Inflammatory pathways of seizure disorders

Real-time visualization of epileptic seizures using photoacoustic imaging with a peroxynitrite-responsive manganese(ii) texaphyrin

Real-time visualization and tracking of epileptic seizures are important for studying epilepsy pathogenesis and treating epilepsy; however, the requisite sensing is extremely challenging, primarily due to the transient and intricate nature of neural activity associated with epilepsy. The onset of epilepsy is closely correlated with increases in peroxynitrite (ONOO-) levels, a reactive nitrogen species that can serve as a biomarker for epilepsy. However, the fleeting biological half-life and high reactivity of ONOO- has historically impeded its direct visualization within the epileptic brain. This study explores the efficacy of manganese(ii) texaphyrin (MMn), a water-soluble and stable expanded porphyrin, in dynamically sensing ONOO- and providing real-time tracking of epileptic seizures using a custom-built photoacoustic imaging (PAI) setup. UV-vis spectral analyses established the preferential sensitivity of MMn to ONOO- over other reactive oxygen species (ROS), as well as its effectiveness through multiple usage cycles when rejuvenated via reaction with suitable reducing agents. This selectivity was recapitulated in vitro as determined through PAI experiments. In vivo application of this technique revealed that MMn administered intravenously crosses the blood-brain barrier (BBB) in a pentylenetetrazole (PTZ)-induced epilepsy mouse model and provides an observable 14.1 ± 3.7% reduction in photoacoustic (PA) signal intensity within the hippocampal region during epileptic seizures. Multiple decreasing-increasing cycles of PA signal intensity could be detected in the hippocampal region in this model; the observed effect thus mirrors closely the course of epileptic seizures inferred from mouse tail curling. Similar cyclical patterns were also seen in the motor cortex, a finding consistent with the extensive spread of epileptic activity throughout the brain. To the best of our knowledge, the present investigation represents the first real-time visualization and tracking of epileptic seizures using a peroxynitrite-specific sensing probe in combination with photoacoustic imaging (PAI). This approach enables deeper brain imaging while simultaneously capturing dynamic ONOO- fluctuations, offering biochemical insights into epilepsy pathogenesis. By integrating deep-tissue imaging with neurochemical monitoring, this method lays the foundation for potential advances in epilepsy management and treatment.

The Interactions of Resveratrol and Sodium Valproate on Penicillin-Induced Epilepsy Model: Electrophysiological and Molecular Study

Epilepsy represents the most prevalent chronic neurological disease, characterized by spontaneous recurrent seizures. In experimental epilepsy models created by different methods, resveratrol has been demonstrated to reduce epileptiform activity and exhibit neuroprotective properties. A penicillin-induced model of epileptogenesis was used to investigate the effects of resveratrol and its combination with sodium valproate on epileptiform activity. The study design was an in vivo animal experimental study. Forty Wistar-albino rats were divided into five groups, each with eight rats. The groups are categorized as the saline group, penicillin group (only penicillin), resveratrol group, sodium valproate group, and resveratrol + sodium valproate group. ECoG recording was taken for 180 min in all groups and statistically evaluated. GABAα1, mGluR1/mGluR5, NMDAR1 receptor expressions in the hippocampus, and S100B level in serum were measured. The spike frequency decreased statistically to 60th min in the sodium valproate group and 150th min in the resveratrol group. The spike frequency decreased statistically in the 20th min and later measurements of the recording in the resveratrol + sodium valproate group. GABAα1 receptor expression was increased in all groups compared to the penicillin group. mGluR1/mGluR5, NMDAR1 receptor expression was decreased in all groups compared to the penicillin group. Serum S100B level increased in all groups compared to the penicillin group. There was no statistically significant difference in epileptiform activity when resveratrol alone was administered in the penicillin-induced epilepsy model. Resveratrol co-administered with sodium valproate significantly reduced epileptiform activity. Co-administration of the sodium valproate + resveratrol group made the receptor level's highest GABAα1receptor expression at receptors.

Drug-resistant epilepsy associated with peripheral complement decreases and sex-specific cytokine imbalances: a pilot study

Drug-resistant epilepsy (DRE) presents significant challenges in treatment and management. While seizure-related alterations in peripheral immune players are increasingly recognized, the involvement of the immune complement system remains insufficiently explored in DRE. We studied complement components and their relationship to cytokine profiles in serum samples from 46 DRE patients and 45 matched healthy controls. We examined relationships between these molecules and clinical outcomes, including epilepsy duration, intelligence scores, and age. We identified DRE-associated complement decreases, including reduced levels of C1q, Factor H, C4, C4b, C3, and C3b/iC3b, as well as elevated bFGF. DRE females showed dysregulation of the classical complement pathway and lower TNFα and interleukin-8 compared to healthy females. DRE males exhibited dysregulation of the classical, lectin, and terminal complement pathways, with trends of increased CCL2 and CCL5 compared to healthy males. Specific complement and inflammatory markers (C2, IL-8, and IL-9) correlated with full-scale IQ scores in DRE patients. Our study reveals significantly lower levels of circulating complement components in DRE and sex-specific complement dysregulation and cytokine imbalances. These findings suggest an underlying peripheral immune system vulnerability that may be sex-dependent and warrants further investigation in DRE.

From Gut Microbiomes to Infectious Pathogens: Neurological Disease Game Changers

Gut microbiota and infectious diseases affect neurological disorders, brain development, and function. Compounds generated in the gastrointestinal system by gut microbiota and infectious pathogens may mediate gut-brain interactions, which may circulate throughout the body and spread to numerous organs, including the brain. Studies shown that gut bacteria and disease-causing organisms may pass molecular signals to the brain, affecting neurological function, neurodevelopment, and neurodegenerative diseases. This article discusses microorganism-producing metabolites with neuromodulator activity, signaling routes from microbial flora to the brain, and the potential direct effects of gut bacteria and infectious pathogens on brain cells. The review also considered the neurological aspects of infectious diseases. The infectious diseases affecting neurological functions and the disease modifications have been discussed thoroughly. Recent discoveries and unique insights in this perspective need further validation. Research on the complex molecular interactions between gut bacteria, infectious pathogens, and the CNS provides valuable insights into the pathogenesis of neurodegenerative, behavioral, and psychiatric illnesses. This study may provide insights into advanced drug discovery processes for neurological disorders by considering the influence of microbial communities inside the human body.

Sex-Specific Complement and Cytokine Imbalances in Drug-Resistant Epilepsy: Biomarkers of Immune Vulnerability

Objective

Drug-resistant epilepsy (DRE) poses significant challenges in treatment and management. While seizure-related alterations in peripheral immune players are increasingly recognized, the involvement of the complement system, central to immune function, remains insufficiently explored in DRE. This study aimed to investigate the levels of complement system components and their association with cytokine profiles in patients with DRE.

Methods

We analyzed serum samples from DRE patients (n = 46) and age- and sex-matched healthy controls (n = 45). Complement components and cytokines were quantified using Multi- and Single-plex ELISA. Statistical analyses examined relationships between complement molecules, cytokines, and clinical outcomes including epilepsy duration, Full-Scale Intelligence Quotient (FSIQ) scores, and age.

Results

We found common alterations in all DRE cases, including significant complement deficiencies (C1q, Factor H, C4, C4b, C3, and C3b/iC3b) and detectable bFGF levels. DRE females showed significantly lower levels of TNFα and IL-8 compared to healthy females. We observed a trend towards elevated CCL2 and CCL5 levels in DRE males compared to healthy males. These findings suggest potential sex dimorphism in immune profiles. Our analysis also indicated associations between specific complement and inflammatory markers (C2, IL-8, and IL-9) and Full-Scale Intelligence Quotient (FSIQ) scores in DRE patients.

Interpretation

Our study reveals sex-specific peripheral complement deficiencies and cytokine dysregulation in DRE patients, indicating an underlying immune system vulnerability. These findings provide new insights into DRE mechanisms, potentially guiding future research on complement and cytokine signaling toward personalized treatments for DRE patients.

Use of Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers Is Associated With a Reduced Risk of Poststroke Epilepsy in Patients With Ischemic Stroke

BACKGROUND

Poststroke epilepsy (PSE) is a common complication after ischemic stroke. This study investigates the association between the use of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) and the risk of PSE in patients with ischemic stroke.

