Plasma cytokines associated with febrile status epilepticus in children: A potential biomarker for acute hippocampal injury

mTOR and neuroinflammation in epilepsy: implications for disease progression and treatment

Epilepsy remains a major health concern as anti-seizure medications frequently fail, and there is currently no treatment to stop or prevent epileptogenesis, the process underlying the onset and progression of epilepsy. The identification of the pathological processes underlying epileptogenesis is instrumental to the development of drugs that may prevent the generation of seizures or control pharmaco-resistant seizures, which affect about 30% of patients. mTOR signalling and neuroinflammation have been recognized as critical pathways that are activated in brain cells in epilepsy. They represent a potential node of biological convergence in structural epilepsies with either a genetic or an acquired aetiology. Interventional studies in animal models and clinical studies give strong support to the involvement of each pathway in epilepsy. In this Review, we focus on available knowledge about the pathophysiological features of mTOR signalling and the neuroinflammatory brain response, and their interactions, in epilepsy. We discuss mitigation strategies for each pathway that display therapeutic effects in experimental and clinical epilepsy. A deeper understanding of these interconnected molecular cascades could enhance our strategies for managing epilepsy. This could pave the way for new treatments to fill the gaps in the development of preventative or disease-modifying drugs, thus overcoming the limitations of current symptomatic medications.

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.

The non-clinical burden of febrile seizures: a systematic review

Febrile seizures (FS) can be frightening for parents, even though they are usually harmless. Various questionnaires have been used to assess parental reactions and awareness about FS, revealing insufficient knowledge. Studies have shown that educational interventions significantly reduce parental concerns, improve knowledge, and promote better first-aid measures. Providing clear information and emotional support to parents is important to reduce their concerns and improve FS management. Healthcare providers should give comprehensive information about FS, including the risk of recurrence, and provide clear instructions on their management. The economic impact of FS includes direct and indirect costs. Studies have shown a decrease of hospitalizations and associated costs due to improved clinical adherence to guidelines, which also reduces the inappropriate use of healthcare resources. This systematic review provides a comprehensive overview of the existing literature on parental anxiety and education about FS, as well as their economic impact, aiming at identifying areas for improvement in the management of FS and providing valuable insights for healthcare providers and policymakers to better address the non-clinical burden of this condition.

The molecular fingerprint of neuroinflammation in COVID-19: A comprehensive discussion on molecular mechanisms of neuroinflammation due to SARS-COV2 antigens

BACKGROUND AND OBJECTIVE

Severe acute respiratory syndrome coronavirus 2 attacks the neural system directly and indirectly via various systems, such as the nasal cavity, olfactory system, and facial nerves. Considering the high energy requirement, lack of antioxidant defenses, and high amounts of metal ions in the brain, oxidative damage is very harmful to the brain. Various neuropathic pain conditions, neurological disorders, and neuropsychiatric complications were reported in Coronavirus disease 2019, prolonged Coronavirus disease 2019, and after Coronavirus disease 2019 immunization. This manuscript offers a distinctive outlook on the interconnectedness between neurology and neuropsychiatry through its meticulous analysis of complications.

DISCUSSION

After recovering from Coronavirus disease 2019, approximately half of the patients reported developing Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Long Coronavirus disease 2019 imaging reports illustrated the hypometabolism in various parts of the brain, such as olfactory bulbs, limbic/paralimbic domains, the brainstem, and the cerebellum. Ninety imaging and neuropathological studies of Coronavirus disease 2019 have shown evidence of white matter, brainstem, frontotemporal, and oculofrontal lesions. Emotional functions, such as pleasant, long/short-term memory, movement, cognition and cognition in decision-making are controlled by these regions. The neuroinflammation and the mechanisms of defense are well presented in the discussion. The role of microglia activation, Inducible NO synthase, Cyclooxygenases ½, Reactive oxygen species, neurotoxic toxins and pro-inflammatory cytokines, such as Interleukin-1 beta, Interleukin-6 and Tumor Necrosis Factor-alpha are highlighted in neuronal dysfunction and death. Nuclear factor kappa-light-chain-enhancer of activated B cells, Mitogen-activated protein kinase, Activator Protein 1, and Interferon regulatory factors are the main pathways involved in microglia activation in Coronavirus disease 2019 neuroinflammation.

CONCLUSION

The neurological aspect of Coronavirus disease 2019 should be highlighted. Neurological, psychological, and behavioral aspects of Coronavirus disease 2019, prolonged Coronavirus disease 2019, and Coronavirus disease 2019 vaccines can be the upcoming issues. We need a global awareness where this aspect of the disease should be more considered in health research.

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.

Etiological and risk factors in recurrent febrile seizures: Insights through EEG analysis

BACKGROUND

Febrile seizures, convulsive episodes in young children during febrile illnesses, are a significant concern due to their potential for recurrence and associated uncertainties. This study investigated the causes and risks associated with recurrent febrile seizures and the critical role of electroencephalogram (EEG) in their accurate diagnosis.

METHODS

Following Institutional Review Board approval and going through the consenting process with parents, this study gathered the clinical features and EEG recordings of children admitted with febrile seizures in the Department of Pediatrics, Mahatma Gandhi Memorial Hospital, Kakatiya Medical College, Warangal, Telangana, India. Descriptive statistics, including mean, standard deviation (SD), frequencies, and percentages, were computed to understand the data comprehensively. The Chi-Square test was employed to analyze the association between variables, with a significance level of 0.05, ensuring reliable and trustworthy findings.

RESULTS

Out of 42 children studied, 28 (66.67%) presented with simple febrile seizures, with the mean time of occurrence of seizures from the onset of fever being 7.85 hours. Abnormal EEG was seen in 50% of children with complex febrile seizures and 16% with simple febrile seizures. Generalized epileptiform discharges were the most common epileptic activity observed. Low sodium levels had a significant relationship with febrile seizures in the analysis.

CONCLUSIONS

This study emphasizes the importance of EEG in diagnosing febrile seizures, particularly in complex cases. Our findings suggest that low sodium levels may be a significant risk factor for febrile seizures. Further research is necessary to identify other preventable risk factors to reduce the burden of the medical condition.

