Risk factors for drug-resistant epilepsy: A systematic review and meta-analysis

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.

Continuous epileptiform discharges are associated with worse neurodevelopmental findings in a congenital Zika syndrome prospective cohort

PURPOSE

This study aimed to identify continuous epileptiform discharges (CEDs) on electroencephalograms (EEG) and to determine their clinical significance in children with congenital Zika syndrome (CZS).

METHODS

This prospective cohort study included 75 children diagnosed with CZS born from March 2015 and followed up until September 2018 (age up to 36 months). EEG was performed to detect CEDs up to 24 months old. Data on obstetric, demographic, and clinical signs; cranial computed tomography (CT); ophthalmology examination; anti-seizure medication; growth; and motor development were collected. Fisher's exact test was used to verify the associations between categorical variables, and the T- test was used to compare the mean z-scores of anthropometric measurements between the groups with and without CED.

RESULTS

CEDs were identified in 41 (54.67 %) children. The mean age of CEDs identification was 12.24 ± 6.86 months. Bilateral CEDs were shown in 62.89 % of EEGs. CEDs were associated with severe congenital microcephaly, defined by z-score >3 standard deviation of head circumference (HC) below the mean for sex and age (p = 0.025), and worse outcomes, including first seizure before 6 months (p = 0.004), drug-resistant epilepsy (p < 0.001), chorioretinal scarring or mottling (p = 0.002), and severe CT findings (p = 0.002). The CED group had lower mean z-scores of HC up to 24 months of age.

CONCLUSION

This is the first description of the prevalence and significance of CEDs that also remains during wakefulness in patients with CZS. New investigations may suggest that it is more appropriate to classify the EEG not as a CED, but as a periodic pattern. Anyway, CEDs may be a marker of neurological severity in children with CSZ.

Microglia Mitigate Neuronal Activation in a Zebrafish Model of Dravet Syndrome

It has been known for a long time that epileptic seizures provoke brain neuroinflammation involving the activation of microglial cells. However, the role of these cells in this disease context and the consequences of their inflammatory activation on subsequent neuron network activity remain poorly understood so far. To fill this gap of knowledge and gain a better understanding of the role of microglia in the pathophysiology of epilepsy, we used an established zebrafish Dravet syndrome epilepsy model based on Scn1Lab sodium channel loss-of-function, combined with live microglia and neuronal Ca2+ imaging, local field potential (LFP) recording, and genetic microglia ablation. Data showed that microglial cells in scn1Lab-deficient larvae experiencing epileptiform seizures displayed morphological and biochemical changes characteristic of M1-like pro-inflammatory activation; i.e., reduced branching, amoeboid-like morphology, and marked increase in the number of microglia expressing pro-inflammatory cytokine Il1β. More importantly, LFP recording, Ca2+ imaging, and swimming behavior analysis showed that microglia-depleted scn1Lab-KD larvae displayed an increase in epileptiform seizure-like neuron activation when compared to that seen in scn1Lab-KD individuals with microglia. These findings strongly suggest that despite microglia activation and the synthesis of pro-inflammatory cytokines, these cells provide neuroprotective activities to epileptic neuronal networks, making these cells a promising therapeutic target in epilepsy.

Predictors of medical intractability in children with epilepsy onset during the first two years of life, excluding infantile epileptic spasm syndrome

PURPOSE

Early childhood epilepsy presents a significant challenge, with approximately 30 % of individuals experiencing treatment failure. This study aimed to identify predictors of medical intractability in children with epilepsy onset during the first two years of life, excluding infantile epileptic spasm syndrome.

METHODS

A total of 323 children were retrospectively evaluated. The analyses included a review of medical records for demographic, laboratory, radiological, and electroencephalographic (EEG) findings. Children were diagnosed with drug-resistant epilepsy (DRE) according to the ILAE diagnostic criteria. Twenty-one potential prognostic predictors were examined in relation to medical intractability.

RESULTS

Among the 323 children (56.7 % male), 119 (36.8 %) had unknown epilepsy, 131 (40.6 %) had structural epilepsy, 53 (16.4 %) had genetic epilepsy, and 20 (6.2 %) had metabolic epilepsy. Over a median follow-up of 68 months, 55.4 % of the children achieved ≥6 months of seizure freedom, 33.1 % developed DRE, and the remaining 11.5 % had rare ongoing seizures but did not meet the criteria for DRE because they were only treated with one antiseizure medication at the last follow-up. Univariate logistic regression analyses identified ten risk factors significantly associated with DRE. Multivariate logistic regression analyses revealed that the presence of developmental delay at epilepsy onset (p = 0.000; OR 7.890; 95 %CI 2.713 to 22.945), history of status epilepticus (p = 0.000; OR 8.247; 95 %CI 3.619 to 18.793), number of antiseizure medications (ASMs) at the sixth month of diagnosis (p = 0.000; OR 20.585; 95 %CI 8.993 to 47.117), and initial EEG findings (p = 0.046; OR 2.366; 95 %CI 1.015 to 5.518) were predictors of medical intractability. Nineteen (5.9 %) children died during follow-up for various reasons, including progressive neurogenetic or neurodegenerative disorders.

CONCLUSION

Developmental delay at epilepsy onset, a history of status epilepticus, the use of two or more ASMs in the sixth month of diagnosis, and abnormal initial EEG findings were associated with medical intractability.

Pathophysiology to Risk Factor and Therapeutics to Treatment Strategies on Epilepsy

Epilepsy represents a condition in which abnormal neuronal discharges or the hyperexcitability of neurons occur with synchronicity, presenting a significant public health challenge. Prognostic factors, such as etiology, electroencephalogram (EEG) abnormalities, the type and number of seizures before treatment, as well as the initial unsatisfactory effects of medications, are important considerations. Although there are several third-generation antiepileptic drugs currently available, their multiple side effects can negatively affect patient quality of life. The inheritance and etiology of epilepsy are complex, involving multiple underlying genetic and epigenetic mechanisms. Different neurotransmitters play crucial roles in maintaining the normal physiology of different neurons. Dysregulations in neurotransmission, due to abnormal transmitter levels or changes in their receptors, can result in seizures. In this review, we address the roles played by various neurotransmitters and their receptors in the pathophysiology of epilepsy. Furthermore, we extensively explore the neurological mechanisms involved in the development and progression of epilepsy, along with its risk factors. Furthermore, we highlight the new therapeutic targets, along with pharmacological and non-pharmacological strategies currently employed in the treatment of epileptic syndromes, including drug interventions employed in clinical trials related to epilepsy.

Morphometrics of the preserved post-surgical hemisphere in pediatric drug-resistant epilepsy

Importance

Structural integrity of cortex following cortical resection for epilepsy management has been previously characterized, but only in adult patients.

Objective

This study sought to determine whether morphometrics of the preserved hemisphere in pediatric cortical resection patients differ from non-neurological controls.

Design

This was a case-control study, from 2013-2022.

Setting

This was a single-site study.

Participants

32 patients with childhood epilepsy surgery and 51 age- and gender-matched controls participated.

Main Measures

We quantified morphometrics of the preserved hemisphere at the level of gross anatomy (lateral ventricle size, volume of gray and white matter). Additionally, cortical thickness, volume, and surface area were measured for 34 cortical regions segmented with the Desikan-Killiany atlas, and, last, volumes of nine subcortical regions were also quantified.

