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1.
PLoS Negl Trop Dis ; 18(9): e0012470, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39241094

ABSTRACT

INTRODUCTION: Epidemiological evidence suggests that Onchocerca volvulus is associated with epilepsy, although the exact pathophysiological mechanism is unknown. Mahenge is an endemic focus of onchocerciasis, with the longest-running ivermectin treatment intervention in Tanzania. We assessed the prevalence of onchocerciasis and epilepsy after 25 years of control using ivermectin. METHODS: This was a population-based cross-sectional study in 34 villages in Mahenge in 2021. Community health workers conducted door-to-door household surveys to enumerate the population and screen for individuals suspected of epilepsy using a standardised questionnaire. Trained physicians confirmed epilepsy. Children aged 6-11 years were screened for onchocerciasis antibodies using the Ov16 rapid test. Villages were stratified into three altitude levels (low [<400], medium [400-950], and high [>950 meters above sea level]) as a proxy for rapids, which black flies favour for breeding sites. Incidence of epilepsy was estimated as a ratio of new cases in the year preceding the survey per 100,000 population. RESULTS: 56,604 individuals (median age 20.2 years, 51.1% females) were surveyed. Onchocerciasis prevalence in children was 11.8% and was highest in villages at medium (21.7%) and lowest in low altitudes (3.2%), p<0.001. Self-reported use of ivermectin was 88.4%. Epilepsy prevalence was 21.1 (95%CI: 19.9-22.3) cases per 1000 persons and was highest in medium (29.5%) and lowest in the lowlands (12.7%). The odds ratio (OR) of having epilepsy was significantly higher in females (OR = 1.22, 95%CI: 1.08-1.38), middle altitudes (OR = 2.34 [95%CI: 2.04-2.68]), and in individuals positive for OV16 (OR = 1.98 [95%CI:1.57-2.50]). The incidence of epilepsy a year before the survey was 117 (95%CI: 99.7-160.4) cases per 100,000 person-years. CONCLUSION: Despite ivermectin use for 25 years, the prevalence of onchocerciasis and epilepsy remains high. It is crucial to strengthen bi-annual ivermectin treatment and initiate interventions targeting vectors to control onchocerciasis and epilepsy in the area.


Subject(s)
Epilepsy , Ivermectin , Onchocerciasis , Humans , Ivermectin/therapeutic use , Onchocerciasis/epidemiology , Onchocerciasis/drug therapy , Female , Male , Epilepsy/epidemiology , Epilepsy/drug therapy , Tanzania/epidemiology , Child , Cross-Sectional Studies , Prevalence , Adolescent , Adult , Young Adult , Animals , Child, Preschool , Onchocerca volvulus/drug effects , Middle Aged , Antiparasitic Agents/therapeutic use , Infant , Aged
2.
Epilepsia Open ; 2024 Sep 03.
Article in English | MEDLINE | ID: mdl-39225433

ABSTRACT

OBJECTIVE: To characterize the experience of people with epilepsy and aligned healthcare workers (HCWs) during the first 18 months of the COVID-19 pandemic and compare experiences in high-income countries (HICs) with non-HICs. METHODS: Separate surveys for people with epilepsy and HCWs were distributed online in April 2020. Responses were collected to September 2021. Data were collected for COVID-19 infections, the effect of COVID-related restrictions, access to specialist help for epilepsy (people with epilepsy), and the impact of the pandemic on work productivity (HCWs). The frequency of responses for non-HICs and HICs were compared using non-parametric Chi-square tests. RESULTS: Two thousand one hundred and  five individuals with epilepsy from 53 countries and 392 HCWs from 26 countries provided data. The same proportion of people with epilepsy in non-HICs and HICs reported COVID-19 infection (7%). Those in HICs were more likely to report that COVID-19 measures had affected their health (32% vs. 23%; p < 0.001). There was no difference between non-HICs and HICs in the proportion who reported difficulty in obtaining help for epilepsy. HCWs in non-HICs were more likely to report COVID-19 infection than those in HICs (18% vs 6%; p = 0.001) and that their clinical work had been affected by concerns about contracting COVID-19, lack of personal protective equipment, and the impact of the pandemic on mental health (all p < 0.001). Compared to pre-pandemic practices, there was a significant shift to remote consultations in both non-HICs and HICs (p < 0.001). SIGNIFICANCE: While the frequency of COVID-19 infection was relatively low in these data from early in the pandemic, our findings suggest broader health consequences and an increased psychosocial burden, particularly among HCWs in non-HICs. Planning for future pandemics should prioritize mental healthcare alongside ensuring access to essential epilepsy services and expanding and enhancing access to remote consultations. PLAIN LANGUAGE SUMMARY: We asked people with epilepsy about the effects of COVID-19 on their health and healthcare. We wanted to compare responses from people in high-income countries and other countries. We found that people in high-income countries and other countries had similar levels of difficulty in getting help for their epilepsy. People in high-income countries were more likely to say that their general health had been affected. Healthcare workers in non-high-income settings were more likely to have contracted COVID-19 and have the care they deliver affected by the pandemic. Across all settings, COVID-19 associated with a large shift to remote consultations.

