Neuropsychological characteristics of drug resistant epilepsy patients with and without comorbid functional seizures.

INTRODUCTION: Neuropsychological testing is a mandatory component in the evaluation of drug resistant epilepsy. The results of testing may assist with both the localization of an epilepsy as well as assessment of surgical risk. Previous studies have demonstrated differences in the neuropsychological performance of patients with epilepsy and functional seizures. We hypothesized that comorbid functional seizures could potentially influence neuropsychological test performance. Therefore, we evaluated whether there is a difference in the neuropsychological test results between drug resistant epilepsy patients with and without comorbid functional seizures. METHOD: Neuropsychological test results were compared between 25 patients with drug resistant focal epilepsy and 25 patients that also had documented functional seizures. Univariate analyses and multiple logistic regression models were used to both assess performance differences between the groups and to assess whether test results could be used to accurately identify which patients had comorbid functional seizures. RESULTS: Epilepsy patients with comorbid functional seizures performed significantly worse on the FAS Verbal Fluency Test compared to ES patients (p = 0.047). Digit Span Backwards (p = 0.10), Digit Span Forwards (p = 0.14) and Working Memory Index (p = 0.10) tended to be lower in the epilepsy and functional seizures group but was not statistically significant. A multiple logistic regression model using the results of four neuropsychological tests was able to identify patients with comorbid functional seizures with 83.33% accuracy. CONCLUSIONS: There are appeared to be some differences in the neuropsychological performance among drug resistant epilepsy patients based on whether they have comorbid functional seizures. These findings may have relevant implications for the interpretation of neuropsychological test results.

The landscape of drug resistant absence seizures in adolescents and adults: Pathophysiology, electroclinical spectrum and treatment options.

The persistence of typical absence seizures (AS) in adolescence and adulthood may reduce the quality of life of patients with genetic generalized epilepsies (GGEs). The prevalence of drug resistant AS is probably underestimated in this patient population, and treatment options are relatively scarce. Similarly, atypical absence seizures in developmental and epileptic encephalopathies (DEEs) may be unrecognized, and often persist into adulthood despite improvement of more severe seizures. These two seemingly distant conditions, represented by typical AS in GGE and atypical AS in DEE, share at least partially overlapping pathophysiological and genetic mechanisms, which may be the target of drug and neurostimulation therapies. In addition, some patients with drug-resistant typical AS may present electroclinical features that lie in between the two extremes represented by these generalized forms of epilepsy.

Real-world evidence of epidemiology, patient characteristics, and mortality in people with drug-resistant epilepsy in the United Kingdom, 2011-2021.

BACKGROUND: A third of people with epilepsy are drug resistant. People with drug-resistant epilepsy (DRE) have a higher risk of mortality and physical injuries than those who respond to anti-seizure medication (ASM). This study describes patient characteristics, comorbidities, and mortality in people with DRE in the UK. METHODS: The Clinical Practice Research Datalink was utilised to select people with DRE prescribed a third ASM between 1 January 2011 and 31 March 2021. Annual incidence and prevalence of DRE, patient characteristics, comorbidities, and mortality rates were analysed. Subgroup analysis was performed by age, sex, presence of intellectual disabilities and time from epilepsy diagnosis to DRE. RESULTS: A total of 34,647 people with DRE were included (mean ± SD age 42.68 ± 23.59 years, 52.6% females). During the study period, annual DRE incidence ranged from 1.99% to 3.12%. As of 31 March 2021, DRE prevalence was 26.6% (95% confidence interval [CI] 26.3%-26.8%). A greater proportion of people with DRE resided in the most deprived regions, with 21.1% and 16.7% in the top two quintiles of the Index of Multiple Deprivation respectively, compared to < 15% in the three less deprived regions. All-cause mortality ranged from 3,687 to 4,802 per 100,000 persons with DRE, four times higher than that in the general population in the UK. Variations existed across subgroups. CONCLUSIONS: Considerable disease burden was observed in people with DRE in the UK. The findings emphasise the importance of early DRE diagnosis and appropriate disease management in people who develop DRE.

Characterising people with focal drug-resistant epilepsy: A retrospective cohort study.

