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1.
Further evidence of affected females with a heterozygous variant in FGF13 causing X-linked developmental and epileptic encephalopathy 90.
Narayanan, DL, Majethia, P, Shrikiran, A, Siddiqui, S, Dalal, A, Shukla, A
European journal of medical genetics. 2022;(1):104403
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Abstract
Developmental and epileptic encephalopathies (DEE) are a genetically heterogeneous group of disorders characterised by early onset epilepsy, epileptiform activity on electroencephalogram and associated developmental delay or neuroregression. With the advent of high throughput sequencing, novel gene-disease associations have been described for DEEs. Voltage activated sodium channels (Nav) regulate neuronal excitability. Fibroblast growth factor homologous factors (FHFs) are proteins, which bind to the C terminal cytoplasmic tails of alpha subunits of Nav channels and influence their function and surface expression. Gain of function hemizygous or heterozygous variants in FGF13 (also known as FHF2) were recently identified as the cause for X-linked developmental and epileptic encephalopathy 90 (DEE90; MIM# 301058) in seven individuals from five families, which included one female. We report an additional female, providing further evidence for a novel de novo heterozygous missense variant in FGF13, NM_004114.5: c.14T > G p.(Ile5Ser) causing X-linked DEE90. In addition, we review the genotype and phenotype of affected individuals with DEE90.
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Evaluation of diazepam nasal spray in patients with epilepsy concomitantly using maintenance benzodiazepines: An interim subgroup analysis from a phase 3, long-term, open-label safety study.
Segal, EB, Tarquinio, D, Miller, I, Wheless, JW, Dlugos, D, Biton, V, Cascino, GD, Desai, J, Hogan, RE, Liow, K, et al
Epilepsia. 2021;(6):1442-1450
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Abstract
OBJECTIVE Diazepam nasal spray (Valtoco), indicated for acute treatment of frequent seizure activity (seizure clusters) in patients with epilepsy ≥6 years of age, is designed to be a rapid, noninvasive, socially acceptable route of administration. This interim analysis evaluated the safety profile of diazepam nasal spray in patients with and without concomitant use of benzodiazepines, with use of a second dose for a seizure cluster as a proxy for effectiveness. METHODS A long-term, phase 3, open-label safety study enrolled patients with epilepsy who had seizures despite a stable antiseizure medication regimen. RESULTS Among 175 patients enrolled by October 31, 2019, a total of 158 were treated with diazepam nasal spray (aged 6-65 years; 53.8% female). Of those, 119 (75.3%) received concomitant benzodiazepines (60, chronic; 59, intermittent); 39 (24.7%) did not. Use of a second dose was similar in patients using chronic concomitant benzodiazepines (second dose in 11.1% [144/1299]) and those with no concomitant benzodiazepines (second dose in 10.3% [41/398]). Treatment emergent adverse events (TEAEs) occurred for 80.0% with chronic use of concomitant benzodiazepines and 61.5% without. Cardiorespiratory depression was not reported, and no serious TEAEs were treatment related. Study retention was high: 83.3% in the chronic benzodiazepine group and 76.9% in the no-benzodiazepine group. Findings were similar in a sub-analysis of patients who were (n = 44) or were not (n = 75) taking clobazam. SIGNIFICANCE This analysis of patients from a long-term study shows a similar safety profile of diazepam nasal spray in patients with and without concomitant benzodiazepines, and consistent with the established profile for diazepam. Use of a single dose of diazepam nasal spray and high study retention rates suggest the effectiveness of diazepam nasal spray in patients irrespective of chronic daily benzodiazepine use. Results were similar in the clobazam sub-analysis. These results support the safety and effectiveness of diazepam nasal spray in patients with concomitant benzodiazepine use.
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Reviving mitochondrial bioenergetics: A relevant approach in epilepsy.
