Long-term effectiveness and seizure recurrence risk factors of ketogenic diet for pediatric refractory epilepsy: Experience from a tertiary care center in China

OBJECTIVE

This study aimed to assess the long-term effectiveness and seizure recurrence risk in children with drug-resistant epilepsy who achieved seizure freedom on a ketogenic diet (KD). Predictors associated with seizure recurrence were also evaluated.

METHODS

Patients with drug-resistant epilepsy who received KD therapy for at least 3 months between May 2011 and April 2020 were included. The clinical efficacy of the KD was evaluated. Patients who achieved seizure freedom for at least 3 months on the KD were focused. Multivariate Cox regression models were used to explore the risk factors of seizure relapse in patients who achieved seizure freedom.

RESULTS

This study included 288 patients (163 males, 125 females). The seizure-free rates of the KD at 3, 6, 12, and 24 months were 9.7%, 16.7%, 14.2%, and 9.0%, respectively. Additionally, the seizure reduction rates between 50% and 99% were 46.5%, 39.9%, 30.2%, and 20.5%, respectively. Patients with Angelman syndrome (AS) showed the highest efficacy rate, followed by those with Dravet syndrome (DS). 51 patients achieved at least 3 months of seizure freedom on the KD. Seizures recurred in 24 (47.1%) patients. None of the patients with AS relapsed, while those with DS had the highest recurrence rate. The etiology of epilepsy, KD maintenance treatment period, and electroencephalography (EEG) abnormalities during follow-up differed significantly between patients with and without recurrence. However, multivariate Cox regression analysis indicated that a KD maintenance treatment period of less than 12 months and the presence of EEG abnormalities during follow-up were significantly correlated with a higher risk of relapse. Epilepsy control was restored in 3 of the 24 (12.5%) patients who experienced relapse.

SIGNIFICANCE

KD appears to be effective in children with various types of drug-resistant epilepsy. A short KD maintenance treatment period and EEG abnormalities during follow-up were associated with an increased risk of seizure recurrence.

Profiles of resting state functional connectivity in temporal lobe epilepsy associated with post-laser interstitial thermal therapy seizure outcomes and semiologies

Introduction

It is now understood that in focal epilepsy, impacted neural regions are not limited to the epileptogenic zone. As such, further investigation into the underlying functional connectivity (FC) patterns in those enduring Temporal Lobe Epilepsy (TLE) with Mesial Temporal Sclerosis (MTS) is imperative to understanding the intricacies of the disease.

Methods

The rsfMRIs of 17 healthy participants, 10 left-sided TLE-MTS patients with a pre-operative history of focal impaired awareness seizures (FIA), and 13 left-sided TLE-MTS patients with a pre-operative history of focal aware seizures (FA) were compared to determine the existence of distinct FC patterns with respect to seizure types. Similarly, the rsfMRIs of the above-mentioned healthy participants, 16 left-sided TLE-MTS individuals who were seizure-free (SF) 12 months postoperatively, and 16 left-sided TLE-MTS persons without seizure freedom (nSF) were interrogated. The ROI-to-ROI connectivity analysis included a total of 175 regions of interest (ROIs) and accounted for both age and duration of epileptic activity. Significant correlations were determined via two-sample t-tests and Bonferroni correction (α = 0.05).

Results

Comparisons of FA and FIA groups depicted significant correlations between the contralateral anterior cingulate gyrus, subgenual region, and the contralateral cerebellum, lobule III (p-value = 2.26e-4, mean z-score = -0.05 ± 0.28, T = -4.23). Comparisons of SF with nSF depicted two significantly paired-ROIs; the contralateral amygdala and the contralateral precuneus (p-value = 2.9e-5, mean z-score = -0.12 ± 0.19, T = 4.98), as well as the contralateral locus coeruleus and the ipsilateral intralaminar nucleus (p-value= 1.37e-4, mean z-score = 0.06 ± 0.17, T = -4.41).

Significance

FC analysis proves to be a lucrative modality for exploring unique signatures with respect to seizure types and postoperative outcomes. By furthering our understanding of the differences between epileptic phenotypes, we can achieve improvement in future treatment modalities not limited to targeting advancements.

The clinical features of patients with seizure freedom and failure after total corpus callosotomy for childhood-onset refractory epilepsy

BACKGROUND

Corpus callosotomy is a palliative surgery for medically refractory epilepsy. We aim to analyze the clinical features of patients with seizure freedom and failure after total corpus callosotomy for childhood-onset refractory epilepsy.

METHODS

We retrospectively reviewed the clinical courses of patients with childhood-onset refractory epilepsy undergoing total corpus callosotomy between May 2009 and March 2019. Seizure outcome at the last follow-up was the primary outcome. The clinical features of patients with seizure freedom and failure after callosotomy were compared.

RESULTS

Eighty patients with childhood-onset refractory epilepsy underwent total corpus callosotomy; 15 (18.8%) obtained freedom from all seizures and 19 (23.8%) had unworthwhile improvement and failure. The mean ages at seizure onset in patients with seizure freedom and failure after callosotomy were 5.7 and 5.9 years; and mean seizure durations were 9.4 and 11.5 years, respectively. Univariate analysis found epilepsy syndrome (p = 0.047), mental retardation (p = 0.007), previous medical history (p = 0.004), ≥10 seizures per day (p = 0.024), theta waves in the background electroencephalogram (p = 0.024), and acute postoperative seizure (p = 0.000) were associated with failure after callosotomy. Seizure freedom after callosotomy was more common among patients with less than 10 seizures per day.

CONCLUSIONS

Total corpus callosotomy is an effective palliative procedure for childhood-onset refractory epilepsy, particularly for patients with specific clinical characteristics. Callosotomy has a high seizure-free rate in well-selected patients.

Molecular subtypes of epilepsy associated with post-surgical seizure recurrence

Approximately 50% of individuals who undergo resective epilepsy surgery experience seizure recurrence. The heterogenous post-operative outcomes are not fully explained by clinical, imaging and electrophysiological variables. We hypothesized that molecular features may be useful in understanding surgical response, and that individuals with epilepsy can be classified into molecular subtypes that are associated with seizure freedom or recurrence after surgical resection. Pre-operative blood samples, brain tissue and post-operative seizure outcomes were collected from a cohort of 40 individuals with temporal lobe epilepsy, 23 of whom experienced post-operative seizure recurrence. Messenger RNA and microRNA extracted from the blood and tissue samples were sequenced. The messenger RNA and microRNA expression levels from the blood and brain were each subjected to a novel clustering approach combined with multiple logistic regression to separate individuals into genetic clusters that identify novel subtypes associated with post-operative seizure outcomes. We then compared the microRNAs and messenger RNAs from patient blood and brain tissue that were significantly associated with each subtype to identify signatures that are similarly over- or under-represented for an outcome and more likely to represent endophenotypes with common molecular aetiology. These target microRNAs and messenger RNAs were further characterized by pathway analysis to assess their functional role in epilepsy. Using blood-derived microRNA and messenger RNA expression levels, we identified two subtypes of epilepsy that were significantly associated with seizure recurrence (clusters A1 and B4) (adjusted P < 0.20). A total of 551 microRNAs and 2486 messenger RNAs were associated with clusters A1 and B4, respectively (adjusted P < 0.05). Clustering of brain-tissue messenger RNA expression levels revealed an additional subtype (C2) associated with seizure recurrence that had high overlap of dysregulated messenger RNA transcripts with cluster B4. Clusters A1, B4 and C2 also shared significant overlap of subjects, which altogether suggests a coordinated mechanism by which microRNA and messenger RNA transcripts may be related to seizure recurrence. Epileptic subtypes A1, B4 and C2 reveal both known and novel microRNA and messenger RNA targets in seizure recurrence. Furthermore, targets identified in A1 and B4 are quantifiable in pre-operative blood samples and could potentially serve as biomarkers for surgical resection outcomes.

Prescribed antiseizure medication doses and their relation to defined daily doses for achieving seizure freedom in newly diagnosed patients with epilepsy

OBJECTIVES

To investigate the antiseizure medication (ASM) doses required to achieve seizure freedom and their correlation with the World Health Organization's defined daily doses (DDDs) in patients aged 16 years or older with newly diagnosed epilepsy.

METHODS

The study included 459 patients with a validated diagnosis of new-onset epilepsy. Patient records were retrospectively analyzed to determine the ASM doses in patients with or without seizure freedom during follow-up. The DDD of the relevant ASM was then retrieved.

RESULTS

The seizure-freedom rate with first and subsequent ASMs was 88% (404/459 patients) during the follow-up. The mean prescribed doses (PDDs) and PDD/DDD ratio of the most commonly used ASMs, ie, oxcarbazepine (OXC), carbamazepine (CBZ), and valproic acid (VPA), differed significantly between seizure-free and non-seizure-free status (992 mg and 0.99 vs 1132 mg and 1.13; 547 mg and 0.55 vs 659 mg and 0.66; and 953 mg and 0.64 vs 1260 mg and 0.84, respectively). The effect of the OXC dose as the first failed ASM on the possibility of achieving seizure freedom was significant (Fisher's exact test, p = 0.002). Thirty-four of 43 patients (79%) in which an OXC dose of ≤900 mg failed became seizure-free, as compared with 24 of 54 patients (44%) with a failed OXC dose >900 mg.

SIGNIFICANCE

The present study provides new insights into the doses of the commonly used ASMs such as OXC, CBZ, and VPA that can lead to seizure freedom as monotherapy or as combination therapy. The higher PDD/DDD ratio of OXC (0.99) than that of CBZ or VPA renders a generalized PDD/DDD comparison highly problematic.

Effect of clinical features on antiseizure medication doses in patients with newly diagnosed epilepsy

Objective

We evaluate the effect of distinct clinical features on anti-seizure medication (ASM) doses in seizure-free and not seizure-free patients aged ≥16 years with new-onset epilepsy.

Materials and methods

This study included 459 patients with a validated diagnosis of epilepsy. The most prescribed ASMs were oxcarbazepine (OXC; n = 307), followed by valproic acid (VPA; n = 115), carbamazepine (CBZ; n = 81), and lamotrigine (LTG; n = 67). The seizure freedom rate with their first or subsequent ASM was 88.0%. A retrospective analysis of patient records was performed to determine any association between doses of ASMs and patient characteristics.

Results

The median OXC dose in seizure-free patients aged >60 years was 600 mg compared to 900 mg in younger patients. When controlling for age but not in an unadjusted model, the median dose of OXC was lower (300 mg, p = 0.018) for seizure-free patients compared to non-seizure-free patients, and the median dose of OXC was also 300 mg lower among older patients aged >60 years (p < 0.001). The median OXC doses for men aged ≤60 years were 300 mg higher than for women aged >60 years (900 mg vs. 600 mg, p = 0.021). The median dose of VPA was 400 mg higher in men than in women (p < 0.001) and 400 mg higher in not seizure-free patients compared to seizure-free patients only when adjusting for sex (p < 0.001). Higher median doses for CBZ were registered with FAS compared with FBTCS (difference in median doses of 200 mg; p = 0.017).