4.
BMC Public Health ; 24(1): 2608, 2024 Sep 27.
Article in English | MEDLINE | ID: mdl-39333993

ABSTRACT

BACKGROUND: Epilepsy remains a significant public health concern in Tanzania, with affected individuals enduring stigma, whether through actions or perceptions. Myths, misunderstandings, and misconceptions about epilepsy have persisted due to a multitude of factors. Here, we assessed attitudes and perceptions toward epilepsy in Mahenge. METHODS: A cross-sectional study utilising a mixed-methods approach was undertaken in eight villages in the Ulanga district of Mahenge, integrating a semi-structured questionnaire and focus group discussions (FGDs). The questionnaire involved 778 community members, and 15 FGDs were conducted (seven groups with people with epilepsy and eight without). Descriptive statistics, chi-square, and logistic regression were used for quantitative analysis, while we used NVivo version 14 for thematic analysis of qualitative data. RESULTS: Of 778 participants, over half were women (425, 54.6%) with a median age of 41 years (IQR: 30-55) and most had completed primary education (79.9%). The majority of participants were aware of epilepsy (96.8%), yet they displayed low knowledge (51%), negative attitudes (45.5%), and perceptions (42.1%) towards the disorder. A low level of understanding was significantly associated with negative attitudes (Adjusted Odds Ratio [AOR] = 1.89, 95%CI: 1.41-2.53) and perceptions (AOR = 3.22, 95%CI: 2.05-5.04) towards epilepsy. In the qualitative analysis, often hereditary factors and infections were named as causes of epilepsy, along with misconceptions involving witchcraft and divine punishment. There was also a misconception about the contagiousness of epilepsy. Traditional healers were often the initial point of treatment. Epilepsy-related stigma was evident, with individuals with epilepsy facing derogatory labels, social isolation, and barriers to education. Lastly, there was a lack of understanding regarding a possible association between epilepsy and onchocerciasis. CONCLUSIONS: Despite high awareness of epilepsy, there is insufficient understanding, negative attitudes, and perceptions, including misconceptions and stigma about this neurologic condition. Community-based education programmes are essential for promoting proper healthcare-seeking behaviour and dispelling myths.


Subject(s)
Epilepsy , Focus Groups , Health Knowledge, Attitudes, Practice , Onchocerciasis , Humans , Tanzania/epidemiology , Epilepsy/psychology , Epilepsy/epidemiology , Female , Male , Adult , Cross-Sectional Studies , Middle Aged , Onchocerciasis/psychology , Onchocerciasis/epidemiology , Surveys and Questionnaires , Social Stigma , Young Adult , Endemic Diseases , Adolescent , Qualitative Research
5.
Epilepsia Open ; 2024 Aug 24.
Article in English | MEDLINE | ID: mdl-39180426

ABSTRACT

OBJECTIVE: Vagus nerve stimulation (VNS) Therapy is routinely indicated for people with drug-resistant epilepsy (DRE). We analyzed the baseline characteristics of individuals receiving the recently released VNS models and identified factors associated with early or late implantation. METHODS: The Comprehensive Outcomes Registry of subjects with Epilepsy (CORE-VNS), a prospective observational study evaluating the clinical and psychosocial outcomes of VNS Therapy®, is following participants for up to 60 months after VNS implantation. In this analysis, we used Cox proportional hazards model to identify baseline characteristics associated with the time from diagnosis to first implantation. RESULTS: Of the 819 enrolled, 792 (96.7%) participants implanted with a VNS device were evaluated. 529 (64.6%) underwent the first implantation and 263 (32.1%) a re-implantation. Participants' median age at first implant was 24 years; 492 (62.1%) were ≥18 years old and 166 (20.3%) were < 12 years old. The average number of failed ASMs prior to VNS implantation was 7.1, and 145 (17.7%) had undergone previous epilepsy-related surgery. Epilepsy was classified as focal in 47.7% of participants, generalized in 16.1% and combined focal and generalized in 34.2%. Many of the participants (40.9%) had epilepsy of unknown etiology. The median time from diagnosis to first implantation was 10.33 years and was significantly shorter in participants with combined focal and generalized epilepsy compared to those with focal epilepsy alone, and in participants with genetic and immune epilepsy compared to those with unknown etiologies. SIGNIFICANCE: In people with DRE, VNS Therapy is provided after multiple failures of ASMs and after failure of epilepsy surgery in one in six individuals. Time from diagnosis to first implantation is associated with epilepsy type and etiology, likely reflecting variable treatment pathways. Clearer guidelines on when and how non-drug therapies should be deployed in people with DRE related to different epilepsy factors are needed. PLAIN LANGUAGE SUMMARY: Neuromodulation can be a very helpful treatment in people who have seizures that do not respond to medications. The most widely utilized neuromodulation therapy is vagus nerve stimulation (VNS). We present data from a large, global study to show that people use an average of seven anti-seizure medications before attempting VNS Therapy and that it takes about 10 years for people to get their first VNS implant. We advocate for clearer treatment guidelines on how and when to consider VNS Therapy in people with seizures that are resistant to medication.

6.
Epilepsy Res ; 206: 107425, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39168079

ABSTRACT

OBJECTIVE: We retrospectively explored patients with drug-resistant epilepsy (DRE) who previously underwent presurgical evaluation to identify correlations between surgical outcomes and pathogenic variants in epilepsy genes. METHODS: Through an international collaboration, we evaluated adult DRE patients who were screened for surgical candidacy. Patients with pathogenic (P) or likely pathogenic (LP) germline variants in genes relevant to their epilepsy were included, regardless of whether the genetic diagnosis was made before or after the presurgical evaluation. Patients were divided into two groups: resective surgery (RS) and non-resective surgery candidates (NRSC), with the latter group further divided into: palliative surgery (vagus nerve stimulation, deep brain stimulation, responsive neurostimulation or corpus callosotomy) and no surgery. We compared surgical candidacy evaluations and postsurgical outcomes in patients with different genetic abnormalities. RESULTS: We identified 142 patients with P/LP variants. After presurgical evaluation, 36 patients underwent RS, while 106 patients were NRSC. Patients with variants in ion channel and synaptic transmission genes were more common in the NRSC group (48 %), compared with the RS group (14 %) (p<0.001). Most patients in the RS group had tuberous sclerosis complex. Almost half (17/36, 47 %) in the RS group had Engel class I or II outcomes. Patients with channelopathies were less likely to undergo a surgical procedure than patients with mTORopathies, but when deemed suitable for resection had better surgical outcomes (71 % versus 41 % with Engel I/II). Within the NRSC group, 40 underwent palliative surgery, with 26/40 (65 %) having ≥50 % seizure reduction after mean follow-up of 11 years. Favourable palliative surgery outcomes were observed across a diverse range of genetic epilepsies. SIGNIFICANCE: Genomic findings, including a channelopathy diagnosis, should not preclude presurgical evaluation or epilepsy surgery, and appropriately selected cases may have good surgical outcomes. Prospective registries of patients with monogenic epilepsies who undergo epilepsy surgery can provide additional insights on outcomes.