METHODS AND RESULTS

A population-based retrospective cohort study was conducted using Taiwan's National Health Insurance Research Database between 2000 and 2015. Patients with hypertension with a history of ischemic stroke were classified into prevalent, new, and nonusers according to their use of ACEIs/ARBs. Prevalent ACEI/ARB users were further classified into continuing or discontinued users, based on their poststroke medication adherence. We used multivariate Cox regression models, adjusted for demographics and comorbidities, to assess the risk of PSE among different ACEI/ARB user groups. There were 182 983 ACEI/ARB users and 38 365 nonusers included. There were 7387 patients diagnosed with PSE, whereas 213 961 were not. Nonusers exhibited a higher risk of PSE (adjusted hazard ratio [aHR], 1.72 [95% CI, 1.63-1.82]). Both prevalent and nonusers had higher risks compared with new ACEI/ARB users, with respective aHRs of 1.33 (95% CI, 1.25-1.41) and 2.00 (95% CI, 1.87-2.14). Discontinued ACEI/ARB users showed the highest risk of PSE (aHR, 2.34 [95% CI, 2.15-2.54]), suggesting the importance of continuing ACEI/ARB use after stroke. Treatment-by-age interaction was significant among patients with or without ACEI/ARB use before stroke (P value for interaction 0.004 and <0.001, respectively), suggesting a stronger beneficial association in younger patients.

CONCLUSIONS

The use of ACEIs/ARBs after ischemic stroke in patients with hypertension is associated with a reduced risk of PSE, especially among younger patients.

Interplay between immune cells and metabolites in epilepsy: insights from a Mendelian randomization analysis

Background

Epilepsy is associated with the immune system and metabolism; however, its etiology remains insufficiently understood. Here, we aim to elucidate whether circulating immune cell profiles and metabolites impact the susceptibility to epilepsy.

Methods

We used publicly available genetic data and two-sample Mendelian randomization (MR) analyses to establish causal relationships and mediating effects between 731 immune cells and 1,400 metabolites associated with epilepsy. Sensitivity analyses were conducted to detect heterogeneity and horizontal pleiotropy in the study results.

Results

MR analysis examining the relationship between immune cells, metabolites, and epilepsy revealed significant causal associations with 28 different subtypes of immune cells and 14 metabolites. Besides, the mediation effects analysis revealed that eight metabolites mediated the effects of six types of immune cells on epilepsy and that 3-hydroxyoctanoylcarnitine (2) levels exhibited the highest mediating effect, mediating 15.3% (95%CI, -0.008, -30.6%, p = 0.049) of the effect of DN (CD4-CD8-) AC on epilepsy. 1-(1-enyl-stearoyl)-2-linoleoyl-GPE (p-18:0/18:2) levels (95%CI, 0.668, 10.6%, p = 0.026) and X-12544 levels (95%CI, -15.1, -0.856%, p = 0.028) contributed 5.63 and 8%, respectively, to the causal effect of FSC-A on myeloid DC on epilepsy.

Conclusion

This study revealed a significant causal link between immune cells, metabolites, and epilepsy. It remarkably enhances our understanding of the interplay between immune responses, metabolites, and epilepsy risk, providing insights into the development of therapeutic strategies from both immune and metabolic perspectives.

In Silico Screening Identification of Fatty Acids and Fatty Acid Derivatives with Antiseizure Activity: In Vitro and In Vivo Validation

High fat diets have been used as complementary treatments for seizure disorders for more than a century. Moreover, many fatty acids and derivatives, including the broad-spectrum antiseizure medication valproic acid, have been explored and used as pharmacological agents to treat epilepsy. In this work, we have explored the anticonvulsant potential of a large library of fatty acids and fatty acid derivatives, the LIPID MAPS Structure Database, using structure-based virtual screening to assess their ability to block the voltage-gated sodium channel 1.2 (NaV1.2), a validated target for antiseizure medications. Four of the resulting in silico hits were submitted for experimental confirmation using in vitro patch clamp experiments, and their protective role was evaluated in an acute mice seizure model, the Maximal Electroshock seizure model. These four compounds were found to protect mice against seizures. Two of them exhibited blocking effects on NaV1.2, CaV2.2, and CaV3.1.

Temporal changes in mouse hippocampus transcriptome after pilocarpine-induced seizures

Introduction

Status epilepticus (SE) is a seizure lasting more than 5 min that can have lethal consequences or lead to various neurological disorders, including epilepsy. Using a pilocarpine-induced SE model in mice we investigated temporal changes in the hippocampal transcriptome.

Methods

We performed mRNA-seq and microRNA-seq analyses at various times after drug treatment.

Results

At 1 h after the start of seizures, hippocampal cells upregulated transcription of immediate early genes and genes involved in the IGF-1, ERK/MAPK and RNA-PolII/transcription pathways. At 8 h, we observed changes in the expression of genes associated with oxidative stress, overall transcription downregulation, particularly for genes related to mitochondrial structure and function, initiation of a stress response through regulation of ribosome and translation/EIF2 signaling, and upregulation of an inflammatory response. During the middle of the latent period, 36 h, we identified upregulation of membrane components, cholesterol synthesis enzymes, channels, and extracellular matrix (ECM), as well as an increased inflammatory response. At the end of the latent period, 120 h, most changes in expression were in genes involved in ion transport, membrane channels, and synapses. Notably, we also elucidated the involvement of novel pathways, such as cholesterol biosynthesis pathways, iron/BMP/ferroptosis pathways, and circadian rhythms signaling in SE and epileptogenesis.

Discussion

These temporal changes in metabolic reactions indicate an immediate response to injury followed by recovery and regeneration. CREB was identified as the main upstream regulator. Overall, our data provide new insights into molecular functions and cellular processes involved at different stages of seizures and offer potential avenues for effective therapeutic strategies.

Investigative analysis of blood-brain barrier penetrating potential of electronic nicotine delivery systems (e-cigarettes) chemicals using predictive computational models

INTRODUCTION

Seizures are known potential side effects of nicotine toxicity and have been reported in electronic nicotine delivery systems (ENDS, e-cigarettes) users, with the majority involving youth or young adults.

AREAS COVERED

Using chemoinformatic computational models, chemicals (including flavors) documented to be present in ENDS were compared to known neuroactive compounds to predict the blood-brain barrier (BBB) penetration potential, central nervous system (CNS) activity, and their structural similarities. The literature search used PubMed/Google Scholar, through September 2023, to identify individual chemicals in ENDS and neuroactive compounds.The results show that ENDS chemicals in this study contain >60% structural similarity to neuroactive compounds based on chemical fingerprint similarity analyses. The majority of ENDS chemicals we studied were predicted to cross the BBB, with approximately 60% confidence, and were also predicted to have CNS activity; those not predicted to passively diffuse through the BBB may be actively transported through the BBB to elicit CNS impacts, although it is currently unknown.

EXPERT OPINION

In lieu of in vitro and in vivo testing, this study screens ENDS chemicals for potential CNS activity and predicts BBB penetration potential using computer-based models, allowing for prioritization for further study and potential early identification of CNS toxicity.

A Reduction in the Readily Releasable Vesicle Pool Impairs GABAergic Inhibition in the Hippocampus after Blood-Brain Barrier Dysfunction

Major burdens for patients suffering from stroke are cognitive co-morbidities and epileptogenesis. Neural network disinhibition and deficient inhibitive pulses for fast network activities may result from impaired presynaptic release of the inhibitory neurotransmitter GABA. To test this hypothesis, a cortical photothrombotic stroke was induced in Sprague Dawley rats, and inhibitory currents were recorded seven days later in the peri-infarct blood-brain barrier disrupted (BBBd) hippocampus via patch-clamp electrophysiology in CA1 pyramidal cells (PC). Miniature inhibitory postsynaptic current (mIPSC) frequency was reduced to about half, and mIPSCs decayed faster in the BBBd hippocampus. Furthermore, the paired-pulse ratio of evoked GABA release was increased at 100 Hz, and train stimulations with 100 Hz revealed that the readily releasable pool (RRP), usually assumed to correspond to the number of tightly docked presynaptic vesicles, is reduced by about half in the BBBd hippocampus. These pathophysiologic changes are likely to contribute significantly to disturbed fast oscillatory activity, like cognition-associated gamma oscillations or sharp wave ripples and epileptogenesis in the BBBd hippocampus.