Conclusion

Significant OXC dose differences were detected between age groups, whereas VPA dosing was different in men and women. Moreover, CBZ doses were dependent on some seizure types. These data allow for the individualization of the initial target dosing based on key clinical characteristics.

Cenobamate significantly improves seizure control in intellectually disabled patients with drug-resistant epilepsy and allows drug load reduction

Introduction

Epilepsy patients with intellectual disability often suffer from drug-resistant epilepsy (DRE), which severely affects patients' quality of life. Cenobamate (CNB) is a recently approved novel and effective ASM that can achieve high rates of seizure freedom in previously drug-resistant patients.

Methods

We performed a retrospective data analysis of the first patients treated with CNB at a single center. Outcome and treatment response were assessed at two different time points, and ASM burden was calculated.

Results

A 12 patients (7 males and 5 females) began treatment at a median age of 43 years, six of whom had developmental and epileptic encephalopathies. Prior to treatment with CNB, patients had tried a median of 13 different ASM. At the start of CNB therapy, patients were taking a median of 3 ASM. Treatment outcomes were available for 11 patients. After the first follow-up period (median 9 months), 55% of patients showed a significant seizure reduction of more than 50%, with three patients showing a reduction of more than 75% (27%). One patient achieved complete seizure freedom, while one patient did not respond to treatment. These response rates were consistently maintained at second follow-up after a median of 22 months. Ten patients (83%) reported adverse events (AE), the most common of which were dizziness and fatigue. No cases of drug reactions with eosinophilia and systemic symptoms (DRESS) were observed. The majority of AEs were mild and resolved over time. In addition, most patients were able to reduce their concomitant ASM.

Discussion

Cenobamate has been shown to be an effective ASM in patients with DRE and in patients with intellectual disabilities. After more than 1 year of treatment with CNB, close monitoring and management of drug-drug interactions may reduce enzyme-inducing ASMs and lead to better long-term outcomes. With CNB treatment, many patients can achieve a reduced overall drug burden while maintaining a reduction in seizures.

Long-term epilepsy outcome dynamics revealed by natural language processing of clinic notes

OBJECTIVE

Electronic medical records allow for retrospective clinical research with large patient cohorts. However, epilepsy outcomes are often contained in free text notes that are difficult to mine. We recently developed and validated novel natural language processing (NLP) algorithms to automatically extract key epilepsy outcome measures from clinic notes. In this study, we assessed the feasibility of extracting these measures to study the natural history of epilepsy at our center.

METHODS

We applied our previously validated NLP algorithms to extract seizure freedom, seizure frequency, and date of most recent seizure from outpatient visits at our epilepsy center from 2010 to 2022. We examined the dynamics of seizure outcomes over time using Markov model-based probability and Kaplan-Meier analyses.

RESULTS

Performance of our algorithms on classifying seizure freedom was comparable to that of human reviewers (algorithm F1 = .88 vs. human annotatorκ = .86). We extracted seizure outcome data from 55 630 clinic notes from 9510 unique patients written by 53 unique authors. Of these, 30% were classified as seizure-free since the last visit, 48% of non-seizure-free visits contained a quantifiable seizure frequency, and 47% of all visits contained the date of most recent seizure occurrence. Among patients with at least five visits, the probabilities of seizure freedom at the next visit ranged from 12% to 80% in patients having seizures or seizure-free at the prior three visits, respectively. Only 25% of patients who were seizure-free for 6 months remained seizure-free after 10 years.

SIGNIFICANCE

Our findings demonstrate that epilepsy outcome measures can be extracted accurately from unstructured clinical note text using NLP. At our tertiary center, the disease course often followed a remitting and relapsing pattern. This method represents a powerful new tool for clinical research with many potential uses and extensions to other clinical questions.

Postoperative seizure freedom after vagus nerve stimulator placement in children 6 years of age and younger

OBJECTIVE

Food and Drug Administration (FDA) approval for vagus nerve stimulator (VNS) implantation is limited to patients older than 4 years of age with medically refractory partial-onset seizures. In younger children with severe generalized epilepsy, however, VNS implantation remains off-label. In this study, the authors followed up on their previously reported cohort to review the longer-term safety and efficacy of VNS placement in children younger than 6 years with generalized medically refractory epilepsy (MRE), providing the largest cohort with > 2 years of follow-up to date in this age group.

METHODS

This was a retrospective observational cohort study of patients younger than 6 years of age with generalized MRE who underwent VNS implantation at a single institution between 2010 and 2020. Inclusion criteria encompassed failure of more than two antiepileptic drugs alone or in combination, neurologist referral for vagus nerve stimulation, informed consent with knowledge of the off-label status in young children, and > 1 year of follow-up. Outcome measures included seizure reduction rate ≥ 50% and postoperative morbidity defined nominally. Statistical analysis was conducted with Stata/SE.

RESULTS

Forty-five patients were included: 11 patients younger than 4 years of age and 34 between 4 and 6 years of age. There were no intraoperative complications. Perioperative complications within 1 year occurred in 11% (n = 5) of the patients and included two wound infections, a mild cough, hyperactivity, hoarseness, and 1 patient with persistent surgical site pain. A seizure reduction ≥ 50% was observed in 36.4% (n = 4) of the patients younger than 4 years of age at the 6-month and 1-, 2-, and 5-year follow-ups. In the 4- to 6-year-old cohort, this was observed in 32.4% (n = 11) of the patients at 6 months, 41.2% (n = 14) at 1 year, 38.2% (n = 13) at 2 years, and 41.2% (n = 14) at 5 years.

CONCLUSIONS

VNS implantation for patients younger than 4 years of age with generalized onset MRE has not been approved by the FDA. This retrospective study establishes feasibility, illustrates an acceptable safety profile in children younger than 6 years, and demonstrates efficacy comparable to that reported in older patients.

Long-term follow-up seizure outcomes after corpus callosotomy: A systematic review with meta-analysis

BACKGROUND

Corpus callosotomy (CC) is appropriate for patients with seizures of a bilateral or diffuse origin, or those with seizures of a unilateral origin with rapid spread to the contralateral cerebral hemisphere. The efficiency of CC in patients with drug-resistant epilepsy is a long-term concern because most articles reporting the surgical results of CC arise from small case series, and the durations of follow-up vary.

METHODS

PubMed, Embase, Cochrane Library, and Web of Science were searched to identify papers published before November 8, 2021. The systematic review was completed following PRISMA guidelines. Outcomes were analyzed by meta-analysis of the proportions.

RESULTS

A total of 1644 patients with drug-resistant epilepsy (49 retrospective or prospective case series studies) underwent CC, and the follow-up time of all patients was at least 1 year. The rate of complete seizure freedom (SF) was 12.38% (95% confidence interval [CI], 8.17%-17.21%). Meanwhile, the rate of complete SF from drop attacks was 61.86% (95% CI, 51.87%-71.41%). The rates of complete SF after total corpus callosotomy (TCC) and anterior corpus callosotomy (ACC) were 11.41% (95% CI, 5.33%-18.91%) and 6.75% (95% CI, 2.76%-11.85%), respectively. Additionally, the rate of complete SF from drop attacks after TCC was significantly higher than that after ACC (71.52%, 95% CI, 54.22%-86.35% vs. 57.11%, 95% CI, 42.17%-71.49%). The quality of evidence for the three outcomes by GRADE assessment was low to moderate.

CONCLUSION

There was no significant difference in the rate of complete SF between TCC and ACC. TCC had a significantly higher rate of complete SF from drop attacks than did ACC. Furthermore, CC for the treatment of drug-resistant epilepsy remains an important problem for further investigation because there are no universally accepted standardized guidelines for the extent of CC and its benefit to patients. In future research, we will focus on this issue.

Beyond seizure freedom: Dissecting long-term seizure control after surgical resection for drug-resistant epilepsy

OBJECTIVE

This study was undertaken to better understand the long-term palliative and disease-modifying effects of surgical resection beyond seizure freedom, including frequency reduction and both late recurrence and remission, in patients with drug-resistant epilepsy.

METHODS

This retrospective database-driven cohort study included all patients with >9 years of follow-up at a single high-volume epilepsy center. We included patients who underwent lobectomy, multilobar resection, or lesionectomies for drug-resistant epilepsy; we excluded patients who underwent hemispherectomies. Our main outcomes were (1) reduction in frequency of disabling seizures (at 6 months, each year up to 9 years postoperatively, and at last follow-up), (2) achievement of seizure remission (>6 months, >1 year, and longest duration), and (3) seizure freedom at last follow-up.

RESULTS

We included 251 patients; 234 (93.2%) achieved 6 months and 232 (92.4%) experienced 1 year of seizure freedom. Of these, the average period of seizure freedom was 10.3 years. A total of 182 (72.5%) patients were seizure-free at last follow-up (defined as >1 year without seizures), with a median 11.9 years since remission. For patients not completely seizure-free, the mean seizure frequency reduction at each time point was 76.2%, and ranged from 66.6% to 85.0%. Patients decreased their number of antiseizure medications on average by .58, and 53 (21.2%) patients were on no antiseizure medication at last follow-up. Nearly half (47.1%) of those seizure-free at last follow-up were not seizure-free immediately postoperatively.

SIGNIFICANCE

Patients who continue to have seizures after resection often have considerable reductions in seizure frequency, and many are able to achieve seizure freedom in a delayed manner.

Seizure control in successive pregnancies in Australian women with epilepsy

OBJECTIVES

To investigate control of epileptic seizures during pairs of successive pregnancies in antiseizure medication (ASM)-treated women with epilepsy.

MATERIALS AND METHODS

Analysis of seizure freedom rates during 436 pairs of successive pregnancies in Australian women with epilepsy, in nearly all instances long-standing epilepsy.

RESULT

There was a higher rate of seizure-free second pregnancies compared with first paired pregnancies (63.1% vs. 51.4%; Relative Risk (R.R.) = 1.2277; 95% CI 1.0930, 1.3789) and of seizure-free pre-pregnancy years before second as compared with first paired pregnancies in the same women (63.6% vs. 52.4%; R.R. = 1.2616; 95% CI 1.1337, 1.4040). In 108 women whose ASM therapy was unaltered throughout both of their pregnancies, the seizure-freedom rate was higher in the second of the paired pregnancies (82.4% vs. 69.4%; R.R. = 1.1867, 95% CI 1.0189, 1.3821).

CONCLUSIONS

Altered ASM therapy after the first of a pair of successive pregnancies did not fully account for the better overall seizure control in the corresponding second pregnancies. Some additional factor may have been in operation, possibly a greater preparedness to undertake a further pregnancy if seizures were already fully controlled.

