The goal of epilepsy therapy: no seizures, no side effects, as soon as possible

Epilepsy Surgery: A Story of Diminishing Returns Over Time? Think Differently and Think Again

Beyond Seizure Freedom: Dissecting Long-Term Seizure Control After Surgical Resection for Drug-Resistant Epilepsy Hsieh JK, Pucci FG, Sundar SJ, Kondylis E, Sharma A, Sheikh SR, Vegh D, Moosa AN, Gupta A, Najm I, Rammo R, Bingaman W, Jehi L. Epilepsia . 2023;64(1):103-113. doi:10.1111/epi.17445 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.

Effect of valproate and add-on levetiracetam on inflammatory biomarkers in children with epilepsy

BACKGROUND

Contemporary research indicates the role of neuroinflammation/inflammatory markers in epilepsy. In addition, comorbidities such as anxiety and poor health-related quality of life are vital concerns in clinical care of pediatric patients with epilepsy. This open-label, prospective, observational study evaluated the effect of valproate and add-on levetiracetam on serum levels of C-C motif ligand 2 (CCL2) and Interleukin-1 beta (IL-1β) in pediatric patients with epilepsy. We also studied effect of valproate and add-on levetiracetam on anxiety and health-related quality of life (HRQoL) in specified age subgroups.

METHODS

Children aged 1 to 12 years, diagnosed with epilepsy (generalized or focal seizures), treated with valproate (n = 40) and valproate with add-on levetiracetam (n = 40) were included. All patients were followed up for 16 weeks and assessed for changes in serum CCL2 and IL-1β levels. Spence Children Anxiety Scale short version (SCAS-S) and QOLCE-16 scales were used to measure anxiety and HRQoL, respectively, in specific age groups.

RESULTS

The serum CCL2 level decreased significantly (p < .001) from 327.95 ± 59.07 pg/ml to 207.02 ± 41.50 pg/ml in the valproate group and from 420.65 ± 83.72 pg/ml to 250.06 ± 46.05 pg/ml in the add-on levetiracetam group. Serum IL-1β level did not change significantly in both groups. Spence Children Anxiety Scale short version scores were decreased and QOLCE-16 scores were increased significantly (p < .001) in both valproate and add-on levetiracetam groups.

CONCLUSIONS

The results of our study suggest that valproate and levetiracetam led to decrease serum CCL2 levels without any change in serum IL-1β levels in children with epilepsy. Anti-inflammatory property of valproate and levetiracetam might underlie their antiepileptic effect and CCL2 could be a potential marker of drug efficacy in epilepsy. Also, valproate and levetiracetam reduced anxiety and improved quality of life in children with epilepsy in the age groups evaluated.

Epilepsy surgery in tuberous sclerosis complex (TSC): emerging techniques and redefinition of treatment goals

Epilepsy occurs in nearly all patients with tuberous sclerosis and is often refractory to medical treatment. The definition of surgical candidacy in these patients has broadened in recent years due to philosophical and technological advances. The goals of surgery have shifted to focusing on quality of life and maximizing neurodevelopmental potential in patients unable to obtain seizure freedom. Novel diagnostic, ablative, and neuromodulatory techniques have been developed that may help patients that were previously considered inoperable to have an improved quality of life. In the coming years, it is expected that these techniques will be further refined and lead to an improvement of neurological prognosis in patients with tuberous sclerosis.

Epilepsy and aging

The intersection of epilepsy and aging has broad, significant implications. Substantial increases in seizures occur both in the elderly population, who are at a higher risk of developing new-onset epilepsy, and in those with chronic epilepsy who become aged. There are notable gaps in our understanding of aging and epilepsy at the basic and practical levels, which have important consequences. We are in the early stages of understanding the complex relationships between epilepsy and other age-related brain diseases such as stroke, dementia, traumatic brain injury (TBI), and cancer. Furthermore, the clinician must recognize that the presentation and treatment of epilepsy in the elderly are different from those of younger populations. Given the developing awareness of the problem and the capabilities of contemporary, multidisciplinary approaches to advance understanding about the biology of aging and epilepsy, it is reasonable to expect that we will unravel some of the intricacies of epilepsy in the elderly; it is also reasonable to expect that these gains will lead to further improvements in our understanding and treatment of epilepsy for all age groups.