Results

13 patients with left hemisphere (LH) surgery and a preserved right hemisphere (RH) (median age/median absolute deviation of age: 15.7/1.7 yr; 6 females, 7 males) and 19 patients with RH surgery and a preserved LH (15.4/3.7 yr; 11 females, 8 males) were compared to 51 controls (14.8/4.9 yr; 24 females, 27 males). Patient groups had larger ventricles and reduced total white matter volume relative to controls, and only patients with a preserved RH, but not patients with a preserved LH, had reduced total gray matter volume relative to controls. Furthermore, patients with a preserved RH had lower cortical thickness and volume and greater surface area of several cortical regions, relative to controls. Patients with a preserved LH had no differences in thickness, volume, or area, of any of the 34 cortical regions, relative to controls. Moreover, both LH and RH patients showed reduced volumes in select subcortical structures, relative to controls.

Conclusions and Relevance

That left-sided, but not right-sided, resection is associated with more pronounced reduction in cortical thickness and volume and increased cortical surface area relative to typically developing, age-matched controls suggests that the preserved RH undergoes structural plasticity to an extent not observed in cases of right-sided pediatric resection. Future work probing the association of the current findings with neuropsychological outcomes will be necessary to understand the implications of these structural findings for clinical practice.

Early prediction of drug-resistant epilepsy using clinical and EEG features based on convolutional neural network

OBJECTIVE

Machine learning utilization in electroencephalogram (EEG) analysis and epilepsy care is fast evolving. Thus, we aim to develop and validate two one-dimensional convolutional neural network (CNN) algorithms for predicting drug-resistant epilepsy (DRE) in patients with newly-diagnosed epilepsy based on EEG and clinical features.

METHODS

We included a total of 1010 EEG signal epochs and 15 clinical features from 101 patients with epilepsy. Each patient had 10 epochs of EEG signal data, with each signal recorded for 90 s. The ratio of development set and validation set was 80:20, and ten-fold cross validation was performed. First, a CNN algorithm was used to extract EEG features automatically. Then, Two one-dimensional CNNs were crafted.. Accuracy, specificity, precision, sensitivity, F1-score, kappa statistics, mean square error (MSE) and area under the curve (AUC) were calculated to evaluate the classifiers performance.

RESULTS

The clinical-EEG model showed good performance and clinical practical value, with the accuracy, specificity, precision, sensitivity, F1-score, kappa statistics, best MSE and AUC in test set were 0.99, 0.72, 0.82, 0.96, 0.89, 0.83, 32.00, 0.81, respectively, and the accuracy in validation set was 0.84. In the EEG model, the accuracy, specificity, precision, sensitivity, F1-score, kappa statistics, best MSE and AUC in test set were 0.99, 0.59, 0.82, 0.90, 0.86, 0.72, 181.76, 0.76, respectively, and the accuracy in validation set was 0.81.

CONCLUSION

We constructed a clinical-EEG model showed good potential for predicting DRE in patients with newly-diagnosed epilepsy, which could help identify patients at high risk of developing DRE at earlier stages.

[Long-term follow-up of adult patients with serial and status course of epileptic seizures]

OBJECTIVE

To study the follow-up of adult patients with status epilepticus or a history of serial seizures, assessing the likelihood of achieving long-term remission and identifying predictors of treatment effectiveness.

MATERIAL AND METHODS

The study included 280 patients divided into 137 patients with epilepsy with a series of seizures or a history of status epilepticus (group 1) and 143 patients, who had not previously received therapy and did not have a series of seizures or a history of status epilepticus (group 2). A clinical and neurological examination, analysis of medical documentation data, electroencephalography, and MRI were performed.

RESULTS

After correction of therapy, remission in patients in group 1 was achieved in 21.9%, improvement in 30%, no effect was observed in 48.1%; in group 2 the indicators were 51%, 28.7%, 20.3%, respectively. The onset of epilepsy in childhood, frequent seizures, and regional epileptiform activity were associated with the lack of treatment effect.

CONCLUSION

The results confirm the main role of the clinical examination in determining the prognosis of epilepsy in a particular patient. Currently available instrumental techniques have limited predictive value.

Bidirectional Neuronal Control of Epileptiform Activity by Repetitive Transcranial Focused Ultrasound Stimulations

Repetitive stimulation procedures are used in neuromodulation techniques to induce persistent excitatory or inhibitory brain activity. The directivity of modulation is empirically regulated by modifying the stimulation length, interval, and strength. However, bidirectional neuronal modulations using ultrasound stimulations are rarely reported. This study presents bidirectional control of epileptiform activities with repetitive transcranial-focused ultrasound stimulations in a rat model of drug-induced acute epilepsy. It is found that repeated transmission of elongated (40 s), ultra-low pressure (0.25 MPa) ultrasound can fully suppress epileptic activities in electro-encephalography and cerebral blood volume measurements, while the change in bursting intervals from 40 to 20 s worsens epileptic activities even with the same burst length. Furthermore, the suppression induced by 40 s long bursts is transformed to excitatory states by a subsequent transmission. Bidirectional modulation of epileptic seizures with repeated ultrasound stimulation is achieved by regulating the changes in glutamate and γ-Aminobutyric acid levels, as confirmed by measurements of expressed c-Fos and GAD65 and multitemporal analysis of neurotransmitters in the interstitial fluid obtained via microdialysis.

Real-world antiseizure medication treatment outcomes in drug-resistant focal epilepsy patients

OBJECTIVE

To gather real-world evidence on antiseizure medications (ASMs) treatment patterns and related outcomes in patients with drug-resistant focal epilepsy.

METHODS

Medical insurance claims from the start of 2014 till the end of 2019 were used. Patient selection criteria included International Classification of Diseases (ICD) codes followed by documented ASM use. Baseline patient demographics along with ASM and rescue medication use patterns and related patient outcome were documented for first (index) ASM regimen. Patients who failed the first regimen and then failed the second regimen were considered drug resistant. Multivariate analyses were performed to identify risks and other characteristics for positive or negative treatment outcomes.

RESULTS

Study cohort consisted of 46 474 patients with a mean age of 47.23 (SD: 16.94). Levetiracetam was the most first-encountered ASM (37.94%). At baseline, 87.14% were treated with ASMs prior to having study-confirmed diagnoses. Mental comorbidities were present in 37.86% of patients. After first-year ASM treatment, 34.61% of patients persisted on their index regimen and 5.91% were seizure-free. Patients failing first ASM regimen numbered 12 868 (27.69%). Drug-resistant patients who failed first and then second ASM regimens numbered 6335 (49.23%). Percentages of patients who had successful second treatment and seizure-free were 21.32 and 3.65, respectively. Initiating patients on lamotrigine or carbamazepine (relative to levetiracetam), baseline use of index ASM, rescue medications, and older age or male gender all lowered the risk for treatment failure. Having higher comorbidity, comorbid mental illness, headache, or neoplasty increased such a risk. Baseline use of index ASM, depressive episode, or anxiety disorder all entailed higher risk of failing second ASM treatment.

SIGNIFICANCE

Overall, reported findings indicated that patient history at baseline and the early selection of an ASM all influenced treatment outcomes. Findings pointed to the complex nature of ASM treatment in drug-resistant focal epilepsy patients calling for additional research to identify the optimal treatment to achieve beneficial patient outcomes.

Cenobamate in refractory epilepsy: Overview of treatment options and practical considerations

Management of drug resistant epilepsy (DRE) represents a challenge to the treating clinician. This manuscript addresses DRE and provides an overview of treatment options, medical, surgical, and dietary. It addresses treatment strategies in polytherapy, then focuses on the role cenobamate (CNB) may play in reducing the burden of DRE while providing practical advice for its introduction. CNB is a recently approved, third generation, anti-seizure medication (ASM), a tetrazole-derived carbamate, thought to have a dual mechanism of action, through its effect on sodium channels as well as on GABAA receptors at a non-benzodiazepine site. CNB, having a long half-life, is an effective add-on ASM in refractory focal epilepsy with a higher response rate and a higher seizure-freedom rate than is usually seen in regulatory clinical trials. Experience post-licensing, though still limited, supports the findings of clinical trials and is encouraging. Its spectrum of action in relation to generalized epilepsies and seizures remains to be established, and there are no data on its efficacy in monotherapy. At the time of writing, CNB has been prescribed for some 50 000 individuals with DRE and focal epilepsy. A larger number is needed to fully establish its safety profile. It should at all times be introduced slowly to minimize the risk of serious allergic drug reactions. It has clinically meaningful interactions which must be anticipated and managed to maximize tolerability and likelihood of successful treatment. Despite the above, it may well prove to be of major benefit in the treatment of many patients with drug resistant epilepsy.

