The neurobiology and consequences of epilepsy in the developing brain

Evaluation of lateralization and localization value of hand postures in Pediatric Epilepsy

INTRODUCTION

Identifying epileptogenic zone is essential for selecting patients for epilepsy surgery and understanding seizure pathophysiology. This study aimed to evaluate the role of ictal hand postures in localization and lateralization value in children.

MATERIAL AND METHODS

We conducted a retrospective evaluation of 628 individuals utilizing long-term video EEG recordings of Gazi University Video EEG Monitoring Unit (VEMU) between 2013 and 2022. Distinct hand postures were identified in fifty-six patients. The localization and lateralization value of the hand postures identified in these patients were assessed.

RESULTS

A total of 91 seizures from 56 patients were analyzed, and hand postures were categorized as fist, thumb upside fist (TUF), fanning, holding, index-finger pointing (IFP), and pincer grasp. Fist posture was most frequently observed in frontal lobe seizures, while TUF was dominant in temporal lobe seizures. Fanning was primarily associated with generalized seizures. Lateralization analysis revealed that ipsilateral postures were more common in frontal lobe seizures, whereas contralateral postures were prevalent in temporal lobe seizures (p < 0.05).

CONCLUSION

In conclusion, ictal hand postures may serve as a straightforward and accessible tool for identifying seizure onset zones in children, especially in resource-limited settings. Semiological classification plays a crucial role in the interpretation of video EEG. Accurate identification of semiological manifestations can facilitate timely referral of patients with suspected drug-resistant focal epilepsy for presurgical evaluation.

Comprehensive Serum Analysis via an AI-Assisted Magnetically Driven SERS Platform for the Diagnosis and Etiological Differentiation of Childhood Epilepsy

Timely and accurate diagnosis of childhood epilepsy and identification of its etiology are crucial for early interventional treatment, yet still, effective detection methods are lacking. Blood analysis is a promising strategy for disease diagnosis. However, due to the complex composition and lack of definite childhood epilepsy diagnostic markers in serum, comprehensively profiling serum molecular signals to accurately reveal diagnostic information is still challenging. Herein, we developed a novel magnetically driven SERS platform, which utilized specially designed branched Au nanostructure-embedded magnetic microspheres to achieve simultaneous detection of small molecules and biomacromolecules in serum, thus providing comprehensive serum molecular SERS signals. By using this platform, the SERS data sets of serum samples from 90 healthy controls and 585 epileptic patients were collected to train a self-built lightweight convolutional neural network (MLS-CNN) model, which successfully identified the serum epileptic diagnostic and etiological differentiation information, including causes of autoimmune encephalitis, febrile infection, developmental disability, structural brain lesions, and unknown etiology. The MLS-CNN model exhibits excellent diagnostic accuracy (100%) and etiological differentiation accuracy (>89%) for epilepsy. This AI-assisted magnetically driven SERS platform for comprehensively profiling the molecular information on serum might provide a novel strategy for childhood epilepsy diagnosis and etiological identification.

Exploring common mechanisms of adverse drug reactions and disease phenotypes through network-based analysis

The need for a deeper understanding of adverse drug reaction (ADR) mechanisms is vital for improving drug safety and repurposing. This study introduces Drug Adverse Reaction Mechanism Explainer (DREAMER), a network-based framework that uses a comprehensive knowledge graph to uncover molecular mechanisms underlying ADRs and disease phenotypes. By examining shared phenotypes of drugs and diseases and their effects on protein-protein interaction networks, DREAMER identifies proteins linked to ADR mechanisms. Applied to 649 ADRs, DREAMER identified molecular mechanisms for 67 ADRs, including ventricular arrhythmia and metabolic acidosis, and emphasized pathways like GABAergic signaling and coagulation proteins in personality disorders and intracranial hemorrhage. We further demonstrate the application of DREAMER in drug repurposing and propose sotalol, ranolazine, and diltiazem as candidate drugs to be repurposed for cardiac arrest. In summary, DREAMER effectively detects molecular mechanisms underlying phenotypes, emphasizing the importance of network-based analyses with integrative data for enhancing drug safety and accelerating the discovery of novel therapeutic strategies.