A Systematic Review of the Predictive and Diagnostic Uses of Neuroinflammation Biomarkers for Epileptogenesis

A central role for neuroinflammation in epileptogenesis has recently been suggested by several investigations. This systematic review explores the role of inflammatory mediators in epileptogenesis, its association with seizure severity, and its correlation with drug-resistant epilepsy (DRE). The study analysed articles published in JCR journals from 2019 to 2024. The search strategy comprised the MESH, free terms of "Neuroinflammation", and selective searches for the following single biomarkers that had previously been selected from the relevant literature: "High mobility group box 1/HMGB1", "Toll-Like-Receptor 4/TLR-4", "Interleukin-1/IL-1", "Interleukin-6/IL-6", "Transforming growth factor beta/TGF-β", and "Tumour necrosis factor-alpha/TNF-α". These queries were all combined with the MESH terms "Epileptogenesis" and "Epilepsy". We found 243 articles related to epileptogenesis and neuroinflammation, with 356 articles from selective searches by biomarker type. After eliminating duplicates, 324 articles were evaluated, with 272 excluded and 55 evaluated by the authors. A total of 21 articles were included in the qualitative evaluation, including 18 case-control studies, 2 case series, and 1 prospective study. As conclusion, this systematic review provides acceptable support for five biomarkers, including TNF-α and some of its soluble receptors (sTNFr2), HMGB1, TLR-4, CCL2 and IL-33. Certain receptors, cytokines, and chemokines are examples of neuroinflammation-related biomarkers that may be crucial for the early diagnosis of refractory epilepsy or may be connected to the control of epileptic seizures. Their value will be better defined by future studies.

Delayed Deterioration of Electroencephalogram in Patients with Cardiac Arrest: A Cohort Study

BACKGROUND

The aim of this study was to assess the prevalence of delayed deterioration of electroencephalogram (EEG) in patients with cardiac arrest (CA) without early highly malignant patterns and to determine their associations with clinical findings.

METHODS

This was a retrospective study of adult patients with CA admitted to the intensive care unit (ICU) of a university hospital. We included all patients with CA who had a normal voltage EEG, no more than 10% discontinuity, and absence of sporadic epileptic discharges, periodic discharges, or electrographic seizures. Delayed deterioration was classified as the following: (1) epileptic deterioration, defined as the appearance, at least 24 h after CA, of sporadic epileptic discharges, periodic discharges, and status epilepticus; or (2) background deterioration, defined as increasing discontinuity or progressive attenuation of the background at least 24 h after CA. The end points were the incidence of EEG deteriorations and their association with clinical features and ICU mortality.

RESULTS

We enrolled 188 patients in the analysis. The ICU mortality was 46%. Overall, 30 (16%) patients presented with epileptic deterioration and 9 (5%) patients presented with background deterioration; of those, two patients presented both deteriorations. Patients with epileptic deterioration more frequently had an out-of-hospital CA, and higher time to return of spontaneous circulation and less frequently had bystander resuscitation than others. Patients with background deterioration showed a predominantly noncardiac cause, more frequently developed shock, and had multiple organ failure compared with others. Patients with epileptic deterioration presented with a higher ICU mortality (77% vs. 41%; p < 0.01) than others, whereas all patients with background deterioration died in the ICU.

CONCLUSIONS

Delayed EEG deterioration was associated with high mortality rate. Epileptic deterioration was associated with worse characteristics of CA, whereas background deterioration was associated with shock and multiple organ failure.

Effects of L-Type Voltage-Gated Calcium Channel (LTCC) Inhibition on Hippocampal Neuronal Death after Pilocarpine-Induced Seizure

Epilepsy, marked by abnormal and excessive brain neuronal activity, is linked to the activation of L-type voltage-gated calcium channels (LTCCs) in neuronal membranes. LTCCs facilitate the entry of calcium (Ca2+) and other metal ions, such as zinc (Zn2+) and magnesium (Mg2+), into the cytosol. This Ca2+ influx at the presynaptic terminal triggers the release of Zn2+ and glutamate to the postsynaptic terminal. Zn2+ is then transported to the postsynaptic neuron via LTCCs. The resulting Zn2+ accumulation in neurons significantly increases the expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits, contributing to reactive oxygen species (ROS) generation and neuronal death. Amlodipine (AML), typically used for hypertension and coronary artery disease, works by inhibiting LTCCs. We explored whether AML could mitigate Zn2+ translocation and accumulation in neurons, potentially offering protection against seizure-induced hippocampal neuronal death. We tested this by establishing a rat epilepsy model with pilocarpine and administering AML (10 mg/kg, orally, daily for 7 days) post-epilepsy onset. We assessed cognitive function through behavioral tests and conducted histological analyses for Zn2+ accumulation, oxidative stress, and neuronal death. Our findings show that AML's LTCC inhibition decreased excessive Zn2+ accumulation, reactive oxygen species (ROS) production, and hippocampal neuronal death following seizures. These results suggest amlodipine's potential as a therapeutic agent in seizure management and mitigating seizures' detrimental effects.

Serum concentrations of complement C3 and C4 in dogs with idiopathic epilepsy

BACKGROUND

High concentrations of complement factors are presented in serum of animal epilepsy models and human patients with epilepsy.

OBJECTIVES

To determine whether complement dysregulation occurs in dogs with idiopathic epilepsy (IE).

ANIMALS

The study included 49 dogs with IE subgrouped into treatment (n = 19), and nontreatment (n = 30), and 29 healthy dogs.

METHODS

In this case-control study, the serum concentrations of the third (C3) and fourth (C4) components of the complement system were measured using a canine-specific ELISA kit.

RESULTS

Serum C3 and C4 concentrations were significantly higher in dogs with IE (C3, median; 4.901 [IQR; 3.915-6.673] mg/mL, P < .001; C4, 0.327 [0.134-0.557] mg/mL, P = .03) than in healthy control dogs (C3, 3.550 [3.075-4.191] mg/mL; C4, 0.267 [0.131-0.427] mg/mL). No significant differences were observed in serum C3 and C4 concentrations between dogs in the treatment (C3, median; 4.894 [IQR; 4.192-5.715] mg/mL; C4, 0.427 [0.143-0.586] mg/mL) and nontreatment groups (C3, 5.051 [3.702-7.132] mg/mL; C4, 0.258 [0.130-0.489] mg/mL). Dogs with a seizure frequency >3 times/month had significantly higher serum C3 (6.461 [4.695-8.735] mg/mL; P < .01) and C4 (0.451 [0.163-0.675] mg/mL; P = .01) concentrations than those with a seizure frequency ≤3 times/month (C3, 3.859 [3.464-5.142] mg/mL; C4, 0.161 [0.100-0.325] mg/mL).

CONCLUSIONS AND CLINICAL IMPORTANCE

Dysregulation of classical complement pathway was identified in IE dogs. Serum C3 and C4 concentrations could be diagnostic biomarkers for IE in dogs with higher seizure frequency.

Sex differences in physiological response to increased neuronal excitability in a knockin mouse model of pediatric epilepsy

BACKGROUND

Epilepsy is a common neurological disease; however, few if any of the currently marketed antiseizure medications prevent or cure epilepsy. Discovery of pathological processes in the early stages of epileptogenesis has been challenging given the common use of preclinical models that induce seizures in physiologically normal animals. Moreover, despite known sex dimorphism in neurological diseases, females are rarely included in preclinical epilepsy models.

METHODS

We characterized sex differences in mice carrying a pathogenic knockin variant (p.N1768D) in the Scn8a gene that causes spontaneous tonic-clonic seizures (TCs) at ∼3 months of age and found that heterozygous females are more resilient than males in mortality and morbidity. To investigate the cellular mechanisms that underlie female resilience, we utilized blood-brain barrier (BBB) and hippocampal transcriptomic analyses in heterozygous mice before seizure onset (pre-TC) and in mice that experienced ∼20 TCs (post-TC).

RESULTS

In the pre-TC latent phase, both sexes exhibited leaky BBB; however, patterns of gene expression were sexually dimorphic. Females exhibited enhanced oxidative phosphorylation and protein biogenesis, while males activated gliosis and CREB signaling. After seizure onset (chronic phase), females exhibited a metabolic switch to lipid metabolism, while males exhibited increased gliosis and BBB dysfunction and a strong activation of neuroinflammatory pathways.

CONCLUSION

The results underscore the central role of oxidative stress and BBB permeability in the early stages of epileptogenesis, as well as sex dimorphism in response to increasing neuronal hyperexcitability. Our results also highlight the need to include both sexes in preclinical studies to effectively translate results of drug efficacy studies.