Singh, S, Singh, TG, Rehni, AK, Sharma, V, Singh, M, Kaur, R
Mitochondrion. 2021;:213-226
Abstract
Epileptogenesis is most commonly associated with neurodegeneration and a bioenergetic defect attributing to the fact that mitochondrial dysfunction plays a key precursor for neuronal death. Mitochondria are the essential organelle of neuronal cells necessary for certain neurophysiological processes like neuronal action potential activity and synaptic transmission. The mitochondrial dysfunction disrupts calcium homeostasis leading to inhibitory interneuron dysfunction and increasing the excitatory postsynaptic potential. In epilepsy, the prolonged repetitive neuronal activity increases the excessive demand for energy and acidosis in the brain further increasing the intracellular calcium causing neuronal death. Similarly, the mitochondrial damage also leads to the decline of energy by dysfunction of the electron transport chain and abnormal production of the ROS triggering the apoptotic neuronal death. Thus, the elevated level of cytosolic calcium causes the mitochondria DNA damage coinciding with mtROS and releasing the cytochrome c binding to Apaf protein further initiating the apoptosis resulting in epileptic encephalopathies. The various genetic and mRNA studies of epilepsy have explored the various pathogenic mutations of genes affecting the mitochondria functioning further initiating the neuronal excitotoxicity. Based on the results of previous studies, the recent therapeutic approaches are targeting basic mitochondrial processes, such as energy metabolism or free-radical generation, or specific interactions of disease-related proteins with mitochondria and hold great promise to attenuate epileptogenesis. Therefore, the current review emphasizes the emerging insights to uncover the relation between mitochondrial dysfunction and ROS generation contributing to mechanisms underlying epileptic seizures.
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Symptomatology of carbamazepine- and oxcarbazepine-induced hyponatremia in people with epilepsy.
Berghuis, B, Hulst, J, Sonsma, A, McCormack, M, de Haan, GJ, Sander, JW, Lindhout, D, Koeleman, BPC
Epilepsia. 2021;(3):778-784
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Abstract
OBJECTIVE To ascertain whether adverse effects experienced by people taking carbamazepine or oxcarbazepine could be attributed to carbamazepine- or oxcarbazepine-induced hyponatremia (COIH). METHODS We performed an observational study, collecting data between 2017 and 2019 on serum sodium levels and adverse effects retrospectively in people with epilepsy while receiving treatment with either carbamazepine (CBZ) or oxcarbazepine (OXC). We defined hyponatremia as sodium level ≤134 mEq/L and severe hyponatremia as sodium level ≤128 mEq/L. Adverse effects experienced were compared between groups of individuals with and without hyponatremia. RESULTS A total of 1370 people using CBZ or OXC were identified, of whom 410 had at least one episode of hyponatremia. We checked for symptoms related to the use of CBZ and OXC in 710 people (410 with and 300 without hyponatremia) and found relevant information in 688. Adverse effects occurred in 65% of people with hyponatremia compared to 21% with normal sodium levels (odds ratio [OR] 7.5, P ≤ .001) and in 83% of people with severe hyponatremia compared to 55% in those with mild hyponatremia (P ≤ .001). Significant predictors of adverse effects were the drug (OXC vs CBZ), and the number of concomitant anti-seizure medications. Dizziness (28% vs 6%), tiredness (22% vs 7%), instability (19% vs 3%), and diplopia (16% vs 4%) were reported more often in the hyponatremia group than in patients with normal levels. SIGNIFICANCE People with COIH had a 7-fold increased risk of developing adverse effects during treatment. Clinicians should consider ascertainment of sodium levels in patients taking CBZ and OXC and act upon findings.
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The initial impact of the SARS-CoV-2 pandemic on epilepsy research.
Volkers, N, Wiebe, S, Asadi-Pooya, AA, Balagura, G, Gómez-Iglesias, P, Guekht, A, Hall, J, Ikeda, A, Jetté, N, Kishk, NA, et al
Epilepsia open. 2021;(2):255-265
Abstract
The COVID-19 pandemic has changed the face of many practices throughout the world. Through necessity to minimize spread and provide clinical care to those with severe disease, focus has been on limiting face-to-face contact. Research in many areas has been put on hold. We sought to determine the impact of the COVID-19 pandemic on epilepsy research from international basic science and clinical researchers. Responses to five questions were solicited through a convenience sample by direct email and through postings on the ILAE social media accounts and an ILAE online platform (utilizing Slack). Information was collected from 15 respondents in 11 countries by email or via Zoom interviews between May 19, 2020, and June 4, 2020. Several themes emerged including a move to virtual working, project delays with laboratory work halted and clinical work reduced, funding concerns, a worry about false data with regard to COVID research and concern about research time lost. However, a number of positive outcomes were highlighted, not least the efficiency of online working and other adaptations that could be sustained in the future.
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KCNT1-related epilepsies and epileptic encephalopathies: phenotypic and mutational spectrum.