Clinical and pathological risk factors for postencephalitic epilepsy after herpes simplex virus-1 encephalitis in children

The high rate of postencephalitic epilepsy (PE) contributes to the unfavorable clinical outcome of herpes simplex virus-1 encephalitis (HSE). We aimed to identify the risk factors and explore possible mechanisms of PE in childhood following HSE. We conducted a retrospective review of children diagnosed with HSE and patients were categorized into two groups based on the presence or absence of PE. Multivariate logistic regression analysis was used to analyze factors associated with PE. Furthermore, cytokine and albumin levels in paired cerebrospinal fluid (CSF) and blood samples during acute HSE were also retrospectively reviewed. 97 HSE patients were included in the study and PE was diagnosed in 46. On multivariate analysis, the features predictive of PE (presented as odds ratio [OR] with confidence intervals [CIs]) were status epilepticus (OR 9.38, CI 1.71-10.37), focal seizures (7.41, 1.42-16.97), and restricted diffusion on MRI (6.15, 1.16-20.31). The median QAlb value (CSF to serum albumin ratio, a marker of blood-brain-barrier [BBB] integrity), levels of interleukin (IL)-6 and IL-6:IL-10 ratio in CSF were higher in children with PE during acute HSE. However, CSF levels of IL-10 were higher in non-PE patients. Furthermore, greater CSF IL-6 levels were associated with higher QAlb. These results demonstrated that enhanced BBB impairment and exaggerated proinflammatory response may play a role in the pathogenesis of PE following HSE.

Therapeutic Efficacy of Lavandula dentata's Oil and Ethanol Extract in Regulation of the Neuroinflammation, Histopathological Alterations, Oxidative Stress, and Restoring Balance Treg Cells Expressing FoxP3+ in a Rat Model of Epilepsy

Background/Objectives: Despite the availability of antiepileptic drugs (AEDs) that can manage seizures, they often come with cognitive side effects. Furthermore, the role of oxidative stress and neuroinflammatory responses in epilepsy and the limitations of current AEDs necessitate exploring alternative therapeutic options. Medicinal plants, e.g., Lavandula dentata L., are rich in phenolic compounds and may provide neuroprotective and anti-inflammatory benefits. However, limited research evaluates their effectiveness in modulating neuroinflammation and histopathological changes in epilepsy models. Therefore, the current study hypothesized that treating Lavandula dentata L. extract or essential oils may reduce neuroinflammatory responses and mitigate histopathological changes in the brain, providing a natural alternative or adjunct therapy for epilepsy management. Methods: Five groups of male Wistar rats were used: control, pilocarpine-treated epileptic, valproic acid (VPA-treated epileptic), L. dentata extract, and essential oils. Numerous electrolyte levels, monoamine levels, neurotransmitter levels, and the mRNA expression of specific gate channel subtypes were evaluated in homogenate brain tissue. Additionally, histological changes in various brain regions were investigated. Results: The investigation revealed that the extract and essential oils obtained from L. dentata L. exhibited the ability to improve the modulation of electrolytes and ions across voltage- and ligand-gated ion channels. Furthermore, it was revealed that they could decrease neuronal excitability by facilitating repolarization. Moreover, L. dentata's oil and ethanol extract re-balances T-reg/Th-17 cytokines, restoring the pro/anti-inflammatory cytokines and Treg markers, e.g., FOXP3 and CTLA-4, to their normal level. Conclusions: The present work confirms that the extract and essential oils of L. dentata L. have different activities to ameliorate the progression of histopathological alterations. Therefore, when used in conjunction with other AEDs, the extract and essential oils of L. dentata can slow the progression of epileptogenesis.