OBJECTIVES: To describe the demographics, clinical characteristics, drug treatment outcomes, healthcare resource utilization, and injuries among people with focal drug-resistant epilepsy (F-DRE) analysed separately for six European countries. METHODS: We used electronic medical record data from six European (Belgium, Spain, Italy, France, UK and Germany) primary care/specialist care databases to identify antiseizure medication (ASM) treatment-naïve people (aged ≥ 18 years at F-DRE diagnosis). They were followed from their epilepsy diagnosis until death, the date of last record available, or study end. We used descriptive analyses to characterise the F-DRE cohort, and results were reported by country. RESULTS: One-thousand-seventy individuals with F-DRE were included (mean age 52.5 years; 55.4 % female). The median follow-up time from the first diagnosis to the end of the follow-up was 95.5 months across all countries. The frequency of F-DRE diagnosis in 2021 ranged from 8.8 % in Italy to 18.2 % in Germany. Psychiatric disorders were the most common comorbidity across all countries. Frequently reported psychiatric disorders were depression (26.7 %) and anxiety (11.8 %). The median time from epilepsy diagnosis to the first ASM failure ranged from 5.9 (4.2-10.2) months in France to 12.6 (5.8-20.4) months in Spain. Levetiracetam and lamotrigine were the most commonly used ASM monotherapies in all countries. Consultation with a general practitioner is sought more frequently after F-DRE diagnosis than after epilepsy diagnosis, except in the UK. SIGNIFICANCE: No one ASM is optimal for all people with F-DRE, and the risks and benefits of the ASM must be considered. Comorbidities must be an integral part of the management strategy and drive the choice of drugs.

[Epilepsy and inequality: demographic description and analysis of the difficulty in accessing advanced resources in a population in a small health area]. / Epilepsia y desigualdad: descripción demográfica y análisis de la dificultad para el acceso a recursos avanzados en una población de un área de salud pequeña.

INTRODUCTION: Epilepsy is a very common neurological disease with high morbidity and mortality. Drug-resistant epilepsy (DRE) poses a major therapeutic challenge, even for experts in the field. Despite this, access to advanced resources for this type of patient remains difficult and unequal. The aim of this study is to analyse inequality in a population belonging to a first level hospital. PATIENTS AND METHODS: An analytical observational cross-sectional study was conducted on epileptic patients attending neurology consultations in Area IX of the Murcian Health Service. Demographic, clinical, therapeutic, prognostic and equity variables are described, and significant differences between different subgroups are analysed. RESULTS: The study included 68 patients with a mean age of 42.93 years. Focal epilepsy was the main type (64.7%), and the most commonly used drugs were levetiracetam (33.8%), valproic acid (27.9%) and lamotrigine (22.1%). DRE occurred in 18 patients (26.5% of the total) and only four were under active follow-up in an epilepsy unit, meaning that 71% did not have access to a necessary resource (advanced therapeutic gap). CONCLUSIONS: This study demonstrates that epilepsy inequality continues to be a problem, especially in certain geographical areas, with a lack of access to advanced care for patients who need it most. The solution can be achieved by increasing human and material resources to improve overall patient care, thus strengthening both referral hospitals and epilepsy units.

TITLE: Epilepsia y desigualdad: descripción demográfica y análisis de la dificultad para el acceso a recursos avanzados en una población de un área de salud pequeña.Introducción. La epilepsia es una enfermedad neurológica muy frecuente que implica una elevada morbimortalidad. La epilepsia farmacorresistente (EFR) supone un desafío terapéutico superior, incluso para expertos en la materia. A pesar de ello, el acceso a recursos avanzados para este tipo de pacientes continúa siendo dificultoso y desigual. El objetivo de este estudio es analizar la desigualdad en una población perteneciente a un hospital de primer nivel. Pacientes y métodos. Se llevó a cabo un estudio transversal observacional analítico con pacientes epilépticos que acuden a consultas de neurología del área IX del Servicio Murciano de Salud. Se describen variables demográficas, clínicas, terapéuticas, pronósticas y de equidad, y se analizan diferencias significativas entre distintos subgrupos. Resultados. En el estudio se incluyó a 68 pacientes con una media de edad de 42,93 años. El tipo de epilepsia principal fue la focal (64,7%), y los fármacos más usados fueron el levetiracetam (33,8%), el ácido valproico (27,9%) y la lamotrigina (22,1%). La EFR se dio en 18 pacientes (el 26,5% del total) y sólo cuatro se encontraban en seguimiento activo en una unidad de epilepsia, lo que implica que el 71% no accedía a un recurso necesario (advanced therapeutic gap). Conclusiones. Este estudio demuestra que la desigualdad en la epilepsia continúa siendo un problema, especialmente en ciertas áreas geográficas, con una falta de acceso a atención avanzada en pacientes que más lo necesitan. La solución puede conseguirse aumentando recursos humanos y materiales que mejoren la atención global del paciente, reforzando así tanto los hospitales de referencia como las unidades de epilepsia.