Effectiveness of Perampanel as the Only Add-on: Retrospective, Multicenter, Observational Real Life Study on epilepsy patients

OBJECTIVE

Perampanel (PER) is indicated as adjunctive antiseizure medication (ASM) in adolescents and adults with epilepsy. Data from clinical trials show good efficacy and tolerability, while limited information is available on the routine clinical use of PER, especially when used as only add-on treatment.

METHODS

we performed an observational, retrospective, multicenter study on people with focal or generalized epilepsy aged >12 years, consecutively recruited from 52 Italian epilepsy centers. All patients received PER as the only add-on treatment to a background ASM according to standard clinical practice. Retention rate, seizure frequency and adverse events were recorded at 3, 6 and 12 months after PER introduction. Sub-analyses by early or late use of PER and by concomitant ASM were also conducted.

RESULTS

503 patients were included (age 36.5±19.9 years). Eighty-one per cent had focal epilepsy. Overall, the retention rate was very high in the whole group (89% at 12 months) according with efficacy measures. No major differences were observed in the sub-analyses, although patients who used PER as early add-on, as compared with late add-on, more often reached early seizure freedom at 3 months follow-up (66% vs. 53%, p=0.05). Treatment-emergent adverse events occurred in 25%, far less commonly than in PER randomized trials.

SIGNIFICANCE

this study confirms the good efficacy and safety of PER for focal or generalized epilepsy in real-life conditions. We provide robust data about its effectiveness as only add-on treatment even in patients with a long-standing history of epilepsy and previously treated with many ASMs.

Surgical approaches to refractory central lobule epilepsy: a systematic review on the role of resection, ablation, and stimulation in the contemporary era

OBJECTIVE

Epilepsy originating from the central lobule (i.e., the primary sensorimotor cortex) is a challenging entity to treat given its involvement of eloquent cortex. The objective of this study was to review available evidence on treatment options for central lobule epilepsy.

METHODS

A comprehensive literature search (PubMed/Medline, EMBASE, and Scopus) was conducted for studies (1990 to date) investigating postoperative outcomes for central lobule epilepsy. The primary and secondary endpoints were seizure freedom at last follow-up and postoperative neurological deficit, respectively. The following procedures were included: open resection, multiple subpial transections (MSTs), laser and radiofrequency ablation, deep brain stimulation (DBS), responsive neurostimulation (RNS), and continuous subthreshold cortical stimulation (CSCS).

RESULTS

A total of 52 studies and 504 patients were analyzed. Most evidence was based on open resection, yielding a total of 400 patients (24 studies), of whom 62% achieved seizure freedom at a mean follow-up of 48 months. A new or worsened motor deficit occurred in 44% (permanent in 19%). Forty-six patients underwent MSTs, of whom 16% achieved seizure freedom and 30% had a neurological deficit (permanent in 12%). There were 6 laser ablation cases (cavernomas in 50%) with seizure freedom in 4 patients and 1 patient with temporary motor deficit. There were 5 radiofrequency ablation cases, with 1 patient achieving seizure freedom, 2 patients each with Engel class III and IV outcomes, and 2 patients with motor deficit. The mean seizure frequency reduction at the last follow-up was 79% for RNS (28 patients), 90% for CSCS (15 patients), and 73% for DBS (4 patients). There were no cases of temporary or permanent neurological deficit in the CSCS or DBS group.

CONCLUSIONS

This review highlights the safety and efficacy profile of resection, ablation, and stimulation for refractory central lobe epilepsy. Resection of localized regions of epilepsy onset zones results in good rates of seizure freedom (62%); however, nearly 20% of patients had permanent motor deficits. The authors hope that this review will be useful to providers and patients when tailoring decision-making for this intricate pathology.

Outcomes of cingulate epilepsy surgery: insights from an institutional and patient-level systematic review and meta-analysis

OBJECTIVE

Due to their deep and medial location, range of seizure semiologies, and poor localization on ictal electroencephalography (EEG), cingulate gyrus seizures can be difficult to diagnose and treat. The aim of this study was to review the available evidence on postoperative outcomes after cingulate epilepsy surgery.

METHODS

A comprehensive literature search of the PubMed/MEDLINE, Ovid Embase, Ovid Scopus, and Cochrane Library databases was conducted to identify studies that investigated postoperative outcomes of patients with cingulate epilepsy. Seizure freedom at the last follow-up (at least 12 months) was the primary endpoint. The literature search was supplemented by the authors' institutional series (4 patients).

RESULTS

Twenty-one studies were identified, yielding a total of 105 patients (68 with lesional epilepsy [65%]). Median age at surgery was 23 years, and 56% of patients were male. Median epilepsy duration was 7.5 years. Invasive EEG recording was performed on 69% of patients (53% of patients with lesional epilepsy and 97% of those with nonlesional epilepsy, p < 0.001). The most commonly resected region was the anterior cingulate (55%), followed by the posterior (17%) and middle (14%) cingulate. Lesionectomy alone was performed in 9% of patients. Additional extracingulate treatment was performed in 54% of patients (53% of patients with lesional epilepsy vs 57% of those with nonlesional epilepsy, p = 0.87). The most common pathology was cortical dysplasia (54%), followed by low-grade neoplasm (29%) and gliosis (8%). Seizure freedom was noted in 72% of patients (median follow-up 24 months). A neurological deficit was noted in 27% of patients (24% had temporary deficit), with the most common deficit being motor weakness (13%) followed by supplementary motor area syndrome (9.5%). Univariate survival analysis revealed significantly greater probability of seizure freedom in patients with lesional epilepsy (p = 0.015, log-rank test).

CONCLUSIONS

Surgical treatment of drug-resistant focal epilepsy originating from the cingulate gyrus is safe, leads to low rates of permanent adverse effects, and leads to high rates of long-term seizure freedom in carefully selected patients. These data may serve as a benchmark for surgical counseling of patients with cingulate epilepsy.

Development and validation of machine learning models for prediction of seizure outcome after pediatric epilepsy surgery

OBJECTIVE

There is substantial variability in reported seizure outcome following pediatric epilepsy surgery, and lack of individualized predictive tools that could evaluate the probability of seizure freedom postsurgery. The aim of this study was to develop and validate a supervised machine learning (ML) model for predicting seizure freedom after pediatric epilepsy surgery.

METHODS

This is a multicenter retrospective study of children who underwent epilepsy surgery at five pediatric epilepsy centers in North America. Clinical information, diagnostic investigations, and surgical characteristics were collected, and used as features to predict seizure-free outcome 1 year after surgery. The dataset was split randomly into 80% training and 20% testing data. Thirty-five combinations of five feature sets with seven ML classifiers were assessed on the training cohort using 10-fold cross-validation for model development. The performance of the optimal combination of ML classifier and feature set was evaluated in the testing cohort, and compared with logistic regression, a classical statistical approach.

RESULTS

Of the 801 patients included, 61.3% were seizure-free 1 year postsurgery. During model development, the best combination was XGBoost ML algorithm with five features from the univariate feature set, including number of antiseizure medications, magnetic resonance imaging lesion, age at seizure onset, video-electroencephalography concordance, and surgery type, with a mean area under the curve (AUC) of .73 (95% confidence interval [CI] = .69-.77). The combination of XGBoost and univariate feature set was then evaluated on the testing cohort and achieved an AUC of .74 (95% CI = .66-.82; sensitivity = .87, 95% CI = .81-.94; specificity = .58, 95% CI = .47-.71). The XGBoost model outperformed the logistic regression model (AUC = .72, 95% CI = .63-.80; sensitivity = .72, 95% CI = .63-.82; specificity = .66, 95% CI = .53-.77) in the testing cohort (p = .005).

SIGNIFICANCE

This study identified important features and validated an ML algorithm, XGBoost, for predicting the probability of seizure freedom after pediatric epilepsy surgery. Improved prognostication of epilepsy surgery is critical for presurgical counseling and will inform treatment decisions.

Epileptic seizure control during and after pregnancy in Australian women

OBJECTIVES

To study factors that affected previous epileptic seizure control throughout pregnancy, during labour, and in the post-natal weeks.

MATERIALS & METHODS

Analysis of data concerning seizure freedom that was available at various stages of 2337 pregnancies in the Raoul Wallenberg Australian Pregnancy Register of Antiepileptic Drugs, mainly employing multiple variable logistic regression techniques.

RESULTS

Based on data available at the outset of pregnancy, the risk of seizure-affected that is, not seizure-free pregnancy was statistically significantly (p < .05) higher in pregnancies where there was previously uncontrolled epilepsy (78.1% vs. 20.8%) and focal epilepsy (51.3% vs. 39.7%), and decreased with later onset-age epilepsy (41.8% vs. 52.2% with onset before age 13 years), The risk did not differ between initially antiseizure medication (ASM)-treated or untreated pregnancies. For epilepsy receiving ASM therapy, 90.6% of 160 pregnancies of women with uncontrolled focal epilepsy that began before the age of 13 were seizure-affected. None of the above factors influenced the risk of seizures during labour, though having seizures during pregnancy increased the hazard (3.93 vs. 0.6%). Either ASM-treated pregnancy or labour being seizure-affected increased the risk of post-partum period seizures (33.0% vs. 6.67% for both stages being seizure-free). Use of particular ASMs had no statistically significant effect on the seizure control situation at any of the pregnancy stages studied.

CONCLUSIONS

Obtaining full seizure control before pregnancy appeared to be the main factor in maintaining seizure freedom during pregnancy, labour and the post-natal weeks.

Ordinal regression increases statistical power to predict epilepsy surgical outcomes

Studies of epilepsy surgery outcomes are often small and thus underpowered to reach statistically valid conclusions. We hypothesized that ordinal logistic regression would have greater statistical power than binary logistic regression when analyzing epilepsy surgery outcomes. We reviewed 10 manuscripts included in a recent meta-analysis which found that mesial temporal sclerosis (MTS) predicted better surgical outcomes after a stereotactic laser amygdalohippocampectomy (SLAH). We extracted data from 239 patients from eight studies that reported four discrete Engel surgical outcomes after SLAH, stratified by the presence or absence of MTS. The rate of freedom from disabling seizures (Engel I) was 64.3% (110/171) for patients with MTS compared to 44.1% (30/68) without MTS. The statistical power to detect MTS as a predictor for better surgical outcome after a SLAH was 29% using ordinal regression, which was significantly more than the 13% power using binary logistic regression (paired t-test, P < .001). Only 120 patients are needed for this example to achieve 80% power to detect MTS as a predictor using ordinal regression, compared to 210 patients that are needed to achieve 80% power using binary logistic regression. Ordinal regression should be considered when analyzing ordinal outcomes (such as Engel surgical outcomes), especially for datasets with small sample sizes.