Seizure burden in severe early-life epilepsy: Perspectives from parents

OBJECTIVES

Seizure burden is typically measured by seizure frequency yet it entails more than seizure counts, especially for people with severe epilepsies and their caregivers. We aimed to characterize the multi-faceted nature of seizure burden in young people and their parents who are living with severe early-life epilepsies.

METHODS

A one-day workshop and a series of teleconferences were held with parents of children with severe, refractory epilepsy of early-life origin and providers for children with epilepsy. The workshop sessions were structured as focus groups and aimed to identify components of seizure burden and their impact from the perspective of parents and providers. Data were gathered, organized, and refined during the workshop using an iterative 4-step process that drew upon grounded theory.

RESULTS

Three primary components of seizure burden were identified: frequency, severity, and unpredictability, which was as important if not more important at times than frequency and severity. Caregivers noted that the impacts of seizures were experienced as acute-immediate consequences, longer-term consequences, and as chronic effects that develop and evolve over time. The severity of the child's neurological and medical status as well as where in the disease journey a family was represented additional contextual factors that influenced the experience of seizure burden.

SIGNIFICANCE

Patient-reported and patient-centered outcomes are increasingly incorporated into the evaluation of treatment effectiveness. Without understanding how the disease creates burden for the patient (or family), it is difficult to know how to assess the impact of treatment. Our preliminary findings indicate seizure burden is a complex construct and unpredictability can be as important as frequency and severity.

Comparison of brand versus generic antiepileptic drug adverse event reporting rates in the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS)

OBJECTIVE

Despite the cost saving role of generic anti-epileptic drugs (AEDs), debate exists as to whether generic substitution of branded AEDs may lead to therapeutic failure and increased toxicity. This study compared adverse event (AE) reporting rates for brand vs. authorized generic (AG) vs. generic AEDs. Since AGs are pharmaceutically identical to brand but perceived as generics, the generic vs. AG comparison minimized potential bias against generics.

METHODS

Events reported to the U.S. Food and Drug Administration Adverse Event Reporting System between January 2004 to March 2015 with lamotrigine, carbamazepine, and oxcarbazepine listed as primary or secondary suspect were classified as brand, generic, or AG based on the manufacturer. Disproportionality analyses using the reporting odds ratio (ROR) assessed the relative rate of reporting of labeled AEs compared to reporting these events with all other drugs. The Breslow-Day statistic compared RORs across brand, AG, and other generics using a Bonferroni-corrected P<0.01.

RESULTS

A total of 27,150 events with lamotrigine, 13,950 events with carbamazepine, and 5077 events with oxcarbazepine were reported, with generics accounting for 27%, 41%, and 32% of reports, respectively. Although RORs for the majority of known AEs were different between brand and generics for all three drugs of interest (Breslow-Day P<0.001), RORs generally were similar for AG and generic comparisons. Generic lamotrigine and carbamazepine were more commonly involved in reports of suicide or suicidal ideation compared with the respective AGs based on a multiple comparison-adjusted P<0.01.

SIGNIFICANCE

Similar AED reporting rates were observed for the AG and generic comparisons for most outcomes and drugs, suggesting that brands and generics have similar reporting rates after accounting for generic perception biases. Disproportional suicide reporting was observed for generics compared with AGs and brand, although this finding needs further study.

Predictive model for refractoriness in temporal lobe epilepsy based on clinical and diagnostic test data

INTRODUCTION

Temporal Lobe Epilepsy (TLE) is frequently resistant to drug treatment, but a high percentage of these patients can be free of seizures after epilepsy surgery. Delay in the surgical decision has been related to quality of life impairment, social and work limitations, and increased mortality risk. A predictive model for refractoriness based on clinical and diagnostic factors may allow its earlier detection and a shorter delay before surgery.