Drug-resistant idiopathic generalized epilepsy: A meta-analysis of prevalence and risk factors.

BACKGROUND: Idiopathic generalized epilepsy (IGE) is a common epilepsy syndrome with early age onset and generally good seizure outcomes. This study aims to determine the incidence and predictive risk factors for drug-resistant IGE. METHODS: We systematically searched three databases (PubMed, Embase, and Cochrane Library) in November 2022 and included 12 eligible studies which reported long-term outcomes (mean = 14.05) after antiseizure medications (ASMs) from 2001 to 2020. We defined drug resistance as the persistence of any seizure despite ASMs treatment (whether as monotherapies or in combination) given the criteria of drug resistance varied in original studies. A random-effects model was used to evaluate the prevalence of refractory IGE. Studies reporting potential poor prognostic factors were included for subsequent subgroup meta-analysis. RESULTS: The pooled prevalence of drug resistance in IGE cohorts was 27% (95% CI: 0.19-0.36). Subgroup analysis of the risk factors revealed that the psychiatric comorbidities (odds ratio (OR): 4.87, 95% confidence interval (CI): 2.97-7.98), combined three seizure types (absences, myoclonic jerks, and generalized tonic-clonic seizures) (OR: 5.37, 95% CI: 3.16-9.13), the presence of absence seizure (OR: 4.38, 95% CI: 2.64-7.28), generalized polyspike trains (GPT) (OR: 4.83, 95% CI: 2.42-9.64), sex/catamenial epilepsy (OR: 3.25, 95% CI: 1.97-5.37), and status epilepticus (OR: 5.94, 95% CI: 2.23-15.85) increased the risk of poor prognosis. Other factors, including age onset, family history, and side effects of ASMs, were insignificantly associated with a higher incidence of refractory IGE. CONCLUSION: Drug resistance is a severe complication of IGE. Further standardized research about clinical and electroencephalography factors is warranted.

Patterns of utilization and cost of healthcare services and pharmacotherapy among patients with drug-resistant epilepsy during the two-year period before neurostimulation: A descriptive analysis of the journey to implantation based on analyses of a large United States healthcare claims database.

OBJECTIVE: To conduct a descriptive assessment of patterns of utilization and cost of healthcare services and pharmacotherapies among patients with drug-resistant epilepsy (DRE) before neurostimulator implantation. METHODS: Using a large United States healthcare claims database, we identified all patients with DRE who were implanted with neurostimulators between January 1, 2012, and December 31, 2019. Patients without an epilepsy diagnosis on their implantation date were excluded, as were those without (1) anti-seizure medication (ASM) dispenses within 12 months of implantation date, and (2) continuous enrollment for the 24-month period before this date. Demographic and clinical characteristics were assessed over the two-year period before implantation, as were patterns of utilization and cost of healthcare services and pharmacotherapy. Care was assessed as all-cause or epilepsy-related, with the latter defined as all medical (inpatient and outpatient) care resulting in diagnoses of epilepsy and all ASM dispenses. RESULTS: Eight hundred sixty patients met all selection criteria. Among these patients, comorbidities were common, including depression (27%), anxiety (30%), and learning disabilities (25%). Fifty-nine percent of patients had ≥1 all-cause hospitalizations; 57% had ≥1 epilepsy-related admissions. Patients averaged 8.6 epilepsy-related visits to physicians' offices, including 5.1 neurologist visits. Mean all-cause and epilepsy-related healthcare costs during the pre-implantation period were $123,500 and $91,995, respectively; corresponding median values were $74,567 and $53,029. Median monthly all-cause healthcare costs increased by 138% during the 24-month period (from $1,042 to $2,481 in the month prior to implantation); median epilepsy-related costs, by 290% (from $383 to $1,492). CONCLUSIONS: The two-year period before neurostimulator implantation is a long and costly journey. Estimates likely minimize the burden experienced during this period, given that seizure frequency and severity-and corresponding impacts on quality of life-were unavailable in these data. Further research is needed to understand the clinical, economic, and psychological impact of the time between DRE onset and implantation among qualifying patients.

