Interleukin-1beta contributes to the generation of experimental febrile seizures

Upregulations of high mobility group box 1 and TLR4/NF-κB signaling pathway in hippocampus and serum of rats with febrile seizure

PURPOSE

The aim of this study was to explore the alternations regarding the HMGB1 and TLR4/NF-κB signaling pathway in juvenile rats with febrile seizure (FS).

MATERIALS AND METHODS

During the animal modeling of the FS, seizures were triggered every four days by hot water (45 °C), and repeated ten times. After forty days' modeling, rats were divided into different groups according to the degree of seizure (FS (0) - FS (V)). Reverse transcription-polymerase chain reaction (RT-PCR) was used to evaluate the mRNA expressions of the HMGB1, TLR4 and NF-κB in the hippocampus, while Western-blot (WB) and immunofluorescence (IF) were employed to assess protein expressions. The enzyme-linked immunosorbent assay (ELISA) was used for analyzing the protein expressions in peripheral blood.

RESULTS

The mRNA levels of the HMGB1, TLR4 and NF-κB in the hippocampus of both FS (V) and FS (IV) groups were significantly higher than WT, while there was no difference between FS (III) and WT. Concerning protein expressions, increased levels of the HMGB1, TLR4, and NF-κB in FS (V) were observed with a good consistency between the WB and IF, while no significant upregulation was shown in FS (IV). The ELISA results showed that the significance of the augmented proteins between the FS (V) and WT were smaller in the serum than the hippocampus.

CONCLUSIONS

Our study shows seizure degree-related upregulations of HMGB1 and TLR4/NF-κB signaling pathway both in hippocampus and serum of juvenile rats with FS, suggesting the involvement of TLR/NF-κB pathway in inflammation promoted by HMGB1 during FS.

Modeling Alzheimer's disease using human cell derived brain organoids and 3D models

Age-related neurodegenerative diseases, like Alzheimer's disease (AD), are challenging diseases for those affected with no cure and limited treatment options. Functional, human derived brain tissues that represent the diverse genetic background and cellular subtypes contributing to sporadic AD (sAD) are limited. Human stem cell derived brain organoids recapitulate some features of human brain cytoarchitecture and AD-like pathology, providing a tool for illuminating the relationship between AD pathology and neural cell dysregulation leading to cognitive decline. In this review, we explore current strategies for implementing brain organoids in the study of AD as well as the challenges associated with investigating age-related brain diseases using organoid models.

The Impact of Inflammation on Thermal Hyperpnea: Relevance for Heat Stress and Febrile Seizures

Extreme heat caused by climate change is increasing the transmission of infectious diseases, resulting in a sharp rise in heat-related illness and mortality. Understanding the mechanistic link between heat, inflammation, and disease is thus important for public health. Thermal hyperpnea, and consequent respiratory alkalosis, is crucial in febrile seizures and convulsions induced by heat stress in humans. Here, we address what causes thermal hyperpnea in neonates and how it is affected by inflammation. Transient receptor potential cation channel subfamily V member 1 (TRPV1), a heat-activated channel, is sensitized by inflammation and modulates breathing and thus may play a key role. To investigate whether inflammatory sensitization of TRPV1 modifies neonatal ventilatory responses to heat stress, leading to respiratory alkalosis and an increased susceptibility to hyperthermic seizures, we treated neonatal rats with bacterial LPS, and breathing, arterial pH, in vitro vagus nerve activity, and seizure susceptibility were assessed during heat stress in the presence or absence of a TRPV1 antagonist (AMG-9810) or shRNA-mediated TRPV1 suppression. LPS-induced inflammatory preconditioning lowered the threshold temperature and latency of hyperthermic seizures. This was accompanied by increased tidal volume, minute ventilation, expired CO2, and arterial pH (alkalosis). LPS exposure also elevated vagal spiking and intracellular calcium concentrations in response to hyperthermia. TRPV1 inhibition with AMG-9810 or shRNA reduced the LPS-induced susceptibility to hyperthermic seizures and altered the breathing pattern to fast shallow breaths (tachypnea), making each breath less efficient and restoring arterial pH. These results indicate that inflammation exacerbates thermal hyperpnea-induced respiratory alkalosis associated with increased susceptibility to hyperthermic seizures, primarily mediated by TRPV1 localized to vagus neurons.

Conditional Knockout of IL-1R1 in Endothelial Cells Attenuates Seizures and Neurodegeneration via Inhibiting Neuroinflammation Mediated by Nrf2/HO-1/NLRP3 Signaling in Status Epilepticus Model

Studies on the bench and at bedside have demonstrated that the process of epileptogenesis is involved in neuroinflammatory responses. As the receptor of proinflammatory cytokine IL-1β, IL-1β type 1 receptor (IL-1R1) is reported to express abundantly in the endothelial cells in epileptic brains, which is deemed to be implicated in the epileptogenic process. However, whether and how endothelial IL-1R1 modulates neuroinflammatory responses in the pathological process of epileptic seizures and/or status epilepticus (SE) remains obscure. Here, we indicated endothelial IL-1R1 is involved in neuroinflammation, facilitating epilepsy progress via Nrf2/HO-1/NLRP3. In vitro, we observed upregulation of inflammatory cytokines in co-culture model under IL-1β challenge, as well as in BV2 cells after stimulation with conditional medium (CM) from IL-1β-stimulated bEnd.3 cells. In vivo, mice with conditional knockout of endothelial IL-1R1 (IL-1R1-CKO) were generated by hybrid IL-1R1flox/flox mice with Tek-Cre mice. IL-1R1-CKO reduced seizure susceptibility in kainic acid (KA)-induced SE model. In addition, IL-1R1-CKO KA mice exhibited lessened hippocampal neuroinflammation, mitigated neuronal damage, and decreased abnormal neurogenesis. In cognitive behavioral tests, IL-1R1-CKO KA mice presented improvement in learning and memory. Furthermore, we also indicated blockage of endothelial IL-1R1 downregulated the expressions of Nrf2/HO-1/NLRP3 pathway-related proteins. Nrf2-siRNA reversed the downregulation of HO-1, NLRP3, caspase-1, and IL-1β. These results demonstrated CKO of endothelial IL-1R1 reduces seizure susceptibility and attenuates SE-related neurobehavioral damage by suppressing hippocampal neuroinflammation via Nrf2/HO-1/NLRP3.

Interleukins in Epilepsy: Friend or Foe

Epilepsy is a chronic neurological disorder with recurrent unprovoked seizures, affecting ~ 65 million worldwide. Evidence in patients with epilepsy and animal models suggests a contribution of neuroinflammation to epileptogenesis and the development of epilepsy. Interleukins (ILs), as one of the major contributors to neuroinflammation, are intensively studied for their association and modulatory effects on ictogenesis and epileptogenesis. ILs are commonly divided into pro- and anti-inflammatory cytokines and therefore are expected to be pathogenic or neuroprotective in epilepsy. However, both protective and destructive effects have been reported for many ILs. This may be due to the complex nature of ILs, and also possibly due to the different disease courses that those ILs are involved in. In this review, we summarize the contributions of different ILs in those processes and provide a current overview of recent research advances, as well as preclinical and clinical studies targeting ILs in the treatment of epilepsy.

Second-line immunotherapy in new onset refractory status epilepticus

Several pieces of evidence suggest immune dysregulation could trigger the onset and modulate sequelae of new onset refractory status epilepticus (NORSE), including its subtype with prior fever known as febrile infection-related epilepsy syndrome (FIRES). Consensus-driven recommendations have been established to guide the initiation of first- and second-line immunotherapies in these patients. Here, we review the literature to date on second-line immunotherapy for NORSE/FIRES, presenting results from 28 case reports and series describing the use of anakinra, tocilizumab, or intrathecal dexamethasone in 75 patients with NORSE. Among them, 52 patients were managed with anakinra, 21 with tocilizumab, and eight with intrathecal dexamethasone. Most had elevated serum or cerebrospinal fluid cytokine levels at treatment initiation. Treatments were predominantly initiated during the acute phase of the disease (92%) and resulted, within the first 2 weeks, in seizure control for up to 73% of patients with anakinra, 70% with tocilizumab, and 50% with intrathecal dexamethasone. Cytokine levels decreased after treatment for most patients. Anakinra and intrathecal dexamethasone were mainly initiated in children with FIRES, whereas tocilizumab was more frequently prescribed for adults, with or without a prior febrile infection. There was no clear correlation between the response to treatment and the time to initiate the treatment. Most patients experienced long-term disability and drug-resistant post-NORSE epilepsy. Initiation of second-line immunotherapies during status epilepticus (SE) had no clear effect on the emergence of post-NORSE epilepsy or long-term functional outcomes. In a small number of cases, the initiation of anakinra or tocilizumab several years after SE onset resulted in a reduction of seizure frequency for 67% of patients. These data highlight the potential utility of anakinra, tocilizumab, and intrathecal dexamethasone in patients with NORSE. There continues to be interest in the utilization of early cytokine measurements to guide treatment selection and response. Prospective studies are necessary to understand the role of early immunomodulation and its associations with epilepsy and functional outcomes.

