Perry, Μ. Scott

Abstract Objective The evaluation to determine candidacy and treatment for epilepsy surgery in persons with drug‐resistant epilepsy (DRE) is not uniform. Many non‐invasive and invasive tests are available to ascertain an appropriate treatment strategy. This study examines expert response to clinical vignettes of magnetic resonance imaging (MRI)–positive lesional focal cortical dysplasia in both temporal and extratemporal epilepsy to identify associations in evaluations and treatment choice. Methods We analyzed annual report data and a supplemental epilepsy practice survey reported in 2020 from 206 adult and 136 pediatric epilepsy center directors in the United States. Non‐invasive and invasive testing and surgical treatment strategies were compiled for the two scenarios. We used chi‐square tests to compare testing utilization between the two scenarios. Multivariable logistic regression modeling was performed to assess associations between variables. Results The supplemental survey response rate was 100% with 342 responses included in the analyses. Differing testing and treatment approaches were noted between the temporal and extratemporal scenarios such as chronic invasive monitoring selected in 60% of the temporal scenario versus 93% of the extratemporal scenario. Open resection was the most common treatment choice; however, overall treatment choices varied significantly ( p < .001). Associations between non‐invasive testing, invasive testing, and treatment choices were present in both scenarios. For example, in the temporal scenario stereo‐electroencephalography (SEEG) was more commonly associated with fluorodeoxyglucose–positron emission tomography (FDG‐PET) (odds ratio [OR] 1.85; 95% confidence interval [CI] 1.06–3.29; p = .033), magnetoencephalography (MEG) (OR 2.90; 95% CI 1.60–5.28; p = <.001), high density (HD) EEG (OR 2.80; 95% CI 1.27–6.24; p = .011), functional MRI (fMRI) (OR 2.17; 95% CI 1.19–4.10; p = .014), and Wada (OR 2.16; 95% CI 1.28–3.66; p = .004). In the extratemporal scenario, choosing SEEG was associated with increased odds of neuromodulation over open resection (OR 3.13; 95% CI 1.24–7.89; p = .016). Significance In clinical vignettes of temporal and extratemporal lesional DRE, epilepsy center directors displayed varying patterns of non‐invasive testing, invasive testing, and treatment choices. Differences in practice underscore the need for comparative trials for the surgical management of DRE.

Abstract Objective Persons with drug‐resistant epilepsy may benefit from epilepsy surgery and should undergo presurgical testing to determine potential candidacy and appropriate intervention. Institutional expertise can influence use and availability of evaluations and epilepsy surgery candidacy. This census survey study aims to examine the influence of geographic region and other center characteristics on presurgical testing for medically intractable epilepsy. Methods We analyzed annual report and supplemental survey data reported in 2020 from 206 adult epilepsy center directors and 136 pediatric epilepsy center directors in the United States. Test utilization data were compiled with annual center volumes, available resources, and US Census regional data. We used Wilcoxon rank‐sum, Kruskal–Wallis, and chi‐squared tests for univariate analysis of procedure utilization. Multivariable modeling was also performed to assign odds ratios (ORs) of significant variables. Results The response rate was 100% with individual element missingness < 11% across 342 observations undergoing univariate analysis. A total of 278 complete observations were included in the multivariable models, and significant regional differences were present. For instance, compared to centers in the South, those in the Midwest used neuropsychological testing (OR = 2.87, 95% confidence interval [CI] = 1.2–6.86; p = .018) and fluorodeoxyglucose–positron emission tomography (OR = 2.74, 95% CI = = 1.14–6.61; p = .025) more commonly. For centers in the Northeast (OR = .46, 95% CI = .23–.93; p = .031) and West (OR = .41, 95% CI = .19–.87; p = .022), odds of performing single‐photon emission computerized tomography were lower by nearly 50% compared to those in the South. Center accreditation level, demographics, volume, and resources were also associated with varying individual testing rates. Significance Presurgical testing for drug‐resistant epilepsy is influenced by US geographic region and other center characteristics. These findings have potential implications for comparing outcomes between US epilepsy centers and may inject disparities in access to surgical treatment.