Clinico-Etiologic Profile of Children and Adolescents with Drug-Resistant Epilepsy in a low-Resource Setting: 10 Years' Experience.

Purpose: Nearly 25% to 30% of children with epilepsy develop drug-resistant epilepsy. Etiology of epilepsy, including drug-resistant epilepsy, varies with geographical region. Identifying paucity of etiologic data on drug-resistant epilepsy from our region and similar low-resource settings, we aimed to describe the clinical and etiologic profile of children and adolescents with drug-resistant epilepsy, to better inform region-specific concerns. Methods: A chart-based retrospective review covering 10 years (January 2011-December 2020) was conducted. Participants between 1 months and 18 years of age who fulfilled International League Against Epilepsy (ILAE) definition of drug-resistant epilepsy were enrolled. Clinical details, perinatal history, electroencephalography (EEG), magnetic resonance imaging (MRI), and other evaluation-based data were analyzed. Results: Five hundred ninety-three children (52.3% males) were enrolled. The median age at presentation was 63 (interquartile range [IQR] 12-72) months and median age at onset was 12 (IQR 2-18) months. The most frequent seizure type was generalized (76.6%). Of these, epileptic spasms (48.1%) were most frequent. Focal seizures comprised 22.9%. The predominant contributor to etiology was perinatal adverse events, including perinatal asphyxia (37.9%), neonatal hypoglycemic brain injury (15.6%), and neonatal sepsis/meningitis. Electroclinical syndromes were observed in 361 (60.9%) children. Of these, the most frequent were West syndrome (48%) and Lennox-Gastaut syndrome (6.2%). Conclusion: Perinatal brain injury and brain infections were the most common causes of drug-resistant epilepsy identified. These findings indicate an opportunity for reducing the burden of pediatric drug-resistant epilepsy in our region by instituting preventive measures, including improved perinatal care, promotion of institutional deliveries, optimized obstetric and neonatal care, and immunization for vaccine-preventable infections such as bacterial meningitis and Japanese B encephalitis.

Risk factors for drug-resistant epilepsy in adult patients.

INTRODUCTION: Drug-resistant epilepsy occurs in about 30% of epilepsy patients. It has been suggested that etiology or seizure type would increase the risk of pharmacoresistance. This study aims to compare the characteristics of patients with drug-sensitive epilepsy with patients with drug-resistant epilepsy to identify risk factors. PATIENT AND METHODS: A multicentric cohort study was conducted between 2019 and 2022. We included patients >18 years-old with epilepsy but excluded psychogenic non-epileptic seizures and less than 2 years of follow-up. RESULTS: We included 128 patients, of whom 46 had drug-resistance epilepsy, and 82 responding to medication. Both groups showed similar characteristics. Febrile seizures (OR: 7.25), focal epilepsy (OR: 2.4), focal seizures with loss of consciousness (OR: 2.36), structural etiology (OR: 2.2) and abnormal MRI (OR: 4.6) were significant risk factors for drug-resistance epilepsy. CONCLUSION: Following other studies, we observed that factors such as epilepsy type, seizure type, structural etiology, abnormal MRI, and febrile seizure increased the risk for drug-resistance epilepsy, in our population.

The seasonality of new-onset refractory status epilepticus (NORSE).

