Faculty Bibliography

OBJECTIVE:This study was undertaken to conduct external validation of previously published epilepsy surgery prediction tools using a large independent multicenter dataset and to assess whether these tools can stratify patients for being operated on and for becoming free of disabling seizures (International League Against Epilepsy stage 1 and 2). METHODS:We analyzed a dataset of 1562 patients, not used for tool development. We applied two scales: Epilepsy Surgery Grading Scale (ESGS) and Seizure Freedom Score (SFS); and two versions of Epilepsy Surgery Nomogram (ESN): the original version and the modified version, which included electroencephalographic data. For the ESNs, we used calibration curves and concordance indexes. We stratified the patients into three tiers for assessing the chances of attaining freedom from disabling seizures after surgery: high (ESGS = 1, SFS = 3-4, ESNs > 70%), moderate (ESGS = 2, SFS = 2, ESNs = 40%-70%), and low (ESGS = 2, SFS = 0-1, ESNs < 40%). We compared the three tiers as stratified by these tools, concerning the proportion of patients who were operated on, and for the proportion of patients who became free of disabling seizures. RESULTS:The concordance indexes for the various versions of the nomograms were between .56 and .69. Both scales (ESGS, SFS) and nomograms accurately stratified the patients for becoming free of disabling seizures, with significant differences among the three tiers (p < .05). In addition, ESGS and the modified ESN accurately stratified the patients for having been offered surgery, with significant difference among the three tiers (p < .05). SIGNIFICANCE/CONCLUSIONS:ESGS and the modified ESN (at thresholds of 40% and 70%) stratify patients undergoing presurgical evaluation into three tiers, with high, moderate, and low chance for favorable outcome, with significant differences between the groups concerning having surgery and becoming free of disabling seizures. Stratifying patients for epilepsy surgery has the potential to help select the optimal candidates in underprivileged areas and better allocate resources in developed countries.

IMPORTANCE/UNASSIGNED:The association of fetal exposure to antiseizure medications (ASMs) with outcomes in childhood are not well delineated. OBJECTIVE/UNASSIGNED:To examine the association of fetal ASM exposure with subsequent adaptive, behavioral or emotional, and neurodevelopmental disorder outcomes at 2, 3, and 4.5 years of age. DESIGN, SETTING, AND PARTICIPANTS/UNASSIGNED:The Maternal Outcomes and Neurodevelopmental Effects of Antiepileptic Drugs (MONEAD) study is a prospective, observational cohort study conducted at 20 epilepsy centers in the US. A total of 456 pregnant women with epilepsy or without epilepsy were enrolled from December 19, 2012, to January 13, 2016. Children of enrolled women were followed up with formal assessments at 2, 3, 4.5, and 6 years of age. Statistical analysis took place from August 2022 to May 2023. EXPOSURES/UNASSIGNED:Exposures included mother's epilepsy status as well as mother's ASM blood concentration in the third trimester (for children of women with epilepsy). Women with epilepsy were enrolled regardless of ASM regimen. MAIN OUTCOMES AND MEASURES/UNASSIGNED:The primary outcome was the Adaptive Behavior Assessment System, Third Edition (ABAS-3) General Adaptive Composite (GAC) score among children at 4.5 years of age. Children of women with epilepsy and children of women without epilepsy were compared, and the associations of ASM exposures with outcomes among exposed children were assessed. Secondary outcomes involved similar analyses of other related measures. RESULTS/UNASSIGNED:Primary analysis included 302 children of women with epilepsy (143 boys [47.4%]) and 84 children of women without epilepsy (45 boys [53.6%]). Overall adaptive functioning (ABAS-3 GAC score at 4.5 years) did not significantly differ between children of women with epilepsy and children of women without epilepsy (parameter estimate [PE], 0.4 [95% CI, -2.5 to 3.4]; P = .77). However, in adjusted analyses, a significant decrease in functioning was seen with increasing third-trimester maximum ASM blood concentrations (PE, -7.8 [95% CI, -12.6 to -3.1]; P = .001). This decrease in functioning was evident for levetiracetam (PE, -18.9 [95% CI, -26.8 to -10.9]; P < .001) and lamotrigine (PE, -12.0 [95% CI, -23.7 to -0.3]; P = .04), the ASMs with sample sizes large enough for analysis. Results were similar with third-trimester maximum daily dose. CONCLUSIONS AND RELEVANCE/UNASSIGNED:This study suggests that adaptive functioning of children of women with epilepsy taking commonly used ASMs did not significantly differ from that of children of women without epilepsy, but there was an exposure-dependent association of ASMs with functioning. Thus, psychiatric or psychological screening and referral of women with epilepsy and their offspring are recommended when appropriate. Additional research is needed to confirm these findings.