Is There a Role for Temozolomide in Glioma Related Seizures? A Systematic Review

BACKGROUND

Seizures often herald the clinical appearance of glioma. Temozolomide (TMZ) is the first-line chemotherapeutic agent that has been used to treat glioma.

OBJECTIVE

We conducted a systematic review to determine seizure outcomes in glioma patients treated with TMZ.

METHODS AND MATERIAL

We searched EMBASE and PubMed databases (January 1, 2003-August 26, 2021) by using search terms closely related to glioma, seizure, and temozolomide. Titles, abstracts, and full texts were screened and selected using previously established inclusion and exclusion criteria. The research team members reviewed potential articles and reached a consensus on the final articles to be included.

RESULTS

Nine studies containing data from three continents met our inclusion criteria. From several descriptive studies on low-grade gliomas (LGGs), the percentage of patients with partial seizure control after TMZ treatment ranged from 29% to 89.7%, and the percentage of patients with complete seizure control after TMZ ranged from 19.4% to 72%. In a retrospective cohort study of patients with LGGs, there was a marked difference in decreased seizure frequency between patients receiving TMZ and those who did not receive TMZ. In a randomized trial, TMZ seemed to have little effect on seizure control in elderly patients with glioblastoma.

CONCLUSIONS

At present, there are few high-quality and well-designed clinical studies on TMZ for gliomas-related seizures. In terms of the literature included in this review, TMZ has an inhibitory effect on epilepsy. More randomized controlled trials are needed to elucidate the clinical benefits of TMZ in the treatment of gliomas-related seizures.

Long-term seizure and psychiatric outcomes following laser ablation of mesial temporal structures

OBJECTIVE

Postsurgical seizure outcome following laser interstitial thermal therapy (LiTT) for the management of drug-resistant mesial temporal lobe epilepsy (MTLE) has been limited to 2 years. Furthermore, its impact on presurgical mood and anxiety disorders has not been investigated. The objectives of this study were (1) to identify seizure outcome changes over a period ranging from 18 to 81 months; (2) to investigate the seizure-free rate in the last follow-up year; (3) to identify the variables associated with seizure freedom; and (4) to identify the impact of LiTT on presurgical mood and anxiety disorders.

METHODS

Medical records of all patients who underwent LiTT for MTLE from 2013 to 2019 at the University of Miami Comprehensive Epilepsy Center were retrospectively reviewed. Demographic, epilepsy-related, cognitive, psychiatric, and LiTT-related data were compared between seizure-free (Engel Class I) and non-seizure-free (Engel Class II + III + IV) patients. Statistical analyses included univariate and multivariate stepwise logistic regression analyses.

RESULTS

Forty-eight patients (mean age = 43 ± 14.2 years, range = 21-78) were followed for a mean period of 50 ± 20.7 months (range = 18-81); 29 (60.4%) achieved an Engel Class I outcome, whereas 11 (22.9%) had one to three seizures/year. Seizure-freedom rate decreased from 77.8% to 50% among patients with 24- and >61-month follow-up periods, respectively. In the last follow-up year, 83% of all patients were seizure-free. Seizure freedom was associated with having mesial temporal sclerosis (MTS), no presurgical focal to bilateral tonic-clonic seizures, and no psychopathology in the last follow-up year. Presurgical mood and/or anxiety disorder were identified in 30 patients (62.5%) and remitted after LiTT in 19 (62%).

SIGNIFICANCE

LiTT appears to be a safe and effective surgical option for treatment-resistant MTLE, particularly among patients with MTS. Remission of presurgical mood and anxiety disorders can also result from LiTT.

Experience of perampanel monotherapy beyond initial titration to achieve seizure freedom in patients with focal-onset seizures with newly diagnosed or currently untreated recurrent epilepsy: A post hoc analysis of the open-label Study 342 (FREEDOM)

Objective

This post hoc analysis evaluated whether continued treatment with perampanel monotherapy beyond initial titration may be appropriate for patients with focal‐onset seizures (FOS) with currently untreated epilepsy to achieve seizure freedom with an effective dose.

Methods

Study 342 (NCT03201900; FREEDOM) is a single‐arm, open‐label, Phase III study of perampanel monotherapy. Patients aged ≥12 years with untreated FOS received perampanel 4 mg/d in a 32‐week Treatment Phase (6‐week Titration and 26‐week Maintenance Periods); in case of seizure(s) during Maintenance Period, patients could enter a 30‐week Treatment Phase (4‐week Titration and 26‐week Maintenance Periods) to be up‐titrated to perampanel 8 mg/d. The primary endpoint was seizure‐freedom rate during Maintenance Period in the modified Intent‐to‐Treat (mITT) Analysis Set (patients who had ≥1 post‐dose efficacy measurement during Maintenance Period); safety was monitored. This analysis of 4‐mg/d efficacy data assessed the proportion of patients achieving seizure freedom during the Maintenance Period (responders) relative to patients with an early/later response (depending on seizure status during the Titration Period).

Results

In the mITT population (n = 73), 46 patients were 4‐mg/d responders; of whom, 37 (80.4%) were early responders and nine (19.6%) were later responders. The mean (standard deviation) percent reductions in FOS frequency from baseline at the end of the 4‐mg/d Titration Period were 100.0% (0.0%; early responders) and 46.3% (97.3%; later responders). Among the 27 4‐mg/d nonresponders, nine (33.3%) patients who had an early response experienced seizure(s) during the subsequent 4‐mg/d Maintenance Period. Safety outcomes were similar, regardless of responder status, without new safety concerns.

Significance

Some patients with untreated FOS may benefit from continued treatment beyond initial titration of perampanel monotherapy to achieve seizure freedom, suggesting that it may not be appropriate to make treatment decisions to discontinue or switch from perampanel monotherapy solely based on seizure response before an effective dose has been reached.

Outcomes of epilepsy surgery in the older population: not too old, not too late

OBJECTIVE

The prevalence of epilepsy in the older adult population is increasing. While surgical intervention in younger patients is supported by level I evidence, the safety and efficacy of epilepsy surgery in older individuals is less well established. The aim of this study was to evaluate seizure freedom rates and surgical outcomes in older epilepsy patients.

METHODS

The authors' institutional electronic database was queried for patients older than 50 who had undergone epilepsy surgery during 2002-2018. Cases were grouped into 50-59, 60-69, and 70+ years old. Seizure freedom at the last follow-up constituted the primary outcome of interest. The institutional analysis was supplemented by a literature review and meta-analysis (random effects model) of all published studies on this topic as well as by an analysis of complication rates, mortality rates, and cost data from a nationwide administrative database (Vizient Inc., years 2016-2019).

RESULTS

A total of 73 patients (n = 16 for 50-59 years, n = 47 for 60-69, and n = 10 for 70+) were treated at the authors' institution. The median age was 63 years, and 66% of the patients were female. At a median follow-up of 24 months, seizure freedom was 73% for the overall cohort, 63% for the 50-59 group, 77% for the 60-69 group, and 70% for the 70+ group. The literature search identified 15 additional retrospective studies (474 cases). Temporal lobectomy was the most commonly performed procedure (73%), and mesial temporal sclerosis was the most common pathology (52%), followed by nonspecific gliosis (19%). The pooled mean follow-up was 39 months (range 6-114.8 months) with a pooled seizure freedom rate of 65% (95% CI 59%-72%). On multivariable meta-regression analysis, an older mean age at surgery (coefficient [coeff] 2.1, 95% CI 1.1-3.1, p < 0.001) and the presence of mesial temporal sclerosis (coeff 0.3, 95% CI 0.1-0.6, p = 0.015) were the most important predictors of seizure freedom. Finally, analysis of the Vizient database revealed mortality rates of 0.5%, 1.1%, and 9.6%; complication rates of 7.1%, 10.1%, and 17.3%; and mean hospital costs of $31,977, $34,586, and $40,153 for patients aged 50-59, 60-69, and 70+ years, respectively.

CONCLUSIONS

While seizure-free outcomes of epilepsy surgery are excellent, there is an expected increase in morbidity and mortality with increasing age. Findings in this study on the safety and efficacy of epilepsy surgery in the older population may serve as a useful guide during preoperative decision-making and patient counseling.

Efficacy and Tolerability of Perampanel as Adjunctive Therapy in Chinese Patients With Focal-Onset Seizures: An Observational, Prospective Study

Purpose: To evaluate the efficacy and tolerability of adjunctive perampanel (PER) in Chinese patients with focal-onset seizures, with or without secondarily generalized tonic-clonic seizures. Methods: Fifty-six patients aged 14-72 years were recruited consecutively in this single-center prospective observational study. All patients received PER as add-on treatment on the basis of clinical judgment. Seizure frequency, adverse events (AEs), and retention rates were obtained at 3 and 6 months after PER introduction. Results: The overall response rates were 60 and 71.1% after 3 and 6 months, respectively, and the freedom of seizures at the same points were reached in 8 and 15.8%. The retention rates were 89.3% at the 3-month follow-up and 67.9% at the 6-month follow-up. The overall incidence of adverse events was 55.4%. The leading reported AEs were dizziness (39.3%) and somnolence (25%). Conclusions: Our study confirmed the efficacy and tolerability of adjunctive PER in Chinese patients in real-life conditions. Based on our treatment experience, a lower maintenance dose of PER would be needed in Chinese patients.

Predictors of Seizure Freedom in Patients Undergoing Surgery for Central Nervous System Infection-Related Epilepsy: A Systematic Review and Meta-Analysis

Objective: Central nervous system infections (CNSIs), especially viral encephalitis and meningitis, are well-recognized causes of medically refractory epilepsy. Although surgery is an effective and durable intervention against these infections, the seizure control outcomes described in previous surgical series have been variable. Accordingly, it is not clear which variables are most valuable in predicting seizure control following surgery for CNSI. The aim of this meta-analysis was to identify the predictors of favorable surgical outcomes in CNSI-related epilepsy.

Methods: The PubMed, EMBASE, Cochrane Library, WANGFANG, VIP, CBM, and CNKI databases were searched for studies according to the inclusion criteria. Prognostic factors, surgical outcomes, and patient characteristics were extracted. Heterogeneity was detected by the I² and Q statistics.

Results: Seventeen studies were included in our meta-analysis. Eight predictors of favorable outcomes (Engel Class I/II) were determined, including abnormal MRI findings, meningitis, temporal location only, regional ictal pattern, unilateral ictal pattern, older age at epilepsy, longer silent period, and longer time from infection, as follows: OR = 3.34 (95% CI 1.44–7.74), OR = 0.31 (95% CI 0.13–0.70), OR = 0.34 (95% CI 0.16–0.74), OR = 5.65 (95% CI 1.75–18.30), and OR = 9.53 (95% CI 2.36–38.48), respectively, and MD = 2.15 (95% CI 0.20–4.11), MD = 2.40 (95% CI 0.09–4.70), and MD = 8.49 (95% CI 1.50–15.48), respectively. A subgroup analysis found the following associations: regional and unilateral ictal patterns in viral encephalitis, a younger age at infection in parasitic encephalopathy, an older age at surgery, a longer time from onset, and a longer time from infection in unexplained meningitis. A sensitivity analysis restricted to studies that included each variable yielded robust results. Little evidence of publication bias was observed.

