months (IQR 63-168) and 54.9% of patients were in Engel's class I at final control. In the whole cohort, variables independently associated with an unfavorable seizure outcome (Engel's classes II-IV) were: preoperative non-focal interictal EEG (RR 5, CI 2.46-6.39), presence of sub-ependymal nodules (SEN) (RR 3.53, CI 1.71-4.56) and seizure onset before the first year of age (RR 3.56, CI 0.91-6.89). Non-focal interictal EEG was independently associated with an unfavorable outcome also in the subgroup of patients with multiple tubers (RR 4.34, CI 2.23-5.37), while the presence of SEN (p=0.0221) and of extra-central nervous system lesions (p= 0.0152) predicted an unfavorable seizure outcome in patients with a single tuber.Conclusion: Surgery represents an effective option for seizure control in patients with TSC-related epilepsy. The identification of preoperative risk factors for seizure outcome could be helpful for optimizing patients' selection for surgery and pre-surgical counseling. [ABSTRACT FROM AUTHOR]

The insular cortex is an eloquent island of mesocortex surrounded by vital structures making this region relatively challenging to neurosurgeons. Historically, lesions in this region were considered too high risk to approach given the strong chance of poor surgical outcome. Advances in recent decades have meant that surgeons can more safely access this eloquent region. Seizure outcome after excision of insular low-grade gliomas is well reported, but little is known about seizure outcomes after excision of insular high-grade gliomas. A retrospective analysis was performed of all patients presenting with new-onset seizures during 2015–2019 who underwent excision of an insular high-grade glioma at 3 regional neurosurgical centers in the United Kingdom. We identified 38 patients with a mean (SD) age of 45.7 (15.3) years with median follow-up of 21 months. At long-term follow-up, of 38 patients, 23 were seizure-free (Engel class I), 2 had improved seizures (Engel class II), 6 had poor seizure control (Engel class III/IV), and 7 died. Excision of insular high-grade gliomas is safe and results in excellent postoperative seizure control. [ABSTRACT FROM AUTHOR]

Objective: This longitudinal study aimed to measure the time course of intellectual changes after pediatric focal resective epilepsy surgery and to identify their predictors.Methods: We analyzed a cohort of 81 school-aged children with focal epilepsy and intractable seizures who underwent neurosurgery (focal resection) from 2000 to 2018 in La Timone Hospital (Marseille). Neuropsychological assessments were carried out before and then 1, 2, 3, and 5 years after epilepsy surgery.Results: Eighty-one patients with a median age at surgery of 13.74 years [4.25] were enrolled. Overall, 45 of the 81 (55%) recruited patients were improved after the surgery on at least one of the five domains of the Wechsler Intelligence Scale. Temporal lobe localization and postoperative seizure freedom were the main prognostic factors impacting intellectual outcome (improvement and decline) after epilepsy surgery. Younger patients at surgery were less likely to have a postoperative IQ decline. Intellectual improvement after epilepsy surgery could be delayed for up to 5 years after surgery and concerned all intellectual domains except the Verbal Comprehension Index (VCI). Intellectual decline after epilepsy surgery occurred mainly during the first two years after the surgery and was reflected in full-scale intelligence quotient (FSIQ) and Working Memory Index (WMI).Conclusions: Our study points out that children and adolescents with TLE who achieved freedom from seizure after epilepsy surgery are the leading candidates for achieving postoperative intellectual improvement. This enhancement in intellectual function shows a long time course, whereas intellectual decline is evidenced earlier. [ABSTRACT FROM AUTHOR]

Objective: To identify prognostic factors and long-term seizure outcomes for patients with tuberous sclerosis complex (TSC) who underwent resective treatment for epilepsy.Methods: We enrolled 81 patients with TSC who had undergone resective epilepsy surgery at Sanbo Brain Hospital, Capital Medical University, between April 2004 and June 2019. We estimated cumulative probability of remaining seizure-free and plotted survival curves. Variables were compared using Mann-Whitney U, Pearson's correlation, continuity correction, and Fisher's exact chi-square tests. Prognostic predictors were analysed using log-rank (Mantel-Cox) tests and Cox regression models.Results: At the last follow-up, 48 (59.3%) patients were classified as International League Against Epilepsy Class 1 (including 14 patients who had seizures <3 times postoperatively on the same or different day and were seizure-free at all other times). The estimated cumulative probability of remaining seizure-free postoperatively was 69.0% (95% confidence interval [CI] 58.8-79.2%), 61.9% (95% CI 51.1-72.7%), and 55.0% (95% CI 42.8-67.2%) at 2, 5, and 10 years, respectively. The mean time of remaining seizure-free was 7.24 ± 0.634 years (95% CI 6.00-8.49); en bloc resection was an essential positive predictor of postoperative seizure freedom, as was age at seizure onset, regional interictal video-electroencephalography pattern, and temporal lobe surgery. The longer the seizure-free time, the less likely a relapse. Patients who postoperatively experienced seizures remained likely to recover.Conclusions: We demonstrated the efficacy of surgical treatment for patients with TSC and intractable epilepsy. Detailed perioperative tests are a reliable predictor of postoperative seizure freedom. [ABSTRACT FROM AUTHOR]

To investigate benefits of in-hospital, long-term video EEG monitoring (LVEM) for pediatric patients, from a therapeutic perspective and from the perspectives of patients and their families. A monocentric retrospective cohort study was conducted. Patients aged 0–18 years who underwent LVEM for epilepsy surgery eligibility, epilepsy syndrome clarification, or medication adjustment were evaluated regarding paroxysmal event type, change in seizure frequency and patients' benefits using a standardized evaluation protocol. A total of 163 (88 boys and 75 girls, mean age 10.9 years) pediatric patients underwent 178 LVEM sessions, with a mean duration of 5.4 days. The rate of habitual event detection was 69.1%. Epilepsy diagnosis was confirmed in 147 patients and excluded in 16 patients (9.8%). LVEM results altered the diagnosis of 37.4% of patients. Diagnosis remained unchanged in 49.1% of patients and was specified in 13.5% of patients. Epilepsy surgery was performed in 32 patients, and 64% of epilepsy patients deemed ineligible for epilepsy surgery underwent medication adjustments. Patients or their families found LVEM helpful in 75% of cases. Significant seizure reductions and improvements in the disease course were reported by 45% of epilepsy patients. Three episodes of non-convulsive status epilepticus occurred, representing 1.7% of admissions and 1.9% of patients diagnosed with epilepsy, while no injuries were observed. LVEM is beneficial for pediatric patients from both a medical perspective and from the perspective of patients and their families, even if patients are ineligible for epilepsy surgery. LVEM is well-tolerated with a low risk of status epilepticus and injuries. • LVEM is useful to classify epilepsy, leading to optimized treatment strategies with positive impact on course of disease. • Families considered LVEM to be helpful, even if not eligible for epilepsy surgery. • LVEM is well-tolerated with low risk for status epilepticus and no injuries. [ABSTRACT FROM AUTHOR]