Comprehensive Evaluation of Inflammatory Biomarkers and Osmolarity to Distinguish Simple and Complex Febrile Seizures in Children

With limited sample sizes and varying study outcomes regarding complete blood count (CBC)-associated biomarkers and their febrile seizure (FS) classification, along with limited research on osmolarity, this study aims to evaluate CBC-associated biomarkers, including osmolarity, for a comprehensive view of their diagnostic value. This single-center retrospective study used data from 364 children (aged 5-60 months) diagnosed with FS. The patients were categorized into simple FS (n = 221) and complex FS (n = 143) groups. CBC and biochemical tests, including sodium, potassium, chloride, glucose, blood urea nitrogen, and C-reactive protein levels, were evaluated. The neutrophil-to-lymphocyte ratio (NLR), mean platelet volume-to-lymphocyte ratio, and osmolarity were calculated and compared between FS types and the number of seizures. Receiver operating characteristic (ROC) curve analysis was conducted to assess the predictive utility of these markers. Inflammatory markers, including NLR, were ineffective in predicting FS types. Complex FS cases exhibited a significantly lower osmolarity than simple FS cases. The area under the ROC curve for osmolarity to distinguish complex FS was 0.754, while other markers did not reach the desired threshold of 0.700. Including osmolarity in the classification of FS has clinical applicability. Physicians may consider osmolarity as an additional tool to aid in clinical decision-making.

Review and standard operating procedures for collection of biospecimens and analysis of biomarkers in new onset refractory status epilepticus

New onset refractory status epilepticus (NORSE), including its subtype with a preceding febrile illness known as febrile infection-related epilepsy syndrome (FIRES), is one of the most severe forms of status epilepticus. The exact causes of NORSE are currently unknown, and there is so far no disease-specific therapy. Identifying the underlying pathophysiology and discovering specific biomarkers, whether immunologic, infectious, genetic, or other, may help physicians in the management of patients with NORSE. A broad spectrum of biomarkers has been proposed for status epilepticus patients, some of which were evaluated for patients with NORSE. Nonetheless, none has been validated, due to significant variabilities in study cohorts, collected biospecimens, applied analytical methods, and defined outcome endpoints, and to small sample sizes. The NORSE Institute established an open NORSE/FIRES biorepository for health-related data and biological samples allowing the collection of biospecimens worldwide, promoting multicenter research and sharing of data and specimens. Here, we suggest standard operating procedures for biospecimen collection and biobanking in this rare condition. We also propose criteria for the appropriate use of previously collected biospecimens. We predict that the widespread use of standardized procedures will reduce heterogeneity, facilitate the future identification of validated biomarkers for NORSE, and provide a better understanding of the pathophysiology and best clinical management for these patients.

The long-term neurodevelopmental outcomes of febrile seizures and underlying mechanisms

Febrile seizures (FSs) are convulsions caused by a sudden increase in body temperature during a fever. FSs are one of the commonest presentations in young children, occurring in up to 4% of children between the ages of about 6 months and 5 years old. FSs not only endanger children's health, cause panic and anxiety to families, but also have many adverse consequences. Both clinical and animal studies show that FSs have detrimental effects on neurodevelopment, that cause attention deficit hyperactivity disorder (ADHD), increased susceptibility to epilepsy, hippocampal sclerosis and cognitive decline during adulthood. However, the mechanisms of FSs in developmental abnormalities and disease occurrence during adulthood have not been determined. This article provides an overview of the association of FSs with neurodevelopmental outcomes, outlining both the underlying mechanisms and the possible appropriate clinical biomarkers, from histological changes to cellular molecular mechanisms. The hippocampus is the brain region most significantly altered after FSs, but the motor cortex and subcortical white matter may also be involved in the development disorders induced by FSs. The occurrence of multiple diseases after FSs may share common mechanisms, and the long-term role of inflammation and γ-aminobutyric acid (GABA) system are currently well studied.

Cytokines in New-Onset Refractory Status Epilepticus Predict Outcomes

OBJECTIVE

The objective of this study was to investigate inflammation using cerebrospinal fluid (CSF) and serum cytokines/chemokines in patients with new-onset refractory status epilepticus (NORSE) to better understand the pathophysiology of NORSE and its consequences.

METHODS

Patients with NORSE (n = 61, including n = 51 cryptogenic), including its subtype with prior fever known as febrile infection-related epilepsy syndrome (FIRES), were compared with patients with other refractory status epilepticus (RSE; n = 37), and control patients without SE (n = 52). We measured 12 cytokines/chemokines in serum or CSF samples using multiplexed fluorescent bead-based immunoassay detection. Cytokine levels were compared between patients with and without SE, and between the 51 patients with cryptogenic NORSE (cNORSE) and the 47 patients with a known-etiology RSE (NORSE n = 10, other RSE n = 37), and correlated with outcomes.

RESULTS

A significant increase of IL-6, TNF-α, CXCL8/IL-8, CCL2, MIP-1α, and IL-12p70 pro-inflammatory cytokines/chemokines was observed in patients with SE compared with patients without SE, in serum and CSF. Serum innate immunity pro-inflammatory cytokines/chemokines (CXCL8, CCL2, and MIP-1α) were significantly higher in patients with cNORSE compared to non-cryptogenic RSE. Patients with NORSE with elevated innate immunity serum and CSF cytokine/chemokine levels had worse outcomes at discharge and at several months after the SE ended.

INTERPRETATION

We identified significant differences in innate immunity serum and CSF cytokine/chemokine profiles between patients with cNORSE and non-cryptogenic RSE. The elevation of innate immunity pro-inflammatory cytokines in patients with NORSE correlated with worse short- and long-term outcomes. These findings highlight the involvement of innate immunity-related inflammation, including peripherally, and possibly of neutrophil-related immunity in cNORSE pathogenesis and suggest the importance of utilizing specific anti-inflammatory interventions. ANN NEUROL 2023.