Mice deficient in complement C3 are protected against recognition memory deficits and astrogliosis induced by status epilepticus

Introduction

Status epilepticus (SE) can significantly increase the risk of temporal lobe epilepsy (TLE) and cognitive comorbidities. A potential candidate mechanism underlying memory defects in epilepsy may be the immune complement system. The complement cascade, part of the innate immune system, modulates inflammatory and phagocytosis signaling, and has been shown to contribute to learning and memory dysfunctions in neurodegenerative disorders. We previously reported that complement C3 is elevated in brain biopsies from human drug-resistant epilepsy and in experimental rodent models. We also found that SE-induced increases in hippocampal C3 levels paralleled the development of hippocampal-dependent spatial learning and memory deficits in rats. Thus, we hypothesized that SE-induced C3 activation contributes to this pathophysiology in a mouse model of SE and acquired TLE.

Methods

In this study C3 knockout (KO) and wild type (WT) mice were subjected to one hour of pilocarpine-induced SE or sham conditions (control; C). Following a latent period of two weeks, recognition memory was assessed utilizing the novel object recognition (NOR) test. Western blotting was utilized to determine the protein levels of C3 in hippocampal lysates. In addition, we assessed the protein levels and distribution of the astrocyte marker glial fibrillary acidic protein (GFAP).

Results

In the NOR test, control WT + C or C3 KO + C mice spent significantly more time exploring the novel object compared to the familiar object. In contrast, WT+SE mice did not show preference for either object, indicating a memory defect. This deficit was prevented in C3 KO + SE mice, which performed similarly to controls. In addition, we found that SE triggered significant increases in the protein levels of GFAP in hippocampi of WT mice but not in C3 KO mice.

Discussion

These findings suggest that ablation of C3 prevents SE-induced recognition memory deficits and that a C3-astrocyte interplay may play a role. Therefore, it is possible that enhanced C3 signaling contributes to SE-associated cognitive decline during epileptogenesis and may serve as a potential therapeutic target for treating cognitive comorbidities in acquired TLE.

The efficacy and safety of cannabidiol as adjunct treatment for drug-resistant idiopathic epilepsy in 51 dogs: A double-blinded crossover study

BACKGROUND

Approximately 30% of dogs with idiopathic epilepsy (IE) are drug-resistant. Recent studies have suggested cannabidiol (CBD) may be an effective anticonvulsant in dogs with IE.

OBJECTIVE

To evaluate the addition of CBD to antiseizure drugs (ASDs) on seizure frequency and to report adverse events in dogs with drug-resistant IE.

ANIMALS

Fifty-one dogs. Dogs having at least 2 seizures per month while receiving at least 1 ASD were included in the trial.

METHODS

Double-blinded placebo-controlled crossover study. The 5 mg/kg/day dosage met futility requirements after 12 dogs, and a dosage of 9 mg/kg/day was used in the next 39 dogs. Dogs were randomly assigned to receive CBD or placebo for 3 months, with a 1-month washout period between oils. Total numbers of seizures and seizure days were recorded. Diagnostic testing was performed periodically throughout the trial.

RESULTS

At the 9 mg/kg/day dose, the decrease in total seizure frequency was significant compared with placebo. A 24.1% decrease in seizure days occurred in dogs receiving CBD and a 5.8% increase occurred in dogs receiving placebo (P ≤ .05). No significant difference was found in the number of responders (≥50% decrease in total seizures or seizure days). Liver enzyme activities increased at both dosages. Decreased appetite and vomiting were more common in the CBD phase (P ≤ .05).

CONCLUSIONS AND CLINICAL IMPORTANCE

Cannabidiol decreased total seizures and seizure days compared to placebo when administered to dogs PO at 9 mg/kg/day. Liver enzymes should be monitored with administration of CBD in dogs.

Identification of drug resistance in a validated cohort of incident epilepsy patients in the Danish National Patient Register

OBJECTIVE

The main purposes of this study were to validate the epilepsy diagnosis in incident epilepsy cases in the Danish National Patient Registry (DNPR), which contains information on nearly 9 000 000 individuals, and to identify persons in the validated cohort who fulfilled the International League Against Epilepsy (ILAE) criteria for drug-resistant epilepsy (DRE).

METHODS

We reviewed a random sample of medical records from all individuals registered with a first diagnosis of epilepsy (International Classification of Diseases, 10th Revision [ICD-10]: G40) or seizures (ICD-10: G41, R56, or F445) in the Central Denmark Region from 2010 to 2019. In persons with a validated incident epilepsy diagnosis, we determined the proportion with DRE at the latest contact. We performed logistic regression analyses to identify clinical factors that correlated with risk of DRE.

RESULTS

Of 20 723 persons with a first diagnosis of epilepsy (n = 11 812) or seizures (n = 8911), we reviewed the medical records of n = 1067 with incident epilepsy and n = 610 with incident seizures. Among those with a register diagnosis of epilepsy, the diagnosis was confirmed in 838 cases (45% females, mean age at onset = 42.4 years), providing a positive predictive value (PPV) of 79% (95% confidence interval [CI] = 76%-81%). The PPV of focal epilepsy was 86% (95% CI = 82%-89%), and the PPV of generalized epilepsy was 71% (95% CI = 61%-80%). Of 740 patients with confirmed incident epilepsy and ≥1 year of follow-up, 103 (14%) fulfilled the definition of DRE, 476 (64%) were drug responsive, and 161 (22%) had undefined responsiveness. In multivariable logistic regression analysis, early age at epilepsy onset, cognitive impairment, and a history of status epilepticus were associated with DRE.

SIGNIFICANCE

In the DNPR, we found a PPV of the epilepsy diagnosis of 79%. Among persons with confirmed epilepsy, 14% fulfilled ILAE criteria for DRE. Early age at epilepsy onset, cognitive impairment, and a history of status epilepticus were independently associated with drug resistance.

Drug-resistant epilepsy: Definition, pathophysiology, and management

There are currently >51 million people with epilepsy (PWE) in the world and every year >4.9 million people develop new-onset epilepsy. The cornerstone of treatment in PWE is drug therapy with antiseizure medications (ASMs). However, about one-third of PWE do not achieve seizure control and do not respond well to drug therapy despite the use of appropriate ASMs [drug-resistant epilepsy (DRE)]. The aims of the current narrative review are to discuss the definition of DRE, explain the biological underpinnings and clinical biomarkers of this condition, and finally to suggest practical management strategies to tackle this issue appropriately, in a concise manner.

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.

Prevalence and risk factors of anxiety and depression in adult patients with epilepsy: a multicenter survey-based study

Background

Depression and anxiety are the most common psychiatric comorbidities in patients with epilepsy (PWE). However, they are often unrecognized and consequently untreated.

Objective

The study was conducted to evaluate the prevalence and risk factors of anxiety and depression among Chinese adult PWE.

Design

Cross-sectional study.

Methods

Adult PWE were recruited from 13 tertiary epilepsy centers from February to September 2022. Generalized Anxiety Disorder-7 and Neurological Disorders Depression Inventory for Epilepsy were applied to evaluate anxiety and depression, respectively. Both univariate and multivariate logistic regression analyses models were performed to explore the risk factors of anxiety and depression.