Peripheral blood regulatory B and T cells are decreased in patients with focal epilepsy

Patients with focal epilepsy of unknown cause (FEoUC) may display T cell infiltration in post-surgery brain specimens and increased serum levels of pro-inflammatory cytokines produced by B and T cells, indicating potential involvement of adaptive immunity. Our study aimed to investigate the peripheral blood distribution of B and T cell subgroups to find clues supporting the distinct organization of adaptive immunity in FEoUC. Twenty-two patients with FEoUC and 25 age and sex matched healthy individuals were included. Peripheral blood mononuclear cells were immunophenotyped by flow cytometry. Expression levels of anti-inflammatory cytokines and FOXP3 were measured by real-time PCR. Carboxyfluorescein succinimidyl ester (CFSE) proliferation assay was conducted using CD4+ T cells. Patients with FEoUC showed significantly decreased regulatory B (Breg), B1a, plasmablast and regulatory T (Treg) cell percentages, and increased switched memory B and Th17 cell ratios. Moreover, CD4+CD25+CD49d- Tregs of FEoUC patients displayed significantly reduced TGFB1 and FOXP3, but increased IL10 gene expression levels. CD4+ helper T cells of patients with FEoUC gave more exaggerated proliferation responses to phytohemagglutinin, anti-CD3 and anti-CD28 stimulation. Patients with FEoUC display increased effector lymphocyte, decreased regulatory lymphocyte ratios, and impaired Treg function and enhanced lymphocyte proliferation capacity. Overall, this pro-inflammatory phenotype lends support to the involvement of adaptive immunity in FEoUC.

Evaluation of systemic inflammation in seizure phenotypes following meningioma resection

PURPOSE

To investigate the association between perioperative peripheral blood inflammatory markers and seizures in patients who have undergone meningioma resection.

MATERIALS AND METHODS

A single neurosurgery tertiary centre blood bank database was screened to extract pre-operative and post-operative white cell count (WCC), neutrophils, lymphocytes, monocytes, platelets and neutrophil-lymphocyte ratio (NLR) and derived NLR (dNLR). All patients who underwent resection of meningioma from 2012 to 2020 were eligible. Patients were excluded if they had an inflammatory condition, peri-operative infection, medical illness or operative complication.

RESULTS

30 patients suffered pre-operative seizures only, 16 experienced de novo post-operative seizures within 1 year and 42 patients did not experience seizures throughout their treatment timeline. Patients with post-operative de novo seizures had a significantly higher WCC when compared those who never had a seizure (7.1 vs. 4.8x109/L, p =.048, 95 % 1.96 to 5.60). However, this difference of WCC was poorly predictive of de novo seizures at one year (AUC 0.61). dNLR was significantly higher in patients with continued post-operative seizures than in patients in which seizures were terminated with tumour resection (1.2 vs. 0.1, p =.035, 95 % 1.47 to 2.29). dNLR was predictive of seizures at one year with an 87.5 % sensitivity and 82.1 % specificity.

CONCLUSIONS

There is a significantly higher post-operative systemic white cell count response in patients who suffered de novo seizures after meningioma resection. Peripheral blood markers have the potential to predict seizures in patients with meningioma.

Autoimmune and paraneoplastic seizures

Seizures are a common feature of autoimmune encephalitis and are especially prevalent in patients with the commonest autoantibodies, against LGI1, CASPR2 and the NMDA, GABAB, and GABAA receptors. In this chapter, we discuss the classification, clinical, investigation, and treatment aspects of patients with these, and other autoantibody-mediated and -associated, illnesses. We highlight distinctive and common seizure semiologies which, often alongside other features we outline, can help the clinical diagnosis of an autoantibody-associated syndrome. Next, we classify these syndromes by either focusing on whether they represent underlying causative autoantibodies or T-cell-mediated syndromes and on the distinction between acute symptomatic seizures and a more enduring tendency to autoimmune-associated epilepsy, a practical and valuable distinction for both patients and clinicians which relates to the pathogenesis. We emphasize the more effective immunotherapy response in patients with causative autoantibodies, and discuss the emerging evidence for various first-, second-, and third-line immunotherapies. Finally, we highlight available clinical rating scales which can guide autoantibody testing and immunotherapy in patients with seizures of unknown etiology. Throughout, we relate the clinical and therapeutic observations to the immunobiology and neuroscience which drive these seizures.

Neuroinflammation in epileptogenesis: from pathophysiology to therapeutic strategies

Epilepsy is a group of enduring neurological disorder characterized by spontaneous and recurrent seizures with heterogeneous etiology, clinical expression, severity, and prognosis. Growing body of research investigates that epileptic seizures are originated from neuronal synchronized and excessive electrical activity. However, the underlying molecular mechanisms of epileptogenesis have not yet been fully elucidated and 30% of epileptic patients still are resistant to the currently available pharmacological treatments with recurrent seizures throughout life. Over the past two decades years accumulated evidences provide strong support to the hypothesis that neuroinflammation, including microglia and astrocytes activation, a cascade of inflammatory mediator releasing, and peripheral immune cells infiltration from blood into brain, is associated with epileptogenesis. Meanwhile, an increasing body of preclinical researches reveal that the anti-inflammatory therapeutics targeting crucial inflammatory components are effective and promising in the treatment of epilepsy. The aim of the present study is to highlight the current understanding of the potential neuroinflammatory mechanisms in epileptogenesis and the potential therapeutic targets against epileptic seizures.

Microglia in epilepsy

Epilepsy is one of most common chronic neurological disorders, and the antiseizure medications developed by targeting neurocentric mechanisms have not effectively reduced the proportion of patients with drug-resistant epilepsy. Further exploration of the cellular or molecular mechanism of epilepsy is expected to provide new options for treatment. Recently, more and more researches focus on brain network components other than neurons, among which microglia have attracted much attention for their diverse biological functions. As the resident immune cells of the central nervous system, microglia have highly plastic transcription, morphology and functional characteristics, which can change dynamically in a context-dependent manner during the progression of epilepsy. In the pathogenesis of epilepsy, highly reactive microglia interact with other components in the epileptogenic network by performing crucial functions such as secretion of soluble factors and phagocytosis, thus continuously reshaping the landscape of the epileptic brain microenvironment. Indeed, microglia appear to be both pro-epileptic and anti-epileptic under the different spatiotemporal contexts of disease, rendering interventions targeting microglia biologically complex and challenging. This comprehensive review critically summarizes the pathophysiological role of microglia in epileptic brain homeostasis alterations and explores potential therapeutic or modulatory targets for epilepsy targeting microglia.

The Interface between Inflammatory Bowel Disease, Neuroinflammation, and Neurological Disorders

Inflammatory Bowel Disease (IBD) is a complex, chronic inflammatory condition affecting the gastrointestinal tract. IBD has been associated with a variety of neurologic manifestations including peripheral nerve involvement, increased risk of thrombotic, demyelinating and events. Furthermore, an evolving association between IBD and neurodegenerative disorders has been recognized, and early data suggests an increased risk of these disorders in patients diagnosed with IBD. The relationship between intestinal inflammatory disease and neuroinflammation is complex, but the bidirectional interaction between the brain-gut-microbiome axis is likely to play an important role in the pathogenesis of these disorders. Identification of common mechanisms and pathways will be key to developing potential therapies. In this review, we discuss the evolving interface between IBD and neurological conditions, with a focus on clinical, mechanistic, and potentially therapeutic implications.

Mass Spectrometry as a Quantitative Proteomic Analysis Tool for the Search for Temporal Lobe Epilepsy Biomarkers: A Systematic Review

Temporal lobe epilepsy (TLE) is the most common form of epilepsy in adults. Tissue reorganization at the site of the epileptogenic focus is accompanied by changes in the expression patterns of protein molecules. The study of mRNA and its corresponding proteins is crucial for understanding the pathogenesis of the disease. Protein expression profiles do not always directly correlate with the levels of their transcripts; therefore, it is protein profiling that is no less important for understanding the molecular mechanisms and biological processes of TLE. The study and annotation of proteins that are statistically significantly different in patients with TLE is an approach to search for biomarkers of this disease, various stages of its development, as well as a method for searching for specific targets for the development of a further therapeutic strategy. When writing a systematic review, the following aggregators of scientific journals were used: MDPI, PubMed, ScienceDirect, Springer, and Web of Science. Scientific articles were searched using the following keywords: "proteomic", "mass-spectrometry", "protein expression", "temporal lobe epilepsy", and "biomarkers". Publications from 2003 to the present have been analyzed. Studies of brain tissues, experimental models of epilepsy, as well as biological fluids, were analyzed. For each of the groups, aberrantly expressed proteins found in various studies were isolated. Most of the studies omitted important characteristics of the studied patients, such as: duration of illness, type and response to therapy, gender, etc. Proteins that overlap across different tissue types and different studies have been highlighted: DPYSL, SYT1, STMN1, APOE, NME1, and others. The most common biological processes for them were the positive regulation of neurofibrillary tangle assembly, the regulation of amyloid fibril formation, lipoprotein catabolic process, the positive regulation of vesicle fusion, the positive regulation of oxidative stress-induced intrinsic apoptotic signaling pathway, removal of superoxide radicals, axon extension, and the regulation of actin filament depolymerization. MS-based proteomic profiling for a relevant study must accept a number of limitations, the most important of which is the need to compare different types of neurological and, in particular, epileptic disorders. Such a criterion could increase the specificity of the search work and, in the future, lead to the discovery of biomarkers for a particular disease.

