Etiology-specific response to antiseizure medication in focal epilepsy

Ketogenic diet therapy leads to antiseizure medication reduction in children and adults with drug-resistant epilepsy

AIMS

This study aimed to evaluate the safety of reducing or withdrawing anti-seizure medications (ASMs) in a cohort comprising both adults and children with drug-resistant epilepsy (DRE) undergoing ketogenic diet therapy (KDT).

METHODS

We conducted a comprehensive analysis of clinical profiles in adults and children with DRE who had adhered to KDT for at least 6 months. Successful withdrawal or reduction of an ASM was defined as discontinuation or dose reduction without subsequent resumption or increase and without initiation of any new ASM throughout the entire follow-up period. Changes in the ASM load were calculated specifically for adult patients.

RESULTS

The study enrolled 56 participants (34 children and 22 adults) with DRE, with 64.3% achieving successful withdrawal of at least one ASM. The probability of ASM withdrawal remained consistent for children (64.7%) versus adults (63.6%), as well as for responders (62.5%) versus non-responders (68.8%), and it was not associated with other clinical factors. Early ASM reduction (including withdrawal) after diet initiation occurred in 15 patients (26.8%), with treatment outcomes comparable to those of the remaining participants. Among the 22 adults, the mean values of ASM load reduced by 24.5%, with a similar magnitude observed for responders (24.2%) versus non-responders (25.1%). In addition, adults tend to have a slower elevation in serum ketone levels compared to children.

CONCLUSION

This study demonstrates the safe achievability of ASM withdrawal through KDT in most patients with DRE, irrespective of age or seizure frequency reduction.

Risk of breakthrough seizures depends on type and etiology of epilepsy

OBJECTIVE

This study was undertaken to analyze whether the rate of breakthrough seizures in patients taking antiseizure medication (ASM) who have been seizure-free for at least 12 months varies among different types and etiologies of epilepsy. Given the relative ease of achieving seizure freedom with ASM in patients with post-ischemic stroke epilepsy, we hypothesized that this etiology is associated with a reduced risk of breakthrough seizures.

METHODS

We defined a breakthrough seizure as an unprovoked seizure occurring while the patient was taking ASM after a period of at least 12 months without seizures. Data were analyzed retrospectively from a tertiary epilepsy outpatient clinic. Patients were eligible for inclusion if they either had a breakthrough seizure at any time or a seizure-free interval of at least 2 years. Our primary endpoint was rate of breakthrough seizures. We conducted univariable and multivariable analyses to identify variables associated with breakthrough seizures.

RESULTS

Of 521 patients (53% females, median age = 49 years) included, 29% had a breakthrough seizure, which occurred after a median seizure-free interval of 34 months (quartiles = 22, 62). When controlling for clinically relevant covariates, breakthrough seizures were associated with post-ischemic stroke epilepsy (odds ratio [OR] = .267, 95% confidence interval [CI] = .075-.946), genetic generalized epilepsy (OR = .559; 95% CI = .319-.978), intellectual disability (OR = 2.768, 95% CI = 1.271-6.031), and the number of ASMs previously and currently tried (OR = 1.203, 95% CI = 1.056-1.371). Of the 151 patients with breakthrough seizures, 34.3% did not reachieve terminal 12-month seizure freedom at the last visit.

SIGNIFICANCE

This is the first study to show an association between type and etiology of epilepsy and risk of breakthrough seizures. Our data suggest that epilepsies in which seizure freedom can be obtained more easily also exhibit a lower risk of breakthrough seizures. These findings may help to better counsel seizure-free patients on their further seizure prognosis.

Effectiveness and tolerability of brivaracetam in patients with epilepsy stratified by comorbidities and etiology in the real world: 12-month subgroup data from the international EXPERIENCE pooled analysis

OBJECTIVE

To assess the effectiveness and tolerability of brivaracetam (BRV) in adults with epilepsy by specific comorbidities and epilepsy etiologies.

METHODS

EXPERIENCE/EPD332 was a pooled analysis of individual patient records from several non-interventional studies of patients with epilepsy initiating BRV in clinical practice. Outcomes included ≥ 50% reduction from baseline in seizure frequency, seizure freedom (no seizures within prior 3 months), continuous seizure freedom (no seizures since baseline), BRV discontinuation, and treatment-emergent adverse events (TEAEs) at 3, 6, and 12 months. Analyses were performed for all adult patients (≥ 16 years of age) and stratified by comorbidity and by etiology at baseline (patients with cognitive/learning disability [CLD], psychiatric comorbidity, post-stroke epilepsy, brain tumor-related epilepsy [BTRE], and traumatic brain injury-related epilepsy [TBIE]).