Results

A total of 1326 PWE were enrolled in this study. The prevalence of anxiety and depression was 31.45% and 27.30%, respectively. Being female [odds ratio (OR) = 1.467, 95% CI: 1.134-1.899; p = 0.004], focal and focal to bilateral tonic-clonic seizures (TCSZ) (OR = 1.409, 95% CI: 1.021-1.939; p = 0.036), and seizure occurrence in the last 3 months (OR = 1.445, 95% CI: 1.026-2.044; p = 0.036) were the risk factors for anxiety. Focal and focal to bilateral TCSZ (OR = 1.531, 95% CI: 1.094-2.138; p = 0.013) and seizure occurrence in the last 3 months (OR = 1.644, 95% CI: 1.130-2.411; p = 0.010) were the risk factors for depression. In addition, for every 1-year increment of age, the odds of developing depression were decreased by 3.8% (p = 4.12e-5). Nevertheless, up to 70% of PWE did not receive any treatment for comorbidity.

Conclusion

There were approximately 30% of PWE screened positive for anxiety or depression. Both focal and focal to bilateral TCSZ and seizure occurrence in the last 3 months were estimated as risk factors for anxiety and depression. However, the current status of treatment was not optimal.

Xenon inhalation attenuates neuronal injury and prevents epilepsy in febrile seizure Sprague-Dawley pups

Background

Febrile seizures (FS) usually occur in childhood and may cause irreversible neuronal damage, cognitive functional defects, and an increase in the risk of epilepsy later in life. Anti-epileptic drugs (AEDs), currently used to treat FS in children, can relieve seizures. However, their effects in preventing the risk of developing epilepsy in later life are unsatisfactory. Moreover, AEDs may damage child brain development. Here, we evaluated the efficiency of xenon in treating prolonged FS (PFS) and preventing epilepsy in Sprague-Dawley pups.

Methods

Prolonged FS was induced by hyperthermic treatment. After 90 min of PFS, the pups in the xenon treatment group were immediately treated with 70% xenon/21% oxygen/9% nitrogen for 60 min. The levels of glutamate, mitochondrial oxidative stress, mitophagy, and neuronal injury, seizures, learning, and memory functions were measured at specific time points.

Results

Neonatal period PFS led to spontaneous seizure, learning and memory dysfunction, accompanied by increased levels of glutamate, mitochondrial oxidative stress, mitophagy, and neuronal injury. Xenon treatment alleviated the changes caused by PFS and reduced the risk of PFS developing into epilepsy later.

Conclusion

Our results suggest that xenon inhalation could be a potential therapeutic strategy to attenuate neuronal injury and prevent epilepsy in patients with FS.

Clinical features and drug-resistance in pediatric epilepsy with co-occurring autism: A retrospective comparative cohort study

OBJECTIVE

We conducted a retrospective comparative cohort study to determine the phenotypic and real-world management differences in children with epilepsy and co-occurring autism as compared to those without autism.

METHODS

Clinical variables, EEG, brain MRI, genetic results, medical and non-medical treatment were compared between 156 children with both epilepsy and autism, 156 randomly selected and 156 demographically matched children with epilepsy only. Logistic regression analyses were conducted to determine predictors of drug-resistant epilepsy (DRE).

RESULTS

As compared to the'matched' cohort, more patients with autism had generalized motor seizures although not statistically significant after Benjamini-Hochberg correction (54.5%, vs 42.3%, p = .0314); they had a lower rate of electroclinical syndromes (12.8%, vs 30.1%, p = .0002). There were more incidental MRI findings but less positive MRI findings to explain their epilepsy in children with autism (26.3%, vs 13.8% and 14.3%, vs 34.2%, respectively; p = .0003). In addition, LEV, LTG, and VPA were the most common ASMs prescribed to children with autism, as opposed to LEV, OXC, and LTG in children without autism. No difference in the major EEG abnormalities was observed. Although the rates of DRE were similar (24.8%, vs 26.6%, p = .7203), we identified two clinical and five electrographic correlates with DRE in children with both epilepsy and autism and a final prediction modeling of DRE that included EEG ictal findings, focal onset seizures, generalized motor seizures, abnormal EEG background, age of epilepsy onset, and history of SE, which were distinct from those in children without autism.

SIGNIFICANCE

Our study indicates that detailed seizure history and EEG findings are the most important evaluation and prediction tools for the development of DRE in children with epilepsy and co-occurring autism. Further studies of epilepsy in specific autism subgroups based on their etiology and clinical severity are warranted.

Non-invasive mapping of epileptogenic networks predicts surgical outcome

Epilepsy is increasingly considered a disorder of brain networks. Studying these networks with functional connectivity can help identify hubs that facilitate the spread of epileptiform activity. Surgical resection of these hubs may lead patients who suffer from drug-resistant epilepsy to seizure freedom. Here, we aim to map non-invasively epileptogenic networks, through the virtual implantation of sensors estimated with electric and magnetic source imaging, in patients with drug-resistant epilepsy. We hypothesize that highly connected hubs identified non-invasively with source imaging can predict the epileptogenic zone and the surgical outcome better than spikes localized with conventional source localization methods (dipoles). We retrospectively analysed simultaneous high-density electroencephalography (EEG) and magnetoencephalography data recorded from 37 children and young adults with drug-resistant epilepsy who underwent neurosurgery. Using source imaging, we estimated virtual sensors at locations where intracranial EEG contacts were placed. On data with and without spikes, we computed undirected functional connectivity between sensors/contacts using amplitude envelope correlation and phase locking value for physiologically relevant frequency bands. From each functional connectivity matrix, we generated an undirected network containing the strongest connections within sensors/contacts using the minimum spanning tree. For each sensor/contact, we computed graph centrality measures. We compared functional connectivity and their derived graph centrality of sensors/contacts inside resection for good (n = 22, ILAE I) and poor (n = 15, ILAE II-VI) outcome patients, tested their ability to predict the epileptogenic zone in good-outcome patients, examined the association between highly connected hubs removal and surgical outcome and performed leave-one-out cross-validation to support their prognostic value. We also compared the predictive values of functional connectivity with those of dipoles. Finally, we tested the reliability of virtual sensor measures via Spearman's correlation with intracranial EEG at population- and patient-level. We observed higher functional connectivity inside than outside resection (P < 0.05, Wilcoxon signed-rank test) for good-outcome patients, on data with and without spikes across different bands for intracranial EEG and electric/magnetic source imaging and few differences for poor-outcome patients. These functional connectivity measures were predictive of both the epileptogenic zone and outcome (positive and negative predictive values ≥55%, validated using leave-one-out cross-validation) outperforming dipoles on spikes. Significant correlations were found between source imaging and intracranial EEG measures (0.4 ≤ rho ≤ 0.9, P < 0.05). Our findings suggest that virtual implantation of sensors through source imaging can non-invasively identify highly connected hubs in patients with drug-resistant epilepsy, even in the absence of frank epileptiform activity. Surgical resection of these hubs predicts outcome better than dipoles.

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.

Clinical, radiological and electrophysiological predictors for drug-resistant epilepsy

Background

Epilepsy is the third chronic brain illness worldwide. About a third of the epileptic patients will be drug resistant. Early identification of these patients is critical for appropriate treatment selection and prevention of the devastating consequences of recurrent seizures. The objective of this study aims to detect clinical, electrophysiological, and radiological predictors for drug-resistant epilepsy patients.