Background: Individuals with Sturge-Weber syndrome (SWS) often expereince intractable epilepsy and cognitive decline. We hypothesized that the extent of the leptomeningeal capillary malformation (LCM) may correlate with the severity of neurological impairment due to SWS. We tested the hypothesis in a cross-sectional study of seizure severity and electroencephalographic (EEG) findings and a retrospective cohort study for surgical indications related to the extent of the LCM.Methods: We enrolled 112 patients and classified them according to LCM distribution: (1) bilateral, (2) hemispheric, (3) multilobar, and (4) single lobe. Age at seizure onset, seizure semiology and frequency, and EEG findings were compared. Surgical indications were evaluated for each group by Fisher exact test, and predictors for surgery were evaluated by univariate and multivariate analyses. Therapeutic efficacy was evaluated by the SWS-Neurological Score (SWS-NS).Results: The bilateral and hemispheric groups had early seizure onset (4.0 months old and 3.0 months old), frequent seizures (88.9% and 80.6% had more than one per month), focal-to-bilateral tonic-clonic seizures (88.9% and 74.2%), and status epilepticus (100% and 87.1%). The groups' EEG findings did not differ substantially. Surgical indications were present in 77.8% of the bilateral, 88.1% of the hemispheric, and 46.8% of the multilobar groups. Seizure more than once per month was a predictor of surgical treatment. Seizure subscore improved postoperatively in the hemispheric and multilobar groups. Even after surgical treatment, the bilateral and hemispheric groups exhibited higher SWS-NSs than members of the other groups.Conclusion: Our study demonstrated a strong association between extensive LCM and epilepsy severity. Surgical intervention improved seizure outcome in patients with SWS with large LCMs. [ABSTRACT FROM AUTHOR]

Tumors presenting with drug-resistant seizures are termed as long-term epilepsy-associated tumors (LEATs). LEATs are more common in the temporal lobe, occur predominantly in pediatric age, and focal neurological deficits are rare. In this article, we aim to highlight our surgical experience in terms of seizure outcome among LEATs and discuss the factors affecting outcome. We have retrospectively analyzed all the operated cases of intra-axial brain tumors with seizures (2015–2019). The clinical and radiographic data were collected from the hospital record system. For comparison, 2 groups were made (group 1 with good seizure control, i.e., Engel 1; and group 2 poor seizure outcome, i.e., Engel 2 and 3). A total of 51 cases were included; the temporal lobe was the most common location (n = 27); 23 patients had seizure frequency of "more than 1 seizure per week." Focal unaware seizures/complex partial seizures were the most common type of seizures encountered (n = 28). At a mean follow-up of 39.60 months, 38 patients had Engel 1 (78.5%) outcome (35 cases [71.05%] had the seizure duration of ≤2 years). The median duration of symptoms (group 1, 25 months vs. group 2, 65 months) was significantly different (P = 0.002). On comparing patients with seizure duration, we found a statistically significant difference (P < 0.00001). A shorter duration of symptoms, younger age of the patient, partial/focal seizures, and gross total excision were predictors of a good seizure outcome. Histopathology of the tumor does not affect the outcome when one compares glioneuronal tumors with non–glioneuronal tumors. [ABSTRACT FROM AUTHOR]

To describe our series of a minimally invasive technique using a small scalp incision and keyhole craniotomy for the removal of mesial temporal lobe structures through a transcortical approach in patients with medically intractable mesial temporal lobe epilepsy (MTLE). Studies that directly compare the clinical outcomes between minimally invasive and conventional techniques are scarce, and this information is lacking in the literature. The study enrolled 73 consecutive patients with refractory MTLE and unilateral hippocampal sclerosis; 30 patients were operated on with standard frontotemporal craniotomy between 2010 and 2013 and 43 patients were operated with a minimally invasive craniotomy (nummular craniotomy) between 2014 and 2016. The preoperative evaluation included clinical history, physical examination, video-electroencephalography, neuropsychologic assessment, and magnetic resonance imaging including thin-section coronal sequences. There were no deaths in either group. Postoperative complications in the standard frontotemporal craniotomy group included temporal muscle atrophy (n = 4; 13.3%), cerebrospinal fluid leakage (n = 1; 3.3%), and wound infection (n = 1; 3.3%). No complications were observed in the keyhole craniotomy group. There was no between-group difference in postoperative seizure control. The mean Engel class I seizure-free outcome was 90.4% in the standard frontotemporal craniotomy group and 90.7% in the nummular craniotomy group (P > 0.05). Lengths of hospitalization (2.81 vs. 4.37 days, P < 0.001) and operative time (85.79 vs. 142.73 minutes, P < 0.001) were lower in the keyhole than in the standard frontotemporal craniotomy group, respectively. The nummular technique was associated with faster recovery, early hospital discharge, and fewer complications than the standard technique. No differences were observed in postoperative seizure control. Keyhole craniotomy is a safe, easy, and effective treatment option for medically intractable MTLE. [ABSTRACT FROM AUTHOR]

Purpose: To compare the seizure outcome following early and late complete antiepileptic drug (AED) withdrawal following anterior temporal lobectomy (ATL) for mesial temporal lobe epilepsy (MTLE).Method: All the patients who were seizure free for one year following ATL were offered early or late AED withdrawal. AEDs were discontinued starting at one year in those who opted for early withdrawal. Patients who opted for late withdrawal were continued on single AED for three years following surgery before attempting complete discontinuation.Results: Of the 135 study patients, 65 opted for early AED withdrawal and 70 for late withdrawal. The mean postoperative follow-up duration was 10.4 ± 1.3 (Range, 8-12) years. At three years following surgery, seizure recurrence occurred in 23 (35.4 %) patients in the early withdrawal group and in 10 (14.3 %) patients in late withdrawal group (p = 0.005; relative risk [RR], 2.48; 95 % confidence interval [CI], 1.28-4.80). At last follow-up, 27 (41.5 %) patients in the early withdrawal group and 26 (37.1 %) in late withdrawal group had recurrence (p = 0.60; RR, 1.12, 95 % CI, 0.74-1.70). At last followup, 80 (59.3 %) patients were off AEDs. During the terminal one year, 123 (91 %) patients were seizure free, similar in the two groups.Conclusions: This nonrandomized controlled study suggests that early complete AED withdrawal starting one year following ATL is associated with a higher risk of early seizure recurrence. However, long term seizure outcome is similar in early and late AED withdrawal groups. [ABSTRACT FROM AUTHOR]

• High-density (hd) ECoG increases the number of Fast Ripples (FR) detected during epilepsy surgery. • hd-ECoG improves the prediction of seizure outcome after resective epilepsy surgery. • hd-ECoG may advance seizure freedom after epilepsy surgery. Residual fast ripples (FR) in the intraoperative ECoG are highly specific predictors of postsurgical seizure recurrence. However, a FR is generated by a small patch of cortical tissue. Spatial sampling with standard electrodes may thus miss clinically relevant information. We analyzed FR rates in the intraoperative ECoG of 22 patients that underwent resective epilepsy surgery. We used standard electrodes with 10 mm inter-contact spacing (standard ECoG) in 14 surgeries and high-density grid electrodes with 5 mm spacing (hd-ECoG) in 8 surgeries. We detected FR using a previously validated automatic detector. Postoperative seizure freedom was achieved in 14/22 (64%) cases. Across all 42 ECoG recordings, FR rates were higher for hd-ECoG than for standard ECoG. In the 14 seizure free patients (ILAE 1), no residual FR were detected (specificity = 100%). In the 8 patients with seizure recurrence (ILAE > 1), residual FR were detected in 1/7 standard ECoG and 1/1 hd-ECoG (Accuracy ACC standard ECoG = 57%, CI [29% 82%], ACC hd-ECoG = 100%, CI [63% 100%]). Denser spatial sampling by hd-ECoG improved FR detection compared to standard ECoG. Hd-ECoG may advance seizure freedom after epilepsy surgery. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the accuracy of expert estimations of achieving seizure freedom after epilepsy surgery in the context of presurgical patient counseling.Method: The retrospective study comprised a random sample of 200 patients who underwent any type of resective epilepsy surgery at the University of Bonn Epilepsy Center and the routine 1-year postoperative control visit in the years from 2008-2016. The prediction by a team of epileptologists and the actual seizure outcome were extracted from the pre- and postsurgical medical files, respectively. A deviation of >10% was a priori defined as a relevant discrepancy.Results: Estimated chances of achieving seizure freedom ranged from 30 to 90% (mean: 67%). The actual seizure freedom rate was 66% (Engel Ia/ ILAE 1a). Nine of 12 estimation categories showed a tolerable deviation of ≤10%, none of these with a worse than expected outcome. Two estimation categories (40-50%, and 80%) showed a worse actual seizure outcome with deviations of -40% (n = 3); and -17% (n = 30), respectively. All in all, for 83% of the patients a correct prediction was provided.Conclusions: For the vast majority of surgical patients, the expert prediction of postsurgical seizure freedom at the 1-year follow-up was accurate despite the heterogeneity of patients and surgical procedures. [ABSTRACT FROM AUTHOR]