OBJECTIVE:This study was undertaken to ascertain the natural history and patterns of antiseizure medication (ASM) use in newly diagnosed focal epilepsy patients who were initially started on monotherapy. METHODS:The data were derived from the Human Epilepsy Project. Differences between the durations of the most commonly first prescribed ASM monotherapies were assessed using a Cox proportional hazards model. Subjects were classified into three groups: monotherapy, sequential monotherapy, and polytherapy. RESULTS:A total of 443 patients were included in the analysis, with a median age of 32 years (interquartile range [IQR] = 20-44) and median follow-up time of 3.2 years (IQR = 2.4-4.2); 161 (36.3%) patients remained on monotherapy with their initially prescribed ASM at the time of their last follow-up. The mean (SEM) and median (IQR) duration that patients stayed on monotherapy with their initial ASM was 2.1 (2.0-2.2) and 1.9 (.3-3.5) years, respectively. The most commonly prescribed initial ASM was levetiracetam (254, 57.3%), followed by lamotrigine (77, 17.4%), oxcarbazepine (38, 8.6%), and carbamazepine (24, 5.4%). Among those who did not remain on the initial monotherapy, 167 (59.2%) transitioned to another ASM as monotherapy (sequential monotherapy) and 115 (40.8%) ended up on polytherapy. Patients remained significantly longer on lamotrigine (mean = 2.8 years, median = 3.1 years) compared to levetiracetam (mean = 2.0 years, median = 1.5 years) as a first prescribed medication (hazard ratio = 1.5, 95% confidence interval = 1.0-2.2). As the study progressed, the proportion of patients on lamotrigine, carbamazepine, and oxcarbazepine as well as other sodium channel agents increased from a little more than one third (154, 34.8%) of patients to more than two thirds (303, 68.4%) of patients. SIGNIFICANCE/CONCLUSIONS:Slightly more than one third of focal epilepsy patients remain on monotherapy with their first prescribed ASM. Approximately three in five patients transition to monotherapy with another ASM, whereas approximately two in five end up on polytherapy. Patients remain on lamotrigine for a longer duration compared to levetiracetam when it is prescribed as the initial monotherapy.

IMPORTANCE/UNASSIGNED:Many patients with focal epilepsy experience seizures despite treatment with currently available antiseizure medications (ASMs) and may benefit from novel therapeutics. OBJECTIVE/UNASSIGNED:To evaluate the efficacy and safety of XEN1101, a novel small-molecule selective Kv7.2/Kv7.3 potassium channel opener, in the treatment of focal-onset seizures (FOSs). DESIGN, SETTING, AND PARTICIPANTS/UNASSIGNED:This phase 2b, randomized, double-blind, placebo-controlled, parallel-group, dose-ranging adjunctive trial investigated XEN1101 over an 8-week treatment period from January 30, 2019, to September 2, 2021, and included a 6-week safety follow-up. Adults experiencing 4 or more monthly FOSs while receiving stable treatment (1-3 ASMs) were enrolled at 97 sites in North America and Europe. INTERVENTIONS/UNASSIGNED:Patients were randomized 2:1:1:2 to receive XEN1101, 25, 20, or 10 mg, or placebo with food once daily for 8 weeks. Dosage titration was not used. On completion of the double-blind phase, patients were offered the option of entering an open-label extension (OLE). Patients not participating in the OLE had follow-up safety visits (1 and 6 weeks after the final dose). MAIN OUTCOMES AND MEASURES/UNASSIGNED:The primary efficacy end point was the median percent change from baseline in monthly FOS frequency. Treatment-emergent adverse events (TEAEs) were recorded and comprehensive laboratory assessments were made. Modified intention-to-treat analysis was conducted. RESULTS/UNASSIGNED:A total of 325 patients who were randomized and treated were included in the safety analysis; 285 completed the 8-week double-blind phase. In the 325 patients included, mean (SD) age was 40.8 (13.3) years, 168 (51.7%) were female, and 298 (91.7%) identified their race as White. Treatment with XEN1101 was associated with seizure reduction in a robust dose-response manner. The median (IQR) percent reduction from baseline in monthly FOS frequency was 52.8% (P < .001 vs placebo; IQR, -80.4% to -16.9%) for 25 mg, 46.4% (P < .001 vs placebo; IQR, -76.7% to -14.0%) for 20 mg, and 33.2% (P = .04 vs placebo; IQR,  -61.8% to 0.0%) for 10 mg, compared with 18.2% (IQR, -37.3% to 7.0%) for placebo. XEN1101 was generally well tolerated and TEAEs were similar to those of commonly prescribed ASMs, and no TEAEs leading to death were reported. CONCLUSIONS AND RELEVANCE/UNASSIGNED:The efficacy and safety findings of this clinical trial support the further clinical development of XEN1101 for the treatment of FOSs. TRIAL REGISTRATION/UNASSIGNED:ClinicalTrials.gov Identifier: NCT03796962.