MATERIAL AND METHODS

A case-control study was conducted in TLE patients over 16 years old. The dependent variable was resistance to medical treatment according to ILAE 2010 criteria. Independent variables were clinical, semiological, therapeutic, neurophysiological, radiological, and neuropsychological variables. A multivariate study was conducted to identify the variables associated with refractoriness, calculating the positive and negative predictive values and positive likelihood ratios of these variables individually and in combination. These data were used to construct a refractoriness predictive model.

RESULTS

ILAE refractoriness criteria were met by 83 patients (50.9%). In the multivariate analysis, refractoriness was significantly associated with one semiological variable, one neuroradiological variable, one neurophysiological variable, and two therapeutic variables but not with neuropsychological test outcomes. These significant variables were used to construct a predictive model.

CONCLUSION

Assessment of semiological, neurophysiological, and neuroradiological data can serve to stratify the risk of refractory epilepsy in TLE patients.

Early surgical therapy for drug-resistant temporal lobe epilepsy: a randomized trial

CONTEXT

Despite reported success, surgery for pharmacoresistant seizures is often seen as a last resort. Patients are typically referred for surgery after 20 years of seizures, often too late to avoid significant disability and premature death.

OBJECTIVE

We sought to determine whether surgery soon after failure of 2 antiepileptic drug (AED) trials is superior to continued medical management in controlling seizures and improving quality of life (QOL).

DESIGN, SETTING, AND PARTICIPANTS

The Early Randomized Surgical Epilepsy Trial (ERSET) is a multicenter, controlled, parallel-group clinical trial performed at 16 US epilepsy surgery centers. The 38 participants (18 men and 20 women; aged ≥12 years) had mesial temporal lobe epilepsy (MTLE) and disabling seizues for no more than 2 consecutive years following adequate trials of 2 brand-name AEDs. Eligibility for anteromesial temporal resection (AMTR) was based on a standardized presurgical evaluation protocol. Participants were randomized to continued AED treatment or AMTR 2003-2007, and observed for 2 years. Planned enrollment was 200, but the trial was halted prematurely due to slow accrual.

INTERVENTION

Receipt of continued AED treatment (n = 23) or a standardized AMTR plus AED treatment (n = 15). In the medical group, 7 participants underwent AMTR prior to the end of follow-up and 1 participant in the surgical group never received surgery.

MAIN OUTCOME MEASURES

The primary outcome variable was freedom from disabling seizures during year 2 of follow-up. Secondary outcome variables were health-related QOL (measured primarily by the 2-year change in the Quality of Life in Epilepsy 89 [QOLIE-89] overall T-score), cognitive function, and social adaptation.

RESULTS

Zero of 23 participants in the medical group and 11 of 15 in the surgical group were seizure free during year 2 of follow-up (odds ratio = ∞; 95% CI, 11.8 to ∞; P < .001). In an intention-to-treat analysis, the mean improvement in QOLIE-89 overall T-score was higher in the surgical group than in the medical group but this difference was not statistically significant (12.6 vs 4.0 points; treatment effect = 8.5; 95% CI, -1.0 to 18.1; P = .08). When data obtained after surgery from participants in the medical group were excluded, the effect of surgery on QOL was significant (12.8 vs 2.8 points; treatment effect = 9.9; 95% CI, 2.2 to 17.7; P = .01). Memory decline (assessed using the Rey Auditory Verbal Learning Test) occurred in 4 participants (36%) after surgery, consistent with rates seen in the literature; but the sample was too small to permit definitive conclusions about treatment group differences in cognitive outcomes. Adverse events included a transient neurologic deficit attributed to a magnetic resonance imaging-identified postoperative stroke in a participant who had surgery and 3 cases of status epilepticus in the medical group.

CONCLUSIONS

Among patients with newly intractable disabling MTLE, resective surgery plus AED treatment resulted in a lower probability of seizures during year 2 of follow-up than continued AED treatment alone. Given the premature termination of the trial, the results should be interpreted with appropriate caution.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00040326.

The role of magnetoencephalography in children undergoing hemispherectomy

OBJECT

Hemispherectomy is an established neurosurgical procedure for medication-resistant epilepsy in children. Despite the effectiveness of this technique, there are patients who do not achieve an optimum outcome after surgery; possible causes of suboptimal results include the presence of bilateral independent epileptogenic foci. Magnetoencephalography (MEG) is an emerging tool that has been found to be useful in the management of lesional and nonlesional epilepsy. The authors analyzed the relative contribution of MEG in patient selection for hemispherectomy.