Conclusions: This meta-analysis suggests that abnormal MRI findings, meningitis, temporal location only, regional and unilateral ictal patterns, older age at epilepsy, longer silent period, and longer time from infection are predictive factors in patients with favorable surgical outcomes in CNSI-related epilepsy. In addition, different infective agents influenced the results in regional and unilateral ictal patterns in ictal electroencephalography, as well as the relationship between age at infection and surgery and the time from epilepsy onset and infection.

The relation of etiology based on the 2017 ILAE classification to the effectiveness of the ketogenic diet in drug-resistant epilepsy in childhood

Objective

To investigate the effectiveness and safety of the ketogenic diet (KD) in drug‐resistant epilepsy in childhood in relation to the new 2017 International League Against Epilepsy (ILAE) classification of etiology.

Methods

A consecutive cohort of patients treated with the KD were categorized according to the ILAE classification into known (structural, genetic, metabolic, infectious, and immune‐mediated) and unknown etiology. Primary outcome was the frequency of patients achieving seizure freedom with the KD at 3 months, secondary outcomes were seizure reduction >50% at 3 months, and both seizure freedom and seizure reduction >50% at 6, 12 months, and at last follow‐up (LFU), and adverse effects. Outcomes were compared between etiology groups.

Results

Etiology was known in 70% (129/183). Outcomes did not differ at 3 months (known vs unknown: seizure freedom 28% vs 33%, seizure reduction 62 vs 67%), but seizure freedom was significantly less frequent in known etiology at 6 months (26% vs 43%) and beyond (22% vs 37%). Logistic regression identified duration of epilepsy, number of previous antiseizure medications (ASMs), and age‐appropriate psychomotor development as positive determinants of outcome. Among individual etiology groups, the effectiveness of KD was relatively best for genetic (33% at LFU) and poorest for metabolic etiology (8% at LFU). The small number of patients with infectious and immune‐mediated etiology requires larger numbers in each etiology group to corroborate our results. No differences in type and frequency of adverse effects (in 71%) between etiology groups were observed, requiring medical intervention in 21%.

Significance

The KD was most effective in genetic and unknown etiology, many unknowns probably represent yet unidentified genetic causes. We recommend consequent diagnostic and genetic work‐up to identify etiologies that respond best to the KD. The KD should be offered early to infants with genetic epilepsy before deterioration of epileptic symptoms and of psychomotor development.

Predictors of surgical outcome in focal cortical dysplasia and its subtypes

OBJECTIVE

The authors analyzed predictors of surgical outcome in patients with focal cortical dysplasia (FCD) and its ILAE (International League Against Epilepsy) subtypes after noninvasive multimodal evaluation and calculated time to first seizure.

METHODS

Data of 355 patients with refractory epilepsy, confirmed FCD pathology, and 2-13 years of postsurgical follow-up were analyzed to determine the predictive roles of clinical, EEG, imaging, and surgical factors that influence seizure freedom.

RESULTS

The mean ± SD age at surgery was 20.26 ± 12.18 years. In total, 142 (40.0%) patients had daily seizures and 90 (25.3%) had multiple seizure types. MRI showed clear-cut FCD in 289 (81.4%) patients. Pathology suggested type I FCD in 27.3% of patients, type II in 28.4%, and type III in 42.8% of patients. At latest follow-up, 72.1% of patients were seizure free and 11.8% were seizure free and not receiving antiepileptic drugs. Among the subtypes, 88.8% of patients with type III, 69.3% with type II, and 50.5% with type I FCD were seizure free. Multiple seizure types, acute postoperative seizures (APOS), and type I FCD were predictors of persistent seizures, whereas type III FCD was the strongest predictor of seizure freedom. Type I FCD was associated with daily seizures, frontal and multilobar distribution, subtle findings on MRI, incomplete resection, and persistent seizures. Type II and III FCD were associated with clear-cut lesion on MRI, regional interictal and ictal EEG onset pattern, focal pattern on ictal SPECT, complete resection, and seizure freedom. Type III FCD was associated with temporal location, whereas type I and II FCD were associated with extratemporal location. Nearly 80% of patients with persistent seizures, mostly those with type I FCD, had their first seizure within 6 months postsurgery.

CONCLUSIONS

Long-term seizure freedom after surgery can be achieved in more than two-thirds of patients with FCD after noninvasive multimodal evaluation. Multiple seizure types, type I FCD, and APOS were predictors of persistent seizures. Seizures recurred in about 80% of patients within 6 months postsurgery.

Etiology-specific response to antiseizure medication in focal epilepsy

OBJECTIVE

In focal epilepsy, data on the etiology-specific response to antiseizure medication (ASM) are surprisingly sparse. In this study, we sought to reappraise whether seizure outcome of pharmacological treatment is linked to the underlying etiology. Furthermore, we assessed ASM load with respect to the cause of epilepsy.

METHODS

Data were retrospectively obtained from the electronic database of the three sites of an academic adult epilepsy outpatient clinic. For each patient, presumed cause of epilepsy was categorized into one of nine etiological groups. Individual drug loads were calculated according to the 2020 World Health Organization Center for Drug Statistics Methodology ATC/DDD Index. Univariate and multivariate analyses were conducted to explore the association between different etiologies and outcome regarding 12-month seizure freedom as well as ASM load.

RESULTS

A total of 591 patients with focal epilepsy were included in the final analysis. Ischemic stroke was the etiology with the highest rate of 12-month terminal seizure freedom (71.2%, 95% confidence interval [CI] = 57.9-82.2) and, considering all etiological groups, was an independent predictor of seizure freedom (odds ratio = 2.093, 95% CI = 1.039-4.216). The lowest rates of seizure freedom were observed in patients with hippocampal sclerosis (28.2%, 95% CI = 15.0-44.9) and malformation of cortical development (16.7%, 95% CI = 2.1-48.4). In patients with ischemic stroke, median ASM load (1.0, interquartile range [IQR] = .5-1.8) was significantly lower compared to that in patients with hippocampal sclerosis (median = 1.8, IQR = 1.2-3.0, p = .008) and brain tumors (median = 1.7, IQR = .7-3.2, p = .049).

SIGNIFICANCE

Response to treatment with ASM is highly etiology-specific and best in patients with epilepsy due to ischemic stroke. Interestingly, this most favorable treatment outcome can be achieved by the lowest ASM load considering all etiological groups. In focal epilepsy, etiology should be taken into account when counseling patients about their expected seizure outcome with pharmacological treatment and when tailoring initial ASM doses.

Response to first antiseizure medication in patients diagnosed with epilepsy

OBJECTIVES

To investigate the interaction among the efficacy, tolerability and overall effectiveness of the first antiseizure medication in patients 16 years or older with newly diagnosed epilepsy.

MATERIALS AND METHODS

The study included 584 patients who were referred to the Tampere University Hospital between 1 January 1995 and 31 December 2005 and were diagnosed with epilepsy. All individuals were retrospectively followed up until 31 December 2006, until reaching at least one year of seizure freedom, or until death if before the cut-off date.

RESULTS

Overall, after thorough validation of the epilepsy diagnosis 459 patients comprised the study cohort; among these patients, 73% of males and 60% of females became seizure-free for at least one year with the first antiseizure medication. The seizure freedom rate for focal epilepsy was 67%. There was no significant difference in focal epilepsy to achieve seizure freedom between oxcarbazepine, carbamazepine or valproic acid. The seizure freedom rate among patients above 60 years of age was 67%. For patients with structural and unknown aetiology, seizure freedom rates were 61.5% and 75.3%, respectively. Additionally, epileptiform activity on EEG in patients with focal epilepsy decreased odds of seizure freedom in adjusted logistic regression models (OR 0.55, p=0.036).

CONCLUSIONS

This study provides a more positive prediction of seizure freedom compared with previous studies with the onset of epilepsy at 16 years or older with an overall estimation that two-thirds of patients with new-onset epilepsy obtain seizure freedom with the first antiseizure medication.

Social outcome and psychiatric comorbidity of generalized epilepsies - A case-control study

OBJECTIVE

To investigate social outcome and psychiatric comorbidity of patients with idiopathic/genetic generalized epilepsies (IGEs) and its subtypes (epilepsy with generalized tonic-clonic seizures alone [EGTCS], juvenile absence epilepsy [JAE], and juvenile myoclonic epilepsy [JME]).

METHODS

A cohort of 402 adult patients with IGE from the Danish island Funen was matched with 4020 randomly selected geography-, age-, and sex-matched controls via the Danish Civil Registration System. Based on register data, we compared social status measured by cohabitant status, educational attainment, income, affiliation to labor market, and psychiatric comorbidity.

RESULTS

As compared to controls, patients with IGE had similar cohabitant status but fewer children (no children: 59.0% vs 50.9%), and lower educational level (primary school only: 46.0% vs 37.3%), employment rate (outside of workforce: 56.7% vs 46.5%), and income (low income: 32.6% vs 24.9%) (P < 0.001 for all comparisons). Having IGE was associated with higher a proportion of psychiatric comorbidity (IGE, 22.6%; controls, 13.0%) (P < 0.001). Seizure-free patients did not differ from controls; patients with persistent seizures had lower incomes and employment rates. In the IGE subgroup analyses, JME was associated with worse social status in all parameters studied (eg, 65.9% of JME patients were outside the workforce vs 44.5% of matched controls; P < 0.001), whereas no adverse social status was identified in patients with EGTCS and JAE.

SIGNIFICANCE

Patients with IGE in general and JME in particular have poorer social status and more psychiatric comorbidity than matched population controls without epilepsy. Poor seizure control was associated with social status and may contribute to negative socioeconomic consequences associated with IGE.

Freedom From Seizures Might Be Key to Continuing Occupation After Epilepsy Surgery

Introduction: We hypothesized that epilepsy surgery for adult patients with temporal lobe epilepsy (TLE) who obtained freedom from seizures could provide opportunities for these patients to continue their occupation, and investigated continuity of occupation to test this postulation.

Methods: Data were obtained from patients who had undergone resective surgery for medically intractable TLE between October 2009 and April 2019 in our hospital. Inclusion criteria were as follows: (1) ≥16 years old at surgery; (2) post-operative follow-up ≥12 months; (3) seizure-free period ≥12 months. As a primary outcome, we evaluated employment status before and after surgery, classified into three categories as follows: Level 0, no job; Level 1, students or homemakers (financially supported by a family member); and Level 2, working. Neuropsychological status was also evaluated as a secondary outcome.