Efficacy and safety of ketamine for pediatric and adolescent super-refractory status epilepticus and the effect of cerebral inflammatory conditions

OBJECTIVE

To investigate the short-term benefits and adverse effects of ketamine in the treatment of pediatric and adolescent super-refractory status epilepticus (SRSE), with a focus on the inflammatory etiology.

METHODS

This retrospective observational cohort study included a consecutive series of 18 pediatric to adolescent patients with SRSE admitted between 2008 and 2023 and treated with ketamine. Seizure frequency per hour before and after ketamine administration and response rate were calculated. Neurological decline, catecholamine administration, and adverse effects were also assessed. The patients were divided into inflammatory and non-inflammatory etiology groups.

RESULTS

The median age at SRSE onset was 1 year 5 months (range: 11 days-24 years), and 78% of the patients were male individuals. The median duration of treatment was 7.5 days (interquartile range: 2.8-15.5 days). Fifteen (83%) patients achieved >50% seizure reduction. The median seizure frequency before and after ketamine treatment was 5.9 and 0.9, respectively, showing a significant reduction in seizure frequency (p < 0.0001). Ten patients had inflammatory etiologies including bacterial meningitis (n = 2), viral encephalitis (n = 3), and febrile infection related epilepsy syndrome (n = 5). The inflammatory etiology group required a longer treatment duration (p = 0.0453) and showed lower seizure reduction (p = 0.0264), lower response rate (p = 0.0044), and higher neurological decline (p = 0.0003) than the non-inflammatory etiology group. Three (17%) patients experienced transient adverse events requiring intervention within 24 h of initiating ketamine administration.

CONCLUSIONS

Ketamine administration was associated with fewer serious adverse events and a reduced seizure frequency. Additionally, inflammatory conditions may weaken the efficacy of ketamine in patients with SRSE.

An overview of risk factors in children with febrile seizures

INTRODUCTION

Febrile seizures (FS) are the most common neurologic disorder seen in children. Caused mainly by fever without any damage to the central nervous system (CNS). The associations of several factors, which we can find in the inflammatory response and genetic predisposition, are involved in the occurrence of FS.

AIM

This review provides insight into risk factors, particularly the involvement of the inflammatory response and genetic susceptibility in the occurrence of FS.

METHODS

A PubMed search was performed using the keywords « febrile seizures », « inflammatory response », « Pro-inflammatory cytokines », «And anti-inflammatory cytokines ». The search strategy included meta-analyses, prospective case-control studies, clinical trials, observational studies, and reviews.

RESULTS

Febrile seizures with a peak incidence of 18 months usually occur between 6 months and 5 years. A variety of genetic, inflammatory, and environmental factors, including viruses and vaccines, trigger FS. A positive family history of febrile seizures increases the risk for FS occurrence with (20%) in siblings and (33%) in one parent. The involvement of inflammatory response genes, including the cytokine genes IL1B, IL1R, IL6, and IL4. According to these findings, FS is associated with the activation of a cascade of pro- and anti-inflammatory cytokines and the unbalance between these cytokines in the inflammation regulation plays a role in the development of FS.

CONCLUSION

Current knowledge suggests that genetic susceptibility and inflammatory response dysregulation contribute to FS's genesis.

Do vaccines cause epilepsy? Review of cases in the National Vaccine Injury Compensation Program

OBJECTIVE

The National Childhood Vaccine Injury Act of 1986 created the National Vaccine Injury Compensation Program (VICP), a no-fault alternative to the traditional tort system. Since 1988, the total compensation paid exceeds $5 billion. Although epilepsy is one of the leading reasons for filing a claim, there has been no review of the process and validity of the legal outcomes given current medical information. The objectives were to review the evolution of the VICP program in regard to vaccine-related epilepsy and assess the rationale behind decisions made by the court.

METHODS

Publicly available cases involving epilepsy claims in the VICP were searched through Westlaw and the US Court of Federal Claims websites. All published reports were reviewed for petitioner's theories supporting vaccine-induced epilepsy, respondent's counterarguments, the final decision regarding compensation, and the rationale underlying these decisions. The primary goal was to determine which factors went into decisions regarding whether vaccines caused epilepsy.

RESULTS

Since the first epilepsy case in 1989, there have been many changes in the program, including the removal of residual seizure disorder as a vaccine-related injury, publication of the Althen prongs, release of the acellular form of pertussis, and recognition that in genetic conditions the underlying genetic abnormality rather than the immunization causes epilepsy. We identified 532 unique cases with epilepsy: 105 with infantile spasms and 427 with epilepsy without infantile spasms. The petitioners' experts often espoused outdated, erroneous causation theories that lacked an acceptable medical or scientific foundation and were frequently criticized by the court.

SIGNIFICANCE

Despite the lack of epidemiological or mechanistic evidence indicating that childhood vaccines covered by the VICP result in or aggravate epilepsy, these cases continue to be adjudicated. After 35 years of intense litigation, it is time to reconsider whether epilepsy should continue to be a compensable vaccine-induced injury.

Distribution of peripheral blood mononuclear cell subtypes in patients with West syndrome: Impact of synacthen treatment

BACKGROUND

West Syndrome (WS) is an epileptic encephalopathy that typically occurs in infants and is characterized by hypsarrhythmia, infantile spasms, and neurodevelopmental impairment. Demonstration of autoantibodies and cytokines in some WS patients and favorable response to immunotherapy have implicated inflammation as a putative trigger of epileptiform activity in WS. Our aim was to provide additional support for altered inflammatory responses in WS through peripheral blood immunophenotype analysis.

METHODS

Eight WS cases treated with synacthen and 11 age- and sex-matched healthy volunteers were included. Peripheral blood mononuclear cells (PBMC) were isolated and immunophenotyping was performed in pre-treatment baseline (8 patients) and 3 months post-treatment (6 patients) samples. The analysis included PBMC expressing NFκB transcription and NLRP3 inflammasome factors.

RESULTS

In pre-treatment baseline samples, switched memory B cells (CD19+IgD-CD27+) were significantly reduced, whereas plasma cells (CD19+CD38+CD138+) and cytotoxic T cells (CD3+CD8+) were significantly increased. Regulatory T and B cell ratios were not significantly altered. Synacthen treatment only marginally reduced helper T cell ratios and did not significantly change other T, B, NK and NKT cell and monocyte ratios.

CONCLUSIONS

Our findings lend further support for the involvement of inflammation-related mechanisms in WS. New-onset WS patients are inclined to display increased plasma cells in the peripheral blood. Synacthen treatment does not show a beneficial effect on most effector acquired and innate immunity subsets.

Microglia play beneficial roles in multiple experimental seizure models

Seizure disorders are common, affecting both the young and the old. Currently available antiseizure drugs are ineffective in a third of patients and have been developed with a focus on known neurocentric mechanisms, raising the need for investigations into alternative and complementary mechanisms that contribute to seizure generation or its containment. Neuroinflammation, broadly defined as the activation of immune cells and molecules in the central nervous system (CNS), has been proposed to facilitate seizure generation, although the specific cells involved in these processes remain inadequately understood. The role of microglia, the primary inflammation-competent cells of the brain, is debated since previous studies were conducted using approaches that were less specific to microglia or had inherent confounds. Using a selective approach to target microglia without such side effects, we show a broadly beneficial role for microglia in limiting chemoconvulsive, electrical, and hyperthermic seizures and argue for a further understanding of microglial contributions to contain seizures.

Recurrent febrile seizures and serum cytokines: a controlled follow-up study

BACKGROUND

The role of cytokines in the pathogenesis of febrile seizures (FSs) is unclear, and information regarding cytokine production outside of FS episodes is scarce.

METHODS

In our controlled follow-up study of patients with FSs, we compared the levels of 12 serum cytokines after the patients' first FSs, during febrile episodes without FSs, after recurrent FSs, during healthy periods after FSs, and between patients and controls.

RESULTS

Two-hundred fifty-one patients with first FS participated in the study, of whom 17 (mean age 1.6 years, SD 0.7) with recurrent FSs completed the protocol as required by the sample size calculations. The mean IL-1RA level was higher after the first FSs (2580 pg/mL, SD 1516) than during febrile episodes without FSs (1336 pg/mL, SD 1364, P = 0.006) and healthy periods after FSs (474 pg/mL, SD 901, P = 0.001). IL-1RA levels were also higher during first (2580 pg/mL) and recurrent FSs (2666 pg/mL, SD 1747) in comparison with febrile controls (746 pg/mL, SD 551) (P < 0.001 and P = 0.001, respectively), but there was no difference in the IL-1RA between febrile episodes without FSs and febrile controls.