Pesticides at brain borders: Impact on the blood-brain barrier, neuroinflammation, and neurological risk trajectories

Pesticides are omnipresent, and they pose significant environmental and health risks. Translational studies indicate that acute exposure to high pesticide levels is detrimental, and prolonged contact with low concentrations of pesticides, as single and cocktail, could represent a risk factor for multi-organ pathophysiology, including the brain. Within this research template, we focus on pesticides' impact on the blood-brain barrier (BBB) and neuroinflammation, physical and immunological borders for the homeostatic control of the central nervous system (CNS) neuronal networks. We examine the evidence supporting a link between pre- and postnatal pesticide exposure, neuroinflammatory responses, and time-depend vulnerability footprints in the brain. Because of the pathological influence of BBB damage and inflammation on neuronal transmission from early development, varying exposures to pesticides could represent a danger, perhaps accelerating adverse neurological trajectories during aging. Refining our understanding of how pesticides influence brain barriers and borders could enable the implementation of pesticide-specific regulatory measures directly relevant to environmental neuroethics, the exposome, and one-health frameworks.

Arundic acid (ONO-2506) downregulates neuroinflammation and astrocyte dysfunction after status epilepticus in young rats induced by Li-pilocarpine

Astrocytes, the most abundant glial cells, have several metabolic functions, including ionic, neurotransmitter and energetic homeostasis for neuronal activity. Reactive astrocytes and their dysfunction have been associated with several brain disorders, including the epileptogenic process. Glial Fibrillary Acidic Protein (GFAP) and S100 calcium-binding protein B (S100B) are astrocyte biomarkers associated with brain injury. We hypothesize that arundic acid (ONO-2506), which is known as an inhibitor of S100B synthesis and secretion, protects the hippocampal tissue from neuroinflammation and astrocyte dysfunction after status epileptics (SE) induction by Li-pilocarpine in young rats. Herein, we investigated the effects of arundic acid treatment, at time points of 6 or 24 h after the induction of SE by Li-pilocarpine, in young rats. In SE animals, arundic acid was able to prevent the damage induced by Li-pilocarpine in the hippocampus, decreasing neuroinflammatory signaling (reducing IL-1β, COX2, TLR4 and RAGE contents), astrogliosis (decreasing GFAP and S100B) and astrocytic dysfunction (recovering levels of GSH, glutamine synthetase and connexin-43). Furthermore, arundic acid improved glucose metabolism and reduced the glutamate excitotoxicity found in epilepsy. Our data reinforce the role of astrocytes in epileptogenesis development and the neuroprotective role of arundic acid, which modulates astrocyte function and neuroinflammation in SE animals.

Kainic acid induced hyperexcitability in thalamic reticular nucleus that initiates an inflammatory response through the HMGB1/TLR4 pathway

OBJECTIVE

To explore the relationship between the proinflammatory factor high-mobility group box 1 (HMGB1) and glutamatergic alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in the development of epilepsy.

METHODS

Thalamic reticular nucleus (TRN) slices were treated with kainic acid (KA) to simulate seizures. Action potentials and spontaneous inhibitory postsynaptic currents (sIPSCs) were recorded within TRN slices using whole-cell patch clamp techniques. The translocation of HMGB1 was detected by immunofluorescence. The HMGB1/TLR4 signaling pathway and its downstream inflammatory factors (IL-1β and NF-κB) were detected by RTPCR, Western blot and ELISA.

RESULTS

KA-evoked spikings were observed in TRN slices and blocked by perampanel. sIPSCs in the TRN were enhanced by KA and reduced by perampanel. The translocation of HMGB1 in the TRN was promoted by KA and inhibited by perampanel. The expression of the HMGB1/TLR4 signaling pathway was promoted by KA and suppressed by perampanel.

CONCLUSION

KA induced hyperexcitability activates the HMGB1/TLR4 pathway, which potentially leading to neuroinflammation in epilepsy.

Immune response in blood before and after epileptic and psychogenic non-epileptic seizures

Inflammatory processes may provoke epileptic seizures and seizures may promote an immune reaction. Hence, the systemic immune reaction is a tempting diagnostic and prognostic marker in epilepsy. We explored the immune response before and after epileptic and psychogenic non-epileptic seizures (PNES). Serum samples collected from patients with videoEEG-verified temporal or frontal lobe epilepsy (TLE or FLE) or TLE + PNES showed increased interleukin-6 (IL-6) levels in between seizures (interictally), compared to controls. Patients with PNES had no increase in IL-6. The IL-6 levels increased transiently even further within hours after a seizure (postictally) in TLE but not in FLE patients. The postictal to interictal ratio of additionally five immune factors were also increased in TLE patients only. We conclude that immune factors have the potential to be future biomarkers for epileptic seizures and that the heterogeneity among different epileptic and non-epileptic seizures may be disclosed in peripheral blood sampling independent of co-morbidities.

From neurons to the neuro-glio-vascular unit: Seizures and brain homeostasis in networks

While seizures are undoubtedly neuronal events, an ensemble of auxiliary brain cells profoundly shapes synaptic transmission in health and disease conditions. Endothelial-astrocyte-pericyte assemblies at the blood-brain barrier (BBB) and neuroglia within the neuro-glio-vascular unit (NGVU) finely tune brain parenchymal homeostasis, safeguarding the ionic and molecular compositions of the interstitial fluid. BBB permeability with neuroinflammation and the resulting loss of brain homeostatic control are unifying mechanisms sustaining aberrant neuronal discharges, with temporal specificities linked to acute (head trauma, stroke, infections) and pre-existent (genetic) or chronic ( dysplasia, tumors, neurodegenerative disorders) pathological conditions. Within this research template, one hypothesis is that the topography of BBB damage and neuroinflammation could associate with symptoms, e.g., limbic structures for seizures or pre-frontal for psychiatric episodes. Another uncharted matter is whether seizure activity, without tissue lesions or sclerosis, is sufficient to promote stable cellular-level maladaptations in networks. Contingent to localization and duration, BBB damage and inflammation forecast pathological trajectories, and the concept of an epileptic NGVU could enable time-sensitive biomarkers to predict disease progression. The coherence between electrographic, imaging and molecular NGVU biomarkers could be established from the epileptogenic to the propagating zones. This paradigm shift could lead to new diagnostic and therapeutic modalities germane to specific epilepsies or when seizure activity represents a comorbidity.

Neuroinflammatory mediators in acquired epilepsy: an update

Epilepsy is a group of chronic neurological disorders that have diverse etiologies but are commonly characterized by spontaneous seizures and behavioral comorbidities. Although the mechanisms underlying the epileptic seizures mostly remain poorly understood and the causes often can be idiopathic, a considerable portion of cases are known as acquired epilepsy. This form of epilepsy is typically associated with prior neurological insults, which lead to the initiation and progression of epileptogenesis, eventually resulting in unprovoked seizures. A convergence of evidence in the past two decades suggests that inflammation within the brain may be a major contributing factor to acquired epileptogenesis. As evidenced in mounting preclinical and human studies, neuroinflammatory processes, such as activation and proliferation of microglia and astrocytes, elevated production of pro-inflammatory cytokines and chemokines, blood-brain barrier breakdown, and upregulation of inflammatory signaling pathways, are commonly observed after seizure-precipitating events. An increased knowledge of these neuroinflammatory processes in the epileptic brain has led to a growing list of inflammatory mediators that can be leveraged as potential targets for new therapies of epilepsy and/or biomarkers that may provide valued information for the diagnosis and prognosis of the otherwise unpredictable seizures. In this review, we mainly focus on the most recent progress in understanding the roles of these inflammatory molecules in acquired epilepsy and highlight the emerging evidence supporting their candidacy as novel molecular targets for new pharmacotherapies of acquired epilepsy and the associated behavioral deficits.