Abstract Brain voltage-gated sodium channel NaV1.1 (SCN1A) loss-of-function variants cause the severe epilepsy Dravet syndrome, as well as milder phenotypes associated with genetic epilepsy with febrile seizures plus. Gain of function SCN1A variants are associated with familial hemiplegic migraine type 3. Novel SCN1A-related phenotypes have been described including early infantile developmental and epileptic encephalopathy with movement disorder, and more recently neonatal presentations with arthrogryposis. Here we describe the clinical, genetic and functional evaluation of affected individuals. Thirty-five patients were ascertained via an international collaborative network using a structured clinical questionnaire and from the literature. We performed whole-cell voltage-clamp electrophysiological recordings comparing sodium channels containing wild-type versus variant NaV1.1 subunits. Findings were related to Dravet syndrome and familial hemiplegic migraine type 3 variants. We identified three distinct clinical presentations differing by age at onset and presence of arthrogryposis and/or movement disorder. The most severely affected infants (n = 13) presented with congenital arthrogryposis, neonatal onset epilepsy in the first 3 days of life, tonic seizures and apnoeas, accompanied by a significant movement disorder and profound intellectual disability. Twenty-one patients presented later, between 2 weeks and 3 months of age, with a severe early infantile developmental and epileptic encephalopathy and a movement disorder. One patient presented after 3 months with developmental and epileptic encephalopathy only. Associated SCN1A variants cluster in regions of channel inactivation associated with gain of function, different to Dravet syndrome variants (odds ratio = 17.8; confidence interval = 5.4–69.3; P = 1.3 × 10−7). Functional studies of both epilepsy and familial hemiplegic migraine type 3 variants reveal alterations of gating properties in keeping with neuronal hyperexcitability. While epilepsy variants result in a moderate increase in action current amplitude consistent with mild gain of function, familial hemiplegic migraine type 3 variants induce a larger effect on gating properties, in particular the increase of persistent current, resulting in a large increase of action current amplitude, consistent with stronger gain of function. Clinically, 13 out of 16 (81%) gain of function variants were associated with a reduction in seizures in response to sodium channel blocker treatment (carbamazepine, oxcarbazepine, phenytoin, lamotrigine or lacosamide) without evidence of symptom exacerbation. Our study expands the spectrum of gain of function SCN1A-related epilepsy phenotypes, defines key clinical features, provides novel insights into the underlying disease mechanisms between SCN1A-related epilepsy and familial hemiplegic migraine type 3, and identifies sodium channel blockers as potentially efficacious therapies. Gain of function disease should be considered in early onset epilepsies with a pathogenic SCN1A variant and non-Dravet syndrome phenotype.

AbstractObjectiveVaccination against the SARS‐CoV‐2 virus is a primary tool to combat the COVID‐19 pandemic. However, vaccination is a common seizure trigger in individuals with Dravet syndrome (DS). Information surrounding COVID‐19 vaccine side effects in patients with DS would aid caregivers and providers in decisions for and management of COVID‐19 vaccination.MethodsA survey was emailed to the Dravet Syndrome Foundation's Family Network and posted to the Dravet Parent & Caregiver Support Group on Facebook between May and August 2021. Deidentified information obtained included demographics and vaccination status for individuals with DS. Vaccine type, side effects, preventative measures, and changes in seizure activity following COVID‐19 vaccination were recorded. For unvaccinated individuals, caregivers were asked about intent to vaccinate and reasons for their decision.ResultsOf 278 survey responses, 120 represented vaccinated individuals with DS (median age = 19.5 years), with 50% reporting no side effects from COVID‐19 vaccination. Increased seizures following COVID‐19 vaccination were reported in 16 individuals, but none had status epilepticus. Of the 158 individuals who had not received a COVID‐19 vaccination, 37 were older than 12 years (i.e., eligible at time of study), and only six of these caregivers indicated intent to seek vaccination. The remaining 121 responses were caregivers to children younger than 12 years, 60 of whom indicated they would not seek COVID‐19 vaccination when their child with DS became eligible. Reasons for vaccine hesitancy were fear of increased seizure activity and concerns about vaccine safety.SignificanceThese results indicate COVID‐19 vaccination is well tolerated by individuals with DS. One main reason for vaccine hesitancy was fear of increased seizure activity, which occurred in only 13% of vaccinated individuals, and none had status epilepticus. This study provides critical and reassuring insights for caregivers and health care providers making decisions about the safety of COVID‐19 vaccinations for individuals with DS.

AbstractObjectiveDrug‐resistant epilepsy (DRE) occurs at higher rates in children <3 years old. Epilepsy surgery is effective, but rarely utilized in young children despite developmental benefits of early seizure freedom. The present study aims to identify unique patient characteristics and evaluation strategies in children <3 years old who undergo epilepsy surgery evaluation as a means to assess contributors and potential solutions to health care disparities in this group.MethodsThe Pediatric Epilepsy Research Consortium Epilepsy Surgery Database, a multicentered, cross‐sectional collaboration of 21 US pediatric epilepsy centers, collects prospective data on children <18 years of age referred for epilepsy surgery evaluation. We compared patient characteristics, diagnostic utilization, and surgical treatment between children <3 years old and those older undergoing initial presurgical evaluation. We evaluated patient characteristics leading to delayed referral (>1 year) after DRE diagnosis in the very young.ResultsThe cohort included 437 children, of whom 71 (16%) were <3 years of age at referral. Children evaluated before the age of 3 years more commonly had abnormal neurological examinations (p = .002) and daily seizures (p = .001). At least one ancillary test was used in 44% of evaluations. Fifty‐nine percent were seizure‐free following surgery (n = 34), with 35% undergoing limited focal resections. Children with delayed referrals more often had focal aware (p < .001) seizures and recommendation for palliative surgeries (p < .001).SignificanceThere are relatively few studies of epilepsy surgery in the very young. Surgery is effective, but may be disproportionally offered to those with severe presentations. Relatively low utilization of ancillary testing may contribute to reduced surgical therapy for those without evident lesions on magnetic resonance imaging. Despite this, a sizeable portion of patients have favorable outcome after focal epilepsy surgery resections.