CONCLUSIONS

Patients with FSs produce stronger inflammatory reactions during febrile episodes with FSs compared with febrile episodes without FSs and febrile controls.

IMPACT

In patients with FSs, IL-1RA was higher following first FS than during febrile episodes without FSs and healthy periods after FSs. IL-1RA was higher in patients with FSs following first and recurrent FSs than in febrile controls. There was no significant difference in IL-1RA between febrile episodes of patients without FSs and febrile controls. Using IL-1RA as a surrogate marker of IL-1 axis activity, our results indicate that patients with FSs produced stronger inflammatory reactions during FS episodes but not during other febrile episodes or healthy periods after FSs. Cytokines may play a role in pathogenesis of FSs.

Jujuboside B inhibits febrile seizure by modulating AMPA receptor activity

ETHNOPHARMACOLOGICAL RELEVANCE

Febrile seizure is a common neurologic disorder with limited treatment occurring in infants and children under the age of five. Jujuboside B (JuB) is a main bioactive saponin component isolated from the Chinese anti-insomnia herbal medicine Ziziphi Spinosae Semen (ZSS), seed of Ziziphus jujuba Mill, which has been proved to exhibit neuroprotective effects recently.

AIM OF THE STUDY

In this study, we aimed at elucidating the effect of JuB on suppressing febrile seizure and the potential mechanisms.

METHODS

Electroencephalogram (EEG) recording was used to monitor the severity of febrile seizures. The JuB in the brain was identified by mass spectrometry. Neuronal excitability was investigated using patch clamp.

RESULTS

JuB (30 mg/kg) significantly prolonged seizure latency and reduced the severity in hyperthermia-induced seizures model mice. Hippocampal neuronal excitability was significantly decreased by JuB. And JuB significantly reduced the excitatory synaptic transmission mediated by α-amino-3-hydroxy-5-methyl-4-iso-xazolepropionic acid receptor (AMPAR), including evoked excitatory postsynaptic currents (eEPSCs), and miniature EPSCs (mEPSCs) in hippocampal neurons. Furthermore, JuB also significantly inhibited recombinant GluA1 and GluA2 mediated AMPA current in HEK293 cell and decreased the upregulation of [Ca²⁺]_i induced by AMPA in primary cultured cortex neurons.

CONCLUSIONS

JuB suppressed the excitability of hippocampal neurons by inhibiting the activity of AMPAR and reducing the intracellular free calcium, thereby relieving febrile seizures.

Microglia play beneficial roles in multiple experimental seizure models

Seizure disorders are common, affecting both the young and the old. Currently available antiseizure drugs are ineffective in a third of patients and have been developed with a focus on known neurocentric mechanisms, raising the need for investigations into alternative and complementary mechanisms that contribute to seizure generation or its containment. Neuroinflammation, broadly defined as the activation of immune cells and molecules in the central nervous system (CNS), has been proposed to facilitate seizure generation, although the specific cells involved in these processes remain inadequately understood. The role of microglia, the primary inflammation-competent cells of the brain, is debated since previous studies were conducted using approaches that were less specific to microglia or had inherent confounds. Using a selective approach to target microglia without such side effects, we show a broadly beneficial role for microglia in limiting chemoconvulsive, electrical, and hyperthermic seizures and argue for a further understanding of microglial contributions to contain seizures.

Anticonvulsant effect of quercetin in pentylenetetrazole (PTZ)-induced seizures in male mice: The role of anti-neuroinflammatory and anti-oxidative stress

BACKGROUND

Epilepsy is one of the major neurological disorders. The inflammatory process and oxidative stress are closely related to seizure progression. Quercetin is a flavonoid with anti-inflammatory and antioxidant properties as well as neuroprotective effects. We aimed to evaluate the effect of quercetin on pentylenetetrazole- (PTZ-) induced seizures in male mice focusing on its possible anti-neuroinflammatory and anti-oxidative stress.

METHODS

In this study, 50 male NMRI mice were divided into five groups (n = 10) and given the following treatments: normal saline, quercetin at doses of 10, 20, and 40 mg/kg, and diazepam at a dose of 10 mg/kg. In order to induce seizures, PTZ was administered intravenously. Drugs were administered intravenously 60 min before the seizure induction. The seizure threshold was measured, and finally, malondialdehyde (MDA), total antioxidant capacity (TAC), and the gene expression of IL-1β, TNF-α, NLRP3, and iNOS were determined in the prefrontal cortex.

RESULTS

It was confirmed that quercetin increased the seizure threshold. And quercetin increased TAC, and decreased levels of MDA as well as gene expression of TNF- α, NLRP3, IL-1β, and iNOS in the prefrontal cortex at the time of seizure induction.

CONCLUSION

It was suggested that the anticonvulsant effect of quercetin in PTZ-induced seizures in mice may be due to the reduction of inflammatory responses and oxidative stress in the prefrontal cortex.

Vascular topology and blood flow are acutely impacted by experimental febrile status epilepticus

Febrile status epilepticus (FSE) is an important risk factor for temporal lobe epilepsy and early identification of those at high risk for epilepsy is vital. In a rat model of FSE, we identified an acute (2 hrs) novel MRI signal where reduced T2 relaxation values in the basolateral amygdala (BLA) predicted epilepsy in adulthood; this T2 signal remains incompletely understood and we hypothesized that it may be influenced by vascular topology. Experimental FSE induced in rat pups reduced blood vessel density of the cortical vasculature in a lateralized manner at 2 hrs post FSE. Middle cerebral artery (MCA) exhibited abnormal topology in FSE pups but not in controls. In the BLA, significant vessel junction reductions and decreased vessel diameter were observed, together with a strong trend for reduced vessel length. Perfusion weighted MRI (PWI) was acutely increased cerebral blood flow (CBF) in cortex, amygdala and hippocampus of FSE pups that correlated to decreased T2 relaxation values compared to controls. This is consistent with increased levels of deoxyhemoglobin associated with increased metabolic demand. In summary, FSE acutely modifies vascular topological and CBF in cortex and BLA that may underlie acute MRI signal changes that predict progression to future epilepsy.

Modulating Expression of Endogenous Interleukin 1 Beta in the Acute Phase of the Pilocarpine Model of Epilepsy May Change Animal Survival

The pilocarpine-induced (PILO) model has helped elucidate the electrophysiological and molecular aspects related to mesial temporal lobe epilepsy. It has been suggested that the extensive cell death and edema observed in the brains of these animals could be induced by increased inflammatory responses, such as the rapid release of the inflammatory cytokine interleukin 1 beta (Il1b). In this study, we investigate the role of endogenous Il1b in the acute phase of the PILO model. Our aim is twofold. First, we want to determine whether it is feasible to silence Il1b in the central nervous system using a non-invasive procedure. Second, we aim to investigate the effect of silencing endogenous Il1b and its antagonist, Il1rn.We used RNA interference applied non-invasively to knockdown Il1b and its endogenous antagonist Il1rn. We found that knocking down Il1b prior to pilocarpine injection increased the mortality rate of treated animals. Furthermore, we observed that, when exposing the animals to more Il1b by silencing its endogenous antagonist Il1rn, there was a better response to status epilepticus with decreased animal mortality in the acute phase of the PILO model. Thus, we show the feasibility of using a novel, less invasive approach to study genes involved in the inflammatory response in the central nervous system. Furthermore, our results provide suggestive evidence that modulating endogenous Il1b improves animal survival in the acute phase of the PILO model and may have effects that extend into the chronic phase.

The JAK-STAT Signaling Pathway in Epilepsy

Epilepsy is defined as spontaneous recurrent seizures in the brain. There is increasing evidence that inflammatory mediators and immune cells are involved in epileptic seizures. As more research is done on inflammatory factors and immune cells in epilepsy, new targets for the treatment of epilepsy will be revealed. The Janus kinase-signal transducer and transcriptional activator (JAKSTAT) signaling pathway is strongly associated with many immune and inflammatory diseases, At present, more and more studies have found that the JAK-STAT pathway is involved in the development and development of epilepsy, indicating the JAK-STAT pathway's potential promise as a target in epilepsy treatment. In this review, we discuss the composition, activation, and regulation of the JAK-STAT pathway and the relationship between the JAK-STAT pathway and epilepsy. In addition, we summarize the common clinical inhibitors of JAK and STAT that we would expect to be used in epilepsy treatment in the future.

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.