The etiology of new-onset refractory status epilepticus (NORSE), including its subtype with prior fever known as FIRES (febrile infection-related epilepsy syndrome), remains uncertain. Several arguments suggest that NORSE is a disorder of immunity, likely post-infectious. Consequently, seasonal occurrence might be anticipated. Herein we investigated if seasonality is a notable factor regarding NORSE presentation. We combined four different data sets with a total of 342 cases, all from the northern hemisphere, and 62% adults. The incidence of NORSE cases differed between seasons (p = .0068) and was highest in the summer (32.2%) (p = .0022) and lowest in the spring (19.0%, p = .010). Although both FIRES and non-FIRES cases occurred most commonly during the summer, there was a trend toward FIRES cases being more likely to occur in the winter than non-FIRES cases (OR 1.62, p = .071). The seasonality of NORSE cases differed according to the etiology (p = .024). NORSE cases eventually associated with autoimmune/paraneoplastic encephalitis occurred most frequently in the summer (p = .032) and least frequently in the winter (p = .047), whereas there was no seasonality for cryptogenic cases. This study suggests that NORSE overall and NORSE related to autoimmune/paraneoplastic encephalitis are more common in the summer, but that there is no definite seasonality in cryptogenic cases.

The epidemiology of epilepsy in older adults: A narrative review by the ILAE Task Force on Epilepsy in the Elderly.

In an aging world, it is important to know the burden of epilepsy affecting populations of older persons. We performed a selective review of epidemiological studies that we considered to be most informative, trying to include data from all parts of the world. We emphasized primary reports rather than review articles. We reviewed studies reporting the incidence and prevalence of epilepsy that focused on an older population as well as studies that included a wider age range if older persons were tabulated as a subgroup. There is strong evidence that persons older than approximately 60 years incur an increasing risk of both acute symptomatic seizures and epilepsy. In wealthier countries, the incidence of epilepsy increases sharply after age 60 or 65 years. This phenomenon was not always observed among reports from populations with lower socioeconomic status. This discrepancy may reflect differences in etiologies, methods of ascertainment, or distribution of ages; this is an area for more research. We identified other areas for which there are inadequate data. Incidence data are scarcer than prevalence data and are missing for large areas of the world. Prevalence is lower than would be expected from cumulative incidence, possibly because of remissions, excess mortality, or misdiagnosis of acute symptomatic seizures as epilepsy. Segmentation by age, frailty, and comorbidities is desirable, because "epilepsy in the elderly" is otherwise too broad a concept. Data are needed on rates of status epilepticus and drug-resistant epilepsy using the newer definitions. Many more data are needed from low-income populations and from developing countries. Greater awareness of the high rates of seizures among older adults should lead to more focused diagnostic efforts for individuals. Accurate data on epilepsy among older adults should drive proper allocation of treatments for individuals and resources for societies.

Cannabis use patterns in drug-resistant and pharmacoresponsive epilepsy: Single tertiary referral center survey investigation.

This study sought to identify differences in cannabis use and perceptions about cannabis in mitigating seizure-related symptoms in patients with epilepsy, and to evaluate differences in these patterns between drug-resistant versus pharmacoresponsive epilepsy. A collection of self-report surveys completed by patients with epilepsy (n = 76) were used to retrospectively compare differences in those with drug-resistant versus pharmacoresponsive epilepsy regarding 1) proportion who used cannabis, 2) frequency of use, 3) method of use, and 4) reason for use. A Cochran-Armitage test for trend indicated that of patients who used cannabis, a higher proportion of patients in the drug-resistant group used more frequently than in the pharmacoresponsive group. Almost half (48%) of those in the drug-resistant group reported daily use compared to approximately a third (36%) of those in the pharmacoresponsive group. Additionally, no patient in either group reported that cannabis was harmful in relation to seizure-related symptoms. Results from this study highlight the need for epilepsy providers to formally assess patients' perceptions and use of non-prescribed cannabis to inform clinical care decisions, particularly in the drug-resistant epilepsy population.

Association Between Characteristics of National Association of Epilepsy Centers and Reported Utilization of Specific Surgical Techniques.