Background: This retrospective study is designed to determine whether the thickness of the corpus callosum can predict corpus callosotomy outcome in pediatric patients with epileptic or tonic spasms.Methods: We retrospectively studied 25 patients (18 boys) with intractable childhood-onset epileptic or tonic spasms who underwent corpus callosotomy between March 2008 and January 2017. Seizure outcomes were classified as favorable (class I and II of Engel's outcome classification) or unfavorable (class III and IV of Engel's outcome classification) at 12 months postoperatively. We measured the corpus callosum area on the midline and maximum cerebral area on the para-midline in sagittal magnetic resonance images just before surgery. We statistically analyzed the associations between surgical outcomes and corpus callosum area, corpus callosum area/maximum cerebral area (corpus callosum/cerebrum ratio), or age at magnetic resonance imaging just before surgery, using univariate and multivariate logistic regression analyses.Results: Age at surgery ranged from six to 237 months (mean: 119). Main seizure types were epileptic spasms in 17 patients and tonic spasms in eight. Favorable outcomes occurred in 10 (40%) patients and unfavorable outcomes in 15 (60%). Both corpus callosum area and corpus callosum/cerebrum ratio did not show significant associations with the outcomes in the univariate and multivariate analyses. The 95% confidence intervals of corpus callosum/cerebrum ratio strongly overlapped between the favorable and unfavorable outcome groups.Conclusions: Our data failed to support that corpus callosum thickness on the sagittal image is associated with corpus callosotomy outcomes in pediatric patients with epileptic spasms or tonic spasms. [ABSTRACT FROM AUTHOR]

Objective We aimed to investigate the possible predictive factors and longitudinal change in long-term surgical outcome after refractory frontal lobe epilepsy surgery. Methods We retrospectively reviewed 82 patients who underwent frontal lobe resection. Invasive monitoring was performed in 43 patients. All patients were followed-up for a minimum of 3 years after surgery. Univariate and multivariate analyses were used to evaluate the predictors. The Kaplan-Meier survival curve showed the estimated probability of complete seizure freedom, and a favorable outcome was defined as Engel class I at the last follow-up. Results The estimated probability of complete seizure freedom was 57.3% at 1 year postoperatively, 51.2% at 2 years, and 50.0% at 5 years. Factors predictive of worse long-term outcome were lack of a lesion in the frontal lobe on magnetic resonance imaging, generalized/nonlocalized ictal discharge, use of subdural grids, and acute postoperative seizure (APOS). After the surgery, 44 patients (53.7%) had seizures at any time during the first 2 years. Five of 44 patients had seizure freedom at the last follow-up. After a seizure-free period of at least 6 months, seizure recurred in 6 patients by 6 months to 1 year (early recurrence) and in 9 patients by 1–3 years (late recurrence). Eight of 43 (18.6%) seizure-free patients had discontinued drugs. Conclusions The overall seizure outcome after surgery changed most during the first 2 years. The presence of frontal focal lesions and ictal frontal rhythm predicted favorable outcome. However, APOS was predictive of early epilepsy recurrence. Highlights • The overall seizure outcome after frontal lobe epilepsy surgery changed most during the first 2 years. • The presence of frontal focal lesions and ictal frontal rhythm predicted favorable outcome. • Acute postoperative seizure was predictive of early epilepsy recurrence. • For seizure-free patients, gradual discontinuation of antiepileptic drugs may be considered after 3 years postoperatively. [ABSTRACT FROM AUTHOR]

Highlights • Prospective study evaluating the significance of epileptic activity in ECoGs in children. • Relationship between fast activity recorded in the ECoGs and unfavourable seizure outcomes. • Fast activity recorded with a relatively simple ECoG-equipment might be an alternative to high-frequency oscillations. Abstract Objective To evaluate prospectively the informative/prognostic value of epileptic discharges in the post-resection ECoGs of children with drug-resistant epilepsies and Focal Cortical Dysplasia type II (FCD-II). Methods Included were consecutive patients with focal epilepsies and suspected FCD-II who were planned for single-stage epilepsy surgery based on non-invasive presurgical evaluation results. Intraoperative ECoGs were recorded using a 32-channel system with strip- and/or grid-electrodes. Spikes were defined as transients with a mainly negative component and duration of 20–70 ms. Fast activity was defined as rhythmic bursts of polyspikes >13 Hz. All ECoGs were analysed visually. The significance of both spikes and fast activity in the post-resection ECoG for seizure outcomes 24 months after surgery was evaluated. Results Data from 18 patients (five girls) were analysed. 10/18 patients (55.6%) showed spikes in their post-resection ECoGs, five of them showed additional fast activity. 24 months after surgery, 12/18 patients (66.7%) were seizure-free. There was a significant correlation between unfavorable seizure outcomes and fast activity in the post-resection ECoGs (p = 0.009), whereas spikes alone were not predictive (p = 0.502). Conclusion Even when recorded with non-sophisticated techniques, presence of fast activity in post-resection ECoGs might be a valid negative outcome-predictor after surgery in paediatric patients with FCD-II associated drug-resistant epilepsies. Significance Fast activity recorded with a relatively simple ECoG equipment seems also to have prognostic significance and by this might be an alternative to HFOs recorded with highly sophisticated and expensive technologies. [ABSTRACT FROM AUTHOR]

Several surgical options are available for treating hypothalamic hamartoma-related epilepsy but their respective efficacy and safety profiles are poorly defined. A literature search identified English-language articles reporting series of patients (minimum 3 patients with a follow-up ≥12 months) operated on by either microsurgery, endoscopic surgery, radiosurgery, radiofrequency thermocoagulation or laser interstitial thermal therapy for hypothalamic hamartoma-related epilepsy. The unit of analysis was each selected study. Pooled rates of seizure freedom and of neurological and endocrinological complications were analyzed using meta-analysis to calculate both fixed and random effects. The results of meta-analyses were compared. Thirty-nine studies were included. There were 568 and 514 participants for seizure outcome and complication analyses, respectively. The pairwise comparison showed that: i) the proportion of seizure-free cases was significantly lower for radiosurgery as compared to microsurgery, radiofrequency thermocoagulation and laser ablation, and significantly lower for endoscopic surgery as compared to radiofrequency thermocoagulation; ii) the proportion of permanent hypothalamic dysfunction was significantly higher for microsurgery as compared to all other techniques, and significantly lower for endoscopic surgery as compared to radiofrequency thermocoagulation and laser ablation; iii) the incidence of permanent neurological disorders was significantly higher for microsurgery as compared to endoscopic surgery, radiosurgery and radiofrequency thermocoagulation, and significantly lower for radiosurgery as compared to laser ablation. Minimally invasive surgical techniques, including endoscopic surgery, radiofrequency thermocoagulation and laser ablation, represent an acceptable compromise between efficacy and safety in the treatment of hypothalamic hamartoma-related epilepsy. Microsurgery and radiosurgery should be considered in carefully selected cases. • Open microsurgery, despite a favorable impact on seizures, presents with the highest risks of complications. • Radiosurgery has the most favorable safety profile at the expense of the poorest seizure outcome. • Endoscopic surgery, radiofrequency thermocoagulation and laser ablation represent a compromise between safety and efficacy. • Customizing the choice of the surgical technique, based on patient features, should be the direction of future research. [ABSTRACT FROM AUTHOR]