Subject(s)
Drug Resistant Epilepsy , Humans , Drug Resistant Epilepsy/genetics , Drug Resistant Epilepsy/surgery , Female , Male , Adult , Retrospective Studies , Treatment Outcome , Young Adult , Middle Aged , Germ-Line Mutation/genetics , Neurosurgical Procedures/methods , Genetic Variation/genetics , Adolescent
7.
Ann Clin Transl Neurol ; 11(7): 1897-1908, 2024 Jul.
Article in English | MEDLINE | ID: mdl-39012808

ABSTRACT

OBJECTIVE: Differentiating forms of autoimmune encephalitis (AE) from other causes of seizures helps expedite immunotherapies in AE patients and informs studies regarding their contrasting pathophysiology. We aimed to investigate whether and how Nuclear Magnetic Resonance (NMR)-based metabolomics could differentiate AE from drug-resistant epilepsy (DRE), and stratify AE subtypes. METHODS: This study recruited 238 patients: 162 with DRE and 76 AE, including 27 with contactin-associated protein-like 2 (CASPR2), 29 with leucine-rich glioma inactivated 1 (LGI1) and 20 with N-methyl-d-aspartate receptor (NMDAR) antibodies. Plasma samples across the groups were analyzed using NMR spectroscopy and compared with multivariate statistical techniques, such as orthogonal partial least squares discriminant analysis (OPLS-DA). RESULTS: The OPLS-DA model successfully distinguished AE from DRE patients with a high predictive accuracy of 87.0 ± 3.1% (87.9 ± 3.4% sensitivity and 86.3 ± 3.6% specificity). Further, pairwise OPLS-DA models were able to stratify the three AE subtypes. Plasma metabolomic signatures of AE included decreased high-density lipoprotein (HDL, -(CH2)n-, -CH3), phosphatidylcholine and albumin (lysyl moiety). AE subtype-specific metabolomic signatures were also observed, with increased lactate in CASPR2, increased lactate, glucose, and decreased unsaturated fatty acids (UFA, -CH2CH=) in LGI1, and increased glycoprotein A (GlycA) in NMDAR-antibody patients. INTERPRETATION: This study presents the first non-antibody-based biomarker for differentiating DRE, AE and AE subtypes. These metabolomics signatures underscore the potential relevance of lipid metabolism and glucose regulation in these neurological disorders, offering a promising adjunct to facilitate the diagnosis and therapeutics.


Subject(s)
Drug Resistant Epilepsy , Encephalitis , Humans , Female , Drug Resistant Epilepsy/blood , Drug Resistant Epilepsy/diagnosis , Male , Adult , Encephalitis/blood , Encephalitis/diagnosis , Middle Aged , Diagnosis, Differential , Young Adult , Autoantibodies/blood , Hashimoto Disease/blood , Hashimoto Disease/diagnosis , Metabolomics , Nerve Tissue Proteins/blood , Adolescent , Membrane Proteins/blood , Magnetic Resonance Spectroscopy , Intracellular Signaling Peptides and Proteins/blood , Biomarkers/blood , Receptors, N-Methyl-D-Aspartate/immunology , Autoimmune Diseases of the Nervous System/blood , Autoimmune Diseases of the Nervous System/diagnosis , Autoimmune Diseases of the Nervous System/immunology
8.
Lancet Glob Health ; 12(8): e1323-e1330, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38976998

ABSTRACT

BACKGROUND: WHO estimates that more than 50 million people worldwide have epilepsy and 80% of cases are in low-income and middle-income countries. Most studies in Africa have focused on active convulsive epilepsy in rural areas, but there are few data in urban settings. We aimed to estimate the prevalence and spatial distribution of all epilepsies in two urban informal settlements in Nairobi, Kenya. METHODS: We did a two-stage population-based cross-sectional study of residents in a demographic surveillance system covering two informal settlements in Nairobi, Kenya (Korogocho and Viwandani). Stage 1 screened all household members using a validated epilepsy screening questionnaire to detect possible cases. In stage 2, those identified with possible seizures and a proportion of those screening negative were invited to local clinics for clinical and neurological assessments by a neurologist. Seizures were classified following the International League Against Epilepsy recommendations. We adjusted for attrition between the two stages using multiple imputations and for sensitivity by dividing estimates by the sensitivity value of the screening tool. Complementary log-log regression was used to assess prevalence differences by participant socio-demographics. FINDINGS: A total of 56 425 individuals were screened during stage 1 (between Sept 17 and Dec 23, 2021) during which 1126 were classified as potential epilepsy cases. A total of 873 were assessed by a neurologist in stage 2 (between April 12 and Aug 6, 2022) during which 528 were confirmed as epilepsy cases. 253 potential cases were not assessed by a neurologist due to attrition. 30 179 (53·5%) of the 56 425 individuals were male and 26 246 (46·5%) were female. The median age was 24 years (IQR 11-35). Attrition-adjusted and sensitivity-adjusted prevalence for all types of epilepsy was 11·9 cases per 1000 people (95% CI 11·0-12·8), convulsive epilepsy was 8·7 cases per 1000 people (8·0-9·6), and non-convulsive epilepsy was 3·2 cases per 1000 people (2·7-3·7). Overall prevalence was highest among separated or divorced individuals at 20·3 cases per 1000 people (95% CI 15·9-24·7), unemployed people at 18·8 cases per 1000 people (16·2-21·4), those with no formal education at 18·5 cases per 1000 people (16·3-20·7), and adolescents aged 13-18 years at 15·2 cases per 1000 people (12·0-18·5). The epilepsy diagnostic gap was 80%. INTERPRETATION: Epilepsy is common in urban informal settlements of Nairobi, with large diagnostic gaps. Targeted interventions are needed to increase early epilepsy detection, particularly among vulnerable groups, to enable prompt treatment and prevention of adverse social consequences. FUNDING: National Institute for Health Research using Official Development Assistance.