Effects of Diclofenac Sodium on Seizure Activity in Rats with Pentylenetetrazole-Induced Convulsions

Epilepsy is a disease which affects between 1 and 2% of the population, and a large proportion of these people do not react to currently available anticonvulsant medications, indicating the need for further research into novel pharmacological therapies. Numerous studies have demonstrated that oxidative stress and inflammation occur during epilepsy and may contribute to its development and progression, indicating higher levels of oxidative and inflammatory parameters in experimental models and clinical patients. This research aimed to assess the impact of diclofenac sodium, a nonsteroidal anti-inflammatory medicine, on seizure and levels of oxidative stress and inflammatory biomarkers in a rat model of epilepsy triggered by pentylenetetrazole (PTZ). 60 rats were randomly allocated to one of two groups: electroencephalography (EEG) recordings or behavioral evaluation. Rats received diclofenac sodium at three various doses (25, 50, and 75 mg/kg) intraperitoneally (IP) or a placebo, followed by intraperitoneal (IP) pentylenetetrazole, a powerful seizure-inducing medication. To investigate if diclofenac sodium had antiseizure properties, seizure activity in rats was evaluated using EEG recordings, the Racine convulsion scale (RCS) behaviour score, the duration of the first myoclonic jerk (FMJ), and the levels of MDA, TNF-α, and SOD. The average percentage of EEG spike waves decreased from 76.8% (placebo) to 64.1% (25 mg/kg diclofenac), 55.9% (50 mg/kg diclofenac), and 37.8% (75 mg/kg diclofenac). FMJ had increased from a mean of 58.8 s (placebo), to 93.6 s (25 mg/kg diclofenac), 185.8 s (50 mg/kg diclofenac) and 231.7 s (75 mg/kg diclofenac). RCS scores decreased from a mean score of 5.6 (placebo), to 3.75 (25 mg/kg diclofenac), 2.8 (50 mg/kg diclofenac) and 1.75 (75 mg/kg diclofenac). MDA levels reduced from 14.2 ng/gr (placebo) to 9.6 ng/gr (25 mg/kg diclofenac), 8.4 ng/gr (50 mg/kg diclofenac) and 5.1 ng/gr (75 mg/kg diclofenac). Likely, TNF-α levels decreased from 67.9 ng/gr (placebo) to 48.1 ng/gr (25 mg/kg diclofenac), 33.5 ng/gr (50 mg/kg diclofenac) and 21.3 ng/gr (75 mg/kg diclofenac). SOD levels, however, enhanced from 0.048 U/mg (placebo) to 0.055 U/mg (25 mg/kg diclofenac), 0.14 U/mg (50 mg/kg diclofenac), and 0.18 U/mg (75 mg/kg diclofenac). Diclofenac sodium (25, 50, and 75 mg/kg i.p.) effectively lowered the spike percentages and RCS scores linked with PTZ-induced epilepsy in rats, as well as significantly decreased MDA, TNF-α, IL-1β, PGE2 and increased SOD levels. Probably as a result of its anti-oxidative and anti-inflammatory effects, diclofenac sodium dramatically lowered seizure activity at both doses compared to placebo control. Each of these results were significant, with p-values of < 0.01, < 0.05. Therefore, the therapeutic application diclofenac sodium as a potential anticonvulsant should be investigated further.

Lipopolysaccharide (LPS) increases susceptibility to epilepsy via interleukin-1 type 1 receptor signaling

Epilepsy is the most common disease of the nervous system, characterized by aberrant normal brain activity. Neuroinflammation is a prominent feature in the brain in epileptic humans and animal models of epilepsy. However, it remains elusive as to how peripheral inflammation affects epilepsy. Herein we demonstrated significantly greater seizure susceptibility and severity of epilepsy under kainic acid (KA) via intraperitoneal (i.p.) injection of lipopolysaccharide (LPS) in mouse model of epilepsy. Nissl staining was employed for assessment of the neuronal damage, immunofluorescence for staining of the microglial cells and astrocytes in the mouse brain slices, and ELISA for detection of the changes of inflammatory factors. We observed a smaller population of viable neurons in CA1 and CA3 regions, a greater population of IBA-1-positive and GFAP-positive cells, with a significant upregulation of IL-1β and IL-6 in hippocampus of epileptic mice when treated with LPS, indicating that LPS aggravates hippocampal neuron injury in epilepsy, and induces neuroinflammation in the hippocampus. In addition, we provide an evident increase in BrdU⁺/DCX⁺ and Nestin⁺ cell populations in dentate gyrus (DG) in LPS-treated group, versus saline group on epileptic mouse model, which demonstrated LPS treatment enhanced hippocampal neurogenesis. In order to investigate whether interleukin-1 type 1 (IL-1R1) signaling is involved in this process, we adopted IL-1R1 globally restored mice (IL-1R1^GR/GR) as an IL-1R1 reporter to visualize labeling of IL-1R1 mRNA and protein by means of RFP staining. Strikingly, the RFP immunofluorescence revealed increased IL-1R1 expression in LPS-treated group, versus saline group. Further, blockage of central IL-1R1 alleviated seizure susceptibility and severity of epilepsy. In summary, our findings suggested that LPS could enhance central inflammatory response and aggravate the susceptibility to epileptic seizure, which we postulated to be mediated by IL-1R1.

Intravenous ganaxolone in pediatric super-refractory status epilepticus: A single hospital experience

Synaptic GABA_A receptor (GABA_AR) internalization contributes to the drug resistant nature of super-refractory status epilepticus (SRSE). Ganaxolone is a 3β-methylated synthetic analog of the endogenous neuroactive steroid, allopregnanolone, that has positive allosteric modulatory activity on synaptic and extrasynaptic GABA_A receptors. Ganaxolone is currently in clinical trials to treat rare pediatric seizure disorders and established and refractory SE. Two pediatric patients with SRSE (age 17 and age 7) were treated under emergency investigational new drug (E-IND) applications with intravenous (IV) ganaxolone administered as an initial bolus and a maintenance infusion for up to 4.5 days with intermittent IV boluses as-needed followed by taper on day 5 and transitioned to chronic treatment using ganaxolone suspension. Adjunctive ganaxolone was effective in terminating SRSE in both patients, safely permitting IV anesthetics to be weaned. Seizure control has been maintained after transitioning to enteric ganaxolone. Further investigation of ganaxolone as a safe and effective treatment for SRSE is warranted.

Neuronal hyperexcitability in Alzheimer's disease: what are the drivers behind this aberrant phenotype?

Alzheimer's disease (AD) is a progressive neurodegenerative disorder leading to loss of cognitive abilities and ultimately, death. With no cure available, limited treatments mostly focus on symptom management. Identifying early changes in the disease course may provide new therapeutic targets to halt or reverse disease progression. Clinical studies have shown that cortical and hippocampal hyperactivity are a feature shared by patients in the early stages of disease, progressing to hypoactivity during later stages of neurodegeneration. The exact mechanisms causing neuronal excitability changes are not fully characterized; however, animal and cell models have provided insights into some of the factors involved in this phenotype. In this review, we summarize the evidence for neuronal excitability changes over the course of AD onset and progression and the molecular mechanisms underpinning these differences. Specifically, we discuss contributors to aberrant neuronal excitability, including abnormal levels of intracellular Ca²⁺ and glutamate, pathological amyloid β (Aβ) and tau, genetic risk factors, including APOE, and impaired inhibitory interneuron and glial function. In light of recent research indicating hyperexcitability could be a predictive marker of cognitive dysfunction, we further argue that the hyperexcitability phenotype could be leveraged to improve the diagnosis and treatment of AD, and present potential targets for future AD treatment development.

The effect of oxytocin and an enriched environment on anxiety-like behaviour and corticosterone levels in a prenatally stressed febrile seizure rat model

Background

Febrile seizures (FS) are a neurological abnormality which occur following a fever that has resulted from a systemic infection and are characterised by convulsions. These convulsions occur due to abnormally increased signalling of interleukin-1 beta, resulting in increased neuronal hyper-excitability. Furthermore, exposure to prenatal stress has been shown to exacerbate seizure duration, elicit anxiety-like behaviour and corticosterone levels. Oxytocin is a neuropeptide with anxiolytic, social bonding, and stress regulation effects. Therefore, the aim of the study was to assess whether oxytocin can attenuate the anxiety-like behaviour and increased corticosterone in rat offspring exposed to prenatal stress and FS.

Method

Sprague Dawley rats were mated. On GND14, prenatal stress was induced on pregnant dams for 1 hr/7 days. On PND 14, rat pups were injected with lipopolysaccharide (LPS, 200 μg/kg, i.p.) followed 2.5 h later by an i.p. injection of kainic acid (KA, 1.75 mg/kg). Oxytocin (1 mg/kg) was induced via different routes (intraperitoneal or intranasal) as well an enriched environment between PND 22-26. The enriched environment included larger cages (1560 cm²) with only 4 pups per cage, compared to those groups not receiving enrichment (646 cm²), as well as cardboard rolls and plastic toys. On PND 27-33 the light/dark box and elevated plus maze were used to assess anxiety-like behaviour. On PND 34 all rats were euthanized using a sharp guillotine, trunk blood and hypothalamic tissue were collected for neurochemical analysis (ELISA kit).