Results

One hundred fifty-five patients were included in this study, divided into a well-controlled epilepsy group (103 patients) and a drug-resistant group (52 patients). Both groups were compared regarding clinical, electrophysiological, and neuro-radiological data. Younger age at onset, history of delayed milestones, history of perinatal insult (especially hypoxia), mental retardation, neurological deficits, depression, status epilepticus (SE), complex febrile seizures, focal seizure to bilateral tonic–clonic convulsion as well as multiple seizures and high seizure frequency (daily) at onset, poor response to first anti-seizure drug (ASD), structural and metabolic etiology, abnormal brain imaging, and slow background and multifocal epileptiform discharges in EEG were significant risk factors for the development of drug-resistant epilepsy.

Conclusion

MRI abnormalities are the most significant predictor for drug-resistant epilepsy. Drug-resistant epilepsy is associated with clinical, electrophysiological, and radiological risk factors that can be used to diagnose drug-resistant patients early and choose the best treatment option and time.

Association of SCN1A Gene Polymorphism with Phenytoin Response in Patients with Epilepsy: Relevance of Stratification by the History of Febrile Seizure

AIM: The SCN1A gene encodes the NaV1.1 sodium channel in the central nervous system that serves as the target for phenytoin. Our study aimed to investigate the association of SCN1A polymorphism (SNP rs3812718) with phenytoin response. MATERIALS AND METHODS: A total of 120 epileptic patients who had received phenytoin for at least 1 year were enrolled in the study and genotyped using the TaqMan assay. They were classified into phenytoin-responsive (n = 62) and phenytoin unresponsive groups (n = 58). Patients were also stratified according to the history of febrile seizure (24 in the febrile seizure subgroup; 96 patients in the no history of febrile seizure subgroup) and epilepsy etiology (47 in idiopathic; 73 in the symptomatic + cryptogenic subgroup). RESULTS: The frequency of AA (19% vs. 11.3%) and AG genotypes (43.1% vs. 40.3%) was found to be more frequent in phenytoin unresponsive. GG genotypes dominated in the phenytoin responsive group (37.9% vs. 48.4%) but were not statistically significant (p > 0.05). We identified two variables associated with phenytoin response: the etiology of epilepsy (p = 0.012) and history of febrile seizure (0.014). A significant positive association between the rs3812718 genotype and phenytoin response was found when patients were stratified by a history of febrile seizures. In patients without a history of febrile seizures, the AA genotype had a higher risk of phenytoin unresponsiveness than the GG genotype (p = 0.048; OR 3.73, 95% CI: 1.01–13.78). CONCLUSION: There was no significant association between the rs3812718 polymorphism and phenytoin responsiveness in patients with epilepsy. In the patients without a history of febrile seizure subgroup, AA increased the risk of phenytoin unresponsiveness compared to the GG genotype.

The Role of Ketogenic Diet in the Treatment of Neurological Diseases

Over a hundred years of study on the favourable effect of ketogenic diets in the treatment of epilepsy have contributed to a long-lasting discussion on its potential influence on other neurological diseases. A significant increase in the number of scientific studies in that field has been currently observed. The aim of this paper is a widespread, thorough analysis of the available scientific evidence in respect of the role of the ketogenic diet in the therapy of neurological diseases such as: epilepsy, Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS) and migraine. A wide range of the mechanisms of action of the ketogenic diet has been demonstrated in neurological diseases, including, among other effects, its influence on the reduction in inflammatory conditions and the amount of reactive oxygen species (ROS), the restoration of the myelin sheath of the neurons, the formation and regeneration of mitochondria, neuronal metabolism, the provision of an alternative source of energy for neurons (ketone bodies), the reduction in glucose and insulin concentrations, the reduction in amyloid plaques, the induction of autophagy, the alleviation of microglia activation, the reduction in excessive neuronal activation, the modulation of intestinal microbiota, the expression of genes, dopamine production and the increase in glutamine conversion into GABA. The studies discussed (including randomised controlled studies), conducted in neurological patients, have stressed the effectiveness of the ketogenic diet in the treatment of epilepsy and have demonstrated its promising therapeutic potential in Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS) and migraine. A frequent advantage of the diet was demonstrated over non-ketogenic diets (in the control groups) in the therapy of neurological diseases, with simultaneous safety and feasibility when conducting the nutritional model.

Potential clinical and biochemical markers for the prediction of drug-resistant epilepsy: A literature review

Drug resistance is a major challenge in the treatment of epilepsy. Drug-resistant epilepsy (DRE) accounts for 30% of all cases of epilepsy and is a matter of great concern because of its uncontrollability and the high burden, mortality rate, and degree of damage. At present, considerable research has focused on the development of predictors to aid in the early identification of DRE in an effort to promote prompt initiation of individualized treatment. While multiple predictors and risk factors have been identified, there are currently no standard predictors that can be used to guide the clinical management of DRE. In this review, we discuss several potential predictors of DRE and related factors that may become predictors in the future and perform evidence rating analysis to identify reliable potential predictors.

Exploring the genetic etiology of drug-resistant epilepsy: incorporation of exome sequencing into practice

BACKGROUND

By affecting about 50 million people worldwide, epilepsy is considered a global concern in neurology. Intolerable enough, up to ¼ of all patients do not respond to antiepileptic drugs and have recurring seizures. Therefore, revealing the underlying etiology is quite demanding in a clinical context to improve diagnosis and disease management.

METHODS

Initially, 85 patients suspected of epilepsy underwent thorough clinical and paraclinical evaluation and 24 individuals with drug-resistant epilepsy entered the study. Using whole-exome sequencing, the genetic etiology of drug-resistant epilepsy was investigated and discerned whether this method could facilitate the management of drug-resistant epilepsy through personalized medicine. Eventually, functional annotation was performed and drug-gene interaction networks were constructed to find potential therapeutic targets.

RESULTS

We found eleven novel variants in various genes including IRF2BPL, ST3GAL3, and GPAA1, for which a few epilepsy-related variants are available in public databases. The overall diagnostic yield for likely pathogenic and pathogenic variants and the detection rate of novel variants were 25% and 84.6%, respectively. Based on the results, two patients were considered potential candidates for personalized medicine. The highest number of interaction with drugs was demonstrated for SCN1A, SCN2A, and GRIN2A genes.

CONCLUSIONS

This study highlighted the importance of consanguineous marriage in drug-resistant epilepsy and suggested the possibility of reduced penetrance and variable expressivity in some of the autosomal dominant cases. We also suggest that whole-exome sequencing could facilitate personalized management of drug-resistant epilepsy. Regarding drug-gene interactions, some genes such as SCN1A and SCN2A might serve as therapeutic targets in drug-resistant epilepsy.

Fruits for Seizures? A Systematic Review on the Potential Anti-Convulsant Effects of Fruits and their Phytochemicals

Epilepsy is a devastating neurological disorder. Current anti-convulsant drugs are only effective in about 70% of patients, while the rest remain drug-resistant. Thus, alternative methods have been explored to control seizures in these drug-resistant patients. One such method may be through the utilization of fruit phytochemicals. These phytochemicals have been reported to have beneficial properties such as anti-convulsant, anti-oxidant, and anti-inflammatory activities. However, some fruits may also elicit harmful effects. This review aims to summarize and elucidate the anti- or pro-convulsant effects of fruits used in relation to seizures in hopes of providing a good therapeutic reference to epileptic patients and their carers. Three databases, SCOPUS, ScienceDirect, and PubMed, were utilized for the literature search. Based on the PRISMA guidelines, a total of 40 articles were selected for critical appraisal in this review. Overall, the extracts and phytochemicals of fruits managed to effectively reduce seizure activities in various preclinical seizure models, acting mainly through the activation of the inhibitory neurotransmission and blocking the excitatory neurotransmission. Only star fruit has been identified as a pro-convulsant fruit due to its caramboxin and oxalate compounds. Future studies should focus more on utilizing these fruits as possible treatment strategies for epilepsy.