Highlights • Significance of auras on surgical outcome in drug-resistant temporal lobe epilepsy was studied. • Presence or absence of auras had no bearing on surgical outcome after anterior temporal lobectomy. • Auditory and vertiginous auras are red herrings while selecting candidates for ATL. • Ictal onset zone should be delineated in patients with auditory and vertiginous auras before ATL. Abstract Purpose The success of epilepsy surgery lies in identifying the ictal onset zone accurately. The significance of auras has little been explored on surgical outcome in drug-resistant epilepsy. This study focuses on the clinicopathological correlation of aura(s) and its role in predicting surgical outcome in drug-resistant temporal lobe epilepsy (TLE). We compared surgical outcome in TLE between patients with and without aura and identified the clinico-pathological, radiological and surgical differences between the two groups. Methods Consecutive patients who underwent presurgical evaluation from January 2009 to December 2014 for drug-resistant TLE who underwent anterior temporal lobectomy (ATL) were included. Patients were followed up at 3months, 12 months and then annually. Results Among 456 patients, 344(75%) had aura. Multivariate logistic regression showed that prototype EEG pattern at ictal onset (OR 2.12, 95% CI 1.18–3.06, p = 0.012) and right sided epileptogenic zone (OR 1.82 95% CI 1.18–3.78, p = 0.007) were significantly associated with presence of aura. There was no difference in surgical outcome between those with and without aura. But patients with auditory aura (OR 7.28, CI 2.80–18.95, p = 0.0002) and vertiginous aura (OR 3.01, CI 1.55–7.85, p = 0.028) had a poor surgical outcome. Bivariate analysis showed that normal MRI (p = 0.028) and normal/indeterminate pathology (p = 0.001) were significantly more common with auditory/vertiginous auras. Conclusions Mere presence of aura does not affect outcome after TLE surgery. However, auditory and vertiginous auras are predictors of poor surgical outcome. These patients require more extensive screening for an ictal onset zone beyond standard limits of ATL before surgery. [ABSTRACT FROM AUTHOR]

Objective To evaluate the prognostic value of postoperative EEGs to estimate post anterior temporal lobectomy (ATL) seizure outcome. Methods We studied postoperative EEGs in 325 consecutive patients who had minimum five years of post-ATL followup. Interictal epileptiform discharges (IEDs) present only during sleep were classified as sleep IEDs. We defined favorable final-year outcome as no seizures during the final one year and favorable absolute-postoperative outcome as no seizures during the entire postoperative period. Results At mean follow-up of 7.3 ± 1.8 years, 281 (86.5%) patients had favorable final-year outcome while 161 (49.5%) had favorable absolute-postoperative outcome. IEDs on three months and one year EEG were associated with unfavorable outcomes while IEDs at 7th day had no association with outcomes. Sleep record increased the yield of IEDs by 30% at each time-point without compromising predictive value. EEG at one year predicted the risk of seizure recurrence on drug withdrawal. Conclusion While EEG at three months and at one-year after ATL predicted seizure outcome, EEG at 7th day was not helpful. Sleep record increases the sensitivity of postoperative EEG without compromising specificity. Significance Both awake and sleep EEG provide useful information in postoperative period following ATL. [ABSTRACT FROM AUTHOR]

Drug-resistant focal epilepsy is a common occurrence in patients with gray matter nodular heterotopia (NH), and surgical treatment is often considered in these cases. NH-related epileptogenicity is sustained by complex networks, which may involve the nodules and extralesional cortex in various combinations. Therefore, invasive EEG is usually required to identify the structures involved in seizure generation. It has been reported that surgery may be effective in cases with unilateral lesions, whereas bilateral cases are not optimal candidates for surgical success. Furthermore, violation of cortical and subcortical structures for approaching deep-seated nodules may result in neurological deficits. For these reasons, selective stereotactic ablation with radiofrequency thermocoagulation (RFTC) has been proposed as an alternative option in these patients. In particular, RFTC may be performed by using the same recording intracerebral electrodes implanted for stereo-electro-encephalo-graphy (SEEG) monitoring, with the advantage of a reliable electro-clinical guide. Excellent results on seizures have been initially reported following coagulation of single, unilateral NH. Subsequent experience has indicated that, basing on the evidence of SEEG recording, promising results may be obtained also in more extended unilateral and bilateral cases. In more complex cases, coagulation of both the nodules and of the involved extralesional cortical structures is often required. In a recently reported series, 67% of patients experienced sustained seizure freedom after the procedure. However, post RFTC seizure outcome in complex cases (NH plus other malformations of cortical development) is not as good as in other patterns of NH. RFTC, especially if guided by SEEG evaluation, should be considered as a first-line treatment option in NH-related epilepsy. Satisfactory results may be obtained also in cases not amenable to traditional surgery. The procedure is safe and does not prevent eventual resective surgery in case of failure in seizure control. For these reasons, in patients undergoing SEEG evaluation, electrode arrangement should be planned with the aim to cover as extensively as possible the heterotopic and extralesional areas, which will presumably be the targets of RFTC. [ABSTRACT FROM AUTHOR]

Purpose: Generalized seizures were often thought to be contraindications for hemispherectomy. However, few studies had investigated this issue comprehensively, as well as the predictors for generalized seizures in hemispheric lesion. We studied the predictors of generalized seizures and their potential link to seizure outcomes in a cohort of children who underwent hemispherectomy.Methods: A cohort of 76 children with hemispherectomy were reviewed and dichotomized into two groups with and without generalized seizures confirmed by vEEG presurgically. All preoperative evaluation data correlated to generalized seizures and postoperative prognosis were collected and analysed.Results: Of 76 patients, 11 (14.5%) cases were documented with various generalized seizures, including atypical absence (54.5%, 6/11), myoclonic (45.5%, 5/11), atonic (36.4%, 4/11), myoclonic-atonic (18.2%, 2/11), myoclonic-absence (9.1%, 1/11) and spasms (9.1%). Electrical status epilepticus during sleep (ESES) was recorded in 3 patients (27.3%, 3/11). At last follow-up, 72.7% (8/11) patients remained seizure-free. ESES was a predictor of generalized seizures (χ2 = 4.69, P = 0.043). No correlation was found between generalized seizures and unfavourable postoperative seizure outcome (P = 0.153). For different seizure types, focal to bilateral tonic-clonic seizures (P = 0.020) and myoclonic-atonic seizures (P = 0.002) might correlate with unfavourable outcomes.Conclusion: Generalized seizures were not an absolute contraindication for hemispherectomy. Those patients with ESES might experience generalized seizures presurgically. Focal to bilateral tonic-clonic seizures and myoclonic-atonic seizures pre-surgery may indicate unfavourable post-operative seizure outcomes. [ABSTRACT FROM AUTHOR]

Purpose: Significant challenges exist for Ketogenic Diet (KD) programs in many populations, mainly due to the variations in local dietary preferences. Here we report a single center experience of KD therapy in a cohort of South Indian children with pharmaco-resistant epilepsies.Methods: Children aged 0-18 years, enrolled in the KD program for pharmacoresistant epilepsies of Amrita institute of Medical Sciences, Kochi, Kerala, India (2010 - 2015) were included in this pragmatic study. Diet efficacy was evaluated according to reduction in seizure frequency and in the number of antiepileptic drugs (AED). Duration of retention, reasons for discontinuation and the rate of adverse events were used for assessing KD tolerability.Results: Seventy four children were enrolled in the KD program. Four children could not complete the initiation process. Median age at KD initiation was 4.2years. 53 children had developmental delay. 89% were on 3 or more AEDs. Baseline seizure frequency was >5/day in 52 children. KD was continued for a median duration of 10.43 months. At the last contact, 59.4% reported seizure reduction of more than 50%. More than 90% reduction was noted in 25 children (33.7%). 6(8.1%) of them became completely seizure free. Four children expired during the study period and four children reported major adverse events necessitating KD withdrawal. Main reasons for discontinuation of KD were poor compliance, lack of response to diet and relapse of seizures.Conclusion: KD may be a safe and effective option for children with pharmacoresistant epilepsies even while on a traditional carbohydrate rich South Indian diet. [ABSTRACT FROM AUTHOR]