Subject(s)
Epilepsy , Urban Population , Humans , Kenya/epidemiology , Epilepsy/epidemiology , Female , Prevalence , Male , Adult , Adolescent , Cross-Sectional Studies , Urban Population/statistics & numerical data , Young Adult , Child , Middle Aged , Child, Preschool , Infant
9.
Epilepsy Behav ; 158: 109906, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38936308

ABSTRACT

INTRODUCTION: In England, nearly a quarter of people with intellectual disability (PwID) have epilepsy. Though 70 % of PwID have pharmaco-resistant seizures only 10 % are prescribed anti-seizure medication (ASMs) licenced for pharmaco-resistance. Brivaracetam (BRV) licenced in 2016 has had nine post-marketing studies involving PwID. These studies are limited either by lack of controls or not looking at outcomes based on differing levels of ID severity. This study looks at evidence comparing effectiveness and side-effects in PwID to those without ID prescribed Brivaracetam (BRV). METHODS: Pooled case note data for patients prescribed BRV (2016-2022) at 12 UK NHS Trusts were analysed. Demographics, starting and maximum dose, side-effects, dropouts and seizure frequency between ID (mild vs. moderate-profound (M/P)) and general population for a 12-month period were compared. Descriptive analysis, Mann-Whitney, Fisher's exact and logistic regression methods were employed. RESULTS: 37 PwID (mild 17 M/P 20) were compared to 102 without ID. Mean start and maximum dose was lower for PwID than non-ID. Mean maximum dose reduced slightly with ID severity. No difference was found between ID and non-ID or between ID groups (Mild vs M/P) in BRV's efficacy i.e. >50 % seizure reduction or tolerability. Mental and behavioural side-effects were more prevalent for PwID (27.0 % ID, 17.6 % no ID) but not significantly higher (P = 0.441) or associated with ID severity (p = 0.255). CONCLUSION: This is the first study on BRV, which compares ID cohorts with differing severity and non-ID. Efficacy, tolerability and side-effects reported are similar across differing ID severity to those with no ID.


Subject(s)
Anticonvulsants , Intellectual Disability , Pyrrolidinones , Humans , Intellectual Disability/complications , Intellectual Disability/drug therapy , Male , Female , Anticonvulsants/therapeutic use , Anticonvulsants/adverse effects , Adult , Middle Aged , Pyrrolidinones/therapeutic use , Pyrrolidinones/adverse effects , Young Adult , Treatment Outcome , Epilepsy/drug therapy , Aged , Adolescent
10.
Seizure ; 120: 25-32, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38897161

ABSTRACT

INTRODUCTION: People with Intellectual Disabilities (PwID) are twenty times more likely than general population to have epilepsy. Guidance for prescribing antiseizure medication (ASM) to PwID is driven by trials excluding them. Levetiracetam (LEV) is a first-line ASM in the UK. Concerns exist regarding LEV's behavioural and psychological adverse effects, particularly in PwID. There is no high-quality evidence comparing effectiveness and adverse effects in PwID to those without, prescribed LEV. METHODS: Pooled casenote data for patients prescribed LEV (2000-2020) at 18 UK NHS Trusts were analysed. Demographics, starting and maximum dose, adverse effects, dropouts and seizure frequency between ID (mild vs. moderate-profound (M/P)) and general population for a 12-month period were compared. Descriptive analysis, Mann-Whitney, Fisher's exact and logistic regression methods were employed. RESULTS: 173 PwID (mild 53 M/P 120) were compared to 200 without ID. Mean start and maximum dose were similar across all groups. PwID (Mild & M/P) were less likely to withdraw from treatment (P = 0.036). No difference was found between ID and non-ID or between ID groups (Mild vs M/P) in LEV's efficacy i.e. >50 % seizure reduction. Significant association emerged between ID severity and psychiatric adverse effects (P = 0.035). More irritability (14.2 %) and aggression (10.8 %) were reported in M/P PwID. CONCLUSION: PwID and epilepsy have high rates of premature mortality, comorbidities, treatment resistance and polypharmacy but remain poorly researched for ASM use. This is the largest studied cohort of PwID trialled on LEV compared to general population controls. Findings support prescribing of LEV for PwID as a first-line ASM.


Subject(s)
Anticonvulsants , Epilepsy , Intellectual Disability , Levetiracetam , Humans , Levetiracetam/adverse effects , Levetiracetam/therapeutic use , Anticonvulsants/adverse effects , Anticonvulsants/therapeutic use , Intellectual Disability/drug therapy , Male , Female , Adult , Middle Aged , Case-Control Studies , Epilepsy/drug therapy , Young Adult , Aged , Treatment Outcome , Adolescent
11.
Physiol Meas ; 45(6)2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38772401