Perampanel as adjunctive therapy in drug resistant epilepsy in adolescents and children waiting for epilepsy surgery: A multicenter observational study in Thailand

PURPOSE

To evaluate the effectiveness and tolerability of perampanel (PER) in real-world settings in patients between 1 month and 18 years of age with drug resistant epilepsy (DRE) waiting for epilepsy surgery.

METHODS

In this multicenter study, patients between 1 month and 18 years of age with DRE treated with PER between January 2020 and June 2021 were selected. The study outcome was effectiveness of PER treatment reported as reduction in seizure frequency and seizure freedom rate. Effectiveness was assessed at 30, 60, 90, 120, 150 and 180 days after initiation of PER. Tolerability profiles were reported as adverse events according to the observations of the patients' family members and physician.

RESULTS

Eighty-five patients treated with PER were included in the study. The mean initial dose and mean maximum dose of adjunctive PER was 2 mg/day and 5.8 mg/day, respectively. The mean seizure frequency (rate/week) was 41.3, 25.4, 18.9, 14.3, 11.2, 11.1 and 8.9 seizures at baseline, 30, 60, 90, 120, 150 and 180 days, respectively; the reduction in the mean seizure frequency at all timepoints was significant compared at the baseline (p<0.001). At 180 days, ≥75% seizure reduction was seen in 64.9% (37/57) of the patients and seizure freedom was achieved in 36.8% (21/57). Drowsiness, ataxia, and behavioral changes were the common adverse events observed, and these improved after the dose of PER was reduced. No discontinuation of PER was required due to side effects or intolerance.

CONCLUSION

In real-world settings, PER is well tolerated and effective in seizure control in pediatric and adolescent patients with DRE.

Pharmacogenetic testing in pediatric neurology: a pragmatic study evaluating clinician and patient perceptions

Aim: To evaluate clinicians' and patients' perceptions of pharmacogenetic testing in a clinical setting. Materials & methods: This is a pragmatic mixed-method prospective observational study. Hospital pharmacists and neurologists participated in focus groups regarding pharmacogenetic testing; patients who received pharmacogenetic testing and their community pharmacists completed surveys to assess their perception of these tests. Results: Most study participants had a positive view of pharmacogenetic testing. Three major themes were identified from the focus groups: receptiveness to pharmacogenetic testing, pharmacogenetic test characteristics and integrating pharmacogenetic tests into practice. Conclusion: The views reported are encouraging for the eventual implementation of pharmacogenetics in practice. Local integration of these tests is an essential step to improve patient care through personalized medicine.

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.

Gene Therapy: Novel Approaches to Targeting Monogenic Epilepsies

Genetic epilepsies are a spectrum of disorders characterized by spontaneous and recurrent seizures that can arise from an array of inherited or de novo genetic variants and disrupt normal brain development or neuronal connectivity and function. Genetically determined epilepsies, many of which are due to monogenic pathogenic variants, can result in early mortality and may present in isolation or be accompanied by neurodevelopmental disability. Despite the availability of more than 20 antiseizure medications, many patients with epilepsy fail to achieve seizure control with current therapies. Patients with refractory epilepsy—particularly of childhood onset—experience increased risk for severe disability and premature death. Further, available medications inadequately address the comorbid developmental disability. The advent of next-generation gene sequencing has uncovered genetic etiologies and revolutionized diagnostic practices for many epilepsies. Advances in the field of gene therapy also present the opportunity to address the underlying mechanism of monogenic epilepsies, many of which have only recently been described due to advances in precision medicine and biology. To bring precision medicine and genetic therapies closer to clinical applications, experimental animal models are needed that replicate human disease and reflect the complexities of these disorders. Additionally, identifying and characterizing clinical phenotypes, natural disease course, and meaningful outcome measures from epileptic and neurodevelopmental perspectives are necessary to evaluate therapies in clinical studies. Here, we discuss the range of genetically determined epilepsies, the existing challenges to effective clinical management, and the potential role gene therapy may play in transforming treatment options available for these conditions.

The GABAergic System and Endocannabinoids in Epilepsy and Seizures: What Can We Expect from Plant Oils?

Seizures and epilepsy are some of the most common serious neurological disorders, with approximately 80% of patients living in developing/underdeveloped countries. However, about one in three patients do not respond to currently available pharmacological treatments, indicating the need for research into new anticonvulsant drugs (ACDs). The GABAergic system is the main inhibitory system of the brain and has a central role in seizures and the screening of new ACD candidates. It has been demonstrated that the action of agents on endocannabinoid receptors modulates the balance between excitatory and inhibitory neurotransmitters; however, studies on the anticonvulsant properties of endocannabinoids from plant oils are relatively scarce. The Amazon region is an important source of plant oils that can be used for the synthesis of new fatty acid amides, which are compounds analogous to endocannabinoids. The synthesis of such compounds represents an important approach for the development of new anticonvulsant therapies.

Current Principles in the Management of Drug-Resistant Epilepsy

Drug-resistant epilepsy is associated with poor health outcomes and increased economic burden. In the last three decades, various new antiseizure medications have been developed, but the proportion of people with drug-resistant epilepsy remains relatively unchanged. Developing strategies to address drug-resistant epilepsy is essential. Here, we define drug-resistant epilepsy and emphasize its relationship to the conceptualization of epilepsy as a symptom complex, delineate clinical risk factors, and characterize mechanisms based on current knowledge. We address the importance of ruling out pseudoresistance and consider the impact of nonadherence on determining whether an individual has drug-resistant epilepsy. We then review the principles of epilepsy drug therapy and briefly touch upon newly approved and experimental antiseizure medications.

Mechanism of cell death pathways in status epilepticus and related therapeutic agents

The most severe form of epilepsy, status epilepticus (SE), causes brain damage and results in the development of recurring seizures. Currently, the management of SE remains a clinical challenge because patients do not respond adequately to conventional treatments. Evidence suggests that neural cell death worsens the occurrence and progression of SE. The main forms of cell death are apoptosis, necroptosis, pyroptosis, and ferroptosis. Herein, these mechanisms of neuronal death in relation to SE and the alleviation of SE by potential modulators that target neuronal death have been reviewed. An understanding of these pathways and their possible roles in SE may assist in the development of SE therapies and in the discovery of new agents.

Estimation of seizure onset zone from ictal scalp EEG using independent component analysis in extratemporal lobe epilepsy

OBJECTIVE

The purpose of this study is to localize the seizure onset zone of patients suffering from drug-resistant epilepsy. During the last two decades, multiple studies proposed the use of Independent Component Analysis (ICA) to analyze ictal electroencephalogram (EEG) recordings. This study aims at evaluating ICA potential with quantitative measurements. In particular, we address the challenging step where the components extracted by ICA of an ictal nature must be selected.

APPROACH

We considered a cohort of 10 patients suffering from extratemporal lobe epilepsy who were rendered seizure-free after surgery. Different sets of pre-processing parameters were compared and component features were explored to help distinguish ictal components from others. Quantitative measurements were implemented to determine whether some of the components returned by ICA were located within the resection zone and thus likely to be ictal. Finally, an assistance to the component selection was proposed based on the implemented features.

MAIN RESULTS

For every seizure, at least one component returned by ICA was localized within the resection zone, with the optimal pre-processing parameters. Three features were found to distinguish components localized within the resection zone: the dispersion of their active brain sources, the ictal rhythm power and the contribution to the EEG variance. Using the implemented component selection assistance based on the features, the probability that the first proposed component yields an accurate estimation reaches 51.43% (without assistance: 24.74%). The accuracy reaches 80% when considering the best result within the first five components.

SIGNIFICANCE

This study confirms the utility of ICA for ictal EEG analysis in extratemporal lobe epilepsy, and suggests relevant features to analyze the components returned by ICA. A component selection assistance is proposed to guide clinicians in their choice for ictal components.