RESULTS

At 12 months, ≥ 50% seizure reduction was achieved in 35.6% (n = 264), 38.7% (n = 310), 41.7% (n = 24), 34.1% (n = 41), and 50.0% (n = 28) of patients with CLD, psychiatric comorbidity, post-stroke epilepsy, BTRE, and TBIE, respectively; and continuous seizure freedom was achieved in 5.7% (n = 318), 13.7% (n = 424), 29.4% (n = 34), 11.4% (n = 44), and 13.8% (n = 29), respectively. During the study follow-up, in patients with CLD, psychiatric comorbidity, post-stroke epilepsy, BTRE, and TBIE, 37.1% (n = 403), 30.7% (n = 605), 33.3% (n = 51), 39.7% (n = 68), and 27.1% (n = 49) of patients discontinued BRV, respectively; and TEAEs since prior visit at 12 months were reported in 11.3% (n = 283), 10.0% (n = 410), 16.7% (n = 36), 12.5% (n = 48), and 3.0% (n = 33), respectively.

CONCLUSIONS

BRV as prescribed in the real world is effective and well tolerated among patients with CLD, psychiatric comorbidity, post-stroke epilepsy, BTRE, and TBIE.

Long-term outcome of treatment-naïve patients with mesial temporal lobe epilepsy with hippocampal sclerosis: A retrospective study in a single center

PURPOSE

This study aimed to describe long-term treatment outcomes of treatment-naïve patients with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS).

METHODS

A retrospective review was conducted of treatment-naïve patients with MTLE-HS who visited the Yonsei Epilepsy Clinic from April 2000 to April 2022 and were followed up for at least 2 years. Seizure freedom (SF) was defined as no seizures or auras only for >1 year, and complete SF was defined as no seizures including auras for >1 year.

RESULTS

Eighty-four treatment-naïve patients with MTLE-HS with a median follow-up of 122 months were included. Except for one patient who underwent early surgical treatment, of the remaining 83 patients, 31 (37.3 %) achieved SF and remained in remission, 38 (45.8 %) had fluctuations in seizure control, and 14 (16.9 %) never achieved SF. Additionally, 18 (21.7 %) patients achieved complete SF and remained in remission, 42 (50.6 %) showed fluctuations, and 23 (27.7 %) never achieved complete SF. Fifty-three (63.9 %) patients achieved SF and 34 (41.0 %) achieved complete SF at their last visit. Older age at epilepsy onset, male sex, low pretreatment seizure density, history of central nervous system infection before age 5, absence of aura, and fewer antiseizure medications in the final regimen were associated with favorable outcome. Of the 84 patients, 11 (13.1 %) underwent temporal lobectomy.

CONCLUSIONS

Medical treatment outcomes in treatment-naïve MTLE-HS were relatively better than previously reported outcomes in MTLE-HS, although frequent fluctuations in seizure control were observed.

Familial occurrence of seizure disorders across MRI defined structural focal epilepsy etiology

BACKGROUND

Previous studies have established familial occurrence of epilepsy and seizure disorders and early age of epilepsy onset as predictors of genetic epilepsy, but have not evaluated the rate of their occurrence in patients with different epilepsy etiology. Our study determines the distribution of familial occurrence and age of epilepsy onset across structural focal epilepsy (FE) etiology in a large FE cohort.

METHODS

Records of 1354 consecutive patients evaluated for epilepsy and seizure disorders in The Neurology Clinic, University Clinical Center of Serbia from 2008 to 2019 were screened for FE. Structural etiology, lobar diagnosis, familial occurrence, and age at epilepsy onset were determined. Patients with a. nonlesional focal epilepsy (NLFE), b. hippocampal sclerosis (HS) and c. congenital or perinatal etiology (CPE) were classified as NAFE, while patients with an identified acquired focal epilepsy (AFE) constituted the control group.

RESULTS

We identified 965 patients with FE, 329 (34.1 %) with NLFE, 213 (22.1 %) with HS, 174 (18.0 %) with CPE and 249 (25.8 %) with AFE. Familial occurrence was identified in 160 (16.6 %), 19.1 % of patients with NAFE and 9.2 % of AFE (p = 0.003). Patients with NAFE had a younger age of epilepsy onset (13 vs. 18 years, p < 0.001). The highest proportion of familial occurrence was found in patients with NLFE (23.7 %), while the youngest median age of epilepsy onset was identified in patients with HS (12 years) and CPE (11 years).