Results

Our findings confirmed that exposure to both prenatal stress and febrile seizures resulted anxiety-like behaviour and significantly higher plasma corticosterone concentrations compared to their counterparts. Environmental enrichment was significantly effective in attenuating the increased basal corticosterone levels and anxiety-like behaviour seen in the prenatally stressed FS rat. Although direct administration of oxytocin showed higher significance in reducing corticosterone plasma levels when compared to the enriched environment. Furthermore, hypothalamic oxytocin levels were not significant in rat exposed to environmental enrichment while oxytocin treatment showed a significant effect when compared to their counterparts.

Conclusion

Therefore, oxytocin administration during early postnatal development shows great potential in reversing the effects of prenatal stress and its subsequent exacerbation of FS.

Molecular Mechanisms in the Genesis of Seizures and Epilepsy Associated With Viral Infection

Seizures are a common presenting symptom during viral infections of the central nervous system (CNS) and can occur during the initial phase of infection ("early" or acute symptomatic seizures), after recovery ("late" or spontaneous seizures, indicating the development of acquired epilepsy), or both. The development of acute and delayed seizures may have shared as well as unique pathogenic mechanisms and prognostic implications. Based on an extensive review of the literature, we present an overview of viruses that are associated with early and late seizures in humans. We then describe potential pathophysiologic mechanisms underlying ictogenesis and epileptogenesis, including routes of neuroinvasion, viral control and clearance, systemic inflammation, alterations of the blood-brain barrier, neuroinflammation, and inflammation-induced molecular reorganization of synapses and neural circuits. We provide clinical and animal model findings to highlight commonalities and differences in these processes across various neurotropic or neuropathogenic viruses, including herpesviruses, SARS-CoV-2, flaviviruses, and picornaviruses. In addition, we extensively review the literature regarding Theiler's murine encephalomyelitis virus (TMEV). This picornavirus, although not pathogenic for humans, is possibly the best-characterized model for understanding the molecular mechanisms that drive seizures, epilepsy, and hippocampal damage during viral infection. An enhanced understanding of these mechanisms derived from the TMEV model may lead to novel therapeutic interventions that interfere with ictogenesis and epileptogenesis, even within non-infectious contexts.

New and emerging pharmacologic treatments for developmental and epileptic encephalopathies

PURPOSE OF REVIEW

Summarize evidence on Developmental and Epileptic Encephalopathies (DEEs) treatments focusing on new and emerging pharmacologic therapies (see Video, http://links.lww.com/CONR/A61, Supplementary Digital Content 1, which provides an overview of the review).

RECENT FINDINGS

Advances in the fields of molecular genetics and neurobiology have led to the recognition of underlying pathophysiologic mechanisms involved in an increasing number of DEEs that could be targeted with precision therapies or repurposed drugs, some of which are currently being evaluated in clinical trials. Prompt, optimal therapy is critical, and promising therapies approved or in clinical trials for tuberous sclerosis complex, Dravet and Lennox-Gastaut Syndromes including mammalian target of rapamycin inhibitors, selective membrane channel and antisense oligonucleotide modulation, and repurposed drugs such as fenfluramine, stiripentol and cannabidiol, among others, may improve seizure burden and neurological outcomes. There is an urgent need for collaborative efforts to evaluate the efficacy and safety of emerging DEEs therapies.

SUMMARY

Development of new therapies promise to address unmet needs for patients with DEEs, including improvement of neurocognitive function and quality of life.

The Function of NF-Kappa B During Epilepsy, a Potential Therapeutic Target

The transcriptional regulator nuclear factor kappa B (NF-κB) modulates cellular biological activity by binding to promoter regions in the nucleus and transcribing various protein-coding genes. The NF-κB pathway plays a major role in the expressing genes related to inflammation, including chemokines, interleukins, and tumor necrosis factor. It also transcribes genes that can promote neuronal survival or apoptosis. Epilepsy is one of the most common brain disorders and it not only causes death worldwide but also affects the day-to-day life of affected individuals. While epilepsy has diverse treatment options, there remain patients who are not sensitive to the existing treatment methods. Recent studies have implicated the critical role of NF-κB in epilepsy. It is upregulated in neurons, glial cells, and endothelial cells, due to neuronal loss, glial cell proliferation, blood-brain barrier dysfunction, and hippocampal sclerosis through the glutamate and γ-aminobutyric acid imbalance, ion concentration changes, and other mechanisms. In this review, we summarize the functional changes caused by the upregulation of NF-κB in the central nervous system during different periods after seizures. This review is the first to deconvolute the complicated functions of NF-κB, and speculate that the regulation of NF-κB can be a safe and effective treatment strategy for epilepsy.

The Therapeutic Prospects of Targeting IL-1R1 for the Modulation of Neuroinflammation in Central Nervous System Disorders

The interleukin-1 receptor type 1 (IL-1R1) holds pivotal roles in the immune system, as it is positioned at the “epicenter” of the inflammatory signaling networks. Increased levels of the cytokine IL-1 are a recognized feature of the immune response in the central nervous system (CNS) during injury and disease, i.e., neuroinflammation. Despite IL-1/IL-1R1 signaling within the CNS having been the subject of several studies, the roles of IL-1R1 in the CNS cellular milieu still cause controversy. Without much doubt, however, the persistent activation of the IL-1/IL-1R1 signaling pathway is intimately linked with the pathogenesis of a plethora of CNS disease states, ranging from Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS), all the way to schizophrenia and prion diseases. Importantly, a growing body of evidence is showing that blocking IL-1R1 signaling via pharmacological or genetic means in different experimental models of said CNS diseases leads to reduced neuroinflammation and delayed disease progression. The aim of this paper is to review the recent progress in the study of the biological roles of IL-1R1, as well as to highlight key aspects that render IL-1R1 a promising target for the development of novel disease-modifying treatments for multiple CNS indications.

Vaccination and childhood epilepsies

INTRODUCTION

The evidence relating vaccination to febrile seizures and epilepsy is evaluated with an emphasis on febrile seizures (FS), Dravet syndrome (DS), West syndrome, and other developmental and epileptic encephalopathies.

METHODS

A systematic literature review using search words vaccination/immunization AND febrile seizures/epilepsy/Dravet/epileptic encephalopathy/developmental encephalopathy was performed. The role of vaccination as the cause/trigger/aggravation factor for FS or epilepsies and preventive measures were analyzed.

RESULTS

From 1428 results, 846 duplicates and 447 irrelevant articles were eliminated; 120 were analyzed.

CONCLUSIONS

There is no evidence that vaccinations cause epilepsy in healthy populations. Vaccinations do not cause epileptic encephalopathies but may be non-specific triggers to seizures in underlying structural or genetic etiologies. The first seizure in DS may be earlier in vaccinated versus non-vaccinated patients, but developmental outcome is similar in both groups. Children with a personal or family history of FS or epilepsy should receive all routine vaccinations. This recommendation includes DS. The known risks of the infectious diseases prevented by immunization are well established. Vaccination should be deferred in case of acute illness. Acellular pertussis DTaP (diphtheria-tetanus-pertussis) is recommended. The combination of certain vaccine types may increase the risk of febrile seizures however the public health benefit of separating immunizations has not been proven. Measles-containing vaccine should be administered at age 12-15 months. Routine prophylactic antipyretics are not indicated, as there is no evidence of decreased FS risk and they can attenuate the antibody response following vaccination. Prophylactic measures (preventive antipyretic medication) are recommended in DS due to the increased risk of prolonged seizures with fever.

Protective effect of Toll-like receptor 4 antagonist on inflammation, EEG, and memory changes following febrile seizure in Wistar rats

Neuroinflammation and fever are the main triggers in febrile seizures (FS). Focusing on inflammatory pathways and anti-inflammatory drugs could compensate for the limitations of existing medications. The aim of this study is to evaluate the neuroprotective effect of specific antagonizing Toll-like receptor 4 (TLR4), as a prominent inflammatory axis, on the consequences of FS and adulthood using animal models. Complex FS was induced on 9-11 day old male rat pups using a heated chamber. TAK-242, as a specific TLR4 inhibitor, was injected intraperitoneally before seizure induction. Seizure threshold, duration, and spike number were measured by electrocorticography. The levels of inflammatory cytokines, TLR4 protein expression, and oxidative stress markers were detected by enzyme-linked immunosorbent assay, western blotting, malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD) assessments in the cortex and hippocampus. Also, spatial and non-spatial memory were evaluated using the novel object recognition test (NORT) and double Y-maze test during adulthood. The results revealed that provoked inflammatory responses in neonate rats, after FS, were associated with the increase of the tumor necrosis factor alpha, interleukin-1β, and enhanced TLR4 protein expression. Meanwhile, based on performed behavioral tests, the inflammatory process was also involved in adulthood memory deficit. Pretreatment with TAK-242 reduced the inflammatory cytokines and TLR4 protein expression in the cortex and hippocampus of neonate rats and improvement in memory deficit in NORT and double Y-maze tasks. Also, pretreatment with TAK-242 elevated seizure threshold, SOD, and CAT activities, and decreased seizure duration and MDA level with no significant change in spike number. TAK-242 possibly controlled FS via inhibiting inflammation.