ABSTRACT

Objective. This paper aims to investigate the possibility of detecting tonic-clonic seizures (TCSs) with behind-the-ear, two-channel wearable electroencephalography (EEG), and to evaluate its added value to non-EEG modalities in TCS detection.Methods. We included 27 participants with a total of 44 TCSs from the European multicenter study SeizeIT2. The wearable Sensor Dot (Byteflies) was used to measure behind-the-ear EEG, electromyography (EMG), electrocardiography, accelerometry (ACC) and gyroscope. We evaluated automatic unimodal detection of TCSs, using sensitivity, precision, false positive rate (FPR) and F1-score. Subsequently, we fused the different modalities and again assessed performance. Algorithm-labeled segments were then provided to two experts, who annotated true positive TCSs, and discarded false positives.Results. Wearable EEG outperformed the other single modalities with a sensitivity of 100% and a FPR of 10.3/24 h. The combination of wearable EEG and EMG proved most clinically useful, delivering a sensitivity of 97.7%, an FPR of 0.4/24 h, a precision of 43%, and an F1-score of 59.7%. The highest overall performance was achieved through the fusion of wearable EEG, EMG, and ACC, yielding a sensitivity of 90.9%, an FPR of 0.1/24 h, a precision of 75.5%, and an F1-score of 82.5%.Conclusions. In TCS detection with a wearable device, combining EEG with EMG, ACC or both resulted in a remarkable reduction of FPR, while retaining a high sensitivity.Significance. Adding wearable EEG could further improve TCS detection, relative to extracerebral-based systems.


Subject(s)
Accelerometry , Electroencephalography , Electromyography , Seizures , Signal Processing, Computer-Assisted , Wearable Electronic Devices , Humans , Electroencephalography/instrumentation , Electroencephalography/methods , Electromyography/instrumentation , Accelerometry/instrumentation , Seizures/diagnosis , Seizures/physiopathology , Male , Female , Adult , Middle Aged , Young Adult
12.
J Neurosci ; 44(20)2024 May 15.
Article in English | MEDLINE | ID: mdl-38604778

ABSTRACT

The reversal potential refers to the membrane potential at which the net current flow through a channel reverses direction. The reversal potential is determined by transmembrane ion gradients and, in turn, determines how the channel's activity will affect the membrane potential. Traditional investigation into the reversal potential of inhibitory ligand-gated ion channels (EInh) has relied upon the activation of endogenous receptors, such as the GABA-A receptor (GABAAR). There are, however, challenges associated with activating endogenous receptors, including agonist delivery, isolating channel responses, and the effects of receptor saturation and desensitization. Here, we demonstrate the utility of using a light-gated anion channel, stGtACR2, to probe EInh in the rodent brain. Using mice of both sexes, we demonstrate that the properties of this optically activated channel make it a suitable proxy for studying GABAAR receptor-mediated inhibition. We validate this agonist-independent optogenetic strategy in vitro and in vivo and further show how it can accurately capture differences in EInh dynamics following manipulations of endogenous ion fluxes. This allows us to explore distinct resting EInh differences across genetically defined neuronal subpopulations. Using this approach to challenge ion homeostasis mechanisms in neurons, we uncover cell-specific EInh dynamics that are supported by the differential expression of endogenous ion handling mechanisms. Our findings therefore establish an effective optical strategy for revealing novel aspects of inhibitory reversal potentials and thereby expand the repertoire of optogenetics.


Subject(s)
Membrane Potentials , Optogenetics , Animals , Optogenetics/methods , Mice , Male , Female , Membrane Potentials/physiology , Receptors, GABA-A/metabolism , Receptors, GABA-A/genetics , Neurons/physiology , Neurons/metabolism , Mice, Inbred C57BL , Neural Inhibition/physiology , Ligand-Gated Ion Channels/metabolism , Ligand-Gated Ion Channels/genetics , Mice, Transgenic
13.
Epilepsia ; 65(6): 1581-1588, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38498313

ABSTRACT

OBJECTIVE: New-onset refractory status epilepticus (NORSE) is a rare but severe clinical syndrome. Despite rigorous evaluation, the underlying cause is unknown in 30%-50% of patients and treatment strategies are largely empirical. The aim of this study was to describe clinical outcomes in a cohort of well-phenotyped, thoroughly investigated patients who survived the initial phase of cryptogenic NORSE managed in specialist centers. METHODS: Well-characterized cases of cryptogenic NORSE were identified through the EPIGEN and Critical Care EEG Monitoring Research Consortia (CCEMRC) during the period 2005-2019. Treating epileptologists reported on post-NORSE survival rates and sequelae in patients after discharge from hospital. Among survivors >6 months post-discharge, we report the rates and severity of active epilepsy, global disability, vocational, and global cognitive and mental health outcomes. We attempt to identify determinants of outcome. RESULTS: Among 48 patients who survived the acute phase of NORSE to the point of discharge from hospital, 9 had died at last follow-up, of whom 7 died within 6 months of discharge from the tertiary care center. The remaining 39 patients had high rates of active epilepsy as well as vocational, cognitive, and psychiatric comorbidities. The epilepsy was usually multifocal and typically drug resistant. Only a minority of patients had a good functional outcome. Therapeutic interventions were heterogenous during the acute phase of the illness. There was no clear relationship between the nature of treatment and clinical outcomes. SIGNIFICANCE: Among survivors of cryptogenic NORSE, longer-term outcomes in most patients were life altering and often catastrophic. Treatment remains empirical and variable. There is a pressing need to understand the etiology of cryptogenic NORSE and to develop tailored treatment strategies.


Subject(s)
Drug Resistant Epilepsy , Status Epilepticus , Survivors , Humans , Male , Female , Adult , Middle Aged , Young Adult , Adolescent , Treatment Outcome , Electroencephalography , Child
14.
Neuron ; 111(22): 3531-3540.e6, 2023 Nov 15.
Article in English | MEDLINE | ID: mdl-37659408

ABSTRACT

Fast synaptic inhibition determines neuronal response properties in the mammalian brain and is mediated by chloride-permeable ionotropic GABA-A receptors (GABAARs). Despite their fundamental role, it is still not known how GABAARs signal in the intact brain. Here, we use in vivo gramicidin recordings to investigate synaptic GABAAR signaling in mouse cortical pyramidal neurons under conditions that preserve native transmembrane chloride gradients. In anesthetized cortex, synaptic GABAARs exert classic hyperpolarizing effects. In contrast, GABAAR-mediated synaptic signaling in awake cortex is found to be predominantly shunting. This is due to more depolarized GABAAR equilibrium potentials (EGABAAR), which are shown to result from the high levels of synaptic activity that characterize awake cortical networks. Synaptic EGABAAR observed in awake cortex facilitates the desynchronizing effects of inhibitory inputs upon local networks, which increases the flexibility of spiking responses to external inputs. Our findings therefore suggest that GABAAR signaling adapts to optimize cortical functions.