CONCLUSION

Patients with NAFE frequently have familial occurrence of epilepsy and have an earlier age of epilepsy onset than patients with AFE.

Non-discontinuation of antiseizure medication in seizure-free epilepsy patients

BACKGROUND AND PURPOSE

In patients with epilepsy and sustained seizure freedom, guidelines recommend considering discontinuation of antiseizure medication (ASM) based on shared decision-making. This study aims to identify factors associated with non-discontinuation of ASM in seizure-free patients.

METHODS

Retrospective data from three sites of an academic outpatient clinic were analyzed. Adult patients with epilepsy who have been seizure-free for ≥24 months on ASM monotherapy were included. The primary end-point was non-discontinuation of ASM, defined as no discontinuation or no dose reduction of ≥25% at the last outpatient clinic visit in the ultimate seizure-free interval. Secondary end-points included frequency of discussion on discontinuation attempts between patients and physicians, adherence to ASM discontinuation decisions, and post-discontinuation seizure outcomes.

RESULTS

Out of 338 included patients, 81.7% did not discontinue ASM and did not reduce its dose, 11.5% discontinued ASM and 6.8% had a significant dose reduction. Factors independently associated with non-discontinuation of ASM were history of focal to bilateral or generalized tonic-clonic seizures (odds ratio [OR] 2.33, 95% confidence interval [CI] 1.08-5.06), history of breakthrough seizures (OR 3.32, 95% CI 1.10-10.04), history of failed attempts to discontinue or reduce the ASM dose (OR 4.67, 95% CI 1.03-21.11) and higher ASM load at the index visit (OR 6.10, 95% CI 2.09-17.78). Discontinuation attempts were made during the entire period of seizure freedom and were most commonly undertaken ≥10 years after the last seizure.

CONCLUSIONS

This study provides insights into factors associated with the shared decision-making process regarding ASM discontinuation in seizure-free patients and highlights the importance of considering individual patient characteristics and seizure history.

Analysis of factors influencing the efficacy of vagus nerve stimulation for the treatment of drug-resistant epilepsy in children and prediction model for efficacy evaluation

Objective

Vagus nerve stimulation (VNS) has been widely used in the treatment of drug-resistant epilepsy (DRE) in children. We aimed to explore the efficacy and safety of VNS, focusing on factors that can influence the efficacy of VNS, and construct a prediction model for the efficacy of VNS in the treatment of DRE children.

Methods

Retrospectively analyzed 45 DRE children who underwent VNS at Qilu Hospital of Shandong University from June 2016 to November 2022. A ≥50% reduction in seizure frequency was defined as responder, logistic regression analyses were performed to analyze factors affecting the efficacy of VNS, and a predictive model was constructed. The predictive model was evaluated by receiver operating characteristic curve (ROC), calibration curves, and decision curve analyses (DCA).

Results

A total of 45 DRE children were included in this study, and the frequency of seizures was significantly reduced after VNS treatment, with 25 responders (55.6%), of whom 6 (13.3%) achieved seizure freedom. There was a significant improvement in the Quality of Life in Childhood Epilepsy Questionnaire (15.5%) and Seizure Severity Score (46.2%). 16 potential factors affecting the efficacy of VNS were included, and three statistically significant positive predictors were ultimately screened: shorter seizure duration, focal seizure, and absence of intellectual disability. We developed a nomogram for predicting the efficacy of VNS in the treatment of DRE children. The ROC curve confirmed that the predictive model has good diagnostic performance (AUC = 0.864, P < 0.05), and the nomogram can be further validated by bootstrapping for 1,000 repetitions, with a C-index of 0.837. Besides, this model showed good fitting and calibration and positive net benefits in decision curve analysis.

Conclusion

VNS is a safe and effective treatment for DRE children. We developed a predictive nomogram for the efficacy of VNS, which provides a basis for more accurate selection of VNS patients.

Epileptogenicity of white matter lesions in cerebral small vessel disease: a systematic review and meta-analysis

BACKGROUND

The epileptogenic properties of white matter lesions (WML) in cerebral small vessel disease (CSVD) are not yet understood. The aim of our systematic review and meta-analysis was to estimate the association between the extent of WML in CSVD and epilepsy, analyze whether these WML are associated with an increased risk of seizure recurrence, and evaluate if treatment with anti-seizure medication (ASM) is justified in first-seizure patients with WML and no cortical lesions.