Pharmacotherapy for SARS-CoV-2 and Seizures for drug repurposing presumed on Mechanistic Targets

BACKGROUND

The currently circulating novel SARS-CoV-2 coronavirus disease (COVID-19) has brought the whole world to a standstill. Recent studies have deciphered the viral genome structure, epidemiology and are in the process of unveiling multiple mechanisms of pathogenesis. Apart from atypical pneumonia and lung disease manifestations, this disease has also been found to be associated with neurological symptoms, which include dizziness, headache, stroke, or seizures, among others. However, a possible direct or indirect association between SARS-CoV-2 and seizures is still not clear. In any manner, it may be of interest to analyze the drugs being used for viral infection in the background of epilepsy or vice versa.

OBJECTIVE

To identify the most credible drug candidate for COVID-19 in persons with epilepsy or COVID-19 patients experiencing seizures.

METHODS

A literature search for original and review articles was performed, and further, the Comparative Toxicogenomics Database was used to unearth the most credible drug candidate.

RESULTS

Our search based on common mechanistic targets affecting SARS-CoV-2 and seizures revealed ivermectin, dexamethasone, anakinra, and tocilizumab for protection against both COVID-19 and seizures. Amongst the antiseizure medications, we found valproic acid as the most probable pharmacotherapy for COVID-19 patients experiencing seizures.

CONCLUSION

These findings would hopefully provide the basis for initiating further studies on the pathogenesis and drug targeting strategies for this emerging infection accompanied with seizures or in people with epilepsy.

Brain profiling in murine colitis and human epilepsy reveals neutrophils and TNFα as mediators of neuronal hyperexcitability

BACKGROUND

Patients with chronic inflammatory disorders such as inflammatory bowel disease frequently experience neurological complications including epilepsy, depression, attention deficit disorders, migraines, and dementia. However, the mechanistic basis for these associations is unknown. Given that many patients are unresponsive to existing medications or experience debilitating side effects, novel therapeutics that target the underlying pathophysiology of these conditions are urgently needed.

METHODS

Because intestinal disorders such as inflammatory bowel disease are robustly associated with neurological symptoms, we used three different mouse models of colitis to investigate the impact of peripheral inflammatory disease on the brain. We assessed neuronal hyperexcitability, which is associated with many neurological symptoms, by measuring seizure threshold in healthy and colitic mice. We profiled the neuroinflammatory phenotype of colitic mice and used depletion and neutralization assays to identify the specific mediators responsible for colitis-induced neuronal hyperexcitability. To determine whether our findings in murine models overlapped with a human phenotype, we performed gene expression profiling, pathway analysis, and deconvolution on microarray data from hyperexcitable human brain tissue from patients with epilepsy.

RESULTS

We observed that murine colitis induces neuroinflammation characterized by increased pro-inflammatory cytokine production, decreased tight junction protein expression, and infiltration of monocytes and neutrophils into the brain. We also observed sustained neuronal hyperexcitability in colitic mice. Colitis-induced neuronal hyperexcitability was ameliorated by neutrophil depletion or TNFα blockade. Gene expression profiling of hyperexcitable brain tissue resected from patients with epilepsy also revealed a remarkably similar pathology to that seen in the brains of colitic mice, including neutrophil infiltration and high TNFα expression.

CONCLUSIONS

Our results reveal neutrophils and TNFα as central regulators of neuronal hyperexcitability of diverse etiology. Thus, there is a strong rationale for evaluating anti-inflammatory agents, including clinically approved TNFα inhibitors, for the treatment of neurological and psychiatric symptoms present in, and potentially independent of, a diagnosed inflammatory disorder.

Serum brain-derived neurotrophic factor in the diagnosis of febrile seizure

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is a noncovalently linked homodimer protein from the neurotrophic growth factor family. Although it is expressed throughout the brain, it is produced more intensively in the entorhinal cortex and hippocampus and can cross the blood-brain barrier in two directions easily. The aim of this study is to understand, for the first time, whether there is a relationship between febrile seizure (FS) and BDNF.

METHODS

The study included cases diagnosed with FS and febrile illness, of similar age, weight, and height, between 6 months and 6 years. Samples for serum BDNF measurement were taken within the first 24-48 h of admission at the hospital and levels were measured using the commercial enzyme-linked immunosorbent assay kit and expressed in ng/mL.

RESULTS

Eighty cases (40 FS, 40 febrile illness) were included in the study. The mean serum BDNF was found to be 6.7 ± 2.4 ng/mL in the FS group and 4.5 ± 2.6 ng/mL in the febrile illness group (P = 0.001). No relation was found between gender, age, body weight, length, and platelet counts and serum BDNF levels. The optimal cut-off value for serum BDNF was found to be 5.2 ng/mL (75% sensitivity, 62.5% specificity, AUC: 0.723) to distinguish between FS and febrile illness.

CONCLUSIONS

Excluding demographic variables such as gender, age, weight, length, and platelet counts serum BDNF levels have increased in children with FS. Considering the hippocampal origin of FS, we can suggest that the pathophysiology of FS may be related to the BDNF.

Multidimensional Approach Assessing the Role of Interleukin 1 Beta in Mesial Temporal Lobe Epilepsy

We aimed to investigate the role of interleukin-1 beta (IL-1β) in the mechanisms underlying mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE+HS). We assessed a cohort of 194 patients with MTLE+HS and 199 healthy controls. Patients were divided into those with positive and negative antecedent febrile seizures (FS). We used a multidimensional approach, including (i) genetic association with single nucleotide polymorphisms (SNPs) in the IL1B gene; (ii) quantification of the IL1B transcript in the hippocampal tissue of patients with refractory seizures; and (iii) quantification of the IL-1β protein in the plasma. We found a genetic association signal for two SNPs, rs2708928 and rs3730364^*C in the IL1B gene, regardless of the presence of FS (adjusted p = 9.62e–11 and 5.14e–07, respectively). We found no difference between IL1B transcript levels when comparing sclerotic hippocampal tissue from patients with MTLE+HS, without FS, and hippocampi from autopsy controls (p > 0.05). Nevertheless, we found increased IL-1β in the plasma of patients with MTLE+HS with FS compared with controls (p = 0.0195). Our results support the hypothesis of a genetic association between MTLE+HS and the IL1B gene

Inflammatory Biomarkers in Febrile Seizure: A Comprehensive Bibliometric, Review and Visualization Analysis

Background: Inflammatory markers association with many diseases is the subject of many articles and reviews. This study presents a comprehensive bibliometric review and visualization analysis of inflammatory biomarkers (IB) in the context of febrile seizure (FS) patients. Methods: The study focused on IB in FS using (1) bibliometric analysis specific indicators and maps in order to analyze and present the network of authors, journals, universities, and countries, and (2) automated literature screening and unsupervised clustering approach for filtering and topic cluster identification. Results: We conducted a literature mining search on FS research, specifically IB in the context of FS, using the automated tools VOSviewer and Bibliometrix. Indices of the inflammatory response (in the context of febrile seizures) identified by the literature mining are (pro/anti-inflammatory) cytokines, such as interleukin IL-1β, IL-6, IL-8, I-10, IL-22, tumor necrosis factor (TNF-α), neutrophil-to-lymphocyte ratio (NLR), mean platelet volume (MPV), platelet count (PLT), and red blood cell distribution width (RDW). The resulted bibliometric maps and topic clusters offer a comprehensive overview, the status and leading trends on existing research of inflammatory biomarkers in FS. Conclusion: The analysis using bibliometrics and review with graphical presentations can be useful in investigating and (better) understanding the relationship between FS and IB.

Seizure control after late introduction of anakinra in a patient with adult onset Rasmussen's encephalitis

Neuroinflammation has been considered an important pathophysiological process involved in epileptogenesis and may provide possibilities for new treatment possibilities. We present the case of a 45-year-old female with drug resistant epilepsy and progressive right-sided cerebral hemiatrophy associated with adult onset Rasmussen's encephalitis. Over a period of 26 years, she was treated with 14 different antiseizure medications, intravenous immunoglobulins, glucocorticosteroids, underwent two operations with focal resection and subpial transections, and tried out trigeminal nerve stimulation. Extensive blood tests, including antibodies relevant for autoimmune encephalitis, and brain biopsy did not show any signs of neuroinflammation. Eventually, the patient received the interleukin-1 receptor antagonist, anakinra. Within 1-2 days after injection, seizure frequency decreased significantly, and, after one week, the seizures stopped completely. Anakinra treatment was continued for 2 months. Stopping medication led to a relapse of seizures after 2 weeks, with a frequency of up to 45 seizures per day. Reintroduction of anakinra led to rapid recovery. Treatment with anakinra was continued for 7 months. The treatment was discontinued in April 2020, and the patient has been completely seizure free since then. There have been no other changes in antiseizure medication.