Role of SIRT3 in neurological diseases and rehabilitation training

Sirtuin3 (SIRT3) is a deacetylase that plays an important role in normal physiological activities by regulating a variety of substrates. Considerable evidence has shown that the content and activity of SIRT3 are altered in neurological diseases. Furthermore, SIRT3 affects the occurrence and development of neurological diseases. In most cases, SIRT3 can inhibit clinical manifestations of neurological diseases by promoting autophagy, energy production, and stabilization of mitochondrial dynamics, and by inhibiting neuroinflammation, apoptosis, and oxidative stress (OS). However, SIRT3 may sometimes have the opposite effect. SIRT3 can promote the transfer of microglia. Microglia in some cases promote ischemic brain injury, and in some cases inhibit ischemic brain injury. Moreover, SIRT3 can promote the accumulation of ceramide, which can worsen the damage caused by cerebral ischemia-reperfusion (I/R). This review comprehensively summarizes the different roles and related mechanisms of SIRT3 in neurological diseases. Moreover, to provide more ideas for the prognosis of neurological diseases, we summarize several SIRT3-mediated rehabilitation training methods.

Chronic stress but not acute stress decreases the seizure threshold in PTZ-induced seizure in mice: role of inflammatory response and oxidative stress

Seizure is paroxysmal abnormal electrical discharges in the cerebral cortex. Inflammatory pathways and oxidative stress are involved in the pathophysiology of seizures. Stress can induce an oxidative stress state and increase the production of inflammatory mediators in the brain. We investigated the effects of acute and chronic stresses on the seizure threshold in pentylenetetrazol (PTZ)-induced seizures in mice, considering oxidative stress and inflammatory mediators in the prefrontal cortex. In this study, 30 male Naval Medical Research Institute (NMRI) mice were divided into 3 groups, including acute stress, chronic stress, and control groups. PTZ was used for the induction of seizures. The gene expression of inflammatory markers (IL-1β, TNF-α, NLRP3, and iNOS), malondialdehyde (MDA) level, nitrite level, and total antioxidant capacity (TAC) were assessed in the prefrontal cortex and serum. Our results showed that stress could increase the expression of inflammatory cytokines genes and oxidative stress in the prefrontal cortex of the brain and serum following PTZ-induced seizures, which is associated with increased seizure sensitivity and decreased the seizure threshold. The effects of chronic stress were much more significant than acute stress. We concluded that the effects of chronic stress on seizure sensitivity and enhancement of neuroinflammation and oxidative stress are much greater than acute stress.

Closed-loop direct control of seizure focus in a rodent model of temporal lobe epilepsy via localized electric fields applied sequentially

Direct electrical stimulation of the seizure focus can achieve the early termination of epileptic oscillations. However, direct intervention of the hippocampus, the most prevalent seizure focus in temporal lobe epilepsy is thought to be not practicable due to its large size and elongated shape. Here, in a rat model, we report a sequential narrow-field stimulation method for terminating seizures, while focusing stimulus energy at the spatially extensive hippocampal structure. The effects and regional specificity of this method were demonstrated via electrophysiological and biological responses. Our proposed modality demonstrates spatiotemporal preciseness and selectiveness for modulating the pathological target region which may have potential for further investigation as a therapeutic approach.

The correlation of temporal changes of neutrophil-lymphocyte ratio with seizure severity and the following seizure tendency in patients with epilepsy

Background

Changes in the neutrophil-lymphocyte ratio (NLR) has been reported to be associated with epilepsy. Here we aim to investigate the correlation of temporal changes of NLR level with seizure severity and the follow-up seizure attacks in patients with epilepsy (PWE).

Methods

We performed a retrospective analysis of the laboratory data including leukocyte count and NLR within 24 h of acute seizure and during the follow-up period of 5–14 days after acute seizure (NLR1, NLR2, respectively) in 115 PWE, and 98 healthy individuals were included as controls in this study. The correlation of laboratory data with seizure types, etiology of epilepsy, anti-seizure drugs (ASDs), seizure severity, and the follow-up seizure attacks in PWE was studied.

Results

Leukocyte count (P < 0.001) and NLR level (P < 0.001) were found significantly different between PWE and controls. On the other hand, a multivariable logistic regression analysis showed that NLR1 level (OR = 2.992, P = 0.001) and admission leukocyte (OR = 2.307, P = 0.002) were both independently associated with acute epileptic seizures. Especially, higher NLR1 level was significantly associated with status epileptics (P = 0.013) and recurrent seizures after admission (P < 0.001). Furthermore, the multivariable logistic regression analysis indicated that higher NLR1 was a predictor for the tendency of the following recurrent seizure attacks (OR = 1.144, P = 0.002). NLR2 was inversely correlated with ASDs taken (P = 0.011). Levels of NLR1 (r = 0.441, P < 0.001) and NLR2 (r = 0.241, P = 0.009) were both positively correlated with seizure severity.

Conclusions

Seizures were correlated with the alterations of systemic inflammation reflected by leukocyte and NLR. NLR1 and admission leukocyte were both independently associated with acute epileptic seizures. Higher NLR1 was associated with status epilepticus and independently predicted the tendency of the following epileptic seizures. NLR2 was significantly associated with ASDs taken. Besides, NLR may be used as a biomarker for seizure severity.

Insights into the development of pentylenetetrazole-induced epileptic seizures from dynamic metabolomic changes

Epilepsy is often considered to be a progressive neurological disease, and the nature of this progression remains unclear. Understanding the overall and common metabolic changes of epileptic seizures can provide novel clues for their control and prevention. Herein, a chronic kindling animal model was established to obtain generalized tonic-clonic seizures via the repeated injections of pentylenetetrazole (PTZ) at subconvulsive dose. Dynamic metabolomic changes in plasma and urine from PTZ-kindled rats at the different kindling phases were explored using NMR-based metabolomics, in combination with behavioral assessment, brain neurotransmitter measurement, electroencephalography and histopathology. The increased levels of glucose, lactate, glutamate, creatine and creatinine, together with the decreased levels of pyruvate, citrate and succinate, ketone bodies, asparagine, alanine, leucine, valine and isoleucine in plasma and/or urine were involved in the development and progression of seizures. These altered metabolites reflected the pathophysiological processes including the compromised energy metabolism, the disturbed amino acid metabolism, the peripheral inflammation and changes in gut microbiota functions. NMR-based metabolomics could provide brain disease information by the dynamic plasma and urinary metabolic changes during chronic epileptic seizures, yielding classification of seizure stages and profound insights into controlling epilepsy via targeting deficient energy metabolism.

Influence of methadone on the anticonvulsant efficacy of valproate sodium gabapentin against maximal electroshock seizure in mice by regulation of brain MDA TNF-α

Methadone is the most frequently used opioid therapy worldwide, with controversial effects on oxidative stress homeostasis. This study investigated the effects of intraperitoneal (i.p.) co-administration of methadone (0.1, 0.3, 1, and 3 mg/kg) and valproate sodium (300 mg/kg) or gabapentin (50 mg/kg) in the mice maximal electroshock (MES)-induced seizure model. The adverse effect of drugs was assessed using the chimney test. The levels of tumor necrosis factor-alpha (TNF-α) and malondialdehyde (MDA) contents were measured in mice brains after a single seizure. Administration of methadone alone resulted in a significant reduction in the duration of hind limb extension (HLE) than that in the control group. Methadone pretreatment at doses of 0.1 and 0.3 mg/kg i.p. decreased, and at doses of 1 and 3 mg/kg i.p. had an increasing effect on anticonvulsant efficacy of gabapentin. Pretreatment with all doses of methadone significantly decreased the valproate anticonvulsive efficacy. At doses of 1 and 3 mg/kg i.p. methadone per se increased brain MDA levels after MES-induced seizure. Administration of methadone (0.3 mg/kg i.p.) enhanced and at 3 mg/kg decreased gabapentin effect on brain MDA level, but their co-treatment did not lead to further increase in MDA. Methadone at 0.3–3 mg/kg enhanced the effect of sodium valproate on MDA levels in the brain, but at all doses significantly potentiated its effect on brain TNF-α levels. The drugs did not produce any side effects on motor coordination in experimental animals. In conclusion, methadone showed different effects on anticonvulsant actions of gabapentin and valproate through regulation of brain levels of MDA and TNF-α.