Results: Fifty-one (87.9%) of the 58 enrolled TLE patients who obtained freedom from seizures after surgery continued working as before or obtained a new job (employment status: Level 2). A significant difference in employment status was identified between before and after surgery (p = 0.007; Wilcoxon signed-rank test). Twenty-eight patients (48.3%) were evaluated for neuropsychological status both before and after surgery. Significant differences in Wechsler Adult Intelligence Scale-III scores were identified between before and after surgery (p < 0.05 each; paired t-test).

Conclusion: Seizure freedom could be a factor that facilitates job continuity, although additional data are needed to confirm that possibility. Further investigation of job continuity after epilepsy surgery warrants an international, multicenter study.

Efficacy and safety of adjunctive perampanel in patients with focal seizures or generalized tonic-clonic seizures: Post hoc analysis of Phase II and Phase III double-blind and open-label extension studies in India

Objective

This post hoc analysis assessed the efficacy and safety of adjunctive perampanel in patients (aged ≥ 12 years) with focal seizures (FS), with/without focal to bilateral tonic‐clonic seizures (FBTCS), or generalized tonic‐clonic seizures (GTCS) in India.

Methods

Centers in India were identified from six double‐blind, randomized, Phase II and Phase III studies of adjunctive perampanel (2–12 mg/day) and their open‐label extensions (OLEx). Efficacy assessments included median percent change in seizure frequency per 28 days, 50% and 75% responder and seizure‐freedom rates. Treatment‐emergent adverse events (TEAEs) were monitored.

Results

Overall, 128 patients (placebo, n = 39; perampanel, n = 89) were included in the double‐blind Safety Analysis Set and 126 (FS, n = 113 [placebo, n = 32; perampanel, n = 81]; FBTCS, n = 35 [placebo, n = 14; perampanel, n = 21]; GTCS, n = 13 [placebo, n = 6; perampanel, n = 7]) comprised the Full Analysis Set. Median percent reductions in seizure frequency per 28 days for placebo vs perampanel for Indian patients were as follows: 34.8% vs 49.8% (FS; not significant [NS]) and 43.1% vs 60.5% (FBTCS; NS) at 4–12 mg/day, respectively, and −22.4% vs 8.2% (GTCS; NS) at 8 mg/day, respectively. Fifty‐percent responder rates were 37.5% vs 55.1% (FS; NS), 42.9% vs 60.0% (FBTCS; NS), and 16.7% vs 42.9% (GTCS; NS), respectively; seizure‐freedom rates were 0.0% vs 5.8%, 7.1% vs 10.0%, and 0.0% vs 14.3%, respectively (all NS). Overall, 110 patients entered OLEx studies (FS, n = 99; GTCS, n = 11). Perampanel was efficacious for up to four years for FS and FBTCS and two years for GTCS. Across double‐blind and OLEx studies, TEAEs occurred in 58.4% and 83.6% of Indian perampanel‐treated patients, respectively; dizziness was most common. Efficacy and safety outcomes were generally similar overall between Indian and non‐Indian patients.

Significance

These data suggest adjunctive perampanel (up to 12 mg/day) may be a suitable anti‐seizure medication for patients (aged ≥ 12 years) with FS, with/without FBTCS, or GTCS in India.

Efficacy, safety, and tolerability of adjunctive perampanel in patients from China with focal seizures or generalized tonic-clonic seizures: Post hoc analysis of phase III double-blind and open-label extension studies

Aims

This post hoc analysis assessed the efficacy and safety/tolerability of adjunctive perampanel in patients from China (aged ≥12 years) with focal seizures (FS), with/without focal to bilateral tonic‐clonic seizures (FBTCS), or generalized tonic‐clonic seizures (GTCS).

Methods

Study centers in China were identified using data from five double‐blind, randomized, phase III studies of adjunctive perampanel (2‐12 mg/day) and their open‐label extensions (OLEx). Efficacy assessments included median percent reduction in seizure frequency per 28 days, and 50% and 75% responder and seizure‐freedom rates. Safety/tolerability assessments included monitoring of treatment‐emergent adverse events (TEAEs).

Results

Overall, 277 patients (placebo, n = 79; perampanel, n = 198) were included in the double‐blind safety analysis set. The full analysis set comprised 274 patients (FS, n = 238 [placebo, n = 60; perampanel, n = 178]; FBTCS, n = 120 [placebo, n = 31; perampanel, n = 89]; GTCS, n = 36 [placebo, n = 18; perampanel, n = 18]). Median percent reductions in seizure frequency for placebo vs perampanel were as follows: 16.6% vs 32.4% (FS; P < 0.05) and 39.1% vs 48.2% (FBTCS; not significant [NS]) at 4‐12 mg/day, and 37.9% vs 82.6% (GTCS; NS) at 8 mg/day; 50% responder rates were 31.7% vs 37.4% (FS; NS), 48.4% vs 51.9% (FBTCS; NS), and 33.3% vs 61.1% (GTCS; NS), respectively. Seizure‐freedom rates were 1.7% vs 9.2%, 16.1% vs 25.3%, and 16.7% vs 44.4%, respectively (all NS). Overall, 262 patients entered the OLEx (FS, n = 228; GTCS, n = 34). Perampanel was efficacious for up to four years for FS and FBTCS and up to two years for GTCS. Across the double‐blind and OLEx studies, TEAEs were reported in 65.7% and 81.3% of perampanel‐treated patients, respectively; the most common was dizziness. Efficacy and safety/tolerability outcomes were generally similar between Chinese and non‐Chinese patients.

Conclusion

Adjunctive perampanel (up to 12 mg/day) may be a suitable treatment for Chinese patients with FS, with/without FBTCS, or GTCS, with similar efficacy and safety/tolerability compared to non‐Chinese patients.

Cross-national disparities contribute to heterogeneity in patient outcomes following invasive monitoring: A hierarchical mixed-effects analysis

There is substantial variability in outcomes following invasive monitoring and surgical treatment of drug-resistant epilepsy (DRE). Patients with DRE are uniquely vulnerable to cross-national health care disparities, as their epilepsy is difficult to treat and requires extensive resources. In a large cross-national database of patients undergoing invasive monitoring for epilepsy surgery, we sought to evaluate the association between social, economic, and educational indicators of the country of treatment and patient outcomes following invasive monitoring. We performed a mixed-effects analysis of an individual patient database of 595 subjects enrolled in 33 studies encompassing 25 neurosurgical centers in 10 countries of invasive monitoring for epilepsy from 1996 to 2019. Upon preliminary univariate analysis, significant nation-level predictors of seizure outcome following either stereoelectroencephalography or subdural electrodes were hospital beds per 100,000 population, physician density, gross domestic product (GDP) growth, male and female educational attainment, and unemployment rate. On multivariate mixed-effects logistic regression, physician density (β = -0.5112, P<.00697) and GDP growth (β = 0.53822, P<.00404) were the only nation-level covariates of significance associated with seizure outcome. A higher physician density was associated with lesser seizure freedom rates, whereas higher GDP growth was associated with greater seizure freedom rates. Although patient-specific variables were the primary determinant of seizure outcomes, cross-national disparities also contribute to heterogeneities. Our findings highlight the importance of a systems-level dialogue to improve surgical outcomes for DRE patients.

Efficacy and safety of perampanel monotherapy in patients with focal-onset seizures with newly diagnosed epilepsy or recurrence of epilepsy after a period of remission: The open-label Study 342 (FREEDOM Study)

Objective

Our study assessed perampanel monotherapy in patients (aged ≥12 years) with focal‐onset seizures (FOS) with or without focal to bilateral tonic‐clonic seizures (FBTCS) in Japan and South Korea.

Methods

Study 342 (NCT03201900; FREEDOM) is a single‐arm, open‐label, Phase III study. Patients initially received perampanel in a 32‐week 4‐mg/d Treatment Phase (6‐week Titration; 26‐week Maintenance Periods). If they experienced a seizure during the 4‐mg/d Maintenance Period, they could be up‐titrated to 8 mg/d across an additional 30‐week Treatment Phase (4‐week Titration; 26‐week Maintenance Periods). Primary endpoint was the seizure‐freedom rate during the Maintenance Period (4 mg/d and last evaluated dose [4 or 8 mg/d]). Secondary endpoints included time to first seizure onset and to withdrawal during Maintenance. Treatment‐emergent adverse events (TEAEs) were monitored.

Results

At data cutoff (February 28, 2019), 89 patients with FOS (84 [94.4%] with newly diagnosed epilepsy and 5 [5.6%] with recurrence of epilepsy after a period of remission) had received ≥1 perampanel dose; 16 patients discontinued during the 4‐mg/d Titration Period, meaning 73 patients entered the 4‐mg/d Maintenance Period and were included in the primary analysis set for efficacy. Seizure‐freedom rate in the 26‐week Maintenance Period was 46/73 (63.0%; 95% confidence interval [CI]: 50.9‐74.0) at 4 mg/d and 54/73 (74.0%; 95% CI: 62.4‐83.5) at 4 or 8 mg/d. Cumulative probability of seizure‐onset and withdrawal rates during Maintenance was 30.8% (95% CI: 21.5‐43.0) and 23.7% (95% CI: 15.4‐35.3) at 4 mg/d, and 18.2% (95% CI: 11.0‐29.3) and 23.3% (95% CI: 15.2‐34.8) at 4 or 8 mg/d. Perampanel was generally well tolerated, and the most common TEAE was dizziness.

Significance

Perampanel monotherapy (4 to 8 mg/d) was efficacious and consistent with the known safety profile up to 26 weeks in patients (≥12 years) with primarily newly diagnosed FOS with or without FBTCS.

Efficacy, Safety, and Economics of Intravenous Levetiracetam for Status Epilepticus: A Systematic Review and Meta-Analysis

Objective

To evaluate efficacy, safety, and economics profiles of intravenous levetiracetam (LEV) for status epilepticus (SE).

Methods

We searched PubMed, Embase, the Cochrane Library, Clinicaltrials.gov, and OpenGrey.eu for eligible studies published from inception to June 12^th 2019. Meta-analyses were conducted using random-effect model to calculate odds ratio (OR) of included randomized controlled trials (RCTs) with RevMan 5.3 software.