Subject(s)
Chlorides , Receptors, GABA-A , Mice , Animals , Chlorides/pharmacology , Neurons , Pyramidal Cells/physiology , gamma-Aminobutyric Acid/pharmacology , Mammals
15.
Seizure ; 108: 24-32, 2023 May.
Article in English | MEDLINE | ID: mdl-37060628

ABSTRACT

BACKGROUND: Women with epilepsy (WWE) are vulnerable in pregnancy, with increased risks to mother and baby including teratogenic risks, especially from valproate. The free EpSMon mobile-phone app allows self-monitoring to afford patient-centred feedback on seizure related risks, such as sudden death in epilepsy (SUDEP) to its users. We sought to generate insights into various seizure related risks and its treatments in WWE of childbearing age (16 to 60 years ) using EpSMon. METHODS: The study utilizes a prospective real-world cohort of 5.5 years. Patient reported data on demographics, medication taken, diagnoses, seizure types and recognised biological, psychological, and social factors of seizure related harm were extracted. Data was stratified according to frequent and infrequent users and those scoring lower and higher risk scores. Multivariate logistic regression and different statistical tests were conducted. FINDINGS: Data from 2158 WWE of childbearing age encompassing 4016 self-assessments were analysed. Overall risk awareness was 25.3% for pregnancy and 54.1% for SUDEP. Frequent users were more aware of pregnancy risks but not of SUDEP. Repeated EpSMon use increased SUDEP awareness but not pregnancy risks. Valproate was used by 11% of WWE, ranging from 6.5% of younger to 31.5% of older women. CONCLUSIONS: The awareness to risks to pregnancy, SUDEP and valproate is low. Valproate is being used by a significant minority. It is imperative risk communication continues for WWE based on their individual situation and need. This is unlikely to be delivered by current clinical models. Digital solutions hold promise but require work done to raise implementation and acceptability.


Subject(s)
Epilepsy , Sudden Unexpected Death in Epilepsy , Female , Humans , Aged , Adolescent , Young Adult , Adult , Middle Aged , Valproic Acid/therapeutic use , Prospective Studies , Epilepsy/drug therapy , Epilepsy/epidemiology , Epilepsy/complications , Seizures/drug therapy , Death, Sudden/etiology , Anticonvulsants/adverse effects
16.
JAMA Neurol ; 80(5): 445-454, 2023 05 01.
Article in English | MEDLINE | ID: mdl-36972059

ABSTRACT

Importance: Epilepsy has been associated with cognitive impairment and potentially dementia in older individuals. However, the extent to which epilepsy may increase dementia risk, how this compares with other neurological conditions, and how modifiable cardiovascular risk factors may affect this risk remain unclear. Objective: To compare the differential risks of subsequent dementia for focal epilepsy compared with stroke and migraine as well as healthy controls, stratified by cardiovascular risk. Design, Setting, and Participants: This cross-sectional study is based on data from the UK Biobank, a population-based cohort of more than 500 000 participants aged 38 to 72 years who underwent physiological measurements and cognitive testing and provided biological samples at 1 of 22 centers across the United Kingdom. Participants were eligible for this study if they were without dementia at baseline and had clinical data pertaining to a history of focal epilepsy, stroke, or migraine. The baseline assessment was performed from 2006 to 2010, and participants were followed up until 2021. Exposures: Mutually exclusive groups of participants with epilepsy, stroke, and migraine at baseline assessment and controls (who had none of these conditions). Individuals were divided into low, moderate, or high cardiovascular risk groups based on factors that included waist to hip ratio, history of hypertension, hypercholesterolemia, diabetes, and smoking pack-years. Main Outcomes and Measures: Incident all-cause dementia; measures of executive function; and brain total hippocampal, gray matter, and white matter hyperintensity volumes. Results: Of 495 149 participants (225 481 [45.5%] men; mean [SD] age, 57.5 [8.1] years), 3864 had a diagnosis of focal epilepsy only, 6397 had a history of stroke only, and 14 518 had migraine only. Executive function was comparable between participants with epilepsy and stroke and worse than the control and migraine group. Focal epilepsy was associated with a higher risk of developing dementia (hazard ratio [HR], 4.02; 95% CI, 3.45 to 4.68; P < .001), compared with stroke (HR, 2.56; 95% CI, 2.28 to 2.87; P < .001), or migraine (HR, 1.02; 95% CI, 0.85 to 1.21; P = .94). Participants with focal epilepsy and high cardiovascular risk were more than 13 times more likely to develop dementia (HR, 13.66; 95% CI, 10.61 to 17.60; P < .001) compared with controls with low cardiovascular risk. The imaging subsample included 42 353 participants. Focal epilepsy was associated with lower hippocampal volume (mean difference, -0.17; 95% CI, -0.02 to -0.32; t = -2.18; P = .03) and lower total gray matter volume (mean difference, -0.33; 95% CI, -0.18 to -0.48; t = -4.29; P < .001) compared with controls. There was no significant difference in white matter hyperintensity volume (mean difference, 0.10; 95% CI, -0.07 to 0.26; t = 1.14; P = .26). Conclusions and Relevance: In this study, focal epilepsy was associated with a significant risk of developing dementia, to a greater extent than stroke, which was magnified substantially in individuals with high cardiovascular risk. Further findings suggest that targeting modifiable cardiovascular risk factors may be an effective intervention to reduce dementia risk in individuals with epilepsy.