Purpose: The incidence of epilepsy in older adults is growing, as does the incidence of comorbidities. Therefore, when it comes to epilepsy surgery in medically intractable epilepsy, age is often seen as a limiting factor. To investigate the outcome after epilepsy surgery in a population of older adults, we compared the benefit for patients aged 50-59 years with those aged 60 years and older in respect of efficacy and safety.Method: Patients aged ≥50 years with medically intractable epilepsy who underwent epilepsy surgery from 1990 to 2013 were selected from the database of a German epilepsy center. All of them received a standardised and detailed presurgical diagnostic evaluation. Follow-up included at least four scheduled visits with EEG, MRI and neuropsychological testing. Outcome was assessed using the Engel outcome scale.Results: 79 patients aged between 50 and 67 years were followed-up for a median of 4.7 years (2-16 years). 68% of patients were free of disabling seizures (Engel class I, ≥60 years: 75%) and 58% were seizure-free (Engel class IA, ≥60 years: 70%). 90% of our patients suffered from temporal lobe epilepsy (TLE), 9% from frontal lobe epilepsy (FLE) and one occipital lobe epilepsy (OLE). After surgery, 9% discontinued or tapered their medication. Permanent surgical complications occurred in 10% of cases and transient neurological deficits were seen in 11%. Older patients had a higher risk for postoperative hygroma (≥60 years 15%; <60 years 8%) and were more prone to postoperative memory deficits (≥60 years 45%), especially after resection of the dominant temporal lobe. Verbal and figural memory testing did not differ significantly between the groups.Conclusions: The results support the view that in selected older patients, epilepsy surgery shows equal or even higher success rates as compared to younger patients. However, patients of older age may be at greater risk for postoperative hygroma and memory deficits, especially after dominant temporal lobe resections. [ABSTRACT FROM AUTHOR]

Purpose To determine the factors predicting seizure outcome in children who underwent anterior temporal lobectomy (ATL) for drug-resistant temporal lobe epilepsy (TLE). Methods Among the 664 patients who underwent ATL for TLE from 1995 to 2008, there were 134 children. “Excellent” outcome in them was defined as seizure freedom during the entire follow-up (Engel class I a); “good outcome”, if in remission last 2 years, and the rest as “unfavorable outcome”. To identify the potential predictors of seizure recurrence, the attributes of recurred and non-recurred groups was compared by univariate and multivariate analysis. Results Of the 134 children, at a mean post-operative follow-up of 8.1 years, there were 82 (61.1%) with excellent outcome and 26 (19.4%) with good outcome (category-1; seizure-free, 80.6%). Drugs could be successfully withdrawn in 69 (63.9%). 26 patients (22.4%) had seizure recurrence, (category-2, treatment/surgical failure).Whereas, of the 530 adults who underwent ATL during this time period, only 46.8% never had seizures (category-1) and 53.2% had seizure recurrence in the form of acute post-operative seizures or auras or habitual or non-habitual seizures ( category-2).The hazard of seizure recurrence in children increased with positive family history of seizures and /or epilepsy, normal neuroimaging, spikes in post-operative EEG at 3-months, normal histopathology and duration of epilepsy ≥5 years. Conclusions The information on the predictive factors causing seizure recurrence/freedom in children with drug-resistant TLE is important in surgical selection. Surgery for pediatric TLE results in favorable outcome, hence one should subject children for resective surgery at the earliest especially in lesions known to cause refractoriness. [ABSTRACT FROM AUTHOR]

Objective Hippocampal sclerosis (HS) is the most prevalent pathology in temporal lobe epilepsy (TLE) characterized by segmental neuronal cell loss in the cornu ammonis (CA) 1–4. In addition, migration of granule cells and reorganization of their axons is observed, known as granule cell dispersion (GCD) and mossy fiber sprouting (MFS). The loss of mossy fibers` (MF) target cells in CA4 and CA3 was considered to be causative for MFS. The ILAE HS (International League Against Epilepsy) classification identifies three subtypes with different cell loss patterns in CA1-4. We studied the relation of ILAE HS subtypes to GCD and MFS to corroborate clinico-pathological subgroups in a large retrospective single-center series. Material and methods Hippocampal specimen of 319 patients were screened, 214 could be used for analysis. Immunohistochemical stainings for semi-quantitative analysis of neuronal cell loss (NeuN) and MFS (synaptoporin) were performed. Presurgical data were available from patient files and seizure outcome was classified according to Engel score after surgery. Results In 39 patients (18%) no neuronal cell loss (ILAE no-HS), no GCD and no MFS was observed. In 154 patients (72%) severe neuronal cell loss was seen in CA1, CA4 and CA3 (ILAE HS 1, typical HS); in addition extensive GCD and MFS was observed. In 17 patients (8%) cell loss was seen predominantly in CA1 (ILAE HS 2); despite different cell loss pattern these hippocampi also showed GCD and MFS. In 4 patients (2%) cell loss was predominately detected in CA3 and CA4 (ILAE HS type 3), consecutively GCD and MFS were observed. Longer epilepsy duration and younger age at surgery was more often associated with ILAE HS 2 and febrile convulsions were completely absent in ILAE no-HS. Yet, seizure onset, age at initial precipitating injury and postsurgical seizure outcome did not show any significant association with ILAE HS subtypes. Conclusion GCD and MFS might develop independently from the neuronal cell loss of MF target cells. [ABSTRACT FROM AUTHOR]

Purpose: Using a novel technique based on phase locking value (PLV), we investigated the potential for features extracted from electrocorticographic (ECoG) recordings to serve as biomarkers to identify the seizure onset zone (SOZ).Methods: We computed the PLV between the phase of the amplitude of high gamma activity (80-150Hz) and the phase of lower frequency rhythms (4-30Hz) from ECoG recordings obtained from 10 patients with epilepsy (21 seizures). We extracted five features from the PLV and used a machine learning approach based on logistic regression to build a model that classifies electrodes as SOZ or non-SOZ.Results: More than 96% of electrodes identified as the SOZ by our algorithm were within the resected area in six seizure-free patients. In four non-seizure-free patients, more than 31% of the identified SOZ electrodes by our algorithm were outside the resected area. In addition, we observed that the seizure outcome in non-seizure-free patients correlated with the number of non-resected SOZ electrodes identified by our algorithm.Conclusion: This machine learning approach, based on features extracted from the PLV, effectively identified electrodes within the SOZ. The approach has the potential to assist clinicians in surgical decision-making when pre-surgical intracranial recordings are utilized. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the relationship between molecular markers and clinicopathological features in patients operated on for low-grade epilepsy-associated neuroepithelial tumors. Molecular-genetic signatures are becoming increasingly important in characterizing these lesions, which represent the second most common cause of focal epilepsy in patients undergoing epilepsy surgery. Data from 22 patients operated on for histopathologically confirmed low-grade epilepsy-associated neuroepithelial tumors were retrospectively collected. All specimens were examined for BRAF and IDH mutational status, 1p/19q codeletion and CD34 expression. The relationship between bio-molecular markers and several demographic, clinical and pathological features were analyzed. BRAF mutation was found in 11 (50.0%) patients and CD34 expression in 13 (59.1%). No patients presented IDH mutation or 1p/19q codeletion. Multiple seizure types were present in 5 (45.5%) patients with BRAF mutation and in none of those with BRAF wild type ( p = 0.035). Moreover, BRAF mutation was predominant in right-sided lesions ( p = 0.004) and CD34 expression was significantly associated with a longer duration of epilepsy ( p = 0.027). Several other clinicopathological features, such as association with focal cortical dysplasia and postoperative seizure outcome, showed no significant correlation with molecular markers. Further studies are necessary both to confirm these data in larger cohort of patients and to investigate possible relationships between molecular markers and other clinicopathological features. [ABSTRACT FROM AUTHOR]