Results

A total of 478 studies were obtained. Five systematic reviews (SRs)/meta-analyses, 9 RCTs, 1 non-randomized trial, and 27 case series/reports and 1 economic study met the inclusion criteria. Five SRs indicated no statistically significant difference in rates of seizure cessation when LEV was compared with lorazepam (LOR), phenytoin (PHT), or valproate (VPA). Pooled results of included RCTs indicated no statistically significant difference in seizure cessation when LEV was compared with LOR [OR = 1.04, 95% confidence interval (CI) 0.37 to 2.92], PHT (OR = 0.90, 95% CI 0.64 to 1.27), and VPA (OR = 1.47, 95% CI 0.81 to 2.67); and no statistically significant difference in seizure freedom within 24 h compared with LOR [OR = 1.83, 95% CI 0.57 to 5.90] and PHT (OR = 1.08, 95% CI 0.63 to 1.87). Meanwhile, LEV did not increase the risk of mortality during hospitalization compared with LOR (OR = 1.03, 95% CI 0.31 to 3.39), PHT (OR = 0.89, 95% CI 0.37 to 2.10), VPA (OR = 1.28, 95% CI 0.32 to 5.07), and placebo (plus clonazepam, OR = 0.73, 95% CI 0.16 to 3.38). LEV had lower need for artificial ventilation (OR = 0.23, 95% CI 0.06 to 0.92) and a lower risk of hypotension (OR = 0.15, 95% CI 0.03 to 0.84) compared to LOR. A trend of lower risk of hypotension and higher risk of agitation was found when LEV was compared with PHT. Case series and case report studies indicated psychiatric and behavioral adverse events of LEV. Cost-effectiveness evaluations indicated LEV as the most cost-effective non-benzodiazepines anti-epileptic drug (AED).

Conclusions

LEV has a similar efficacy as LOR, PHT, and VPA for SE, but a lower need for ventilator assistance and risk of hypotension, thus can be used as a second-line treatment for SE. However, more well-conducted studies to confirm the role of intravenous LEV for SE are still needed.

Frequency of Seizure Clusters and Their Associated Risk Factors in Adult Patients with Epilepsy Referred to Epilepsy Center of Kashani Hospital in Isfahan from 2011 to 2016

Background:

Epilepsy is a chronic neurologic condition and affects people of all ages. Seizure clusters are generally referred to seizures that occur at close intervals with complete recovery between attacks. Various studies have reported a variety of frequencies and risk factors for this condition.

Methods:

We designed a study to determine the frequency of seizure cluster and their associated risk factors in Iranian population for the first time.

Results:

Among 40 variables analyzed, 18 of them were significantly associated with seizure clustering. Risk factors including educational level, age of onset, number of drugs, seizure types, perinatal complication, developmental delay, other illnesses, parental consanguinity, systemic diseases, number of drugs used, mentation, motor signs, sensory signs, cranial nerves signs, cerebellar signs, seizure duration, existence of magnetic resonance imaging (MRI) lesion, and type of MRI pathology are significantly associated with clustering of seizures. When associated risk factors were analyzed with multivariate analysis, age of onset of seizures, number of antiepileptic drugs currently used, lack of seizure-free periods, seizure frequency, and type of MRI pathology are significantly defining for anticipating clustering of seizures.

Conclusions:

Seizure cluster has a significant negative impact on the quality of life of patients. Important risk factors that are found to be associated are age of onset, parental consanguinity, frequency of seizure, lack of have seizure-free period or periods, pathologies in neurological examination, and MRI findings.

Open-label study to investigate the safety and efficacy of adjunctive perampanel in pediatric patients (4 to <12 years) with inadequately controlled focal seizures or generalized tonic-clonic seizures

Objective

Study 311 (NCT02849626) was a global, multicenter, open‐label, single‐arm study that assessed safety, tolerability, pharmacokinetics, and pharmacokinetics/pharmacodynamics of once‐daily adjunctive perampanel oral suspension in pediatric patients (aged 4 to <12 years) with focal seizures (FS) (with/without focal to bilateral tonic‐clonic seizures [FBTCS]) or generalized tonic‐clonic seizures (GTCS).

Methods

In the 311 Core Study, a 4‐week Pre‐treatment Period (Screening/Baseline) preceded a 23‐week Treatment Period (11‐week Titration; 12‐week Maintenance) and 4‐week Follow‐up. Endpoints included safety/tolerability (primary endpoint), median percent change in seizure frequency per 28 days from Baseline (Treatment Period), and 50% responder and seizure‐freedom rates (Maintenance Period). Patients were stratified by age (4 to <7; 7 to <12 years) and concomitant enzyme‐inducing anti‐seizure drug (EIASD) use.

Results

One hundred eighty patients were enrolled (FS, n = 149; FBTCS, n = 54; GTCS, n = 31). The Core Study was completed by 146 patients (81%); the most common primary reason for discontinuation was adverse event (AE) (n = 14 [8%]). Mean (standard deviation) daily perampanel dose was 7.0 (2.6) mg/day and median (interquartile range) duration of exposure was 22.9 (2.0) weeks. The overall incidence of treatment‐emergent AEs (TEAEs; 89%) was similar between patients with FS (with/without FBTCS) and GTCS. The most common TEAEs were somnolence (26%) and nasopharyngitis (19%). There were no clinically important changes observed for cognitive function, laboratory, or electrocardiogram (ECG) parameters or vital signs. Median percent reductions in seizure frequency per 28 days from Baseline were as follows: 40% (FS), 59% (FBTCS), and 69% (GTCS). Corresponding 50% responder and seizure‐freedom rates were as follows: FS, 47% and 12%; FBTCS, 65% and 19%; and GTCS, 64% and 55%, respectively. Improvements in response/seizure frequency from Baseline were seen regardless of age or concomitant EIASD use.

Significance

Results from the 311 Core Study suggest that daily oral doses of adjunctive perampanel are generally safe, well tolerated, and efficacious in children age 4 to <12 years with FS (with/without FBTCS) or GTCS.

Trends in antiepileptic drug treatment and effectiveness in clinical practice in England from 2003 to 2016: a retrospective cohort study using electronic medical records

OBJECTIVE

To assess the evolution of antiepileptic drug (AED) treatment patterns and seizure outcomes in England from 2003 to 2016.

DESIGN, SETTING AND PARTICIPANTS

Retrospective cohort study of electronic medical records from Clinical Practice Research Datalink and National Health Service Digital Hospital Episode Statistics databases. Patients newly diagnosed with epilepsy were identified and followed until end of data availability. Three eras were defined starting 1 April 2003 (first National Institute for Health and Care Excellence (NICE) guideline); 1 September 2007 (Standard and New Antiepileptic Drugs publication); and 1 January 2012 (second NICE guideline).

OUTCOME MEASURES

Time from diagnosis to first AED; AED sequence; time from first AED to first 1-year remission period (no new AED attempts and no seizure-related healthcare events); time from first AED to refractoriness (third AED attempt regardless of reason); Kaplan-Meier analysis of time-to-event variables.

RESULTS

4388 patients were included (mean follow-up: 6.8, 4.2 and 1.7 years by era). 84.6% of adults (≥16 years), 75.5% of children (<16) and 89.1% of elderly subgroup (65+) received treatment within 1 year; rates were generally stable over time. Treatment trends included reduced use of carbamazepine (adult first line, era 1: 34.9%; era 3: 10.7%) and phenytoin, earlier line and increased use of levetiracetam (adult first line, era 1: 2.6%; era 3: 26.2%) and lamotrigine (particularly in adults and elderly subgroup), and a larger number of different AEDs used. Valproate use shifted somewhat to later lines. Rates of 1-year remission within 2 years of starting treatment increased in adults (era 1: 71.9%; era 3: 81.4%) and elderly (era 1: 76.1%; era 3: 81.7%). Overall, 55.5% of patients relapsed after achieving 1-year remission. Refractoriness rates remained stable over time (~26% of adults within 5 years).

CONCLUSION

Treatment trends often were not aligned with era-relevant guidance. However, our results suggest a slight improvement in epilepsy treatment outcomes over the 13-year period.

Neurovascular Lesions in Pediatric Epilepsy

INTRODUCTION

Neurovascular lesions are rare and understudied in the pediatric population. Their initial presentation can range from seizures to focal neurologic deficits, as well as headaches. The goal of this study was to examine the clinical presentation and natural history of neurovascular lesions in children with epilepsy.

METHODS

We reviewed all pediatric epilepsy patients with neurovascular lesions diagnosed between 2006 and 2018 at the University of Alberta and the Stollery Children's Hospital, Edmonton, Canada. Initial clinical presentation and brain imaging, as well as long-term epilepsy and postsurgical outcome, were assessed.

RESULTS

Of the 14 patients, 10 patients had an initial presentation of focal seizures with impaired awareness, whereas 2 patients presented with headache, 1 presented with visual field defects as well as chronic headaches, and 1 with decreased level of consciousness. Seven patients had cavernous angiomas, 6 had arteriovenous malformation, and 1 patient had an arteriovenous fistula. Notably, all patients with cavernous angiomas and 4 of 6 patients with arteriovenous malformations presented with seizures. Among 9 of the 14 who underwent neurovascular corrective surgery, all 9 patients required long-term antiepileptic treatment of at least 1 antiepileptic drug for seizure control after the operation.

CONCLUSION

In this novel case series, we describe focal seizures as the initial presentation of pediatric neurovascular lesions. This clinical presentation appears to be independent of the type of neurovascular lesion. Furthermore, unlike our pediatric surgical patients with epilepsy due to other causes, seizure freedom following neurovascular surgery is limited, and patients require long-term antiepileptic treatment.

The Epilepsy Surgery Grading Scale: Validation in an independent population with drug-resistant focal epilepsy

The Epilepsy Surgery Grading Scale (ESGS) is a simple tool that predicts a patient's likelihood of progressing to resective surgery and becoming seizure-free. The aim of our study was to validate the ESGS in an independent patient cohort. We retrospectively calculated the ESGS score for adult patients with drug-resistant focal epilepsy undergoing presurgical evaluation at two reference centers for drug-resistant epilepsy in Belgium. We classified patients into ESGS grade 1 (most favorable), grade 2 (intermediate), and grade 3 (least favorable). We assessed progression to surgery and postsurgical seizure freedom. A total of 238 patients underwent presurgical evaluation (presurgical cohort), of whom 140 progressed to surgery (surgical cohort). In the presurgical cohort, we observed significant differences in rates of surgery and in rates of seizure freedom between grades 1, 2, and 3. In the surgical cohort, we observed significant differences in rates of seizure freedom between grades 1 and 2 and between grades 1 and 3. We confirm the usefulness of the ESGS for the prognostic stratification of patients with drug-resistant focal epilepsy undergoing presurgical evaluation. Our results support the use of the ESGS in the decision process of presurgical evaluation in clinical practice.