The role of interleukin-17 in epilepsy

Epilepsy is a common neurological disorder that seriously affects human health. It is a chronic central nervous system dysfunction caused by abnormal discharges of neurons. About 50 million patients worldwide are affected by epilepsy. Although epileptic symptoms of most patients are controllable, some patients with refractory epilepsy have no response to antiseizure medications. It is necessary to investigate the pathogenesis of epilepsy and identify new therapeutic targets for refractory epilepsy. Epileptic disorders often accompany cerebral inflammatory reactions. Recently, the role of inflammation in the onset of epilepsy has increasingly attracted attention. The activation of both innate and adaptive immunity plays a significant role in refractory epilepsy. According to several clinical studies, interleukin-17, an essential inflammatory mediator linking innate and adaptive immunity, increased significantly in the body liquid and epileptic focus of patients with epilepsy. Experimental studies also indicated that interleukin-17 participated in epileptogenesis through various mechanisms. This review summarized the current studies about interleukin-17 in epilepsy and aimed at finding new therapeutic targets for refractory epilepsy.

Miconazole exerts disease-modifying effects during epilepsy by suppressing neuroinflammation via NF-κB pathway and iNOS production

Neuroinflammation contributes to the generation of epilepsy and has been proposed as an effective therapeutic target. Recent studies have uncovered the potential effects of the anti-fungal drug miconazole for treating various brain diseases by suppressing neuroinflammation but have not yet been studied in epilepsy. Here, we investigated the effects of different doses of miconazole (5, 20, 80 mg/kg) on seizure threshold, inflammatory cytokines release, and glial cells activation in the pilocarpine (PILO) pentylenetetrazole (PTZ), and intrahippocampal kainic acid (IHKA) models. We demonstrated that 5 and 20 mg/kg miconazole increased seizure threshold, but only 20 mg/kg miconazole reduced inflammatory cytokines release, glial cells activation, and morphological alteration during the early post-induction period (24 h, 3 days). We further investigated the effects of 20 mg/kg miconazole on epilepsy (4 weeks after KA injection). We found that miconazole significantly attenuated cytokines production, glial cells activation, microglial morphological changes, frequency and duration of recurrent hippocampal paroxysmal discharges (HPDs), and neuronal and synaptic damage in the hippocampus during epilepsy. In addition, miconazole suppressed the KA-induced activation of the NF-κB pathway and iNOS production. Our results indicated miconazole to be an effective drug for disease-modifying effects during epilepsy, which may act by attenuating neuroinflammation through the suppression of NF-κB activation and iNOS production. At appropriate doses, miconazole may be a safe and effective approved drug that can easily be repositioned for clinical practice.

Expression Profile of Immunoglobulin G Glycosylation in Children With Epilepsy in Han Nationality

BACKGROUND

Epilepsy is a chronic brain disease that recurs during childhood, and more than half of adult epilepsy originates from childhood. Studies suggested that immunoglobulin G (IgG) glycosylation are closely related to neurological diseases. Here we analyzed the characteristics of the immunoglobulin glycosylation profile of children with epilepsy.

METHODS

Patients were recruited in Taian, Shandong Province from December 2019 to March 2020. Serum IgG glycome composition was analyzed by hydrophilic interaction liquid chromatography with ultra-high-performance liquid chromatography approach.

RESULTS

The proportion of fucosylated glycans in total IgG glycans was 93.72% in the epilepsy patients, which was significantly lower than that in the control group (94.94%). A lower level of total monogalactosylated and digalactosylated glycans were observed in the epilepsy patients group (30.76 and 40.14%) than that in the controls (36.17 and 42.69%). There was no significant difference between the two groups in bisected GlcNAc glycans and sialylated glycans.

CONCLUSION

The decrease of core fucosylation and galactosylation may promote the inflammatory reaction of the body and participate in the occurrence of epilepsy in children.

Inflammation in pediatric epilepsies: Update on clinical features and treatment options

The role of inflammation is increasingly recognized in triggering or sustaining epileptic activity. In the last decades, increasing research has provided definite evidence to support the link between immunity, inflammatory process, and epilepsy. Neuro- and systemic inflammation play a pivotal role in driving epileptogenesis through different pathogenetic mechanisms: the activation of innate immunity in glia, neurons, and microvasculature, the brain mediated by blood-brain barrier (BBB) impairment, and the imbalance of pro- and anti-inflammatory molecules produced by both arms of immunity. More recently, research has focused on the adverse effects of maternal or early-life immune activation and cytokine imbalance on fetal neurodevelopment and postnatal epilepsy. A complex crosstalk between the immune and nervous system, and a crucial interplay of genetic, epigenetic, and environmental factors may influence structures and functions of the developing brain. A better understanding of the inflammatory process in promoting epilepsy implies that targeting specific pathways may be effective in seizure control. Multiple targets have been identified so far, and several antiseizure interventions are obtained by inhibiting inflammatory signaling or protecting/restoring BBB. All this evidence has changed the field of epilepsy research and neuropharmacology. Further developments and new treatments will rapidly emerge to improve seizure management in inflammation-related epilepsies. This article is part of the Special Issue "Severe Infantile Epilepsies".

Therapeutic Potential of Astrocyte Purinergic Signalling in Epilepsy and Multiple Sclerosis

Epilepsy and multiple sclerosis (MS), two of the most common neurological diseases, are characterized by the establishment of inflammatory environment in the central nervous system that drives disease progression and impacts on neurodegeneration. Current therapeutic approaches in the treatments of epilepsy and MS are targeting neuronal activity and immune cell response, respectively. However, the lack of fully efficient responses to the available treatments obviously shows the need to search for novel therapeutic candidates that will not exclusively target neurons or immune cells. Accumulating knowledge on epilepsy and MS in humans and analysis of relevant animal models, reveals that astrocytes are promising therapeutic candidates to target as they participate in the modulation of the neuroinflammatory response in both diseases from the initial stages and may play an important role in their development. Indeed, astrocytes respond to reactive immune cells and contribute to the neuronal hyperactivity in the inflamed brain. Mechanistically, these astrocytic cell to cell interactions are fundamentally mediated by the purinergic signalling and involve metabotropic P2Y1 receptors in case of astrocyte interactions with neurons, while ionotropic P2X7 receptors are mainly involved in astrocyte interactions with autoreactive immune cells. Herein, we review the potential of targeting astrocytic purinergic signalling mediated by P2Y1 and P2X7 receptors to develop novel approaches for treatments of epilepsy and MS at very early stages.

Gut Microbiota as a Hidden Player in the Pathogenesis of Alzheimer's Disease

Alzheimer's disease (AD), the most common neurodegenerative disorder, is accompanied by cognitive impairment and shows representative pathological features, including senile plaques and neurofibrillary tangles in the brain. Recent evidence suggests that several systemic changes outside the brain are associated with AD and may contribute to its pathogenesis. Among the factors that induce systemic changes in AD, the gut microbiota is increasingly drawing attention. Modulation of gut microbiome, along with continuous attempts to remove pathogenic proteins directly from the brain, is a viable strategy to cure AD. Seeking a holistic understanding of the pathways throughout the body that can affect the pathogenesis, rather than regarding AD solely as a brain disease, may be key to successful therapy. In this review, we focus on the role of the gut microbiota in causing systemic manifestations of AD. The review integrates recently emerging concepts and provides potential mechanisms about the involvement of the gut-brain axis in AD, ranging from gut permeability and inflammation to bacterial translocation and cross-seeding.

The Temporal and Spatial Changes of Th17, Tregs, and Related Cytokines in Epilepsy Lesions

The cellular and molecular mechanisms in pathogenesis and development of epilepsy are still unclear. Specific inflammatory mediators and immune cells may play an important role. The aim of the present study was to investigate the temporal and spatial changes of Th17, Tregs, and related cytokines in epilepsy lesions. LiCl-pilocarpine-induced temporal lobe epilepsy (TLE) rat models were established, sensorimotor function was examined using modified neurological severity score (mNSS), cognitive function was evaluated by Morris water maze (MWM) test, pathological damages were detected by H&E staining and Nissl staining, helper T cells 17 (Th17), regulatory CD4+ T cells (Tregs), and their related cytokines were detected by Western blotting and immune staining. Results showed that Th17 and its related cytokines in epilepsy lesions played a role mainly at acute phase of epilepsy, and they were positively correlated with the pathological changes in the hippocampus and neurological and cognitive dysfunction caused by epilepsy. Conversely, Tregs and their related cytokines mainly played a role at progressive phase and had the opposite effect. Th17 and Tregs restricted each other during the recovery phase to achieve functional balance. Our results suggested that Th17, Tregs, and related cytokines in epilepsy lesions played an important role in the pathogenesis and development of epilepsy and balancing Th17 and Tregs may be efficacious therapeutics for patients with epilepsy.