Systemic inflammatory markers and EEG features of children with FIRES receiving anakinra

In a retrospective case series of 10 children with cryptogenic FIRES, we sought to describe the early clinical course and potential biomarkers following anakinra initiation. Six children achieved anesthetic withdrawal within 3 weeks of therapy and one in week four. Of the available cEEG (six children), CRP (10 children), and serum cytokine (six children) studies, there were temporal changes in highly epileptiform bursts (observed in three children), CRP, IL-6, and IL-10 levels that might parallel clinical progression. These observations may represent candidate biomarkers for monitoring clinical progression and therapeutic interventions including anakinra, which merits further investigation in future studies.

Neuroimmunology of status epilepticus

Status epilepticus (SE) is a very heterogeneous clinical condition often refractory to available treatment options. Evidence in animal models shows that neuroinflammation arises in the brain during SE due to the activation of innate immune mechanisms in brain parenchyma cells. Intervention studies in animal models support the involvement of neuroinflammation in SE onset, duration, and severity, refractoriness to treatments, and long-term neurological consequences. Clinical evidence shows that neuroinflammation occurs in patients with SE of diverse etiologies likely representing a common phenomenon, thus broadening the involvement of the immune system beyond the infective and autoimmune etiologies. There is urgent need for novel therapies for refractory SE that rely upon a better understanding of the basic mechanisms underlying this clinical condition. Preclinical and clinical evidence encourage consideration of specific anti-inflammatory treatments for controlling SE and its consequences in patients.

Time course of serum cytokine level changes within 72 h after onset in children with acute encephalopathy and febrile seizures

BACKGROUND

Cytokine levels have been measured in acute encephalopathy (AE) to determine its pathology or as a diagnostic biomarker to distinguish it from febrile seizures (FS); however, the dynamics of cytokine level changes have not yet been fully captured in these two neurological manifestations. Thus, we aimed to explore the time course of serum cytokine level changes within 72 h after onset in AE and FS.

METHODS

We retrospectively measured cytokine level in residual serum samples at multiple timepoints in seven children whose final diagnoses were AE or FS.

RESULTS

The levels of 13 cytokines appeared to increase immediately after onset and peaked within 12-24 h after onset: interleukin (IL)-1β, IL-4 IL-5, IL-6, IL-8, IL-10, IL-17, eotaxin, fibroblast growth factor, granulocyte colony-stimulating factor, interferon gamma, interferon-inducible protein-10, and macrophage chemoattractant protein-1. There were no dynamic changes in the levels of three cytokines (IL-1 receptor agonist, macrophage inflammatory protein-1α, and platelet-derived growth factor-bb) 72 h after onset. Levels of some cytokines decreased to around control levels within 48 h after onset: IL-1β, IL-4, IL-5, IL-17, fibroblast growth factor, and interferon gamma. The levels of most cytokines appeared to be higher in AE, especially in hemorrhagic shock encephalopathy syndrome, than in FS.

CONCLUSIONS

Cytokine levels in both AE and FS change dynamically, such as the levels of several cytokines increased within a few hours after onset and decreased at 12-24 h after onset. Therefore, it will be desirable to make clinical decisions regarding the administration of anti-inflammatory therapy in 24 h after onset in AE.

GABAA receptor function is enhanced by Interleukin-10 in human epileptogenic gangliogliomas and its effect is counteracted by Interleukin-1β

Gangliogliomas (GGs) are low-grade brain tumours that cause intractable focal epilepsy in children and adults. In GG, as in epileptogenic focal malformations (i.e., tuberous sclerosis complex, TSC), there is evidence of sustained neuroinflammation with involvement of the pro-inflammatory cytokine IL-1β. On the other hand, anti-inflammatory mediators are less studied but bear relevance for understanding seizure mechanisms. Therefore, we investigated the effect of the key anti-inflammatory cytokine IL-10 on GABAergic neurotransmission in GG. We assessed the IL-10 dependent signaling by transcriptomic analysis, immunohistochemistry and performed voltage-clamp recordings on Xenopus oocytes microtransplanted with cell membranes from brain specimens, to overcome the limited availability of acute GG slices. We report that IL-10-related mRNAs were up-regulated in GG and slightly in TSC. Moreover, we found IL-10 receptors are expressed by neurons and astroglia. Furthermore, GABA currents were potentiated significantly by IL-10 in GG. This effect was time and dose-dependent and inhibited by blockade of IL-10 signaling. Notably, in the same tissue, IL-1β reduced GABA current amplitude and prevented the IL-10 effect. These results suggest that in epileptogenic tissue, pro-inflammatory mechanisms of hyperexcitability prevail over key anti-inflammatory pathways enhancing GABAergic inhibition. Hence, boosting the effects of specific anti-inflammatory molecules could resolve inflammation and reduce intractable seizures.

International consensus recommendations for management of New Onset Refractory Status Epilepticus (NORSE) incl. Febrile Infection-Related Epilepsy Syndrome (FIRES): Statements and Supporting Evidence

OBJECTIVE

To develop consensus-based recommendations for the management of adult and paediatric patients with NORSE/FIRES based on best evidence and experience.

METHODS

The Delphi methodology was followed. A facilitator group of 9 experts was established, who defined the scope, users and suggestions for recommendations. Following a review of the current literature, recommendation statements concerning diagnosis, treatment and research directions were generated which were then voted on a scale of 1 (strongly disagree) to 9 (strongly agree) by a panel of 48 experts in the field. Consensus that a statement was appropriate was reached if the median score was greater or equal to 7, and inappropriate if the median score was less than or equal to 3. The analysis of evidence was mapped to the results of each statement included in the Delphi survey.

RESULTS

Overall, 85 recommendation statements achieved consensus. The recommendations are divided into five sections: 1) disease characteristics, 2) diagnostic testing and sampling, 3) acute treatment, 4) treatment in the post-acute phase, and 5) research, registries and future directions in NORSE/FIRES. The detailed results and discussion of all 85 statements are outlined herein. A corresponding summary of findings and practical flowsheets are presented in a companion article.