Bonardi, CM, Heyne, HO, Fiannacca, M, Fitzgerald, MP, Gardella, E, Gunning, B, Olofsson, K, Lesca, G, Verbeek, N, Stamberger, H, et al
Brain : a journal of neurology. 2021;(12):3635-3650
Abstract
Variants in KCNT1, encoding a sodium-gated potassium channel (subfamily T member 1), have been associated with a spectrum of epilepsies and neurodevelopmental disorders. These range from familial autosomal dominant or sporadic sleep-related hypermotor epilepsy to epilepsy of infancy with migrating focal seizures (EIMFS) and include developmental and epileptic encephalopathies. This study aims to provide a comprehensive overview of the phenotypic and genotypic spectrum of KCNT1 mutation-related epileptic disorders in 248 individuals, including 66 previously unpublished and 182 published cases, the largest cohort reported so far. Four phenotypic groups emerged from our analysis: (i) EIMFS (152 individuals, 33 previously unpublished); (ii) developmental and epileptic encephalopathies other than EIMFS (non-EIMFS developmental and epileptic encephalopathies) (37 individuals, 17 unpublished); (iii) autosomal dominant or sporadic sleep-related hypermotor epilepsy (53 patients, 14 unpublished); and (iv) other phenotypes (six individuals, two unpublished). In our cohort of 66 new cases, the most common phenotypic features were: (i) in EIMFS, heterogeneity of seizure types, including epileptic spasms, epilepsy improvement over time, no epilepsy-related deaths; (ii) in non-EIMFS developmental and epileptic encephalopathies, possible onset with West syndrome, occurrence of atypical absences, possible evolution to developmental and epileptic encephalopathies with sleep-related hypermotor epilepsy features; one case of sudden unexplained death in epilepsy; (iii) in autosomal dominant or sporadic sleep-related hypermotor epilepsy, we observed a high prevalence of drug-resistance, although seizure frequency improved with age in some individuals, appearance of cognitive regression after seizure onset in all patients, no reported severe psychiatric disorders, although behavioural/psychiatric comorbidities were reported in ∼50% of the patients, sudden unexplained death in epilepsy in one individual; and (iv) other phenotypes in individuals with mutation of KCNT1 included temporal lobe epilepsy, and epilepsy with tonic-clonic seizures and cognitive regression. Genotypic analysis of the whole cohort of 248 individuals showed only missense mutations and one inframe deletion in KCNT1. Although the KCNT1 mutations in affected individuals were seen to be distributed among the different domains of the KCNT1 protein, genotype-phenotype considerations showed many of the autosomal dominant or sporadic sleep-related hypermotor epilepsy-associated mutations to be clustered around the RCK2 domain in the C terminus, distal to the NADP domain. Mutations associated with EIMFS/non-EIMFS developmental and epileptic encephalopathies did not show a particular pattern of distribution in the KCNT1 protein. Recurrent KCNT1 mutations were seen to be associated with both severe and less severe phenotypes. Our study further defines and broadens the phenotypic and genotypic spectrums of KCNT1-related epileptic conditions and emphasizes the increasingly important role of this gene in the pathogenesis of early onset developmental and epileptic encephalopathies as well as of focal epilepsies, namely autosomal dominant or sporadic sleep-related hypermotor epilepsy.
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The effect of sodium channels on neurological/neuronal disorders: A systematic review.
Bagheri, S, Haddadi, R, Saki, S, Kourosh-Arami, M, Komaki, A
International journal of developmental neuroscience : the official journal of the International Society for Developmental Neuroscience. 2021;(8):669-685
Abstract
Neurological and neuronal disorders are associated with structural, biochemical, or electrical abnormalities in the nervous system. Many neurological diseases have not yet been discovered. Interventions used for the treatment of these disorders include avoidance measures, lifestyle changes, physiotherapy, neurorehabilitation, pain management, medication, and surgery. In the sodium channelopathies, alterations in the structure, expression, and function of voltage-gated sodium channels (VGSCs) are considered as the causes of neurological and neuronal diseases. Online databases, including Scopus, Science Direct, Google Scholar, and PubMed were assessed for studies published between 1977 and 2020 using the keywords of review, sodium channels blocker, neurological diseases, and neuronal diseases. VGSCs consist of one α subunit and two β subunits. These subunits are known to regulate the gating kinetics, functional characteristics, and localization of the ion channel. These channels are involved in cell migration, cellular connections, neuronal pathfinding, and neurite outgrowth. Through the VGSC, the action potential is triggered and propagated in the neurons. Action potentials are physiological functions and passage of impermeable ions. The electrophysiological properties of these channels and their relationship with neurological and neuronal disorders have been identified. Subunit mutations are involved in the development of diseases, such as epilepsy, multiple sclerosis, autism, and Alzheimer's disease. Accordingly, we conducted a review of the link between VGSCs and neurological and neuronal diseases. Also, novel therapeutic targets were introduced for future drug discoveries.