METHODS

The medical records of children undergoing hemispherectomy at the Hospital for Sick Children were reviewed. Those patients who underwent MEG as part of the presurgical evaluation were selected.

RESULTS

Thirteen patients were included in the study. Nine patients were boys. The mean age at the time of surgery was 66 months (range 10-149 months). Seizure etiology was Rasmussen encephalitis in 6 patients, hemimegalencephaly in 2 patients, and cortical dysplasia in 4 patients. In 8 patients, video-EEG and MEG results were consistent to localize the primary epileptogenic hemisphere. In 2 patients, video-EEG lateralized the ictal onset, but MEG showed bilateral spikes. Two patients had bilateral video-EEG and MEG spikes. Engel Class I, II, and IV outcomes were seen in 10, 2, and 1 patients, respectively. In 2 of the patients who had an outcome other than Engel Class I, the MEG clusters were concentrated in the disconnected hemisphere. The third patient had bilateral clusters and potentially independent epileptogenic foci from bilateral cortical dysplasia.

CONCLUSIONS

The presence of unilateral MEG spike waves correlated with good outcomes following hemispherectomy. In some cases, MEG provides information that differs from that obtained from video-EEG and conventional MR imaging studies. Further studies with a greater number of patients are needed to assess the role of MEG in the preoperative assessment of candidates for hemispherectomy.

Design considerations for a multicenter randomized controlled trial of early surgery for mesial temporal lobe epilepsy

PURPOSE

To describe the trial design for the multicenter Early Randomized Surgical Epilepsy Trial (ERSET). Patients with pharmacoresistant epilepsy are generally referred for surgical treatment an average of two decades after onset of seizures, often too late to avoid irreversible disability. ERSET was designed to assess the safety and efficacy of early surgical intervention compared to continued pharmacotherapy.

METHODS

ERSET is a randomized controlled, parallel group clinical trial with blinded outcome adjudication. Participants are patients with mesial temporal lobe epilepsy (MTLE) older than the age of 12 who have had pharmacoresistant seizures for not >2 years and are determined by detailed evaluation to be surgical candidates prior to randomization. The primary outcome measure is seizure freedom in the second year of a 2-year follow-up period. Health-related quality of life (HRQOL), neurocognitive function, ancillary outcomes, and adverse events were also measured.

RESULTS

Significant methodologic problems addressed by the study design included the following: recruitment of participants early in the course of epilepsy; establishment of operational definitions for "pharmacoresistant" and "early"; and standardization of diagnostic testing, medical treatment, and surgical interventions across multiple centers.

DISCUSSION

Rigorous trial designs to assess surgical interventions in epilepsy are necessary to provide evidence to guide treatment. This article is the first of a series; trial results will be reported in subsequent publications.

Referral pattern for epilepsy surgery after evidence-based recommendations: a retrospective study

BACKGROUND

Class I evidence for surgical effectiveness in refractory temporal lobe epilepsy (TLE) in 2001 led to an American Academy of Neurology practice parameter in 2003 recommending "referral to a surgical epilepsy center on failing appropriate trials of first-line antiepileptic drugs." We examined whether this led to a change in referral patterns to our epilepsy center.

METHODS

We compared referral data for patients with TLE at our center for 1995 to 1998 (group 1, n = 83) and 2005 to 2008 (group 2, n = 102) to determine whether these recommendations resulted in a change in referral patterns for surgical evaluation. Patients with brain tumors, previous epilepsy surgery evaluations, or brain surgery (including epilepsy surgery) were excluded.

RESULTS

We did not find a difference between the groups in the duration from the diagnosis of habitual seizures to referral (17.1 +/- 10.0 vs 18.6 +/- 12.6 years, p = 0.39) or the age at the time of evaluation (34.1 +/- 10.3 vs 37.0 +/- 11.8 years, p = 0.08). However, there was a difference in the distributions of age at evaluation (p = 0.03) and the duration of pharmacotherapy (p = 0.03) between the groups, with a greater proportion of patients in group 2 with drug-resistant epilepsy both earlier and later in their treatment course. Nonepileptic seizures were referred significantly earlier than TLE in either group or when combined.