The American Society for Stereotactic and Functional Neurosurgery Position Statement on Laser Interstitial Thermal Therapy for the Treatment of Drug-Resistant Epilepsy

Magnetic resonance image-guided laser interstitial thermal therapy (MRgLITT) is a novel tool in the neurosurgical armamentarium for the management of drug-resistant epilepsy. Given the recent introduction of this technology, the American Society for Stereotactic and Functional Neurosurgery (ASSFN), which acts as the joint section representing the field of stereotactic and functional neurosurgery on behalf of the Congress of Neurological Surgeons and the American Association of Neurological Surgeons, provides here the expert consensus opinion on evidence-based best practices for the use and implementation of this treatment modality. Indications for treatment are outlined, consisting of failure to respond to, or intolerance of, at least 2 appropriately chosen medications at appropriate doses for disabling, localization-related epilepsy in the setting of well-defined epileptogenic foci, or critical pathways of seizure propagation accessible by MRgLITT. Applications of MRgLITT in mesial temporal lobe epilepsy and hypothalamic hamartoma, along with its contraindications in the treatment of epilepsy, are discussed based on current evidence. To put this position statement in perspective, we detail the evidence and authority on which this ASSFN position statement is based.

Different Prognostic Patterns in Epilepsies and Considerations About the Denotations of Atypical Patterns

Epilepsy is a dynamic and heterogeneous neurological disease, and in long-term studies on prognosis, classically 5 basic patterns (early remission, late remission, relapsing-remitting, worsening, and non-remitting) have been identified. The most frequent pattern was relapsing-remitting course, and factors such as the presence of genetic etiology, rare seizures at the beginning of epilepsy and the absence of psychiatric comorbid diseases were found to be related with this pattern as well as reaching 5 years of remission in the follow-ups. Anti-seizure drug resistance (ASD-R) and factors affecting the presence of this resistance (such as symptomatic etiology, abnormal electroencephalographic findings, having multiple seizure types together, status epilepticus and febrile seizure history) decrease the chance of remission, while idiopathic/genetic etiology, generalized epilepsy, and absence of comorbid diseases seem to be associated with achieving long-term remission. Apart from these basic course patterns, there are some patients with an "atypical prognosis" such as drug-resistant juvenile myoclonic epilepsy (JME), benign hippocampal sclerosis-related mesial temporal lobe epilepsy (HS-MTLE), and severe childhood epilepsy with centro-temporal spikes (CESTS), in which the pathophysiological mechanisms underlying these patterns have not been clarified despite the suggestions of various hypotheses. The presence of comorbid diseases such as hormonal factors (as in catamenial epilepsy), autoimmune processes, thyroid disorders and metabolic and psychiatric diseases may also cause an atypical prognostic pattern by affecting the course of the disease. In this review, our aim is to provide the clinician with an up-to-date and questioning perspective on the prognostic markers of epilepsy, by examining in detail some specific epilepsy syndromes that may show atypical prognosis as well as the general prognostic features of epilepsy.

Development and validation of a nomogram for the early prediction of drug resistance in children with epilepsy

BACKGROUND AND PURPOSE

This study aimed to effectively identify children with drug-resistant epilepsy (DRE) in the early stage of epilepsy, and take personalized interventions, to improve patients' prognosis, reduce serious comorbidity, and save social resources. Herein, we developed and validated a nomogram prediction model for children with DRE.

METHODS

The training set was patients with epilepsy who visited the Children's Hospital of Soochow University (Suzhou Industrial Park, Jiangsu Province, China) between January 2015 and December 2017. The independent risk factors for DRE were screened by univariate and multivariate logistic regression analyses using SPSS21 software. The nomogram was designed according to the regression coefficient. The nomogram was validated in the training and validation sets. Internal validation was conducted using bootstrapping analyses. We also externally validated this instrument in patients with epilepsy from the Children's Hospital of Soochow University (Gusu District, Jiangsu Province, China) and Yancheng Maternal and Child Health Hospital between January 2018 and December 2018. The nomogram's performance was assessed by concordance (C-index), calibration curves, as well as GiViTI calibration belts.

RESULTS

Multivariate logistic regression analysis of 679 children with epilepsy from the Children's Hospital of Soochow University (Suzhou Industrial Park, Jiangsu Province, China) showed that onset age<1, status epilepticus (SE), focal seizure, > 20 pre-treatment seizures, clear etiology (caused by genetic, structural, metabolic, or infectious), development and epileptic encephalopathy (DEE), and neurological abnormalities were all independent risk factors for DRE. The AUC of 0.92 for the training set compared to that of 0.91 for the validation set suggested a good discrimination ability of the prediction model. The C-index was 0.92 and 0.91 in the training and validation sets. Additionally, both good calibration curves and GiViTI calibration belts (P-value: 0.849 and 0.291, respectively) demonstrated that the predicted risks had strong consistency with the observed outcomes, suggesting that the prediction model in both groups was perfectly calibrated.

CONCLUSION

A nomogram prediction model for DRE was developed, with good discrimination and calibration in the training set and the validation set. Furthermore, the model demonstrated great accuracy, consistency, and prediction ability. Therefore, the nomogram prediction model can aid in the timely identification of DRE in children.

Early epilepsy surgery for non drug-resistant patients

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Absence of drug-resistance is predictor of better post-surgical outcome.

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Post-surgical outcome in non drug-resistant patients is favourable irrespective of both the localization of surgery and the histological diagnosis.

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Non drug-resistant patients who underwent epilepsy surgery are more likely to successfully discontinue ASMs.

The aim of epilepsy treatment is to achieve seizure freedom. Surgery is often still considered a late option when pharmacological treatments have failed and epilepsy has become drug-resistant.

We analyse the clinical features and surgical outcome in patients who underwent surgery without experiencing drug-resistance comparing with those observed in patients who became drug-resistant.

Two-hundred and fifty patients with symptomatic focal epilepsy (12.1% of patients who underwent surgery at the “Claudio Munari” Epilepsy Surgery Center) were selected on the basis of initial period of seizure freedom and followed-up for at least 12 months. Patients were divided into two groups: those who underwent surgery during the initial period of seizure freedom (n = 74), and those who underwent surgery after an initial seizure-free period followed by drug-resistance (n = 176).

Outcomes were significantly better in non-drug-resistant patients (p < 0.001), all of whom had Engel class Ia or Ic. In the drug-resistant group, 136 patients (77.3%) had class Ia or Ic. The median post-operative follow-up was respectively 75.0 and 84.0 months.

Epilepsy surgery is a successful treatment, especially for non-drug-resistant patients with focal epilepsy with structural etiology. The timing of surgery affects the outcomes, and “early” surgery should be preferred to prevent likely drug-resistance and to improve prognosis.

Abnormal functional connectivity profiles predict drug responsiveness in patients with temporal lobe epilepsy

OBJECTIVE

This work was undertaken to study the functional connectivity differences between non-seizure-free and seizure-free patients with temporal lobe epilepsy (TLE) and to identify imaging predictors for drug responsiveness in TLE.

METHODS

In this prospective study, 52 patients with TLE who presented undetermined antiseizure medication responsiveness and 55 demographically matched healthy controls were sequentially recruited from Xiangya Hospital. Functional magnetic resonance imaging data were acquired during a Chinese version of the verbal fluency task. The patients were followed up until the outcome could be classified. The subject groups were compared in terms of activation profile, task-residual functional connectivity (trFC), and generalized psychophysiological interaction (gPPI) analyses. Moreover, we extracted imaging characteristics for logistic regression and receiver operating characteristic evaluation.