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Clinical trials of vitamin-mineral supplementations in people with epilepsy: A systematic review.
Asadi-Pooya, AA, Simani, L
Clinical nutrition (Edinburgh, Scotland). 2021;(5):3045-3051
Abstract
OBJECTIVE The purpose of the current study was to systematically review the literature on the clinical trials of vitamin-mineral supplementations in people with epilepsy (PWE) to treat their seizures. METHODS MEDLINE and Scopus from inception to August 25, 2020 were searched for related published manuscripts. The search keywords included "vitamin or folate or folic acid or biotin or thiamine or carnitine or zinc or manganese or selenium or omega-3 fatty acid or linoleic acid or micronutrient or trace element or supplementation" AND "epilepsy or seizure". RESULTS We could identify 26 related articles. Seventeen studies provided class 2 of evidence and the rest provided class 3 of evidence. Eight studies investigated polyunsaturated fats, seven groups studied folic acid, four studies explored the effects of vitamin D, two investigated vitamin E, and three others studied multivitamin cocktails. There was one study on zinc and one on selenium. There is some evidence on the efficacy of polyunsaturated fats in treating seizures in PWE. The evidence on the efficacy of multivitamin cocktails in adults is promising. CONCLUSION High quality data on the efficacy of nutritional (vitamins-minerals) supplementations in treating seizures in PWE is scarce; however, designing future clinical trials of polyunsaturated fatty acid supplementation for drug-resistant seizures in adults with focal epilepsy and in children, and also multivitamin supplementations in adults with focal epilepsy seems reasonable and promising. Such clinical trials should be well-designed, randomized, and placebo controlled, with enough sample size and adequate follow-up of 12 months or more.
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Genetic potassium channel-associated epilepsies: Clinical review of the Kv family.
Allen, NM, Weckhuysen, S, Gorman, K, King, MD, Lerche, H
European journal of paediatric neurology : EJPN : official journal of the European Paediatric Neurology Society. 2020;:105-116
Abstract
Next-generation sequencing has enhanced discovery of many disease-associated genes in previously unexplained epilepsies, mainly in developmental and epileptic encephalopathies and familial epilepsies. We now classify these disorders according to the underlying molecular pathways, which encompass a diverse array of cellular and sub-cellular compartments/signalling processes including voltage-gated ion-channel defects. With the aim to develop and increase the use of precision medicine therapies, understanding the pathogenic mechanisms and consequences of disease-causing variants has gained major relevance in clinical care. The super-family of voltage-gated potassium channels is the largest and most diverse family among the ion channels, encompassing approximately 80 genes. Key potassium channelopathies include those affecting the KV, KCa and Kir families, a significant proportion of which have been implicated in neurological disease. As for other ion channel disorders, different pathogenic variants within any individual voltage-gated potassium channel gene tend to affect channel protein function differently, causing heterogeneous clinical phenotypes. The focus of this review is to summarise recent clinical developments regarding the key voltage-gated potassium (KV) family-related epilepsies, which now encompasses approximately 12 established disease-associated genes, from the KCNA-, KCNB-, KCNC-, KCND-, KCNV-, KCNQ- and KCNH-subfamilies.
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Families' Perception of Classic Ketogenic Diet Management in Acute Medical Conditions: A Web-Based Survey.
Pasca, L, Varesio, C, Ferraris, C, Guglielmetti, M, Trentani, C, Tagliabue, A, Veggiotti, P, De Giorgis, V
Nutrients. 2020;(10)
Abstract
Objective: To describe families' experiences in managing epileptic patients undergoing ketogenic dietary therapies (KDTs) in acute medical settings. Methods: We conducted a short online survey addressed to the families of patients undergoing a classic ketogenic diet (cKD) for at least three months. The survey was composed of 18 questions exploring the following issues: demographic characteristics, epilepsy diagnosis, ketogenic-diet treatment history, the reason for emergency-ward admission and patient management, surgery-procedure management, and outcomes. Results: A sample of 50 families agreed to participate. Out of 50 patients, 33 (66%) had been undergoing a cKD for more than two years. Fifteen (30%) patients had been admitted at least once to the Emergency Room (ER), and 8.2% had undergone surgical procedures during cKD treatment. The causes of ER admission were the following: seizures, infection, trauma, and gastrointestinal or respiratory problems. In 75% of cases, blood ketonemia was not monitored during ER admission, and according to 46% of responders, the medical staff intervening did not have a basic knowledge of KDTs. Conclusions: According to both our experience and caregivers' reports, it might be useful to search for standardized specific approaches to patients undergoing KDTs in the emergency setting.