SIGNIFICANCE

This detailed analysis offers insight into the supporting evidence and the current gaps in the literature that are associated with expert consensus statements related to NORSE/FIRES. The recommendations generated by this consensus can be used as a guide for the diagnosis, evaluation, and management of patients with NORSE/FIRES, and for planning of future research.

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.

PRRT2 Mutation and Serum Cytokines in Paroxysmal Kinesigenic Dyskinesia

OBJECTIVE

Paroxysmal kinesigenic dyskinesia (PKD) is a rare movement disorder PRRT2 gene mutations have been reported to cause PKD. However, the pathophysiological mechanism of PKD remains unclear, and it is unknown whether an inflammatory response is involved in the occurrence of this disease. We aimed to investigate the symptomatology, genotype, and serum cytokines of patients with PKD.

METHODS

We recruited 21 patients with PKD, including 7 with familial PKD and 14 with sporadic PKD. Their clinical features were investigated, and blood samples were collected, and PRRT2 mutations and cytokine levels were detected.

RESULTS

The mean age at PKD onset was 12.3±2.2 years old. Dystonia was the most common manifestation of dyskinesia, and the limbs were the most commonly affected parts. All attacks were induced by identifiable kinesigenic triggers, and the attack durations were brief (<1 min). Four different mutations from 9 probands were identified in 7 familial cases (71.4%) and 14 sporadic cases (28.6%). Two of these mutations (c.649dupC, c.620_621delAA) had already been reported, while other 2 (c.1018_1019delAA, c.1012+1G>A) were previously undocumented. The tumor necrosis factor (TNF)-α level in the PKD group was significantly higher than that in the age- and sex-matched control group (P=0.025). There were no significant differences in the interleukin (IL)-1β, IL-2R, IL-6, IL-8, or IL-10 levels between the two groups.

CONCLUSION

In this study, we summarized the clinical and genetic characteristics of PKD. We found that the serum TNF-α levels were elevated in patients clinically diagnosed with PKD, suggesting that an inflammatory response is involved in the pathogenesis of PKD.

Neuroinflammation and Proinflammatory Cytokines in Epileptogenesis

Increasing evidence corroborates the fundamental role of neuroinflammation in the development of epilepsy. Proinflammatory cytokines (PICs) are crucial contributors to the inflammatory reactions in the brain. It is evidenced that epileptic seizures are associated with elevated levels of PICs, particularly interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α), which underscores the impact of neuroinflammation and PICs on hyperexcitability of the brain and epileptogenesis. Since the pathophysiology of epilepsy is unknown, determining the possible roles of PICs in epileptogenesis could facilitate unraveling the pathophysiology of epilepsy. About one-third of epileptic patients are drug-resistant, and existing treatments only resolve symptoms and do not inhibit epileptogenesis; thus, treatment of epilepsy is still challenging. Accordingly, understanding the function of PICs in epilepsy could provide us with promising targets for the treatment of epilepsy, especially drug-resistant type. In this review, we outline the role of neuroinflammation and its primary mediators, including IL-1β, IL-1α, IL-6, IL-17, IL-18, TNF-α, and interferon-γ (IFN-γ) in the pathophysiology of epilepsy. Furthermore, we discuss the potential therapeutic targeting of PICs and cytokine receptors in the treatment of epilepsy.

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

CXCL1-CXCR1/2 signaling is induced in human temporal lobe epilepsy and contributes to seizures in a murine model of acquired epilepsy

CXCL1, a functional murine orthologue of the human chemokine CXCL8 (IL-8), and its CXCR1 and CXCR2 receptors were investigated in a murine model of acquired epilepsy developing following status epilepticus (SE) induced by intra-amygdala kainate. CXCL8 and its receptors were also studied in human temporal lobe epilepsy (TLE). The functional involvement of the chemokine in seizure generation and neuronal cell loss was assessed in mice using reparixin (formerly referred to as repertaxin), a non-competitive allosteric inhibitor of CXCR1/2 receptors. We found a significant increase in hippocampal CXCL1 level within 24 h of SE onset that lasted for at least 1 week. No changes were measured in blood. In analogy with human TLE, immunohistochemistry in epileptic mice showed that CXCL1 and its two receptors were increased in hippocampal neuronal cells. Additional expression of these molecules was found in glia in human TLE. Mice were treated with reparixin or vehicle during SE and for additional 6 days thereafter, using subcutaneous osmotic minipumps. Drug-treated mice showed a faster SE decay, a reduced incidence of acute symptomatic seizures during 48 h post-SE, and a delayed time to spontaneous seizures onset compared to vehicle controls. Upon reparixin discontinuation, mice developed spontaneous seizures similar to vehicle mice, as shown by EEG monitoring at 14 days and 2.5 months post-SE. In the same epileptic mice, reparixin reduced neuronal cell loss in the hippocampus vs vehicle-injected mice, as assessed by Nissl staining at completion of EEG monitoring. Reparixin administration for 2 weeks in mice with established chronic seizures, reduced by 2-fold on average seizure number vs pre-treatment baseline, and this effect was reversible upon drug discontinuation. No significant changes in seizure number were measured in vehicle-injected epileptic mice that were EEG monitored in parallel. Data show that CXCL1-IL-8 signaling is activated in experimental and human epilepsy and contributes to acute and chronic seizures in mice, therefore representing a potential new target to attain anti-ictogenic effects.

The Utility of Infectious and Neurodiagnostic Testing in Children With Complex Febrile Seizures Requiring Mechanical Ventilation

A retrospective cohort analysis was performed on 79 consecutive patients between 6 months and 5 years admitted to a tertiary hospital with a diagnosis of complex febrile seizures requiring mechanical ventilation from 2011 to 2017 to determine the utility of infectious and neurologic diagnostics. Intubation was used as a proxy for severity of illness. The overall intensive care unit stay was short (95% intubated <24 hours, 88% admitted <3 days). No life-threatening infections were identified, and none required surgical interventions. Electroencephalogram (EEG) was obtained on 43%, 26% of which were abnormal. Sixty-six percent of patients were discharged on rescue benzodiazepine and 20% with maintenance antiseizure medications. Duration of follow-up averaged 4 years (range 1 month to 9 years); 8 patients (10%) were subsequently diagnosed with epilepsy. Our findings suggest that extensive diagnostic evaluations may not be necessary for children with complex febrile seizures requiring mechanical ventilation although the role of EEG is less understood.