BACKGROUND AND OBJECTIVE: Nearly one-third of persons with epilepsy will continue having seizures despite trialing multiple antiseizure medications. Epilepsy surgery may be beneficial in these cases, and evaluation at a comprehensive epilepsy center is recommended. Numerous palliative and potentially curative approaches exist, and types of surgery performed may be influenced by center characteristics. This article describes epilepsy center characteristics associated with epilepsy surgery access and volumes in the United States. METHODS: We analyzed National Association of Epilepsy Centers 2019 annual report and supplemental survey data obtained with responses from 206 adult epilepsy center directors and 136 pediatric epilepsy center directors in the United States. Surgical treatment volumes were compiled with center characteristics, including US Census region. We used multivariable modeling with zero-inflated Poisson regression models to present ORs and incidence rate ratios of receiving a given surgery type based on center characteristics. RESULTS: The response rate was 100% with individual element missingness less than 4% across 352 observations undergoing univariate analysis. Multivariable models included 319 complete observations. Significant regional differences were present. The rates of laser interstitial thermal therapy (LITT) were lower at centers in the Midwest (incidence rate ratio [IRR] 0.74, 95% CI 0.59-0.92; p = 0.006) and Northeast (IRR 0.77, 95% CI 0.61-0.96; p = 0.022) compared with those in the South. Conversely, responsive neurostimulation implantation rates were higher in the Midwest (IRR 1.45, 95% CI 1.1-1.91; p = 0.008) and West (IRR 1.91, 95% CI 1.49-2.44; p < 0.001) compared with the South. Center accreditation level, institution type, demographics, and resources were also associated with variations in access and rates of potentially curative and palliative surgical interventions. DISCUSSION: Epilepsy surgery procedure volumes are influenced by US epilepsy center region and other characteristics. These variations may affect access to specific surgical treatments for persons with drug resistant epilepsy across the United States.

Psychiatric co-morbidity of drug-resistant epilepsy in Veterans.

OBJECTIVE: Psychiatric conditions are frequently co-morbid in epilepsy and studies examining Veterans with epilepsy suggest this population may present with unique psychiatric and clinical features Drug-resistant epilepsy (DRE) may confer a greater risk of psychiatric dysfunction; however, there is a paucity of literature documenting this. To expand our clinical understanding of Veterans with DRE, we assessed a comprehensive Veterans Health Administration (VHA)-wide sample, describing psychiatric conditions, medications, and healthcare utilization. METHODS: Psychiatric and hospitalization data were collected on 52,579 Veterans enrolled in VHA healthcare between FY2014-2ndQtr.FY2020 from the VHA Corporate Data Warehouse administrative data. Data examined include psychiatric diagnosis, psychotropic medication use, and utilization of hospital services. RESULTS: At least one psychiatric diagnosis was present in 70.2% of patients, while 49.8% had two or more diagnoses. Depression (51.7%), posttraumatic stress disorder (PTSD) (38.8%), and anxiety (38.0%) represented the most common psychiatric co-morbidities. Psychiatric medication use was present in 73.3%. Emergency room (ER) visits were highest in those with suicidality (mean 14.9 visits), followed by bipolar disorder (10.3), and schizophrenia (12.1). Psychiatric-related hospitalizations were highest for schizophrenia (mean 2.5 admissions) and bipolar disorder (2.3). Females had more psychiatric diagnoses (2.4 vs. 1.6, p < 0.001), psychiatric medications (3.4 vs. 2.3, p < 0.001), and ER utilization than males (6.9 vs. 5.5, p < 0.001). SIGNIFICANCE: A substantial psychiatric burden exists among Veterans with DRE. Compared to prior epilepsy literature, results suggest that Veterans with DRE evidence more prevalent psychiatric comorbidity, emergency care usage, and inpatient psychiatric admissions. Females were especially impacted, with greater rates of psychiatric conditions and treatment. Considering the relationship of psychiatric comorbidities in epilepsy with psychosocial functioning and quality of life, our findings highlight the need for screening and provision of services for those with DRE.

Epilepsy Surgery in Adult Stroke Survivors with New-Onset Drug-Resistant Epilepsy.