Serum/glucocorticoid regulated kinase 1 (SGK1) in neurological disorders: pain or gain

Serum/Glucocorticoid Regulated Kinase 1 (SGK1), a serine/threonine kinase, is ubiquitous across a wide range of tissues, orchestrating numerous signaling pathways and associated with various human diseases. SGK1 has been extensively explored in diverse types of immune and inflammatory diseases, cardiovascular disorders, as well as cancer metastasis. These studies link SGK1 to cellular proliferation, survival, metabolism, membrane transport, and drug resistance. Recently, increasing research has focused on SGK1's role in neurological disorders, including a variety of neurodegenerative diseases (e.g., Alzheimer's disease, Huntington's disease and Parkinson's disease), brain injuries (e.g., cerebral ischemia and traumatic brain injury), psychiatric conditions (e.g., depression and drug addiction). SGK1 is emerging as an increasingly compelling therapeutic target across the spectrum of neurological disorders, supported by the availability of several effective agents. However, the conclusions of many studies observing the prevalence and function of SGK1 in neurological disorders are contradictory, necessitating a review of the SGK1 research within neurological disorders. Herein, we review recent literature on SGK1's primary functions within the nervous system and its impacts within different neurological disorders. We summarize significant findings, identify research gaps, and outline possible future research directions based on the current understanding of SGK1 to help further progress the understanding and treatment of neurological disorders.

Preventive, rescue and reparative neuroprotective strategies for the fetus and neonate

Neonatal encephalopathy remains a major contributor to death and disability around the world. Acute hypoxia-ischaemia before, during or after birth creates a series of events that can lead to neonatal brain injury. Understanding the evolution of injury underpinned the development of therapeutic hypothermia. This review discusses the determinants of injury, including maturity, the pattern of exposure to HI, impaired placental function, often associated with fetal growth restriction and in the long-term, socio-economic deprivation. Chorioamnionitis has been associated with the presence of NE, but it is important to note that experimentally, inflammation can either sensitize to greater neural injury after HI or alleviate injury, depending on its precise timing. As fetal surveillance tools improve it is likely that improved detection of specific pathways will offer future opportunities for preventive and reparative interventions in utero and after birth.

Alterations in GABAA receptor-mediated inhibition triggered by status epilepticus and their role in epileptogenesis and increased anxiety

The triggers of status epilepticus (SE) in non-epileptic patients can vary widely, from idiopathic causes to exposure to chemoconvulsants. Regardless of its etiology, prolonged SE can cause significant brain damage, commonly resulting in the development of epilepsy, which is often accompanied by increased anxiety. GABAA receptor (GABAAR)-mediated inhibition has a central role among the mechanisms underlying brain damage and the ensuing epilepsy and anxiety. During SE, calcium influx primarily via ionotropic glutamate receptors activates signaling cascades which trigger a rapid internalization of synaptic GABAARs; this weakens inhibition, exacerbating seizures and excitotoxicity. GABAergic interneurons are more susceptible to excitotoxic death than principal neurons. During the latent period of epileptogenesis, the aberrant reorganization in synaptic interactions that follow interneuronal loss in injured brain regions, leads to the formation of hyperexcitable, seizurogenic neuronal circuits, along with disturbances in brain oscillatory rhythms. Reduction in the spontaneous, rhythmic "bursts" of IPSCs in basolateral amygdala neurons is likely to play a central role in anxiogenesis. Protecting interneurons during SE is key to preventing both epilepsy and anxiety. Antiglutamatergic treatments, including antagonism of calcium-permeable AMPA receptors, can be expected to control seizures and reduce excitotoxicity not only by directly suppressing hyperexcitation, but also by counteracting the internalization of synaptic GABAARs. Benzodiazepines, as delayed treatment of SE, have low efficacy due to the reduction and dispersion of their targets (the synaptic GABAARs), but also because themselves contribute to further reduction of available GABAARs at the synapse; furthermore, benzodiazepines may be completely ineffective in the immature brain.