Biomarkers for posttraumatic epilepsy

A biomarker is a characteristic that can be objectively measured as an indicator of normal biologic processes, pathogenic processes, or responses to an exposure or intervention, including therapeutic interventions. Biomarker modalities include molecular, histologic, radiographic, or physiologic characteristics. To improve the understanding and use of biomarker terminology in biomedical research, clinical practice, and medical product development, the Food and Drug Administration (FDA)-National Institutes of Health (NIH) Joint Leadership Council developed the BEST Resource (Biomarkers, EndpointS, and other Tools). The seven BEST biomarker categories include the following: (a) susceptibility/risk biomarkers, (b) diagnostic biomarkers, (c) monitoring biomarkers, (d) prognostic biomarkers, (e) predictive biomarkers, (f) pharmacodynamic/response biomarkers, and (g) safety biomarkers. We hypothesize some potential overlap between the reported biomarkers of traumatic brain injury (TBI), epilepsy, and posttraumatic epilepsy (PTE). Here, we tested this hypothesis by reviewing studies focusing on biomarker discovery for posttraumatic epileptogenesis and epilepsy. The biomarker modalities reviewed here include plasma/serum and cerebrospinal fluid molecular biomarkers, imaging biomarkers, and electrophysiologic biomarkers. Most of the reported biomarkers have an area under the receiver operating characteristic curve greater than 0.800, suggesting both high sensitivity and high specificity. Our results revealed little overlap in the biomarker candidates between TBI, epilepsy, and PTE. In addition to using single parameters as biomarkers, machine learning approaches have highlighted the potential for utilizing patterns of markers as biomarkers. Although published data suggest the possibility of identifying biomarkers for PTE, we are still in the early phase of the development curve. Many of the seven biomarker categories lack PTE-related biomarkers. Thus, further exploration using proper, statistically powered, and standardized study designs with validation cohorts, and by developing and applying novel analytical methods, is needed for PTE biomarker discovery.

Hypothesis: Febrile infection-related epilepsy syndrome is a microglial NLRP3 inflammasome/IL-1 axis-driven autoinflammatory syndrome

FIRES (febrile infection-related epilepsy syndrome) is a protracted neuroinflammatory condition of obscure cause. It mainly afflicts school-age children and often leads to permanent neurological sequelae. Most treatments to date have been of limited efficacy, while ketogenic diet and anti-interleukin-1 therapy appear beneficial for some patients. Research into this clinical entity is hampered by its rarity and complexity. Nonetheless, accumulating evidence derived from basic investigations and clinical observations converges to implicate the autoinflammatory nature of this syndrome. A closer analysis of current literature suggests that microglia and the NLRP3 inflammasome might be the pivotal cellular and molecular players in FIRES pathogenesis, respectively. Through evidence synthesis, herein we formulate the working hypothesis of overactivation of microglial NLRP3 inflammasome/interleukin-1 axis as the driving event in FIRES by creating a proinflammatory and proconvulsive milieu. The reverberation between neuroinflammation and seizure forms a vicious cycle. The unique properties of microglia might also contribute to unopposed IL-1 signalling and incessant sterile neuroinflammation in this context. The potential therapeutic relevance of the proposed conceptual framework is discussed.

Towards a Treatment for Neuroinflammation in Epilepsy: Interleukin-1 Receptor Antagonist, Anakinra, as a Potential Treatment in Intractable Epilepsy

Febrile Infection-Related Epilepsy Syndrome (FIRES) is a unique catastrophic epilepsy syndrome, and the development of drug-resistant epilepsy (DRE) is inevitable. Recently, anakinra, an interleukin-1 receptor antagonist (IL-1RA), has been increasingly used to treat DRE due to its potent anticonvulsant activity. We here summarized its effects in 38 patients (32 patients with FIRES and six with DRE). Of the 22 patients with FIRES, 16 (73%) had at least short-term seizure control 1 week after starting anakinra, while the remaining six suspected anakinra-refractory cases were male and had poor prognoses. Due to the small sample size, an explanation for anakinra refractoriness was not evident. In all DRE patients, seizures disappeared or improved, and cognitive function improved in five of the six patients following treatment. Patients showed no serious side effects, although drug reactions with eosinophilia and systemic symptoms, cytopenia, and infections were observed. Thus, anakinra has led to a marked improvement in some cases, and functional deficiency of IL-1RA was indicated, supporting a direct mechanism for its therapeutic effect. This review first discusses the effectiveness of anakinra for intractable epileptic syndromes. Anakinra could become a new tool for intractable epilepsy treatment. However, it does not currently have a solid evidence base.

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.

Serotonin and dopamine receptors profile on peripheral immune cells from patients with temporal lobe epilepsy