OBJECTIVE:Visual assessment of magnetic resonance imaging (MRI) from the Human Epilepsy Project 1 (HEP1) found 18% of participants had atrophic brain changes relative to age without known etiology. Here, we identify the underlying factors related to brain volume differences in people with focal epilepsy enrolled in HEP1. METHODS:Enrollment data for participants with complete records and brain MRIs were analyzed, including 391 participants aged 12-60 years. HEP1 excluded developmental or cognitive delay with intelligence quotient <70, and participants reported any formal learning disability diagnoses, repeated grades, and remediation. Prediagnostic seizures were quantified by semiology, frequency, and duration. T1-weighted brain MRIs were analyzed using Sequence Adaptive Multimodal Segmentation (FreeSurfer v7.2), from which a brain tissue volume to intracranial volume ratio was derived and compared to clinically relevant participant characteristics. RESULTS:Brain tissue volume changes observable on visual analyses were quantified, and a brain tissue volume to intracranial volume ratio was derived to compare with clinically relevant variables. Learning difficulties were associated with decreased brain tissue volume to intracranial volume, with a ratio reduction of .005 for each learning difficulty reported (95% confidence interval [CI] = -.007 to -.002, p = .0003). Each 10-year increase in age at MRI was associated with a ratio reduction of .006 (95% CI = -.007 to -.005, p < .0001). For male participants, the ratio was .011 less than for female participants (95% CI = -.014 to -.007, p < .0001). There were no effects from seizures, employment, education, seizure semiology, or temporal lobe electroencephalographic abnormalities. SIGNIFICANCE/CONCLUSIONS:This study shows lower brain tissue volume to intracranial volume in people with newly treated focal epilepsy and learning difficulties, suggesting developmental factors are an important marker of brain pathology related to neuroanatomical changes in focal epilepsy. Like the general population, there were also independent associations between brain volume, age, and sex in the study population.

INTRODUCTION:Maintaining seizure control with lamotrigine is complicated by altered pharmacokinetics and existence of subpopulations in whom clearance increases or remains constant during pregnancy. OBJECTIVE:Our objective was to characterize the potential for particular dosing scenarios to lead to increased seizure risk or toxicity. METHODS:Lamotrigine pharmacokinetic parameters obtained from our previous study were applied to a one-compartment model structure with subpopulations (75:25%) exhibiting different clearance changes. A single-patient simulation was conducted with typical pharmacokinetic parameter values from each subpopulation. Population-level simulations (N = 48,000) included six dosing scenarios and considered four preconception doses using the R package mrgsolve (Metrum Research Group). Thresholds for efficacy and toxicity were selected as drug concentration that are 65% lower than preconception concentrations and doubling of preconception concentrations, respectively. RESULTS:Individual simulation results demonstrated that without dose increases, concentrations fell below 0.65 at 6-8 weeks in the high clearance change (HC) subpopulation, depending on preconception clearance. While no simulated dosing regimen allowed all women in both subpopulations to maintain preconception concentrations, some regimens provided a more balanced risk profile than others. Predicted concentrations suggested potential increased seizure risk for 7%-100% of women in the HC group depending on preconception dose and subpopulation. Additionally, in 63% of dosing scenarios for women with low clearance change (LC), there was an increased risk of toxicity (34%-100% of women). SIGNIFICANCE:A substantial percentage of simulated individuals had concentrations low enough to potentially increase seizure risk or high enough to create toxicity. Early clearance changes indicate possible subpopulation categorization if therapeutic drug monitoring is conducted in the first trimester. An arbitrary "one-size-fits-all" philosophy may not work well for lamotrigine dosing adjustments during pregnancy and reinforces the need for therapeutic drug monitoring until a patient is determined to be in the LC or HC group.

OBJECTIVES:To identify the type, frequency, and consequences of seizures while driving (SzWD) in people with epilepsy before diagnosis. METHODS:We performed a retrospective cohort study using the Human Epilepsy Project (HEP) to identify prediagnostic SzWD. Clinical descriptions from seizure diaries and medical records were used to classify seizure types and frequencies, time to diagnosis, and SzWD outcomes. Data were modeled using multiple logistic regression to assess for factors independently associated with SzWD. RESULTS:= 0.02). DISCUSSION:This study identifies the consequences of seizure-related MVAs and hospitalizations people experience before epilepsy diagnosis. This highlights the need for further research aimed at improving seizure awareness and improving time to diagnosis.

Well-designed placebo-controlled clinical trials are critical to the development of novel treatments for epilepsy, but their design has not changed for decades. Patients, clinicians, regulators, and innovators all have concerns that recruiting for trials is challenging, in part, due to the static design of maintaining participants for long periods on add-on placebo when there are an increasing number of options for therapy. A traditional trial maintains participants on blinded treatment for a static period (e.g., 12 weeks of maintenance), during which participants on placebo have an elevated risk of sudden unexpected death in epilepsy compared to patients on an active treatment. Time-to-event trials observe participants on blinded treatment until a key event occurs (e.g., post-randomization seizure count matches pre-randomization monthly seizure count). In this article, we review the evidence for these designs based on re-analysis of prior trials, one published trial that used a time-to-second seizure design, and experience from an ongoing blinded trial. We also discuss remaining concerns regarding time-to-event trials. We conclude that, despite potential limitations, time-to-event trials are a potential promising mechanism to make trials more patient friendly and reduce placebo exposure, which are urgent needs to improve safety and increase recruitment to trials.