In the surgical management of epilepsy, the resection of cortex exhibiting interictal fast ripples (250–500 Hz) on electrocorticography has been linked to postoperative seizure-freedom. Although fast ripples appear to accurately identify the epileptogenic zone—the minimum tissue that must be removed at surgery to achieve seizure-freedom—it has not been established that fast ripples are a superior biomarker in comparison with multimodal presurgical neuroimaging and other electrocorticography abnormalities. Hence, in the prediction of postoperative seizure-freedom, we compared the value of fast ripples with other intraoperative electocorticography abnormalities including focal slowing, paroxysmal fast activity, intermittent spike discharges, continuous epileptiform discharges, focal attenuation, and intraoperative seizures, as well as complete resection of the lesion defined by MRI and other neuroimaging. In a cohort of 60 children with lesional epilepsy and median postsurgical follow-up exceeding 4 years, who underwent resective epilepsy surgery with intraoperative electrocorticography, we evaluated the extent to which removal of each intraoperative electrocorticography abnormality impacts time to first postoperative seizure using the Kaplan-Meier method and Cox proportional hazards regression. Secondly, we contrasted the predictive value of resection of each competing electrocorticography abnormality using standard test metrics (sensitivity, specificity, positive predictive value, and negative predictive value). In contrast with all other intraoperative electrocorticography abnormalities, fast ripples demonstrated the most favorable combination of positive predictive value (100%) and negative predictive value (76%) in the prediction of postoperative seizures. Among all candidate electrocorticography features, time to first postoperative seizure was most strongly associated with incomplete resection of fast ripples (hazard ratio = 19.8, p < 0.001). In multivariate survival analyses, postoperative seizures were independently predicted by incomplete resection of cortex generating fast ripples (hazard ratio = 25.4, 95%CI 6.71–96.0, p < 0.001) and focal slowing (hazard ratio = 5.79, 95%CI 1.76–19.0, p = 0.004), even after adjustment for the impact of an otherwise complete resection. All children with incomplete resection of interictal FR-generating cortex exhibited postoperative seizures within six months. Notably, this cohort included many patients with large resections and thus limited opportunity to exhibit unresected fast ripples. Future study in a cohort with small resection volume, or a clinical trial in which resection margins are guided by fast ripple distribution, would likely yield a more precise estimate of the risk posed by unresected fast ripples. With a high detection rate during brief intraoperative electrocorticography and favorable positive and negative predictive value, interictal fast ripple characterization during surgery is a feasible and useful adjunct to standard methods for epilepsy surgery planning, and represents a valuable spatially-localizing biomarker of the epileptogenic zone, without the need for prolonged extraoperative electrocorticography. [ABSTRACT FROM AUTHOR]

Purpose: Surgery is an effective treatment for drug resistant focal epilepsy. Predictors of seizure outcome have been extensively addressed in the general population but similar data on older patients are still lacking. The aim of this study is to evaluate effectiveness and safety of surgery for patients over 50 years and to investigate variables associated to seizure outcome.Methods: We performed a single center retrospective study including 50 patients over 50 years treated surgically for drug resistant focal epilepsy between 1997 and 2014. We analyzed the rate of success of seizure control, the association of several clinical variables with seizure outcome and the rate of surgery-related complications. We also investigated the impact of surgery on the patients' cognitive performances and mood profile.Results: At last follow-up 78% of our patients were seizure-free, similar to patients younger than 50 years operated on in the same period (p=1). The rate of surgery-related complications was 10%, higher compared to younger patients (p<0.0001). Pre-surgical daily seizure frequency (p=0.0040) and the histological diagnosis of LEAT (p=0.0233) were associated to a poorer seizure outcome. No significant differences were evidenced between pre- and postoperative neuropsychological profiles. A slight, not statistically significant improvement of the mood profile was observed postoperatively.Conclusion: Our results suggest that surgery is an effective treatment option also for older epileptic patients, although it is burdened by a higher surgical risk as compared to younger patients. The availability of predictors of outcome also for these patients may be helpful for pre-surgical counseling. [ABSTRACT FROM AUTHOR]

Objective To describe the surgery outcomes of RE patients in one centerto identify the indication for surgical treatment that results in the most favorable outcome. Method Forty-five RE patients from a single center were retrospectively reviewed. Preoperative evaluations included assessments of clinical manifestations, cognitive status, a physical examination, MRI, positron emission tomography (PET), electroencephalography (EEG), and magnetoencephalography (MEG). The surgical outcomes included seizure outcome, neurological function, EEG, a cognitive evaluation, and antiepileptic drug withdrawal. Results A total of 45 children (29 male) with RE were included in this study. The mean follow-up period from the first operation was 31.7months (range 6–96). The patients who underwent anatomical hemispherectomy or hemisphere disconnection had better seizure outcomes without greater perioperative complications compared with the patients who underwent functional hemispherectomy. Reoperative hemispherectomy was a safe and effective treatment for patients with postoperative epilepsy recurrence. After the last surgery, 34 patients (74.4%) were evaluated as Engel class I. Most of the patients had favorable neurological outcomes. Analysis revealed that the patientswith IQs greater 70 who underwent operations were more likely to suffer from IQ declines but were also more likely to have higher IQs in the future. Significance Compared with functional hemispherectomy and hemisphere disconnection, anatomical hemispherectomy elicited better seizure outcomes with an acceptable level of complications. Early stage operations might lead to better cognitive status, but they are associated with a high risk of IQ decline. [ABSTRACT FROM AUTHOR]

Objective The most frequent finding in temporal lobe epilepsy is hippocampal sclerosis, characterized by selective cell loss of hippocampal subregions CA1 and CA4 as well as mossy fiber sprouting (MFS) towards the supragranular region and granule cell dispersion. Although selective cell loss is well described, its impact on mossy fiber sprouting and granule cell dispersion remains unclear. Materials and methods In a single center series, we examined 319 human hippocampal specimens, collected in a 15-years period. Hippocampal specimens were stained for neuronal loss, granule cell dispersion (Wyler scale I–IV, Neu-N, HE) and mossy fiber sprouting (synaptoporin-immunohistochemistry). For seizure outcome Engel score I–IV was applied. Results In Wyler I and II specimens, mossy fibers were found along their natural projection exclusively in CA4 and CA3. In Wyler III and IV, sprouting of mossy fibers into the molecular layer and a decrease of mossy fibers in CA4 and CA3 was detected. Mean granule cell dispersion was extended from 121 μm to 185 μm and correlated with Wyler III-IV as well as mossy fiber sprouting into the molecular layer. Wyler grade, mossy fiber sprouting and granule cell dispersion correlated with longer epilepsy duration, late surgery and higher preoperative seizure frequency. Parameters analyzed above did not correlate with postoperative seizure outcome. Discussion Mossy fiber sprouting might be a compensatory phenomenon of cell death of the target neurons in CA4 and CA3 in Wyler III–IV. Axonal reorganization of granule cells is accompanied by their migration and is correlated with the severity of cell loss and epilepsy duration. [ABSTRACT FROM AUTHOR]