Epileptogenesis in Common Parasitic Infections

Purpose of the review

Neurocysticercosis (NCC) has been well recognized as a leading cause of epilepsy. More recently, studies of other parasitic diseases such as cerebral malaria (CM) and onchocerciasis are yielding novel insights into the pathogenesis of parasite-associated epilepsy. We compare the clinical and electrophysiological findings in epilepsy associated with these highly prevalent parasites and discuss the mechanisms involved in epileptogenesis.

Recent Findings

Electrophysiological and imaging biomarkers continue to emerge, and individuals who are at-risk of developing parasite-associated epilepsies are being identified with greater reliability. While both Taenia solium and Plasmodium falciparum directly affect the brain parenchyma, Onchocerca volvulus is not known to invade the central nervous system. Thus, the causal association between O. volvulus and epilepsy remains controversial.

Summary

Both NCC and CM have a well-defined acute phase when the parasites directly or indirectly invade the brain parenchyma and lead to local inflammatory changes. This is followed by a chronic phase marked by recurrent seizures. However, these stages of epileptogenic process have not been identified in the case of O. volvulus.

Not your usual drug-drug interactions: Monoclonal antibody-based therapeutics may interact with antiseizure medications

Therapeutic monoclonal antibodies (mAbs) have emerged as the fastest growing drug class. As such, mAbs are increasingly being co-prescribed with other drugs, including antiseizure medications (ASMs). Although mAbs do not share direct targets or mechanisms of disposition with small-molecule drugs (SMDs), combining therapeutics of both types can increase the risk of adverse effects and treatment failure. The primary goal of this literature review was identifying mAb-ASM combinations requiring the attention of professionals who are treating patients with epilepsy. Systematic PubMed and Embase searches (1980-2021) were performed for terms relating to mAbs, ASMs, drug interactions, and their combinations. Additional information was obtained from documents from the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA). Evidence was critically appraised - key issues calling for clinicians' consideration and important knowledge gaps were identified, and practice recommendations were developed by a group of pharmacists and epileptologists. The majority of interactions were attributed to the indirect effects of cytokine-modulating antibodies on drug metabolism. Conversely, strong inhibitors or inducers of drug-metabolizing enzymes or drug transporters could potentially interact with the cytotoxic payload of antibody-drug conjugates, and ASMs could alter mAb biodistribution. In addition, mAbs could potentiate adverse ASM effects. Unfortunately, few studies involved ASMs, requiring the formulation of class-based recommendations. Based on the current literature, most mAb-ASM interactions do not warrant special precautions. However, specific combinations should preferably be avoided, whereas others require monitoring and potentially adjustment of the ASM doses. Reduced drug efficacy or adverse effects could manifest days to weeks after mAb treatment onset or discontinuation, complicating the implication of drug interactions in potentially deleterious outcomes. Prescribers who treat patients with epilepsy should be familiar with mAb pharmacology to better anticipate potential mAb-ASM interactions and avoid toxicity, loss of seizure control, or impaired efficacy of mAb treatment.

Sleep Disruption Worsens Seizures: Neuroinflammation as a Potential Mechanistic Link

Sleep disturbances, such as insomnia, obstructive sleep apnea, and daytime sleepiness, are common in people diagnosed with epilepsy. These disturbances can be attributed to nocturnal seizures, psychosocial factors, and/or the use of anti-epileptic drugs with sleep-modifying side effects. Epilepsy patients with poor sleep quality have intensified seizure frequency and disease progression compared to their well-rested counterparts. A better understanding of the complex relationship between sleep and epilepsy is needed, since approximately 20% of seizures and more than 90% of sudden unexpected deaths in epilepsy occur during sleep. Emerging studies suggest that neuroinflammation, (e.g., the CNS immune response characterized by the change in expression of inflammatory mediators and glial activation) may be a potential link between sleep deprivation and seizures. Here, we review the mechanisms by which sleep deprivation induces neuroinflammation and propose that neuroinflammation synergizes with seizure activity to worsen neurodegeneration in the epileptic brain. Additionally, we highlight the relevance of sleep interventions, often overlooked by physicians, to manage seizures, prevent epilepsy-related mortality, and improve quality of life.

Glucocorticoid modulation of synaptic plasticity in the human temporal cortex of epilepsy patients: Does chronic stress contribute to memory impairment?

OBJECTIVE

Memory impairment is common in patients with temporal lobe epilepsy and seriously affects life quality. Chronic stress is a recognized cofactor in epilepsy and can also impair memory function. Furthermore, increased cortisol levels have been reported in epilepsy patients. Animal models have suggested that aggravating effects of stress on memory and synaptic plasticity were mediated via glucocorticoids. The aim of this study was, therefore, to investigate the effect of glucocorticoid receptor (GR) modulation on synaptic plasticity in the human cortex of epilepsy patients.

METHODS

We performed field potential recordings in acute slices from the temporal neocortex of patients who underwent surgery for drug-resistant temporal lobe epilepsy. Synaptic plasticity was investigated by a theta-burst stimulation (TBS) protocol for induction of long-term potentiation (LTP) in the presence of GR modulators.

RESULTS

LTP was impaired in temporal cortex from epilepsy patients. Pretreatment of the slices with the GR antagonist mifepristone (RU486) improved LTP induction, suggesting that LTP impairment was due to baseline GR activation in the human cortex. The highly potent GR agonist dexamethasone additionally weakened synaptic strength in an activity-dependent manner when applied after TBS.

SIGNIFICANCE

Our results show a direct negative glucocorticoid effect on synaptic potentiation in the human cortex and imply chronic activation of GRs. Chronic stress may therefore contribute to memory impairment in patients with temporal lobe epilepsy. Furthermore, the activity-dependent acute inhibitory effect of dexamethasone suggests a mechanism of synaptic downscaling by which postictally increased cortisol levels may prevent pathologic plasticity upon seizures.

Altered cytokine levels in cerebrospinal fluid following ketogenic diet of children with refractory epilepsy

Ketogenic diet is an effective treatment which has the potential to achieve a significant seizure reduction in drug-resistant epilepsy. The mechanism behind this effect is unclear, but one hypothesis is that the mechanism is anti-inflammatory. In this prospective study on pediatric patients we compared levels of cytokines and chemokines in the cerebrospinal fluid before and after three months on treatment to evaluate a possible anti-inflammatory effect. We analyzed 34 cytokines and chemokines in the cerebrospinal fluid of pediatric patients (n = 21) with refractory epilepsy by a multiplex assay. Beta-hydroxybutyric acid was measured in blood and cerebrospinal fluid. Seizure frequency in relation to diet treatment was assessed. For 9 different cytokines (CCL 7, CCL 21, CCL 22, CCL 25, CCL 27, IL-2, IL-10, CX3CL1 and MIF), a significant decrease ranging from 7 to 27% was seen after three months as compared to levels before the diet. In contrast, no cytokine displayed a significant increase during diet. A seizure reduction ≥ 50 % was seen in 15/21 patients (71 %) but no significant differences in cytokine decreases were found between responders and non-responders during treatment. A non-significant trend towards higher initial pre-treatment levels of cytokines was seen in responders, which were reduced following treatment. The levels of betahydroxybutyric acid were not related to seizure response. We conclude that while it is not possible to state a primary anti-inflammatory effect by dietary treatment from these data, an unequivocal immunological effect is seen and may be a part of the mechanism of ketogenic dietary treatment.

Attenuation of cerebral edema facilitates recovery of glymphatic system function after status epilepticus

Status epilepticus (SE) is a neurological emergency usually accompanied by acute cerebral edema and long-term cognitive impairment, and is characterized by neurodegeneration and aberrant hyperphosphorylated tau protein (p-tau) aggregation. The glia-lymphatic (glymphatic) system plays a central role in facilitating the clearance of metabolic waste from the brain, but its relationship with cerebral edema and cognitive dysfunction after SE is unclear. We hypothesized that cerebral edema after SE might impair glymphatic system function through compression, thus leading to impaired removal of metabolic waste, and ultimately affecting long-term cognitive function. Our results showed that glymphatic system function was temporarily impaired, as evidenced by 2-photon imaging, MRI enhancement, imaging of brain sections, and astrocytic water channel aquaporin 4 (AQP4) protein polarization. The severity of cerebral edema on MRI correlated well with glymphatic system dysfunction within 8 days following SE. Moreover, when cerebral edema was alleviated by glibenclamide treatment or genetic deletion of Trpm4, post-SE glymphatic system function recovered earlier, along with fewer p-tau–deposited neurons and neuronal degeneration and better cognitive function. These findings suggest that SE-induced cerebral edema may cause glymphatic system dysfunction and render the post-SE brain vulnerable to p-tau aggregation and neurocognitive impairment.