Decreased GABA levels during development result in increased connectivity in the larval zebrafish tectum

γ-aminobutyric acid (GABA) is an abundant neurotransmitter that plays multiple roles in the vertebrate central nervous system (CNS). In the early developing CNS, GABAergic signaling acts to depolarize cells. It mediates several aspects of neural development, including cell proliferation, neuronal migration, neurite growth, and synapse formation, as well as the development of critical periods. Later in CNS development, GABAergic signaling acts in an inhibitory manner when it becomes the predominant inhibitory neurotransmitter in the brain. This behavior switch occurs due to changes in chloride/cation transporter expression. Abnormalities of GABAergic signaling appear to underlie several human neurological conditions, including seizure disorders. However, the impact of reduced GABAergic signaling on brain development has been challenging to study in mammals. Here we take advantage of zebrafish and light sheet imaging to assess the impact of reduced GABAergic signaling on the functional circuitry in the larval zebrafish optic tectum. Zebrafish have three gad genes: two gad1 paralogs known as gad1a and gad1b, and gad2. The gad1b and gad2 genes are expressed in the developing optic tectum. Null mutations in gad1b significantly reduce GABA levels in the brain and increase electrophysiological activity in the optic tectum. Fast light sheet imaging of genetically encoded calcium indicator (GCaMP)-expressing gab1b null larval zebrafish revealed patterns of neural activity that were different than either gad1b-normal larvae or gad1b-normal larvae acutely exposed to pentylenetetrazole (PTZ). These results demonstrate that reduced GABAergic signaling during development increases functional connectivity and concomitantly hyper-synchronization of neuronal networks.

Candesartan restores blood-brain barrier dysfunction, mitigates aberrant gene expression, and extends lifespan in a knockin mouse model of epileptogenesis

Blockade of Angiotensin type 1 receptor (AT1R) has potential therapeutic utility in the treatment of numerous detrimental consequences of epileptogenesis, including oxidative stress, neuroinflammation, and blood-brain barrier (BBB) dysfunction. We have recently shown that many of these pathological processes play a critical role in seizure onset and propagation in the Scn8a-N1768D mouse model. Here we investigate the efficacy and potential mechanism(s) of action of candesartan (CND), an FDA-approved angiotensin receptor blocker (ARB) indicated for hypertension, in improving outcomes in this model of pediatric epilepsy. We compared length of lifespan, seizure frequency, and BBB permeability in juvenile (D/D) and adult (D/+) mice treated with CND at times after seizure onset. We performed RNAseq on hippocampal tissue to quantify differences in genome-wide patterns of transcript abundance and inferred beneficial and detrimental effects of canonical pathways identified by enrichment methods in untreated and treated mice. Our results demonstrate that treatment with CND gives rise to increased survival, longer periods of seizure freedom, and diminished BBB permeability. CND treatment also partially reversed or 'normalized' disease-induced genome-wide gene expression profiles associated with inhibition of NF-κB, TNFα, IL-6, and TGF-β signaling in juvenile and adult mice. Pathway analyses reveal that efficacy of CND is due to its known dual mechanism of action as both an AT1R antagonist and a PPARγ agonist. The robust effectiveness of CND across ages, sexes and mouse strains is a positive indication for its translation to humans and its suitability of use for clinical trials in children with SCN8A epilepsy.

Clinical characteristics and post-operative outcomes in children with malformation of cortical development related drug-resistant epilepsy: 428 cases in one pediatric epilepsy center

AIMS

To investigate post-operative seizure outcomes, and predictors of surgical outcomes of the malformation of cortical development (MCD) in children with drug-resistant epilepsy (DRE) and age-specific characteristics.

METHODS

We retrospectively analyzed clinical data from 428 children with MCD-related DRE who underwent curative surgical treatment. Statistical analyses were conducted to identify correlative characteristics, prognostic predictors, and differences among various age groups.

RESULTS

After more than 3 years of follow-up, 81.3% of patients achieved Engel I outcomes. Prognosis was correlated with factors such as age at surgery, MRI findings, invasive EEG, pathology, acute postoperative seizures (APOS), and the number of preoperative and postoperative anti-seizure medications (AEDs). Age at surgery and the number of preoperative AEDs (p < 0.001) were significant predictors of seizure recurrence. Distinct clinical characteristics were observed among different age groups.