The role of inflammation and immune cells has been demonstrated in neurological diseases, including epilepsy. Leukocytes, as well as inflammatory mediators, contribute to abnormal processes that lead to a reduction in seizure threshold and synaptic reorganization. In this sense, identifying different phenotypes of circulating immune cells is essential to understanding the role of these cells in epilepsy. Immune cells can express a variety of surface markers, including neurotransmitter receptors, such as serotonin and dopamine. Alteration in these receptors expression patterns may affect the level of inflammatory mediators and the pathophysiology of epilepsy. Therefore, in the current study, we evaluated the expression of dopamine and serotonin receptors on white blood cells from patients with temporal lobe epilepsy with hippocampal sclerosis (TLE-HS). Blood samples from 17 patients with TLE-HS and 21 controls were collected. PBMC were isolated and stained ex vivo for flow cytometry. We evaluated the expression of serotonin (5-HT_1A, 5-HT_1B, 5-HT₂, 5-HT_2B, 5-HT_2C, 5-HT₃, 5-HT₄), and dopamine receptors (D₁, D₂, D₃, D₄, and D₅) on the cell surface of lymphocytes and innate immune cells (monocytes and granulocytes). Our results demonstrated that innate cells and lymphocytes from patients with TLE-HS showed high mean fluorescent intensity (MFI) for 5-HT_1A, 5-HT_1B, 5-HT_2A, and 5-HT₄ compared to controls. No difference was observed for 5-HT_2B. For dopamine receptors, the expression of D₁, D₂, D_4, and D₅ receptors was higher on innate cells from patients with TLE-HS when compared to controls for the MFI. Regarding lymphocytes population, D₂ expression was increased in patients with TLE-HS. In conclusion, there are alterations in the expression of serotonin and dopamine receptors on immune blood cells of patients with TLE-HS. Although the biological significance of these findings still needs to be further investigated, these changes may contribute to the understanding of TLE-HS pathophysiology.

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.

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.

Inflammation, ictogenesis, and epileptogenesis: An exploration through human disease

Epilepsy is seen historically as a disease of aberrant neuronal signaling manifesting as seizures. With the discovery of numerous auto-antibodies and the subsequent growth in understanding of autoimmune encephalitis, there has been an increasing emphasis on the contribution of the innate and adaptive immune system to ictogenesis and epileptogenesis. Pathogenic antibodies, complement activation, CD8+ cytotoxic T cells, and microglial activation are seen, to various degrees, in different seizure-associated neuroinflammatory and autoimmune conditions. These aberrant immune responses are thought to cause disruptions in neuronal signaling, generation of acute symptomatic seizures, and, in some cases, the development of long-term autoimmune epilepsy. Although early treatment with immunomodulatory therapies improves outcomes in autoimmune encephalitides and autoimmune epilepsies, patient identification and treatment selection are not always clear-cut. This review examines the role of the different components of the immune system in various forms of seizure disorders including autoimmune encephalitis, autoimmune epilepsy, Rasmussen encephalitis, febrile infection-related epilepsy syndrome (FIRES), and new-onset refractory status epilepticus (NORSE). In particular, the pathophysiology and unique cytokine profiles seen in these disorders and their links with diagnosis, prognosis, and treatment decision-making are discussed.

Anakinra usage in febrile infection related epilepsy syndrome: an international cohort

Febrile-infection related epilepsy syndrome (FIRES) is a devastating neurological condition characterized by a febrile illness preceding new onset refractory status epilepticus (NORSE). Increasing evidence suggests innate immune dysfunction as a potential pathological mechanism. We report an international retrospective cohort of 25 children treated with anakinra, a recombinant interleukin-1 receptor antagonist, as an immunomodulator for FIRES. Anakinra was potentially safe with only one child discontinuing therapy due to infection. Earlier anakinra initiation was associated with shorter duration of mechanical ventilation, ICU and hospital length of stay. Our retrospective data lay the groundwork for prospective consensus-driven cohort studies of anakinra in FIRES.

Systemic Inflammation Persists the First Year after Mild Traumatic Brain Injury: Results from the Prospective Trondheim Mild Traumatic Brain Injury Study

Innate immune activation has been attributed a key role in traumatic brain injury (TBI) and successive morbidity. In mild TBI (mTBI), however, the extent and persistence of innate immune activation are unknown. We determined plasma cytokine level changes over 12 months after an mTBI in hospitalized and non-hospitalized patients compared with community controls; and examined their associations to injury-related and demographic variables at admission. Prospectively, 207 patients presenting to the emergency department (ED) or general practitioner with clinically confirmed mTBI and 82 matched community controls were included. Plasma samples were obtained at admission, after 2 weeks, 3 months, and 12 months. Cytokine levels were analysed with a 27-plex beads-based immunoassay. Brain magnetic resonance imaging (MRI) was performed on all participants. Twelve cytokines were reliably detected. Plasma levels of interferon gamma (IFN-γ), interleukin 8 (IL-8), eotaxin, macrophage inflammatory protein-1-beta (MIP-1β), monocyte chemoattractant protein 1 (MCP-1), IL-17A, IL-9, tumor necrosis factor (TNF), and basic fibroblast growth factor (FGF-basic) were significantly increased at all time-points in patients compared with controls, whereas IFN-γ-inducing protein 10 (IP-10), platelet-derived growth factor (PDGF), and IL-1ra were not. IL-17A and FGF-basic showed significant increases in patients from admission to follow-up at 3 months, and remained increased at 12 months compared with admission. Interestingly, MRI findings were negatively associated with four cytokines: eotaxin, MIP-1β, IL-9, and IP-10, whereas age was positively associated with nine cytokines: IL-8, eotaxin, MIP-1β, MCP-1, IL-17A, IL-9, TNF, FGF-basic, and IL-1ra. TNF was also increased in those with presence of other injuries. In conclusion, mTBI activated the innate immune system consistently and this is the first study to show that several inflammatory cytokines remain increased for up to 1 year post-injury.

Markers in Status Epilepticus Prognosis

Status epilepticus (SE) is a neurologic emergency with high morbidity and mortality. The assessment of a patient's prognosis is crucial in making treatment decisions. In this review, we discuss various markers that have been used to prognosticate SE in terms of recurrence, mortality, and functional outcome. These markers include demographic, clinical, electrophysiological, biochemical, and structural data. The heterogeneity of SE etiology and semiology renders development of prognostic markers challenging. Currently, prognostication in SE is limited to a few clinical scores. Future research should integrate clinical, genetic and epigenetic, metabolic, inflammatory, and structural biomarkers into prognostication models to approach "personalized medicine" in prognostication of outcomes after SE.