BACKGROUND: Despite its effectiveness, surgery for drug-resistant epilepsy is underutilized. However, whether epilepsy surgery is also underutilized among patients with stroke-related drug-resistant epilepsy is unclear. Therefore, our objectives were to estimate the rates of epilepsy surgery assessment and receipt among patients with stroke-related drug-resistant epilepsy and to identify factors associated with these outcomes. METHODS: We used linked health administrative databases to conduct a population-based retrospective cohort study of adult Ontario, Canada residents discharged from an Ontario acute care institution following the treatment of a stroke between January 1, 1997, and December 31, 2020, without prior evidence of seizures. We excluded patients who did not subsequently develop drug-resistant epilepsy and those with other epilepsy risk factors. We estimated the rates of epilepsy surgery assessment and receipt by March 31, 2021. We planned to use Fine-Gray subdistribution hazard models to identify covariates independently associated with our outcomes, controlling for the competing risk of death. RESULTS: We identified 265,081 patients who survived until discharge following inpatient stroke treatment, 1,902 (0.7%) of whom subsequently developed drug-resistant epilepsy (805 women; mean age: 67.0 ± 13.1 years). Fewer than six (≤0.3%) of these patients were assessed for or received epilepsy surgery before the end of follow-up (≤55.5 per 100,000 person-years). Given that few outcomes were identified, we could not proceed with the multivariable analyses. CONCLUSIONS: Patients with stroke-related drug-resistant epilepsy are infrequently considered for epilepsy surgery that could reduce morbidity and mortality.

Gene mutations in comorbidity of epilepsy and arrhythmia.

Epilepsy is one of the most common neurological disorders, and sudden unexpected death in epilepsy (SUDEP) is the most severe outcome of refractory epilepsy. Arrhythmia is one of the heterogeneous factors in the pathophysiological mechanism of SUDEP with a high incidence in patients with refractory epilepsy, increasing the risk of premature death. The gene co-expressed in the brain and heart is supposed to be the genetic basis between epilepsy and arrhythmia, among which the gene encoding ion channel contributes to the prevalence of "cardiocerebral channelopathy" theory. Nevertheless, this theory could only explain the molecular mechanism of comorbid arrhythmia in part of patients with epilepsy (PWE). Therefore, we summarized the mutant genes that can induce comorbidity of epilepsy and arrhythmia and the possible corresponding treatments. These variants involved the genes encoding sodium, potassium, calcium and HCN channels, as well as some non-ion channel coding genes such as CHD4, PKP2, FHF1, GNB5, and mitochondrial genes. The relationship between genotype and clinical phenotype was not simple linear. Indeed, genes co-expressed in the brain and heart could independently induce epilepsy and/or arrhythmia. Mutant genes in brain could affect cardiac rhythm through central or peripheral regulation, while in the heart it could also affect cerebral electrical activity by changing the hemodynamics or internal environment. Analysis of mutations in comorbidity of epilepsy and arrhythmia could refine and expand the theory of "cardiocerebral channelopathy" and provide new insights for risk stratification of premature death and corresponding precision therapy in PWE.

Characteristics associated with drug resistant epilepsy in children up to 36 months old with Congenital Zika Syndrome.

OBJECTIVES: To verify characteristics associated with drug resistant epilepsy in children up to 36 months of age with Congenital Zika Syndrome (CZS). METHODS: This is a prospective cohort study with children aged up to 36 months diagnosed with CZS. Obstetric, demographic, phenotype and other clinical signs, cranial tomography, growth and motor development of the children were collected. RESULTS: Of a total of 109 children diagnosed with CZS, 100 (91.7%) had epilepsy and 68 (68%) with drug resistant seizures. The types of seizures associated with drug resistant epilepsy were focal seizures from the occipital lobe, generalized tonic and generalized tonic-clonic seizures. There was an association between drug resistant epilepsy and microcephaly at birth, severe microcephaly at birth, excess nuchal skin, ventriculomegaly, reduced brain parenchyma volume, and hypoplasia or malformation of the cerebellum. Difficulty sleeping, irritability, continuous crying, dysphagia and gross motor function were clinical signs associated with drug resistant epilepsy, as were the presence of ocular abnormalities, low head circumference in the first year of life and low weight in the first six months. CONCLUSIONS: The prevalence of drug resistant epilepsy in children up to 36 months with CZS was 62.4% and was associated with the severity of the child's neurological damage, with emphasis on the reduction of brain parenchyma volume and damage to the cerebellum.

Risk factors for Drug-resistant Epilepsy (DRE) and a nomogram model to predict DRE development in post-traumatic epilepsy patients.