Long-term seizure outcome after epilepsy surgery in patients with mild malformation of cortical development and focal cortical dysplasia

Focal cortical dysplasia (FCD) and mild malformation of cortical development (mMCD) are frequent histopathologic diagnoses in patients who undergo surgery for refractory epilepsy. Literature concerning surgical outcome in patients with mMCD, as well as its contrast with FCD, has been scarce. We studied 88 patients with a histopathologic diagnosis of isolated FCD (n = 57) or mMCD (n = 31), revised according to the latest International League Against Epilepsy (ILAE) guidelines, who underwent resective or disconnective surgery. Our findings suggest differences between mMCD and FCD in clinical presentation and surgical outcome after surgery. Patients with mMCD developed seizures later in life, and their lesions had a predilection for location in the temporal lobe and remained undetected by magnetic resonance imaging (MRI) more frequently. A diagnosis of mMCD has a less favorable surgical outcome. Still, 32% of these patients reached continuous seizure freedom (Engel class 1A) at a latest median follow-up duration of 8 years, compared to 59% in FCD. A histopathologic diagnosis of mMCD, extratemporal surgery, and indication of an incomplete resection each were independent predictors of poor outcome.

Epilepsy surgery for polymicrogyria: a challenge to be undertaken

Polymicrogyria (PMG) is one of the most common malformations of cortical development (MCDs), with epilepsy affecting most patients. PMG-related drug-resistant epilepsy patients can be considered for epilepsy surgery in well-selected cases. In this context, a comprehensive presurgical evaluation, often including stereo-electroencephalography (SEEG), is warranted to accurately delineate the epileptogenic zone. The heterogeneity of intrinsic epileptogenicity in PMG, together with the additional or predominant involvement of remote cortical areas, calls for a different strategy in PMG compared to other MCDs, namely one that is not predominantly MRI- but rather SEEG-oriented. Favourable results in terms of seizure freedom and antiepileptic drug cessation are feasible in a large proportion of patients with unilateral PMG. PMG extent should not deter from exploring the possibility of epilepsy surgery. On the other hand, patients with hemispheric PMG can be excellent hemispherotomy candidates, particularly when presenting with contralateral hemiparesis. Recent findings support the early consideration of surgery in PMG-related drug-resistant epilepsy.

Levetiracetam for epilepsy: an evidence map of efficacy, safety and economic profiles

OBJECTIVE

To evaluate the efficacy, safety and economics of levetiracetam (LEV) for epilepsy.

MATERIALS AND METHODS

PubMed, Scopus, the Cochrane Library, OpenGrey.eu and ClinicalTrials.gov were searched for systematic reviews (SRs), meta-analyses, randomized controlled trials (RCTs), observational studies, case reports and economic studies published from January 2007 to April 2018. We used a bubble plot to graphically display information of included studies and conducted meta-analyses to quantitatively synthesize the evidence.

RESULTS

A total of 14,803 records were obtained. We included 30 SRs/meta-analyses, 34 RCTs, 18 observational studies, 58 case reports and 2 economic studies after the screening process. The included SRs enrolled patients with pediatric epilepsy, epilepsy in pregnancy, focal epilepsy, generalized epilepsy and refractory focal epilepsy. Meta-analysis of the included RCTs indicated that LEV was as effective as carbamazepine (CBZ; treatment for 6 months: 58.9% vs 64.8%, OR=0.76, 95% CI: 0.50-1.16; 12 months: 54.9% vs 55.5%, OR=1.24, 95% CI: 0.79-1.93), oxcarbazepine (57.7% vs 59.8%, OR=1.34, 95% CI: 0.34-5.23), phenobarbital (50.0% vs 50.9%, OR=1.20, 95% CI: 0.51-2.82) and lamotrigine (LTG; 61.5% vs 57.7%, OR=1.22, 95% CI: 0.90-1.66). SRs and observational studies indicated a low malformation rate and intrauterine death rate for pregnant women, as well as low risk of cognitive side effects. But psychiatric and behavioral side effects could not be ruled out. LEV decreased discontinuation due to adverse events compared with CBZ (OR=0.52, 95% CI: 0.41-0.65), while no difference was found when LEV was compared with placebo and LTG. Two cost-effectiveness evaluations for refractory epilepsy with decision-tree model showed US$ 76.18 per seizure-free day gained in Canada and US$ 44 per seizure-free day gained in Korea.

CONCLUSION

LEV is as effective as CBZ, oxcarbazepine, phenobarbital and LTG and has an advantage for pregnant women and in cognitive functions. Limited evidence supports its cost-effectiveness.

REGISTERED NUMBER

PROSPERO (No CRD 42017069367).

Localization of the Epileptogenic Zone Using Interictal MEG and Machine Learning in a Large Cohort of Drug-Resistant Epilepsy Patients

Objective: Epilepsy surgery results in seizure freedom in the majority of drug-resistant patients. To improve surgery outcome we studied whether MEG metrics combined with machine learning can improve localization of the epileptogenic zone, thereby enhancing the chance of seizure freedom.

Methods: Presurgical interictal MEG recordings of 94 patients (64 seizure-free >1y post-surgery) were analyzed to extract four metrics in source space: delta power, low-to-high-frequency power ratio, functional connectivity (phase lag index), and minimum spanning tree betweenness centrality. At the group level, we estimated the overlap of the resection area with the five highest values for each metric and determined whether this overlap differed between surgery outcomes. At the individual level, those metrics were used in machine learning classifiers (linear support vector machine (SVM) and random forest) to distinguish between resection and non-resection areas and between surgery outcome groups.

Results: The highest values, for all metrics, overlapped with the resection area in more than half of the patients, but the overlap did not differ between surgery outcome groups. The classifiers distinguished the resection areas from non-resection areas with 59.94% accuracy (95% confidence interval: 59.67–60.22%) for SVM and 60.34% (59.98–60.71%) for random forest, but could not differentiate seizure-free from not seizure-free patients [43.77% accuracy (42.08–45.45%) for SVM and 49.03% (47.25–50.82%) for random forest].

Significance: All four metrics localized the resection area but did not distinguish between surgery outcome groups, demonstrating that metrics derived from interictal MEG correspond to expert consensus based on several presurgical evaluation modalities, but do not yet localize the epileptogenic zone. Metrics should be improved such that they correspond to the resection area in seizure-free patients but not in patients with persistent seizures. It is important to test such localization strategies at an individual level, for example by using machine learning or individualized models, since surgery is individually tailored.

Seizures associated with cerebral arteriovenous malformations

Various types of seizures and epilepsy are associated with 20-45% of cerebral arteriovenous malformations (AVMs). The necessity to differentiate between occasional seizures, epilepsy with repetitive seizures, and the much rarer drug-resistant epilepsy (DRE) is underlined. It is clear that where there is frequent seizures or DRE, vascular surgeons should take epilepsy surgery aspects into account. The epidemiology of AVM-associated seizures, assumed pathophysiologic mechanisms, most frequent seizures types, and medical treatment are described. Depending on the severity of the epilepsy, the diagnostic workup, including electroencephalogram (EEG), video-EEG, and, rarely, invasive evaluation, is explained. An invasive presurgical workup is only necessary in rare cases of DRE. The indication to extend the resection to more than just removal of the AVM is defined and the various specific resection techniques for this rare form are outlined. In the vast majority of AVM cases removal of the AVM with some adjoining gliotic or hemosiderotic rim of cortex will be sufficient, however. In the majority of cases with preoperative epilepsy, patients will be seizure-free after surgery. Patients who never had a seizure before AVM removal may develop de novo epilepsy postoperatively (5-15%). Rates of seizure freedom after different treatments (microsurgery, radiosurgery, endovascular) vary.

Minimally resective epilepsy surgery in MRI-negative children

AIM

Performing epilepsy surgery on children with non-lesional brain MRI often results in large lobar or multilobar resections. The aim of this study was to determine if smaller resections result in a comparable rate of seizure freedom.

METHODS

We reviewed 25 children who had undergone focal corticectomies restricted to one aspect of a single lobe or the insula at our institution within a 5.5-year period. Data collected in the comprehensive non-invasive pre-surgical evaluation (including scalp video-EEG, volumetric MRI, functional MRI, EEG source localization, and SPECT and PET), as well as from invasive recordings performed in each patient, was reviewed. Data from each functional modality was identified as convergent or divergent with the epileptogenic zone using image coregistration. Specific biomarkers (from extra-operative and invasive testing) previously indicated to be indicative of focal epileptogenicity were used to further tailor each resection to an epileptogenic epicentre. Tissue pathology and postoperative outcomes were obtained from all 25 patients.

RESULTS

Two years postoperatively, 15/25 (60%) children were seizure-free, three (12%) experienced >90% reduction in seizure frequency, two (8%) had a 50-90% reduction in seizure frequency, and the remaining five (20%) had no change in seizure burden. There was no significant difference in outcome based on numerous pre- and postoperative factors including location of resection, the number of preoperative functional tests providing convergent data, and tissue pathology.

CONCLUSION

In MRI-negative children with focal epilepsy, an epileptogenic epicentre within a larger epileptogenic zone can be identified when specific biomarkers are recognized on non-invasive and invasive testing. When such children undergo resection of a small, well-defined epileptogenic epicentre, favourable outcomes can be achieved.

Infantile spasms: A prognostic evaluation

Background:

Few papers address the comprehensive prognosis in infantile spasms and look into the seizure profile and psychomotor outcome.

Objective:

We aimed to follow up children with infantile spasms to study: a) the etiology, demographics, semiology, electroencephalogram (EEG), and radiological pattern; b) seizure control, psychomotor development, and EEG resolution with treatment; c) the effects of various factors on the control of spasms, resolution of EEG changes, and psychomotor development at 3-year follow-up.

Materials and Methods:

Fifty newly diagnosed cases with a 1-12 month age of onset and who had hypsarrhythmia in their EEG were recruited and 43 were followed up for 3 years.

Results:

Of the children followed up, 51% were seizure-free and 37% had a normal EEG at the 3-year follow-up. Autistic features were seen in 74% of the children. Only 22.7% among the seizure-free (11.6% of the total) children had normal vision and hearing, speech with narration, writing skills, gross and fine motor development, and no autism or hyperactivity. On multivariate analysis, two factors could predict bad seizure outcome — the occurrence of other seizures in addition to infantile spasms and no response to 28 days of adrenocorticotropic hormone (ACTH). No predictor could be identified for abnormal psychomotor development.

Discussion and Conclusion:

In our study, we could demonstrate two factors that predict seizure freedom. The cognitive outcome and seizure control in this group of children are comparable to the existing literature. However, the cognitive outcome revealed by our study and the survey of the literature are discouraging.

Surgical strategies for pediatric epilepsy

Pediatric epilepsy is a debilitating condition that impacts millions of patients throughout the world. Approximately 20-30% of children with recurrent seizures have drug-resistant epilepsy (DRE). For these patients, surgery offers the possibility of not just seizure freedom but significantly improved neurocognitive and behavioral outcomes. The spectrum of surgical options is vast, ranging from outpatient procedures such as vagus nerve stimulation to radical interventions including hemispherectomy. The thread connecting all of these interventions is a common goal-seizure freedom, an outcome that can be achieved safely and durably in a large proportion of patients. In this review, we discuss many of the most commonly performed surgical interventions and describe the indications, complications, and outcomes specific to each.