CONCLUSIONS

Our analysis does not identify a significantly earlier referral for epilepsy surgery evaluation as recommended in the practice parameter, but suggests a hopeful trend in this direction.

Remission of epilepsy after two drug failures in children: a prospective study

OBJECTIVE

Determine the probability of a more than 1-year remission after failure of a second drug in children prospectively followed from initial diagnosis of epilepsy and then from time of second drug failure. Identify prognostic factors for remission after second drug failure.

METHODS

Of 613 children, 128 did not respond favorably to 2 drugs, had a trial of at least a third drug (median, 3), and were followed for more than 1 year (median, 10.1 years) since second drug failure. Product limit and proportional hazards techniques were used to analyze predictors of any 1-year remission (Rem1) and 1- and 3-year remission at last contact (Rem1/3-LC).

RESULTS

Seventy-three patients (57%) had a remission. Repeated remissions and relapses were common. Only 48 (37.5%) achieved Rem1-LC and 28 (23%) Rem3-LC. Idiopathic epilepsy (Rem1: rate ratio [RR], 3.64, p < 0.0001; Rem1-LC: RR, 2.57, p = 0.008) and seizure frequency (Rem1: RR, 0.76, p = 0.003; Rem1-LC: RR, 0.82, p = 0.04 per increase in category) were the most robust predictors. Symptomatic cause was the only correlate of Rem3-LC. Remission before second drug failure did not predict remission after second drug failure.

INTERPRETATION

Remission after second drug failure is common but often temporary. Children who have not responded to two appropriate drugs should be carefully evaluated to maximize therapy and possibly considered for more aggressive treatments.

Non-invasive imaging of epileptic seizures in vivo using photoacoustic tomography

Non-invasive laser-induced photoacoustic tomography (PAT) is an emerging imaging modality that has the potential to image the dynamic function of the brain due to its unique ability of imaging biological tissues with high optical contrast and ultrasound resolution. Here we report the first application of our finite-element-based PAT for imaging of epileptic seizures in an animal model. In vivo photoacoustic images were obtained in rats with focal seizures induced by microinjection of bicuculline, a GABA(A) antagonist, into the neocortex. The seizure focus was accurately localized by PAT as confirmed with gold-standard electroencephalogram (EEG). Compared to the existing neuroimaging modalities, PAT not only has the unprecedented advantage of high spatial and temporal resolution in a single imaging modality, but also is portable and low in cost, making it possible to bring brain imaging to the bedside.

Defining Intractability: Comparisons among Published Definitions

PURPOSE

Intractable epilepsy is the focus of much research; however, this concept is defined in no single way. Individual studies use different definitions, creating difficulties for comparisons of results across studies. A head-to-head comparison of definitions could highlight these differences and motivate the development of consensus guidelines.

METHODS

Within a single prospective study of 613 children in Connecticut with newly diagnosed epilepsy (1993-1997), six different published definitions or indicators for intractability were applied and compared. All definitions were assessed at various times within the first 5 years after diagnosis, with the exact timing reflecting how they were used in their initial reports. Observed and chance-adjusted agreement (kappa) were computed. The associations of each definition with remission status 7-10 years after diagnosis were quantified with a relative risk.

RESULTS

Depending on the specific definition, the epilepsy of 9-24% of children was considered intractable. Observed agreements among the definitions ranged from a low of 0.83 to a high of 0.96. Kappas ranged from low of 0.45 to 0.79. More similar definitions had higher levels of agreement. All definitions were strongly associated with remission status as of last follow-up.

CONCLUSIONS

Agreement among the different definitions is strong but imperfect. All definitions were significantly associated with longer-term outcome. No single preferred definition of intractable epilepsy exists. Some discussion within the field of epilepsy and a consensus process should be considered as a future step for enhancing comparability of research efforts and clinical guidelines. Consideration should be given to whether a single definition will suit all purposes or whether different types of definitions are needed for different purposes.