Differential activation of neuroinflammatory pathways in children with seizures: A cross-sectional study

PURPOSE

Inflammation plays a crucial role in epileptogenesis. We analyzed inflammatory cytokines in plasma and saliva from children with seizures and healthy controls and measured their associations with HHV6 and EBV infection.

METHODS

We analyzed plasma from 36 children within 24 h of seizures (cases) and 43 healthy controls and saliva from 44 cases and 44 controls with a multiplex immunoassay. Saliva from all controls and 65 cases and blood from 26 controls and 35 cases were also analyzed by PCR for viral DNA. Primary outcome was cytokine levels in cases vs. controls. Secondary outcomes included detection of HHV-6 and EBV viral DNA in cases vs. controls and viral loads in cases vs. controls. Statistical analysis included the Wilcoxon Rank Sum test, Fisher's exact test, ANOVA, and Spearman correlation.

RESULTS

Compared to controls, patients had higher levels of CCL11 (p = 0.0018), CCL26 (p<0.001), IL10 (p = 0.044), IL6 (p<0.001), IL8 (p = 0.018), and MIP1β (p = 0.0012). CCL11 was higher with 3 or more seizures (p = 0.01), seizures longer than 10 min (p = 0.001), and when EEG showed focal slowing (p = 0.02). In saliva, febrile seizures had higher levels of IL-1β (n = 7, p = 0.04) and new onset seizures had higher IL-6 (n = 15, p = 0.02). Plasma and saliva cytokine levels did not show a correlation. The frequency of HHV-6 and EBV detection was similar across groups and not different than controls. We found no correlation between viral load and cytokine levels.

CONCLUSIONS

We showed differential activation of neuroinflammatory pathways in plasma from different seizure etiologies compared to controls, unrelated to viral infection.

Microglial Displacement of GABAergic Synapses Is a Protective Event during Complex Febrile Seizures

Complex febrile seizures (FSs) lead to a high risk of intractable temporal lobe epilepsy during adulthood, yet the pathological process of complex FSs is largely unknown. Here, we demonstrate that activated microglia extensively associated with glutamatergic neuronal soma displace surrounding GABAergic presynapses in complex FSs. Patch-clamp electrophysiology establishes that the microglial displacement of GABAergic presynapses abrogates a complex-FS-induced increase in GABAergic neurotransmission and neuronal excitability, whereas GABA exerts an excitatory action in this immature stage. Pharmacological inhibition of microglial displacement of GABAergic presynapses or selective ablation of microglia in CD11b^DTR mice promotes the generation of complex FSs. Blocking or deleting the P2Y₁₂ receptor (P2Y₁₂R) reduces microglial displacement of GABAergic presynapses and shortens the latency of complex FSs. Together, microglial displacement of GABAergic presynapses, regulated by P2Y₁₂R, reduces neuronal excitability to mitigate the generation of complex FSs. Microglial displacement is a protective event during the pathological process of complex FSs.

Proposal to optimize evaluation and treatment of Febrile infection-related epilepsy syndrome (FIRES): A Report from FIRES workshop

Febrile infection-related epilepsy syndrome (FIRES) is a rare catastrophic epileptic encephalopathy that presents suddenly in otherwise normal children and young adults causing significant neurological disability, chronic epilepsy, and high rates of mortality. To suggest a therapy protocol to improve outcome of FIRES, workshops were held in conjunction with American Epilepsy Society annual meeting between 2017 and 2019. An international group of pediatric epileptologists, pediatric neurointensivists, rheumatologists and basic scientists with interest and expertise in FIRES convened to propose an algorithm for a standardized approach to the diagnosis and treatment of FIRES. The broad differential for refractory status epilepticus (RSE) should include FIRES, to allow empiric therapies to be started early in the clinical course. FIRES should be considered in all previously healthy patients older than two years of age who present with explosive onset of seizures rapidly progressing to RSE, following a febrile illness in the preceding two weeks. Once FIRES is suspected, early administrations of ketogenic diet and anakinra (the IL-1 receptor antagonist that blocks biologic activity of IL-1β) are recommended.

The role of inflammatory mediators in epilepsy: Focus on developmental and epileptic encephalopathies and therapeutic implications

In recent years, there has been an increasing interest in the potential involvement of neuroinflammation in the pathogenesis of epilepsy. Specifically, the role of innate immunity (that includes cytokines and chemokines) has been extensively investigated either in animal models of epilepsy and in clinical settings. Developmental and epileptic encephalopathies (DEE) are a heterogeneous group of epileptic disorders, in which uncontrolled epileptic activity results in cognitive, motor and behavioral impairment. By definition, epilepsy in DEE is poorly controlled by common antiepileptic drugs but may respond to alternative treatments, including steroids and immunomodulatory drugs. In this review, we will focus on how cytokines and chemokines play a role in the pathogenesis of DEE and why expanding our knowledge about the role of neuroinflammation in DEE may be crucial to develop new and effective targeted therapeutic strategies to prevent seizure recurrence and developmental regression.

Multiple Disruptions of Glial-Neuronal Networks in Epileptogenesis That Follows Prolonged Febrile Seizures

Background and Rationale: Bi-directional neuronal-glial communication is a critical mediator of normal brain function and is disrupted in the epileptic brain. The potential role of aberrant microglia and astrocyte function during epileptogenesis is important because the mediators involved provide tangible targets for intervention and prevention of epilepsy. Glial activation is intrinsically involved in the generation of childhood febrile seizures (FS), and prolonged FS (febrile status epilepticus, FSE) antecede a proportion of adult temporal lobe epilepsy (TLE). Because TLE is often refractory to treatment and accompanied by significant memory and emotional difficulties, we probed the role of disruptions of glial-neuronal networks in the epileptogenesis that follows experimental FSE (eFSE).

Methods: We performed a multi-pronged examination of neuronal-glia communication and the resulting activation of molecular signaling cascades in these cell types following eFSE in immature mice and rats. Specifically, we examined pathways involving cytokines, microRNAs, high mobility group B-1 (HMGB1) and the prostaglandin E2 signaling. We aimed to block epileptogenesis using network-specific interventions as well as via a global anti-inflammatory approach using dexamethasone.

Results: (A) eFSE elicited a strong inflammatory response with rapid and sustained upregulation of pro-inflammatory cytokines. (B) Within minutes of the end of the eFSE, HMGB1 translocated from neuronal nuclei to dendrites, en route to the extracellular space and glial Toll-like receptors. Administration of an HMGB1 blocker to eFSE rat pups did not decrease expression of downstream inflammatory cascades and led to unacceptable side effects. (C) Prolonged seizure-like activity caused overall microRNA-124 (miR-124) levels to plunge in hippocampus and release of this microRNA from neurons via extra-cellular vesicles. (D) Within hours of eFSE, structural astrocyte and microglia activation was associated not only with cytokine production, but also with activation of the PGE₂ cascade. However, administration of TG6-10-1, a blocker of the PGE₂ receptor EP2 had little effect on spike-series provoked by eFSE. (E) In contrast to the failure of selective interventions, a 3-day treatment of eFSE–experiencing rat pups with the broad anti-inflammatory drug dexamethasone attenuated eFSE-provoked pro-epileptogenic EEG changes.

Conclusions: eFSE, a provoker of TLE-like epilepsy in rodents leads to multiple and rapid disruptions of interconnected glial-neuronal networks, with a likely important role in epileptogenesis. The intricate, cell-specific and homeostatic interplays among these networks constitute a serious challenge to effective selective interventions that aim to prevent epilepsy. In contrast, a broad suppression of glial-neuronal dysfunction holds promise for mitigating FSE-induced hyperexcitability and epileptogenesis in experimental models and in humans.

Augmented seizure susceptibility and hippocampal epileptogenesis in a translational mouse model of febrile status epilepticus

OBJECTIVE

Prolonged fever-induced seizures (febrile status epilepticus [FSE]) during early childhood increase the risk for later epilepsy, but the underlying mechanisms are incompletely understood. Experimental FSE (eFSE) in rats successfully models human FSE, recapitulating the resulting epileptogenesis in a subset of affected individuals. However, the powerful viral and genetic tools that may enhance mechanistic insights into epileptogenesis and associated comorbidities, are better-developed for mice. Therefore, we aimed to determine if eFSE could be generated in mice and if it provoked enduring changes in hippocampal-network excitability and the development of spontaneous seizures.