Inflammation and reactive oxygen species in status epilepticus: Biomarkers and implications for therapy

Preclinical studies in immature and adult rodents and clinical observations show that neuroinflammation and oxidative stress are rapid onset phenomena occurring in the brain during status epilepticus and persisting thereafter. Notably, both neuroinflammation and oxidative stress contribute to the acute and long-term sequelae of status epilepticus thus representing potential druggable targets. Antiinflammatory drugs that interfere with the IL-1β pathway, such as anakinra, can control benzodiazepine-refractory status epilepticus in animals, and there is recent proof-of-concept evidence for therapeutic effects in children with Febrile infection related epilepsy syndrome (FIRES). Inhibitors of monoacylglycerol lipase and P2X7 receptor antagonists are also promising antiinflammatory drug candidates for rapidly aborting de novo status epilepticus and provide neuroprotection. Antiinflammatory and antioxidant drugs administered to rodents during status epilepticus and transiently thereafter, prevent long-term sequelae such as cognitive deficits and seizure progression in animals developing epilepsy. Some drugs are already in medical use and are well-tolerated, therefore, they may be considered for treating status epilepticus and its neurological consequences. Finally, markers of neuroinflammation and oxidative stress are measureable in peripheral blood and by neuroimaging, which offers an opportunity for developing prognostic and predictive mechanistic biomarkers in people exposed to status epilepticus. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures.

Dexamethasone Attenuates Hyperexcitability Provoked by Experimental Febrile Status Epilepticus

The role of neuroinflammation in the mechanisms of epilepsy development is important because inflammatory mediators provide tractable targets for intervention. Inflammation is intrinsically involved in the generation of childhood febrile seizures (FSs), and prolonged FS [febrile status epilepticus (FSE)] precedes a large proportion of adult cases of temporal lobe epilepsy (TLE). As TLE is often refractory to therapy and is associated with serious cognitive and emotional problems, we investigated whether its development can be prevented using anti-inflammatory strategies. Using an immature rat model of FSE [experimental FSE (eFSE)], we administered dexamethasone (DEX), a broad anti-inflammatory agent, over 3 d following eFSE. We assessed eFSE-provoked hippocampal network hyperexcitability by quantifying the presence, frequency, and duration of hippocampal spike series, as these precede and herald the development of TLE-like epilepsy. We tested whether eFSE provoked hippocampal microgliosis, astrocytosis, and proinflammatory cytokine production in male and female rats and investigated blood–brain barrier (BBB) breaches as a potential contributor. We then evaluated whether DEX attenuated these eFSE sequelae. Spike series were not observed in control rats given vehicle or DEX, but occurred in 41.6% of eFSE-vehicle rats, associated with BBB leakage and elevated hippocampal cytokines. eFSE did not induce astrocytosis or microgliosis but provoked BBB disruption in 60% of animals. DEX significantly reduced spike series prevalence (to 7.6%) and frequency, and abrogated eFSE-induced cytokine production and BBB leakage (to 20%). These findings suggest that a short, postinsult intervention with a clinically available anti-inflammatory agent potently attenuates epilepsy-predicting hippocampal hyperexcitability, potentially by minimizing BBB disruption and related neuroinflammation.

Early changes in pro-inflammatory cytokine levels in neonates with encephalopathy are associated with remote epilepsy

BACKGROUND

Neonatal seizures are associated with adverse neurologic sequelae including epilepsy in childhood. Here we aim to determine whether levels of cytokines in neonates with brain injury are associated with acute symptomatic seizures or remote epilepsy.

METHODS

This is a cohort study of term newborns with encephalopathy at UCSF between 10/1993 and 1/2000 who had dried blood spots. Maternal, perinatal/postnatal, neuroimaging, and epilepsy variables were abstracted by chart review. Logistic regression was used to compare levels of cytokines with acute seizures and the development of epilepsy.

RESULTS

In a cohort of 26 newborns with neonatal encephalopathy at risk for hypoxic ischemic encephalopathy with blood spots for analysis, diffuse alterations in both pro- and anti-inflammatory cytokine levels were observed between those with (11/28, 39%) and without acute symptomatic seizures. Seventeen of the 26 (63%) patients had >2 years of follow-up and 4/17 (24%) developed epilepsy. Higher levels of pro-inflammatory cytokines IL-6 and TNF-α within the IL-1β pathway were significantly associated with epilepsy.

CONCLUSIONS

Elevations in pro-inflammatory cytokines in the IL-1β pathway were associated with later onset of epilepsy. Larger cohort studies are needed to confirm the predictive value of these circulating biomarkers.

Inflammation and reactive oxygen species as disease modifiers in epilepsy

Neuroinflammation and reactive oxygen and nitrogen species are rapidly induced in the brain after acute cerebral injuries that are associated with an enhanced risk for epilepsy in humans and related animal models. These phenomena reinforce each others and persist during epileptogenesis as well as during chronic spontaneous seizures. Anti-inflammatory and anti-oxidant drugs transiently administered either before, or shortly after the clinical onset of symptomatic epilepsy, similarly block the progression of spontaneous seizures, and may delay their onset. Moreover, neuroprotection and rescue of cognitive deficits are also observed in the treated animals. Therefore, although these treatments do not prevent epilepsy development, they offer clinically relevant disease-modification effects. These therapeutic effects are mediated by targeting molecular signaling pathways such as the IL-1β-IL-1 receptor type 1 and TLR4, P2X7 receptors, the transcriptional anti-oxidant factor Nrf2, while the therapeutic impact of COX-2 inhibition for reducing spontaneous seizures remains controversial. Some anti-inflammatory and anti-oxidant drugs that are endowed of disease modification effects in preclinical models are already in medical use and have a safety profile, therefore, they provide potential re-purposed treatments for improving the disease course and for reducing seizure burden. Markers of neuroinflammation and oxidative stress can be measured in blood or by neuroimaging, therefore they represent testable prognostic and predictive biomarkers for selecting the patient's population at high risk for developing epilepsy therefore eligible for novel treatments. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.