RESULTS

With a mean follow-up of 1.1 years, we identified 27 non-seizure-free patients and 19 seizure-free patients in the final analyses. The Chinese character verbal fluency task successfully activated the language network and cognitive control network (CCN) and deactivated the default mode network (DMN). In the non-seizure-freedom group, the trFC between the hippocampus and bilateral brain networks was attenuated (p < .05, familywise error corrected). For the gPPI analysis, group differences were mainly located in the precuneus, middle frontal gyrus, and inferior parietal lobule (p < .001, uncorrected; k ≥ 10). The regression model presented high accuracy when predicting non-seizure-free patients (area under the curve = .879, 95% confidence interval = .761-.998).

SIGNIFICANCE

In patients with TLE who would not achieve seizure freedom with current antiseizure medications, the functional connectivity between the hippocampus and central nodes of the DMN, CCN, and language network was disrupted, leading to language decline. Independent of hippocampal sclerosis, abnormalities, especially the effective connectivity from the hippocampus to the DMN, were predictive biomarkers of drug responsiveness in patients with TLE.

Risk Factors for Drug Resistance in Epileptic Children with Age of Onset above Five Years: A Case-Control Study

Background

Children with epilepsy with onset above five years encompass distinct epidemiological and clinical characteristics that may have specific risk factors for resistance to antiseizure medications (ASMs). Studies on this age group are limited.

Purpose

To identify risk factors for drug resistance in children with epilepsy with the age of onset above five years.

Methods

A case-control study was conducted on children with epilepsy with the age of onset above five years visiting the Pediatric Neurology Clinic of Cipto Mangunkusumo and Mohammad Hoesin Hospital between September 2015 and August 2016. Cases consisted of drug-resistant children while control consisted of drug-responsive children according to 2010 ILAE classification. Risk factors studied include onset, number of seizures, illness duration before treatment, cause, seizure type, status epilepticus, initial and evolution of EEG, brain imaging, and initial treatment response.

Results

Thirty-two pairs of children were included in the study. After logistic regression analysis, symptomatic etiology and failure to achieve early response to treatment were found to be associated with drug resistance with adjusted OR of 84.71 (95% CI: 5.18-1359.15) and 72.55 (95% CI: 7.08-743.85), respectively.

Conclusion

Poor initial response to ASM and symptomatic etiology are independent risk factors for drug resistance in children with epilepsy with the age of onset above five years.

Clinical findings, etiological factors, and prognosis markers in status epilepticus: a university hospital experience

OBJECTIVE

To determine the factors affecting mortality and disability in status epilepticus (SE) and to evaluate the prediction ability of the Status Epilepticus Severity Score (STESS) for disability and mortality.

MATERIALS AND METHOD

The demographic and clinical characteristics, prognosis and prognosis predictors of 72 patients who were diagnosed with SE between 2013 and 2018 were retrospectively evaluated. The STESS was used to predict prognosis, and the modified Rankin scale (mRS) was used to determine the disability at discharge.

RESULTS

The study population had a mean age of 45.4 ± 20.7, and it was found that mortality was 22.2% and acute symptomatic etiology played a 54.1% role in etiology. Advanced age, refractory SE or super-refractory SE, acute symptomatic etiology, and a history of epilepsy were related to mortality, symptomatic etiology (acute, progressive, remote), a history of hospitalization and epilepsy in intensive care or in other departments other than the neurology department were associated with disability. The sensitivity of STESS in predicting mortality was 100%, specificity was 69%, accuracy was 76.4%, positive predictive value (PPV) was 48.5%, and the negative predictive value (NPV) was 100%. The sensitivity of STESS in predicting mobilization during discharge was 55.6% with a 63.9% specificity and 59.7% accuracy, PPV was 60.6%, and NPV was 59%.

CONCLUSION

It was observed that STESS strongly predicts a good prognosis; however, it was not found to be useful in predicting motor disability during discharge. Thus, new studies should be conducted to predict and evaluate mobility in SE patients at discharge.

Safety and Efficacy of Natalizumab as Adjunctive Therapy for People With Drug-Resistant Epilepsy: A Phase 2 Study

BACKGROUND AND OBJECTIVES

To explore efficacy/safety of natalizumab, a humanized monoclonal anti-α4-integrin antibody, as adjunctive therapy in adults with drug-resistant focal epilepsy.

METHODS

Participants with ≥6 seizures during the 6-week baseline period were randomized 1:1 to receive natalizumab 300 mg IV or placebo every 4 weeks for 24 weeks. Primary efficacy outcome was change from baseline in log-transformed seizure frequency, with a predefined threshold for therapeutic success of 31% relative reduction in seizure frequency over the placebo group. Countable seizure types were focal aware with motor signs, focal impaired awareness, and focal to bilateral tonic-clonic. Secondary efficacy endpoints/safety were also assessed.

RESULTS

Of 32 and 34 participants dosed in the natalizumab 300 mg and placebo groups, 30 (94%) and 31 (91%) completed the placebo-controlled treatment period, respectively (one participant was randomized to receive natalizumab but not dosed due to IV complications). Estimated relative change in seizure frequency of natalizumab over placebo was -14.4% (95% confidence interval [CI] -46.1%-36.1%; p = 0.51). The proportion of participants with ≥50% reduction from baseline in seizure frequency was 31.3% for natalizumab and 17.6% for placebo (odds ratio 2.09, 95% CI 0.64-6.85; p = 0.22). Adverse events were reported in 24 (75%) and 22 (65%) participants receiving natalizumab vs placebo.

DISCUSSION

Although the threshold to demonstrate efficacy was not met, there were no unexpected safety findings and further exploration of possible anti-inflammatory therapies for drug-resistant epilepsy is warranted.

TRIAL REGISTRATION INFORMATION

The ClinicalTrials.gov registration number is NCT03283371.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that IV natalizumab every 4 weeks, compared to placebo, did not significantly change seizure frequency in adults with drug-resistant epilepsy. The study lacked the precision to exclude an important effect of natalizumab.

The Relationship between Hair Zinc Levels and Drug-resistant Epilepsy in Children at Sanglah Hospital

BACKGROUND: Drug-resistant epilepsy (DRE) is epilepsy that is failed to achieve free of seizure after adequate trials of two tolerated and appropriately chosen antiepileptic drugs. Zinc deficiency could trigger the onset of various neurological disorders, including seizures in epilepsy. AIM: The objective of the study was to determine the relationship between hair zinc levels and DRE in children at Sanglah Hospital, Denpasar. METHODS: This is an analytic observational study using a cross-sectional design, involving 74 subjects. The inclusion criteria were children aged 1 month–18 years who had been diagnosed with epilepsy. Chi-square test and multivariate analysis with logistic regression were used to assess the relation between hair zinc levels and DRE in children. RESULTS: Multivariate analysis found a relationship between low hair zinc level and DRE in children (PR 8.0; 95% CI 2.0–32.2; p = 0.003). The duration of therapy (PR 16.0; 95% CI 3.9–65.4; p = 0.000) and structural abnormalities (PR 4.1; 95% CI 1.1–14.9; p = 0.028) also increased the risk of DRE in this study. CONCLUSION: Low hair zinc level is associated with DRE in children.

Epilepsy and Deep Brain Stimulation of Anterior Thalamic Nucleus

Presently, at least 60 million people are suffering from epilepsy worldwide. Although multiple pharmacological options for treatment exist, about 30% to 40% of these patients are estimated to have drug-resistant epilepsy (DRE), which is associated with severe disability and morbidity. The surgical treatment options are restricted to either open surgical procedures or laser ablations. When a resective option is not favorable, then neuromodulation options such as vagal nerve stimulation and deep brain stimulation are considered. A relatively recent and more commonly used clinical application is the deep brain stimulation (DBS) of the anterior thalamic nucleus, FDA approval for which was obtained in 2018. Furthermore, new technological advances in DBS technology are expected to positively impact the treatment options of these patients.