METHODS

We employed C57BL/6J male mice, the strain used most commonly in transgenic manipulations, and examined if early life eFSE could be sustained and if it led to hyperexcitability of hippocampal networks and to epilepsy. Outcome measures included vulnerability to the subsequent administration of the limbic convulsant kainic acid (KA) and the development of spontaneous seizures. In the first mouse cohort, adult naive and eFSE-experiencing mice were exposed to KA. A second cohort of control and eFSE-experiencing young adult mice was implanted with bilateral hippocampal electrodes and recorded using continuous video-electroencephalography (EEG) for 2 to 3 months to examine for spontaneous seizures (epileptogenesis).

RESULTS

Induction of eFSE was feasible and eFSE increased the susceptibility of adult C57BL/6J mice to KA, thereby reducing latency to seizure onset and increasing seizure severity. Of 24 chronically recorded eFSE mice, 4 (16.5%) developed hippocampal epilepsy with a latent period of ~3 months, significantly different from the expectation by chance (P = .04). The limbic epilepsy that followed eFSE was progressive.

SIGNIFICANCE

eFSE promotes pro-epileptogenic network changes in a majority of C57BL/6J male mice and frank "temporal lobe-like" epilepsy in one sixth of the cohort. Mouse eFSE may thus provide a useful tool for investigating molecular, cellular, and circuit changes during the development of temporal lobe epilepsy and its comorbidities.

Effect of frankincense oil on the neurochemical changes induced in rat model of status epilepticus

Background

The current objective is to evaluate the effect of frankincense oil on the convulsions and the associated neurochemical alterations produced in pilocarpine-induced status epilepticus rat model.

Methods

Rats were divided randomly into: control, status epilepticus rat model and rat model of status epilepticus pretreated with frankincense oil daily for 5 days before pilocarpine treatment. On the fifth day, after pilocarpine injection, rats were observed to evaluate the severity of seizures for 2 h. The oxidative stress parameters malondialdehyde, reduced glutathione and nitric oxide, the proinflammatory cytokines interleukin-6 and interleukin-1β and acetylcholinesterase were determined in the cortex, hippocampus and striatum. Dopamine, norepinephrine and serotonin were measured in the cortex and striatum.

Results

The status epilepticus model exhibited repetitive seizures in the form of generalized tonic- clonic convulsions after 30 min. of pilocarpine injection. This was associated with a significant increase in the levels of malondialdehyde and nitric oxide and a significant decrease in reduced glutathione in the three regions. A significant increase was also observed in interleukin-1β, interleukin-6 and acetylcholinesterase. In the cortex and striatum, a significant decrease was recorded in monoamine levels. Pretreatment of rat model of status epilepticus with frankincense oil decreased the severity of seizures that appeared in the form of tremors and facial automatisms and prevented the increase in malondialdehyde, nitric oxide, interleukin-1β, interleukin-6 and acetylcholinesterase and the decrease in reduced glutathione induced by pilocarpine in the studied brain regions. Frankincense oil failed to restore the decreased level of cortical serotonin and dopamine. In the striatum, frankincense oil improved the levels of serotonin and norepinephrine but failed to restore the decreased dopamine levels.

Conclusion

It is clear from the present results that frankincense oil reduced the severity of seizures induced by pilocarpine. This could be mediated by its potent antioxidant and anti-inflammatory effects.

Anti-convulsant effects of cultures bear bile powder in febrile seizure via regulation of neurotransmission and inhibition of neuroinflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Natural bear bile powder (NBBP) has been used to treat seizures for thousands of years, but its application is greatly restricted due to ethical reasons. Cultured bear bile powder (CBBP), which is produced by biotransformation, may be an appropriate substitute for NBBP. However, the anti-convulsant effects of CBBP and its mechanisms remain unclear.

AIM OF THE STUDY

This study aimed to investigate the anti-convulsant effects and possible mechanisms of CBBP in a febrile seizure (FS) rat model.

MATERIALS AND METHODS

FS was induced by placing the rats in a warm water bath (45.5 °C). The incidence rate and latency of FS, and hematoxylin-eosin staining (HE) were conducted for neurological damage. The levels of 4 bile acids and 8 main neurotransmitters in vivo were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The expression of bile acid related transports, neurotransmitter receptors, inflammatory factors, neurotrophic factors and glial fibrillary acidic protein (GFAP) in hippocampal tissues were detected by real-time PCR, western blotting, and immunohistochemistry.

RESULTS

Pre-treatments with CBBP and similarly, NBBP, significantly reduced the incidence rate and prolonged the latency of FS. Additionally, CBBP alleviated the histological injury induced by FS in the rat hippocampus tissue. LC-MS/MS analyses revealed that CBBP markedly increased the levels of tauroursodeoxycholic acid (TUDCA), taurochenodeoxycholic acid (TCDCA), ursodeoxycholic acid (UDCA), and chenodeoxycholic acid (CDCA) in FS rats. Furthermore, the content of gamma-aminobutyric acid (GABA) was up-regulated in rats pre-treated with CBBP whereas GFAP was down-regulated. CBBP also significantly suppressed the expression of interleukin -1β (IL-1β), tumor necrosis factor α (TNF-α), nuclear factor kappa B (NF-κB), and brain-derived neurotrophic factor (BDNF) and its TrkB receptors, and improved the expression of GABA type A receptors (GABA_AR) and farnesoid X receptors (FXR).

CONCLUSIONS

The present study demonstrated that CBBP had anti-convulsant effects in a FS rat model. CBBP may protect rats against FS, probably by up-regulating FXR, which was activated by increasing brain bile acids, up-regulating GABAergic transmission by inhibiting BDNF-TrkB signaling, and suppressing neuroinflammation by inhibiting the NF-κB pathway.

The Pathogenesis of Fever-Induced Febrile Seizures and Its Current State

Febrile seizures, commonly in children between the ages of 3 months to 5 years, are a neurological abnormality characterized by neuronal hyper-excitability, that occur as a result of an increased core body temperature during a fever, which was caused by an underlying systemic infection. Such infections cause the immune system to elicit an inflammatory response resulting in the release of cytokines from macrophages. The cytokines such as interleukin (IL)- 1β, IL-6, and tumour necrosis factor-α (TNF-α) combat the infection in the localized area ultimately spilling over into circulation resulting in elevated cytokine levels. The cytokines, along with pathogen-associated molecular patterns (PAMPs) expressed on pathogens for example, lipopolysaccharide (LPS), interact with the blood brain barrier (BBB) causing a ‘leaky’ BBB which facilitates cytokines and LPS entry into the central nervous system. The cytokines activate the microglia which release their own cytokines, specifically IL1β. IL-β interacts with the brain endothelium resulting in the activation of cyclooxygenase 2 which catalyzes the production of prostaglandin 2 (PGE2). PGE2 enters the hypothalamic region and induces a fever. Abnormally increased IL-1β levels also progressively increases excitatory (glutamatergic) neurotransmission, and decreases inhibitory (GABAergic) neurotransmission, thus mediating the pathogenesis of convulsions. Current treatments for febrile seizures present with side effects that are detrimental to health, which fosters the need for an alternative, more affordable treatment with fewer adverse side effects, and 1 that is easily accessible, especially in low income areas that are also affected by other underlying socio-economic factors, in which febrile seizures are of growing concern.

The off-label use of anakinra in pediatric systemic autoinflammatory diseases

Interleukin 1 (IL-1), a central mediator of innate immunity, is considered a master cytokine of local and systemic inflammation. IL-1 has emerged as pivotal in the pathogenesis of autoinflammatory diseases (AIDs), and blockade of its pathway has become a crucial target for therapy. Anakinra (ANA), a recombinant IL-1β receptor antagonist, was the first anti-IL-1 agent employed in clinical practice. ANA is currently approved for the treatment of rheumatoid arthritis, systemic juvenile idiopathic arthritis, adult-onset Still’s disease, and cryopyrin-associated autoinflammatory syndrome. It has also been successfully used for off-label treatment of various monogenic, polygenic, or undefined etiology systemic AIDs.

This review describes currently available evidence for the off-label use of ANA in pediatric rheumatologic diseases. Specifically, the use of ANA in Kawasaki disease, idiopathic recurrent pericarditis, Behçet disease, monogenic AIDs, undifferentiated AIDs, chronic non-bacterial osteomyelitis, macrophage activation syndrome, and febrile infection-related epilepsy, in terms of its safety and efficacy. In selected pediatric rheumatic disorders, the off-label administration of ANA appears to be effective and safe. In order to control severe and/or relapsing disease, ANA should be considered as a valuable treatment option in children suffering from rare inflammatory diseases. However, currently available data consist of retrospective studies and short case series; thus, randomized controlled trials and larger series with long-term follow up are mandatory to better assess the efficacy and cost effectiveness of ANA in these challenging patients.