OBJECTIVES: To identify factors affecting the development of drug-resistant epilepsy (DRE), and establish a reliable nomogram to predict DRE development in post-traumatic epilepsy (PTE) patients. METHODS: This study conducted a retrospective clinical analysis in patients with PTE who visited the Epilepsy Center, Beijing Tiantan Hospital from January 2013 to December 2018. All participants were followed up for at least 3 years, and the development of DRE was assessed. Data from January 2013 to December 2017 were used as development dataset for model building. Those independent predictors of DRE were included in the final multivariable logistic regression, and a derived nomogram was built. Data from January 2018 to December 2018 were used as validation dataset for internal validation. RESULTS: Complete clinical information was available for 2830 PTE patients (development dataset: 2023; validation dataset: 807), of which 21.06% (n = 596) developed DRE. Among all parameters of interest including gender, age at PTE, family history, severity of traumatic brain injury (TBI), single or multiple injuries, lesion location, post-TBI treatments, acute seizures, PTE latency, seizure type, status epilepticus (SE), and electroencephalogram (EEG) findings, four predictors showed independent effect on DRE, they were age at PTE, seizure type, SE, and EEG findings. A model incorporating these four variables was created, and a nomogram to calculate the probability of DRE using the coefficients of the model was developed. The C-index of the predictive model and the validation was 0.662 and 0.690, respectively. The goodness-of-fit test indicated good calibration for model development and validation (p = 0.272, 0.572). CONCLUSIONS: The proposed nomogram achieved significant potential for clinical utility in the prediction of DRE among PTE patients. The risk of DRE for individual PTE patients can be estimated by using this nomogram, and identified high-risk patients might benefit from non-pharmacological therapies at an early stage.

Prevalence, risk factors, and prognosis of drug-resistant epilepsy in autoimmune encephalitis.

OBJECTIVE: To evaluate the prevalence and biomarkers of drug-resistant epilepsy (DRE) in patients with autoimmune encephalitis (AIE). METHODS: Sixty-nine patients with AIE were recruited retrospectively and electroencephalographies (EEGs) were reviewed using a standard reporting proforma. Associations between EEG biomarkers and DRE development at 12 months were examined using logistic regression modeling and were utilized to create a DRE risk score. RESULTS: Sixteen percent of patients with AIE developed DRE at 12-month follow-up. The presence of status epilepticus (SE) (OR 11.50, 95% CI [2.81, 51.86], p-value <0.001), temporal lobe focality (OR 9.90, 95% CI [2.60, 50.71], p-value 0.001) and periodic discharges (OR 19.12, 95% CI [3.79, 191.10], p-value 0.001) on the admission EEG were associated with the development of DRE at 12 months. These variables were utilized to create a clinically applicable risk score for the prediction of DRE development. CONCLUSIONS: Drug-resistant epilepsy is an infrequent complication of AIE. Electroencephalography changes during the acute illness can predict the risk of DRE at 12 months post-acute AIE. SIGNIFICANCE: The identified EEG biomarkers provide the basis to generate a clinically applicable prediction tool which could be used to inform treatment, prognosis, and select patients for acute treatment trials.

Drug-resistant epilepsy at the age extremes: Disentangling the underlying etiology.

The incidence of epilepsy is highest at the extreme age ranges: childhood and elderly age. The most common syndromes in these demographics - self-limited epilepsies of childhood and idiopathic generalized epilepsies in pediatric age, focal epilepsy with structural etiology in older people - are expected to be drug responsive. In this work, we focus on such epilepsy types, overviewing the complex clinical background of unexpected drug-resistance. For self-limited epilepsies of childhood and idiopathic generalized epilepsies, we illustrate drug-resistance resulting from syndrome misinterpretation, reason on possible unexpected courses of epilepsy, and explicate the influence of inappropriate treatments. For elderly-onset epilepsy, we show the challenges in differential diagnosis possibly leading to pseudoresistance and analyze how drug-resistant epilepsy can arise in stroke, neurocognitive disorders, brain tumors, and autoimmune encephalitis. In children and senior people, drug-resistance can be regarded as a hint to review the diagnosis or explore alternative therapeutic strategies. Refractory seizures are not only a therapeutic challenge, but also a cardinal sign not to be overlooked in syndromes commonly deemed to be drug-responsive.