METHODS

Following a pre-registered study protocol (PROSPERO-ID CRD42023390665), we systematically searched Pubmed and Embase for relevant literature comparing WML load between patients with epilepsy and controls as well as studies on seizure recurrence risk and ASM therapy in the presence vs. absence of WML. We calculated pooled estimates using a random effects model.

RESULTS

Eleven studies comprising 2983 patients were included in our study. Presence of WML (OR 2.14, 95% CI 1.38-3.33) and presence of relevant WML as assessed by visual rating scales (OR 3.96, 95% CI 2.55-6.16) but not WML volume (OR 1.30, 95% CI 0.91-1.85) were significantly associated with seizures. These results stayed robust in sensitivity analyses restricted to studies on patients with late-onset seizures/epilepsy. Only two studies assessed the association between WML and risk of seizure recurrence with conflicting results. Currently, there are no studies on the efficacy of ASM therapy in the presence of WML in CSVD.

CONCLUSIONS

This meta-analysis suggests an association between presence of WML in CSVD and seizures. More research is needed addressing the association between WML and risk of seizure recurrence and ASM therapy focusing on a population of patients with a first unprovoked seizure.

Early predictors of remission in children and adolescents with new-onset epilepsy: A prospective study

PURPOSE

This study aims to identify predictive factors of a two-year remission (2YR) in a cohort of children and adolescents with new-onset seizures based on baseline clinical characteristics, initial EEG and brain MRI findings.

METHODS

A prospective cohort of 688 patients with new onset seizures, initiated on treatment with antiseizure medication was evaluated. 2YR was defined as achieving at least two years of seizure freedom during the follow-up period. Multivariable analysis was performed and recursive partition analysis was utilized to develop a decision tree.

RESULTS

The median age at seizure onset was 6.7 years, and the median follow-up was 7.4 years. 548 (79.7%) patients achieved a 2YR during the follow up period. Multivariable analysis found that presence and degree of intellectual and developmental delay (IDD), epileptogenic lesion on brain MRI and a higher number of pretreatment seizures were significantly associated with a lower probability of achieving a 2YR. Recursive partition analysis showed that the absence of IDD was the most important predictor of remission. An epileptogenic lesion was a significant predictor of non-remission only in patients without evidence of IDD, and a high number of pretreatment seizures was a predictive factor in children without IDD and in the absence of an epileptogenic lesion.

CONCLUSION

Our results indicate that it is possible to identify patients at risk of not achieving a 2YR based on variables obtained at the initial evaluation. This could allow for a timely selection of patients who require close follow-up, consideration for neurosurgical intervention, or investigational treatments trials.

Levetiracetam, from broad-spectrum use to precision prescription: A narrative review and expert opinion

Levetiracetam (LEV) is an antiseizure medication (ASM) whose mechanism of action involves the modulation of neurotransmitters release through binding to the synaptic vesicle glycoprotein 2A. It is a broad-spectrum ASM displaying favorable pharmacokinetic and tolerability profiles. Since its introduction in 1999, it has been widely prescribed, becoming the first-line treatment for numerous epilepsy syndromes and clinical scenarios. However, this might have resulted in overuse. Increasing evidence, including the recently published SANAD II trials, suggests that other ASMs are reasonable therapeutic options for generalized and focal epilepsies. Not infrequently, these ASMs show better safety and effectiveness profiles compared to LEV (partially due to the latter's well-known cognitive and behavioral adverse effects, present in up to 20% of patients). Moreover, it has been shown that the underlying etiology of epilepsy is significantly linked to ASMs response in particular scenarios, highlighting the importance of an etiology-based ASM choice. In the case of LEV, it has demonstrated an optimal effectiveness in Alzheimer's disease, Down syndrome, and PCDH19-related epilepsies whereas, in other etiologies such as malformations of cortical development, it may show negligible effects. This narrative review analyzes the current evidence related to the use of LEV for the treatment of seizures. Illustrative clinical scenarios and practical decision-making approaches are also addressed, therefore aiming to define a rational use of this ASM.

Valproate in status epilepticus: Correlation between loading dose, serum levels, and clinical response

Background and purpose

Intravenous valproate (VPA) is an established treatment of status epilepticus (SE), but optimal loading dose was not fully assessed. We aimed at analyzing the correlation between VPA loading dose and subsequent plasma levels with clinical response in SE.