Subject(s)
Cardiovascular Diseases , Dementia , Epilepsies, Partial , Epilepsy , Migraine Disorders , Stroke , Male , Humans , Aged , Middle Aged , Female , Risk Factors , Cardiovascular Diseases/epidemiology , Cross-Sectional Studies , Heart Disease Risk Factors , Epilepsies, Partial/epidemiology , Epilepsy/epidemiology , Dementia/epidemiology , Dementia/etiology , Migraine Disorders/epidemiology
17.
Lancet Digit Health ; 5(4): e185-e193, 2023 04.
Article in English | MEDLINE | ID: mdl-36963908

ABSTRACT

BACKGROUND: Identification of convulsive epilepsy in sub-Saharan Africa relies on access to resources that are often unavailable. Infrastructure and resource requirements can further complicate case verification. Using machine-learning techniques, we have developed and tested a region-specific questionnaire panel and predictive model to identify people who have had a convulsive seizure. These findings have been implemented into a free app for health-care workers in Kenya, Uganda, Ghana, Tanzania, and South Africa. METHODS: In this retrospective case-control study, we used data from the Studies of the Epidemiology of Epilepsy in Demographic Sites in Kenya, Uganda, Ghana, Tanzania, and South Africa. We randomly split these individuals using a 7:3 ratio into a training dataset and a validation dataset. We used information gain and correlation-based feature selection to identify eight binary features to predict convulsive seizures. We then assessed several machine-learning algorithms to create a multivariate prediction model. We validated the best-performing model with the internal dataset and a prospectively collected external-validation dataset. We additionally evaluated a leave-one-site-out model (LOSO), in which the model was trained on data from all sites except one that, in turn, formed the validation dataset. We used these features to develop a questionnaire-based predictive panel that we implemented into a multilingual app (the Epilepsy Diagnostic Companion) for health-care workers in each geographical region. FINDINGS: We analysed epilepsy-specific data from 4097 people, of whom 1985 (48·5%) had convulsive epilepsy, and 2112 were controls. From 170 clinical variables, we initially identified 20 candidate predictor features. Eight features were removed, six because of negligible information gain and two following review by a panel of qualified neurologists. Correlation-based feature selection identified eight variables that demonstrated predictive value; all were associated with an increased risk of an epileptic convulsion except one. The logistic regression, support vector, and naive Bayes models performed similarly, outperforming the decision-tree model. We chose the logistic regression model for its interpretability and implementability. The area under the receiver operator curve (AUC) was 0·92 (95% CI 0·91-0·94, sensitivity 85·0%, specificity 93·7%) in the internal-validation dataset and 0·95 (0·92-0·98, sensitivity 97·5%, specificity 82·4%) in the external-validation dataset. Similar results were observed for the LOSO model (AUC 0·94, 0·93-0·96, sensitivity 88·2%, specificity 95·3%). INTERPRETATION: On the basis of these findings, we developed the Epilepsy Diagnostic Companion as a predictive model and app offering a validated culture-specific and region-specific solution to confirm the diagnosis of a convulsive epileptic seizure in people with suspected epilepsy. The questionnaire panel is simple and accessible for health-care workers without specialist knowledge to administer. This tool can be iteratively updated and could lead to earlier, more accurate diagnosis of seizures and improve care for people with epilepsy. FUNDING: The Wellcome Trust, the UK National Institute of Health Research, and the Oxford NIHR Biomedical Research Centre.


Subject(s)
Epilepsy , Humans , Retrospective Studies , Case-Control Studies , Bayes Theorem , Epilepsy/diagnosis , Epilepsy/epidemiology , Seizures/diagnosis , Seizures/epidemiology , Kenya/epidemiology
18.
Epilepsy Behav ; 140: 109065, 2023 03.
Article in English | MEDLINE | ID: mdl-36791631

ABSTRACT

BACKGROUND: Levetiracetam (LVT), while an effective treatment for multiple seizure types, is associated with a high incidence of neuropsychiatric adverse events (NPAEs). In predominantly retrospective studies, supplementation with pyridoxine/vitamin B6 (PN) was associated with improvement in NPAEs in some people. A previous review highlighted a lack of double-blind, controlled trials of PN for the treatment of NPAEs in individuals treated with LVT. The current paper updates the findings from the previous review to include evidence from studies published since June 2019. METHODS: An updated systematic review of the published literature was performed in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, Embase, the Cochrane Library, and Google Scholar were searched to identify studies published between June 2019 and 2nd November 2022 in which supplementary PN was initiated for the treatment of LVT-associated NPAEs. All study types were eligible. The risk of bias in randomized trials was assessed using the Cochrane risk-of-bias tool. RESULTS: Seven additional studies were identified: two double-blind, randomized controlled trials (RCTs), four retrospective studies, and one retrospective case series. One RCT reported significant improvements from baseline in behavioral adverse events (BAEs) in both the intervention (PN) group and the low-dose control group (both p < 0.05), with a significantly greater improvement in the intervention group (p < 0.001). In the second RCT, differences in BAE severity between PN and placebo groups at the endpoint were not statistically significant. In one retrospective study, subjective irritability was reported to have improved from baseline in 9/20 individuals (45%) treated with supplementary PN. Data for systematic assessments (PHQ-9 and GAD-7) were available for 10 individuals. Assessment by PHQ-9 showed that six individuals improved, two worsened and two had no change. Based on the GAD-7, three people improved, two worsened and five had no change. In the second retrospective study, 18/41 individuals (44%) who commenced PN following the emergence of BAEs showed "significant" improvement. In a separate group of individuals with pre-existing behavioral problems in whom PN treatment was initiated at the same time as commencing LVT, 3/18 (16.7%) developed BAEs. This compared with 79/458 people (17.2%) who were initially treated only with LVT. The third retrospective study compared treatment-related irritability in individuals who had been treated with both LVT and perampanel, either sequentially or concomitantly. Two people who developed irritability while receiving LVT monotherapy were able to continue treatment with the addition of PN. The fourth study reported a significantly lower LVT discontinuation rate in individuals taking PN and a higher rate of improved behavior in those who were able to continue LVT. The case series reported improvements in behavioral symptoms in six people within two to three weeks of commencing supplementary PN. CONCLUSION: Data published within the last three years add to earlier evidence suggesting that PN might be effective in the treatment of NPAEs associated with LVT. However, the quality of evidence remains poor and only a few prospective trials have been published. Data from placebo-controlled trials are still largely lacking. Currently, there is insufficient evidence to justify any firm recommendation for PN supplementation to treat NPAEs associated with LVT. Further well-designed, prospective trials are warranted.