Microglial phenotypes in the human epileptic temporal lobe

Microglia, the immune cells of the brain, are highly plastic and possess multiple functional phenotypes. Differences in phenotype in different regions and different states of epileptic human brain have been little studied. Here we use transcriptomics, anatomy, imaging of living cells and ELISA measurements of cytokine release to examine microglia from patients with temporal lobe epilepsies. Two distinct microglial phenotypes were explored. First we asked how microglial phenotype differs between regions of high and low neuronal loss in the same brain. Second, we asked how microglial phenotype is changed by a recent seizure. In sclerotic areas with few neurons, microglia have an amoeboid rather than ramified shape, express activation markers and respond faster to purinergic stimuli. The repairing interleukin, IL-10, regulates the basal phenotype of microglia in the CA1 and CA3 regions with neuronal loss and gliosis. To understand changes in phenotype induced by a seizure, we estimated the delay from the last seizure until tissue collection from changes in reads for immediate early gene transcripts. Pseudotime ordering of these data was validated by comparison with results from kainate-treated mice. It revealed a local and transient phenotype in which microglia secrete the human interleukin CXCL8, IL-1B and other cytokines. This secretory response is mediated in part via the NRLP3 inflammasome.

Highlights From the Annual Meeting of the American Epilepsy Society 2018

The American Epilepsy Society Meeting in New Orleans attracted more than 5900 attendees. There was a lively exchange of new science, innovation, education, clinical practice, and many other items related to epilepsy. Educational symposia were a major part of the meeting and explored varying topics of interest for all types of epilepsy professionals. This article reviews highlights of the meeting presented in major symposia. Topics ranged from how to treat varying aspects of epilepsy as a consultant in the hospital to finding the scientific underpinning of the interaction between sleep and epilepsy. Pros and cons of novel antiseizure medications, dietary, and stimulation treatments were discussed. Epilepsy may impair memory and we need to learn what is the pathophysiologic relationship. Febrile status epilepticus may have severe consequences for a later life with seizures. Epilepsy professionals should be very well aware of the ethical implications of devasting seizures and their associated disability. These are just a few select topics of the many that we need to study further to archive the final goal to improve the lives of patients with epilepsy.

Progress report on new antiepileptic drugs: A summary of the Fourteenth Eilat Conference on New Antiepileptic Drugs and Devices (EILAT XIV). II. Drugs in more advanced clinical development

The Fourteenth Eilat Conference on New Antiepileptic Drugs and Devices (EILAT XIV) took place in Madrid, Spain, on May 13-16, 2018 and was attended by 168 delegates from 28 countries. The conference provided a forum for professionals involved in basic science, clinical research, regulatory affairs, and clinical care to meet and discuss the latest advances related to discovery and development of drugs and devices aimed at improving the management of people with epilepsy. This progress report provides a summary of findings on investigational compounds for which data from both preclinical studies and studies in patients were presented. The compounds reviewed include anakinra, cannabidiol, cannabidivarin, fenfluramine, ganaxolone, medium-chain fatty acids, padsevonil, and the valproic derivatives valnoctamide and sec-butylpropylacetamide. On June 25, 2018, the US Food and Drug Administration approved a standardized formulation of cannabidiol oral solution for the treatment of seizures associated with Lennox-Gastaut syndrome and Dravet syndrome in patients 2 years and older. The report shows that there continues to be a steady flow of potential antiepileptic drugs progressing to clinical development. Many of these compounds show innovative mechanisms of action, and some have already been tested in placebo-controlled randomized controlled trials, with promising efficacy and safety results.

Pharmacological targeting of brain inflammation in epilepsy: Therapeutic perspectives from experimental and clinical studies

Increasing evidence supports a pathogenic role of unabated neuroinflammation in various central nervous system (CNS) diseases, including epilepsy. Neuroinflammation is not a bystander phenomenon of the diseased brain tissue, but it may contribute to neuronal hyperexcitability underlying seizure generation, cell loss, and neurologic comorbidities. Several molecules, which constitute the inflammatory milieu in the epileptogenic area, activate signaling pathways in neurons and glia resulting in pathologic modifications of cell function, which ultimately lead to alterations in synaptic transmission and plasticity. Herein we report the up-to-date experimental and clinical evidence that supports the neuromodulatory role of inflammatory mediators, their related signaling pathways, and involvement in epilepsy. We discuss how these mechanisms can be harnessed to discover and validate targets for novel therapeutics, which may prevent or control pharmacoresistant epilepsies.

Detection of HHV-6 and EBV and Cytokine Levels in Saliva From Children With Seizures: Results of a Multi-Center Cross-Sectional Study

Background and Objective: One third of children with epilepsy are refractory to medications. Growing data support a role of common childhood infections with neurotropic viruses and inflammation in epileptogenesis. Our objective was to determine the frequency of Human Herpesvirus-6 (HHV-6) and Epstein-Barr Virus (EBV) infection and cytokine levels in saliva from children with seizures compared to healthy controls and to controls with a febrile illness without seizures. Methods: In this cross-sectional multi-center study, we collected saliva from 115 consecutive children with acute seizures (cases), 51 children with a fever and no seizures or underlying neurological disease (fever controls) and 46 healthy children (healthy controls). Specimens were analyzed by a novel droplet digital PCR for HHV-6 and EBV viral DNA and a bead-based immunoassay for neuroinflammatory cytokines. Results: Cases included febrile seizures (n = 30), acute seizures without (n = 53) and with fever (n = 4) in chronic epilepsy, new onset epilepsy (n = 13), febrile status epilepticus (n = 3), and first lifetime seizure (n = 12). HHV-6 DNA was found in 40% of cases vs. 37% fever controls and 35% healthy controls, with no statistically significant differences. EBV DNA was also detected with no differences in 17% cases, 16% fever controls, and 28% healthy controls. IL-8 and IL-1β were increased in saliva of 32 random samples from cases compared with 30 fever controls: IL-8 cases mean (SD): 1158.07 pg/mL (1427.41); controls 604.92 (754.04); p = 0.02. IL-1β 185.76 (230.57); controls 86.99 (187.39); p = 0.0002. IL-1β level correlated with HHV6 viral load (p = 0.007). Conclusion: Increase in inflammatory cytokines may play a role in the onset of acute seizures and saliva could represent an inexpensive and non-invasive method for detection of viral DNA and cytokines.