Purpose: There is Class I evidence for short-term efficacy of epilepsy surgery from two randomized controlled studies of temporal lobe resection. Long-term outcome studies are observational. The aim of this narrative review was to summarise long-term outcomes taking the study methodology into account.Methods: A PubMed search was conducted identifying articles on long-term outcomes of epilepsy surgery in adults with regard to seizures, antiepileptic drug treatment and employment. Definitions of seizure freedom were examined in order to identify the proportions of patients with sustained seizure freedom. The quality of the long-term studies was assessed.Results: In a number of high-quality studies 40-50% of patients had been continuously free from seizures with impairment of consciousness 10 years after resective surgery, with a higher proportion seizure-free at each annual follow-up. The proportion of seizure-free adults in whom AEDs have been withdrawn varied widely across studies, from 19-63% after around 5 years of seizure freedom. Few long-term vocational outcome studies were identified and results were inconsistent. Some investigators found no postoperative changes, others found decreased employment for patients with continuing seizures, but no change or increased employment for seizure-free patients. Having employment at baseline and postoperative seizure freedom were the strongest predictors of employment after surgery.Conclusions: Long-term studies of outcomes after epilepsy surgery are by necessity observational. There is a need for more prospective longitudinal studies of both seizure and non-seizure outcomes, considering individual patient trajectories in order to obtain valid outcome data needed for counselling patients about epilepsy surgery. [ABSTRACT FROM AUTHOR]

Objective We hypothesized that the extensive epileptic network in patients with tuberous sclerosis complex (TSC) manifests as clustered and scattered distributions of magnetoencephalography spike sources (MEGSS). Methods We retrospectively analyzed pre-surgical MEG in 15 patients with TSC. We performed single moving dipole analysis to localize and classify clustered and scattered MEGSS. We compared the number of electrodes within the resected area (RA) and the proportions of clustered and scattered MEGSS within RA with the seizure outcome. Results The number of electrodes within RA ranged from 29 to 83 (mean = 51). The MEGSS were distributed over multiple lobes (3–8; mean = 5.9) and bilaterally in 14 patients. Clusters of MEGSS ranged from 1 to 4 (mean = 1.4). The number of MEGSS ranged in total from 28 to 139 (mean = 70); in the clusters, 10–128 (mean = 49); and in the scatters, 0–45 (mean = 21). Four patients achieved an Engel class I surgical outcome, four, a class II outcome; five, a class III outcome; and two, a class IV outcome. The proportion of MEGSS ranged in total from 0 to 92% (mean = 57%) within RA; 0–100% (mean = 67%) in the resection hemisphere; 0–100% (mean = 63%) in the clusters; and 0–81% (mean = 28%) in the scatters. Univariate ordinal logistic regression analyses showed that the proportion of scattered MEGSS within RA (p = 0.049) significantly correlated with seizure outcomes. Multivariate analyses using three covariates (number of electrodes, proportions of clustered and scattered MEGSS within RA) showed that only the proportion of scattered MEGSS within RA significantly correlated with seizure outcomes (p = 0.016). Significance MEG data showed a wide distribution of multilobar MEGSS in patients with TSC. The seizure outcome was not related to the clustered MEGSS within RA, since the grids were essentially planned to cover and resect the clustered MEGSS surrounding tubers. The maximal possible resection of scattered MEGSS correlated with improved seizure outcome in TSC. Some parts of the epileptogenic zone disrupted by multiple tubers did not have a sufficiently large area to produce clustered MEGSS. Although the wide distribution of scattered MEGSS is not interpreted as epileptogenic, they might be interrelated with clustered MEGSS to project a complex epilepsy network and be part of the extensive epileptogenic zones found in TSC. [ABSTRACT FROM AUTHOR]

Objective Fast ripples (FR, 250–500 Hz) are proposed biomarkers of the epileptogenic zone on the basis of several retrospective reports linking postoperative seizure freedom to their complete resection. There are no clinical trials or prospective reports validating the use of FR as characterized by electrocorticography (ECoG), to guide the scope of epilepsy surgery, and to inform prognosis thereafter. We set out to prospectively evaluate the utility of FR resection to predict postoperative epilepsy outcomes, and examine the feasibility of “live” intraoperative FR ascertainment. Methods FR were prospectively reviewed in 30 consecutive pediatric cases including 11 reviewed “live” during surgery. Intraoperative ECoG studies were recorded at 2000 Hz sampling rate, interpreted conventionally to guide surgical resection, and visually inspected for FR. Seizure outcome was tallied for all 30 children. Results Median age at surgery was 9.1 years (interquartile range [IQR] 4.7–13.2), median ECoG duration was 10.5 min (IQR 8.0–13.2), and median postoperative follow-up was 58.4 months (IQR 25.7–79.0). FR were identified in 24 of 30 ECoG studies. The incomplete resection of FR was strongly linked to postoperative seizures (hazard ratio 11.6, p = 0.005). “Live” ECoG review in the operating room to ascertain FR proved feasible and did not differ from conventional FR ascertainment. Significance: In a prospective fashion, including “live” review, FR were detected in 80% of pediatric ECoG studies, and incomplete resection of FR cortex predicted postoperative seizures. These findings extend the notion that interictal FR are surrogate markers of the epileptogenic zone, and that their intraoperative localization could be used to inform prognosis and guide surgical resections in children. [ABSTRACT FROM AUTHOR]

Object The intention of our study was to identify predictive characteristics for long-term seizure control and running down phenomenon after surgical treatment of pharmacoresistant mesiotemporal lobe epilepsy (mTLE) with and without associated cortical dysplasia. Materials and methods Our study comprises a consecutive series of 458 patients who underwent surgical treatment for intractable mTLE at the Epilepsy Center Freiburg. Data evaluated included semiology, duration and frequency of seizures, results of presurgical diagnostics including video-EEG monitoring, MRI, PET and SPECT as well as postoperative seizure outcome. Results were evaluated forming two groups: Group A consisted of isolated mesiotemporal lesions. Group B comprised patients with mTLE and additional focal cortical dysplasia (FCD). Statistical evaluation was based on the Kaplan Meier survival analysis, using log-rank-tests and a multivariate regression model. Postoperative running down phenomenon was defined as seizure freedom after a period of gradual reduction of postoperative seizure frequency. This was compared to patients with ongoing epilepsy. Results Complete seizure freedom was achieved in 65.0% of investigated patients at 1 year and in 56.5% at long-term follow-up of ≥5 years after surgery. Corresponding results were 64.2% and 56.8% at 1 and ≥5 years, respectively in group A and 66.4% and 56.0%, respectively in group B. Predictive for favorable postoperative outcome in the total group were younger age at surgery, shorter duration of epilepsy, absence of secondarily generalized tonic-clonic seizures (SGTCS), presence of strictly ipsilateral temporal interictal epileptiform discharges (IEDs), complete resection of the lesion as well as absence of postoperative epileptiform activity and of early postoperative seizures. In subgroup analyses, patients of group A demonstrated longer postoperative seizure-free intervals with adolescent age at surgery, short duration of epilepsy before surgery and absence of SGTCS, whereas in patients of group B ipsilateral temporal seizure onset and strictly unilateral IEDs in EEG as well as complete resection were predictors for favorable seizure outcome. Furthermore, absence of early postoperative seizures and of spikes in EEG were predictive factors for long-term seizure-freedom in both subgroups. The running down phenomenon was found in 33 (7.2%) patients. None of the parameters evaluated demonstrated significant predictive power. Only late seizure onset and neoplastic lesions showed a trend for postoperative gradual seizure reduction in multivariate analyses. Conclusion Depending on the presence or absence of focal cortical dysplasia in addition to mesiotemporal structural alterations, predictors of long-term seizure control differed regarding the relevant clinical and electrophysiological features. This is important for specific patient counseling in respective groups. [ABSTRACT FROM AUTHOR]