Methods

This was a retrospective study in one referral center of all consecutive VPA‐naïve SE episodes treated with VPA between January 2013 and June 2019, in which total VPA trough plasma levels after intravenous loading dose were available. Response to VPA, defined as last antiseizure medication introduced before SE resolution (without the need for additional treatment), was correlated with VPA loading dose and trough level. Correlations were adjusted for other SE characteristics.

Results

Among 128 SE episodes, 53 (41%) responded to VPA. Median VPA loading dose was 25.2 mg/kg (range, 7–58 mg/kg). Loading doses and total plasma levels were not associated with the probability of response or mortality. Correcting for other possible confounders (number of previously tried treatment, demographics, SE severity) did not alter these findings. Only 3.8% of SE episodes that responded to VPA received >30 mg/kg.

Conclusions

A high loading dose (>30 mg/kg) is not associated with a greater response rate in patients with SE. Therefore, it seems to bring little benefit. If confirmed in further studies, a dosage of 25–30 mg/kg appears adequate in SE.

Patient characteristics and antiseizure medication pathways in newly diagnosed epilepsy: Feasibility and pilot results using the common data model in a single-center electronic medical record database

INTRODUCTION

Efforts to characterize variability in epilepsy treatment pathways are limited by the large number of possible antiseizure medication (ASM) regimens and sequences, heterogeneity of patients, and challenges of measuring confounding variables and outcomes across institutions. The Observational Health Data Science and Informatics (OHDSI) collaborative is an international data network representing over 1 billion patient records using common data standards. However, few studies have applied OHDSI's Common Data Model (CDM) to the population with epilepsy and none have validated relevant concepts. The goals of this study were to demonstrate the feasibility of characterizing adult patients with epilepsy and ASM treatment pathways using the CDM in an electronic health record (EHR)-derived database.

METHODS

We validated a phenotype algorithm for epilepsy in adults using the CDM in an EHR-derived database (2001-2020) against source records and a prospectively maintained database of patients with confirmed epilepsy. We obtained the frequency of all antecedent conditions and procedures for patients meeting the epilepsy phenotype criteria and characterized ASM exposure sequences over time and by age and sex.

RESULTS

The phenotype algorithm identified epilepsy with 73.0-85.0% positive predictive value and 86.3% sensitivity. Many patients had neurologic conditions and diagnoses antecedent to meeting epilepsy criteria. Levetiracetam incrementally replaced phenytoin as the most common first-line agent, but significant heterogeneity remained, particularly in second-line and subsequent agents. Drug sequences included up to 8 unique ingredients and a total of 1,235 unique pathways were observed.

CONCLUSIONS

Despite the availability of additional ASMs in the last 2 decades and accumulated guidelines and evidence, ASM use varies significantly in practice, particularly for second-line and subsequent agents. Multi-center OHDSI studies have the potential to better characterize the full extent of variability and support observational comparative effectiveness research, but additional work is needed to validate covariates and outcomes.

Big data analysis of ASM retention rates and expert ASM algorithm: a comparative study

Objective

Only 50% of patients with new‐onset epilepsy achieve seizure freedom with their first antiseizure medication (ASM). A growing body of data illustrates the complexity of predicting ASM response and tolerability, which is influenced by age, sex, and comorbidities. Randomized data with sufficient resolution for personalized medicine are unlikely to emerge. Two potential facilitators of ASM selection are big data using real‐world retention rates or algorithms based on expert opinion. We asked how these methods compare in adult‐onset focal epilepsy.

Methods

ASM retention rates were determined by cross‐referencing data from comprehensive Swedish registers for 37 643 individuals, with identified comorbidities. Eight fictive cases were created and expert advice was collected from the algorithm Epipick. We compared Epipick suggestions in representative patient subgroups, and determined whether ranking based on retention rate reflected expert advice.

Results

The Epipick algorithm suggested six ASM alternatives for younger patients and three ASM alternatives for older patients. In the real‐world data, retention rates for the ASMs ranked as best options by Epipick were high; 65%–72% for young patients and 71%–84% for older patients. The lowest retention rate for Epipick suggestions was 42%–56% in younger cases, and 70%–80% in older cases. The ASM with the best retention rate was generally recommended by Epipick.

Significance

We found a large overlap between expert advice and real‐world retention rates. Notably, Epipick did suggest some ASMs with more modest retention rates. Conversely, clearly inappropriate ASMs (not recommended by Epipick) had high retention rates in some cases, showing that decision systems should not rely indiscriminately on retention rates alone. In future clinical decision support systems, expert opinion and real‐world retention rates could work synergistically.