Subject(s)
Drug-Related Side Effects and Adverse Reactions , Pyridoxine , Humans , Levetiracetam/adverse effects , Pyridoxine/therapeutic use , Vitamin B 6/therapeutic use , Treatment Outcome , Randomized Controlled Trials as Topic
19.
Neurology ; 100(8): e790-e799, 2023 02 21.
Article in English | MEDLINE | ID: mdl-36384658

ABSTRACT

BACKGROUND AND OBJECTIVES: The relationship between COVID-19 and epilepsy is uncertain. We studied the potential association between COVID-19 and seizures or epilepsy in the 6 months after infection. METHODS: We applied validated methods to an electronic health records network (TriNetX Analytics) of 81 million people. We closely matched people with COVID-19 infections to those with influenza. In each cohort, we measured the incidence and hazard ratios (HRs) of seizures and epilepsy. We stratified data by age and by whether the person was hospitalized during the acute infection. We then explored time-varying HRs to assess temporal patterns of seizure or epilepsy diagnoses. RESULTS: We analyzed 860,934 electronic health records. After matching, this yielded 2 cohorts each of 152,754 patients. COVID-19 was associated with an increased risk of seizures and epilepsy compared with influenza. The incidence of seizures within 6 months of COVID-19 was 0.81% (95% CI 0.75-0.88; HR compared with influenza 1.55 [1.39-1.74]). The incidence of epilepsy was 0.30% (0.26-0.34; HR compared with influenza 1.87 [1.54-2.28]). The HR of epilepsy after COVID-19 compared with influenza was greater in people who had not been hospitalized and in individuals younger than 16 years. The time of peak HR after infection differed by age and hospitalization status. DISCUSSION: The incidence of new seizures or epilepsy diagnoses in the 6 months after COVID-19 was low overall, but higher than in matched patients with influenza. This difference was more marked in people who were not hospitalized, highlighting the risk of epilepsy and seizures even in those with less severe infection. Children appear at particular risk of seizures and epilepsy after COVID-19 providing another motivation to prevent COVID-19 infection in pediatric populations. That the varying time of peak risk related to hospitalization and age may provide clues as to the underlying mechanisms of COVID-associated seizures and epilepsy.


Subject(s)
COVID-19 , Epilepsies, Partial , Epilepsy , Influenza, Human , Child , Humans , Anticonvulsants/therapeutic use , Incidence , Influenza, Human/complications , Influenza, Human/diagnosis , Influenza, Human/epidemiology , Retrospective Studies , Epilepsies, Partial/drug therapy , COVID-19/complications , COVID-19/epidemiology , Seizures/etiology , Seizures/chemically induced , Epilepsy/drug therapy
20.
Brain ; 146(6): 2389-2398, 2023 06 01.
Article in English | MEDLINE | ID: mdl-36415957

ABSTRACT

More than half of adults with epilepsy undergoing resective epilepsy surgery achieve long-term seizure freedom and might consider withdrawing antiseizure medications. We aimed to identify predictors of seizure recurrence after starting postoperative antiseizure medication withdrawal and develop and validate predictive models. We performed an international multicentre observational cohort study in nine tertiary epilepsy referral centres. We included 850 adults who started antiseizure medication withdrawal following resective epilepsy surgery and were free of seizures other than focal non-motor aware seizures before starting antiseizure medication withdrawal. We developed a model predicting recurrent seizures, other than focal non-motor aware seizures, using Cox proportional hazards regression in a derivation cohort (n = 231). Independent predictors of seizure recurrence, other than focal non-motor aware seizures, following the start of antiseizure medication withdrawal were focal non-motor aware seizures after surgery and before withdrawal [adjusted hazard ratio (aHR) 5.5, 95% confidence interval (CI) 2.7-11.1], history of focal to bilateral tonic-clonic seizures before surgery (aHR 1.6, 95% CI 0.9-2.8), time from surgery to the start of antiseizure medication withdrawal (aHR 0.9, 95% CI 0.8-0.9) and number of antiseizure medications at time of surgery (aHR 1.2, 95% CI 0.9-1.6). Model discrimination showed a concordance statistic of 0.67 (95% CI 0.63-0.71) in the external validation cohorts (n = 500). A secondary model predicting recurrence of any seizures (including focal non-motor aware seizures) was developed and validated in a subgroup that did not have focal non-motor aware seizures before withdrawal (n = 639), showing a concordance statistic of 0.68 (95% CI 0.64-0.72). Calibration plots indicated high agreement of predicted and observed outcomes for both models. We show that simple algorithms, available as graphical nomograms and online tools (predictepilepsy.github.io), can provide probabilities of seizure outcomes after starting postoperative antiseizure medication withdrawal. These multicentre-validated models may assist clinicians when discussing antiseizure medication withdrawal after surgery with their patients.


Subject(s)
Epilepsies, Partial , Epilepsy, Generalized , Epilepsy , Humans , Adult , Anticonvulsants/adverse effects , Neoplasm Recurrence, Local/drug therapy , Epilepsy/drug therapy , Epilepsy/surgery , Seizures/drug therapy , Epilepsy, Generalized/drug therapy
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