Objective High frequency oscillations (HFOs) and in particular fast ripples (FRs) in the post-resection electrocorticogram (ECoG) have recently been shown to be highly specific predictors of outcome of epilepsy surgery. FR visual marking is time consuming and prone to observer bias. We validate here a fully automatic HFO detector against seizure outcome. Methods Pre-resection ECoG dataset ( N = 14 patients) with visually marked HFOs were used to optimize the detector’s parameters in the time–frequency domain. The optimized detector was then applied on a larger post-resection ECoG dataset ( N = 54) and the output was compared with visual markings and seizure outcome. The analysis was conducted separately for ripples (80–250 Hz) and FRs (250–500 Hz). Results Channel-wise comparison showed a high association between automatic detection and visual marking ( p < 0.001 for both FRs and ripples). Automatically detected FRs were predictive of clinical outcome with positive predictive value PPV = 100% and negative predictive value NPV = 62%, while for ripples PPV = 43% and NPV = 100%. Conclusions Our automatic and fully unsupervised detection of HFO events matched the expert observer’s performance in both event selection and outcome prediction. Significance The detector provides a standardized definition of clinically relevant HFOs, which may spread its use in clinical application. [ABSTRACT FROM AUTHOR]

Background Hippocampal sclerosis (HS) is the most common cause of drug-resistant medial temporal lobe epilepsy (MTLE). Structural abnormalities such as HS, granule cell pathology (GCP), and focal cortical dysplasia (FCD) have been classified histopathologically, possibly allowing a more accurate assessment of prognostic seizure and neuropsychologic outcomes. We correlated seizure outcome with comprehensive temporal lobe pathologic findings, identified according to the most recent classification systems of HS, GCP, and FCD. Methods All the 83 patients who underwent anterior temporal lobectomy (ATL) for drug-resistant MTLE and with a proven diagnosis of HS between April 2001 and May 2014 were collected. Patients were divided in 2 main groups: 1) isolated HS with/without GCP (HS +/− GCP); and 2) HS associated with FCD with/without GCP (HS+FCD +/− GCP). Patients were followed up at least 1 year, and seizure outcome was reported in accordance with Engel classification. Results Group I: HS +/− GCP: Statistical analysis confirmed a better outcome in HS + GCP patients than in HS-no GCP ( P < 0.05). Moreover, a better outcome for the patients affected by GCP type I was observed ( P < 0.05). Group II: HS+FCD +/− GCP: Patients with HS variant type I presented a better seizure outcome than the patients with HS type II (Engel class IA HS type I vs. type II: 69% vs. 40%). Conclusions A pathology-based approach to epilepsy surgery might improve the interpretation of the results, could predict which cases will enjoy a better seizure outcome, and could help to the comprehension of the causes of failures. [ABSTRACT FROM AUTHOR]

Summary Objective To compare the seizure and developmental outcomes in infants and young children with epileptic encephalopathy who have undergone surgical and medical treatments. Methods An international, multicenter, observational cohort study was undertaken. A total of 317 children aged <6 years, who had frequent disabling seizures despite intensive medical treatments, were registered. Among the enrolled children, 250 were treated medically (medical group), 31 underwent resective surgery (resective group), and 36 underwent palliative surgery [callosotomy ( n = 30) or vagal nerve stimulation ( n = 6); palliative group] on admission. Seizure and developmental outcomes were obtained for 230 children during the 3-year follow-up period. Cox proportional hazard model was used to adjust for clinical backgrounds among treatment groups when comparing the seizure-free survival rates. Results At the 3-year follow-up, seizure-free survival was 15.7%, 32.1%, and 52.4% in the medical, palliative, and resective groups, respectively. The adjusted hazard ratios for seizure recurrence in the resective and palliative groups versus the medical group were 0.43 (95% CI, 0.21–0.87, P = 0.019) and 0.82 (95% CI, 0.46–1.46, P = 0.50), respectively; the former was statistically significant. Regarding the developmental outcome, the mean DQs in the resective group increased significantly compared to those in the medical group during the follow-up ( P < 0.01). As for subgroup analysis, better seizure and development outcomes were demonstrated in the resective group compared to the medical group in children with nonsyndromic epilepsies (those to which no known epilepsy syndromes were applicable). Significance These results suggest that surgical treatments, particularly resective surgeries, are associated with better seizure and developmental outcomes compared with successive medical treatment. The present observations may facilitate the identification of infants and young children with epileptic encephalopathy who could benefit from surgery. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the efficacy of chronic continuous hippocampal deep brain stimulation (DBS) in nonlesional refractory mesial temporal lobe epilepsy.Methods: Three adult patients with medically intractable epilepsy treated with hippocampal DBS were studied. Two patients underwent invasive recordings with depth stereo-electroencephalography (SEEG) electrodes to localize ictal onset zone prior to implantation of DBS electrodes. All the patients with no lesion in brain magnetic resonance imaging (MRI) scan received bilateral implantation of DBS electrodes. Chronic continuous high-frequency hippocampal stimulation was applied during treatment. The number of seizures in each patient before and after stimulation was compared.Results: Long-term hippocampal stimulation produced a median reduction in seizure frequency of 93%. Two out of these patients received unilateral activation of the electrodes and experienced a 95% and 92% reduction in seizure frequency after hippocampal DBS respectively. The last patient had bilateral electrode activation and had a seizure-frequency reduction of 91%. None of the patients had neuropsychological deterioration and showed side effects. Generalized tonic-clonic seizures disappeared completely after hippocampal DBS.Conclusions: Chronic continuous hippocampal DBS demonstrated a potential efficiency and safety in nonlesional refractory mesial temporal lobe epilepsy and might represent an effective therapeutic option for these patients. [ABSTRACT FROM AUTHOR]

Objective To corroborate which pretreatment angioarchitectural characteristics and posttreatment magnetic resonance imaging (MRI) features were associated with better seizure and antiepileptic drug outcomes in patients with brain arteriovenous malformations (AVMs) treated by Gamma Knife radiosurgery. Methods During the period 2007–2010, 220 patients with intracranial AVMs undergoing radiosurgery at our hospital were evaluated. Imaging features on digital subtraction angiography and follow-up MRI, medical records, and direct patient interview were retrospectively assessed. Seizure outcome was assessed using the Engel classification and the status of antiepileptic drug use. Results At the last follow-up, 21 of 31 patients (68%) who met the recruitment criteria had AVM obliteration on digital subtraction angiography or MRI. Seizure-free status (Engel class 1) was achieved in 20 patients (65%), and 13 of 20 (65%) seizure-free patients were medication-free. The presence of total obliteration at last imaging follow-up ( P = 0.013), absent retrograde cortical veins on digital subtraction angiography before GKRS ( P = 0.013), nidus <3.7 cm ( P = 0.006), and lower modified radiosurgery-based AVM score ( P = 0.026) were significant predictors of seizure-free outcome. The strongest independent predictor of seizure-free status was absence of retrograde veins (odds ratio = 9.9). No angioarchitectural feature, postradiosurgery imaging finding on MRI, or radiosurgical treatment parameter was a significant predictor of seizure control or cessation of medication in seizure-free patients. Conclusions This study suggests that radiosurgery provides favorable outcomes in patients with AVM-related epilepsy. Patients with intracranial AVMs can benefit from seizure control after GKRS before undergoing AVM obliteration. Absence of retrograde veins is associated with better seizure-free outcomes, regardless of the parenchymal changes after radiosurgery. [ABSTRACT FROM AUTHOR]