CONCLUSION

Surgery is effective in terminating MCD-related DRE. Younger age at surgery and fewer preoperative AEDs are associated with better prognoses. Clinical characteristics vary significantly with age.

DREAMER: Exploring Common Mechanisms of Adverse Drug Reactions and Disease Phenotypes through Network-Based Analysis

Adverse drug reactions (ADRs) are a major concern in clinical healthcare, significantly affecting patient safety and drug development. This study introduces DREAMER, a novel network-based method for exploring the mechanisms underlying ADRs and disease phenotypes at a molecular level by leveraging a comprehensive knowledge graph obtained from various datasets. By considering drugs and diseases that cause similar phenotypes, and investigating their commonalities regarding their impact on specific modules of the protein-protein interaction network, DREAMER can robustly identify protein sets associated with the biological mechanisms underlying ADRs and unravel the causal relationships that contribute to the observed clinical outcomes. Applying DREAMER to 649 ADRs, we identified proteins associated with the mechanism of action for 67 ADRs across multiple organ systems. In particular, DREAMER highlights the importance of GABAergic signaling and proteins of the coagulation pathways for personality disorders and intracranial hemorrhage, respectively. We further demonstrate the application of DREAMER in drug repurposing and propose sotalol, ranolazine, and diltiazem as candidate drugs to be repurposed for cardiac arrest. In summary, DREAMER effectively detects molecular mechanisms underlying phenotypes.

The homeostatic effects of the RE-1 silencing transcription factor on cortical networks are altered under ictogenic conditions in the mouse

AIM

The Repressor Element-1 Silencing Transcription Factor (REST) is an epigenetic master regulator playing a crucial role in the nervous system. In early developmental stages, REST downregulation promotes neuronal differentiation and the acquisition of the neuronal phenotype. In addition, postnatal fluctuations in REST expression contribute to shaping neuronal networks and maintaining network homeostasis. Here we investigate the role of the early postnatal deletion of neuronal REST in the assembly and strength of excitatory and inhibitory synaptic connections.

METHODS

We investigated excitatory and inhibitory synaptic transmission by patch-clamp recordings in acute neocortical slices in a conditional knockout mouse model (RestGTi) in which Rest was deleted by delivering PHP.eB adeno-associated viruses encoding CRE recombinase under the control of the human synapsin I promoter in the lateral ventricles of P0-P1 pups.

RESULTS

We show that, under physiological conditions, Rest deletion increased the intrinsic excitability of principal cortical neurons in the primary visual cortex and the density and strength of excitatory synaptic connections impinging on them, without affecting inhibitory transmission. Conversely, in the presence of a pathological excitation/inhibition imbalance induced by pentylenetetrazol, Rest deletion prevented the increase in synaptic excitation and decreased seizure severity.

CONCLUSION

The data indicate that REST exerts distinct effects on the excitability of cortical circuits depending on whether it acts under physiological conditions or in the presence of pathologic network hyperexcitability. In the former case, REST preserves a correct excitatory/inhibitory balance in cortical circuits, while in the latter REST loses its homeostatic activity and may become pro-epileptogenic.

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.

Therapeutic Strategies in Children with Epilepsy: A Quality-of-Life-Related Perspective

Back ground: Children with epilepsy are affected by several factors, including clinical and social variables. Among these variables, cognitive decline and behavioral disturbances, perceptions of stigma, and fatigue can lead to reductions in quality of life (QOL). Epileptic activities, including seizure severity, frequent seizures, and status epilepticus (SE), have been identified as important predictors of QOL. In addition, the frequency of interictal epileptiform discharges (IEDs) on electroencephalogram (EEG) may also be an important predictor of QOL, because IEDs can lead to cognitive decline and behavioral disturbances. Moreover, frequent seizures and/or IEDs may play a role in emotional mediators, such as stigma and fatigue, in childhood epilepsy. Seizure severity and/or IEDs are, therefore, important QOL-related factors in childhood epilepsy. Seizure severity as a QOL-related factor: Frontal lobe dysfunctions, such as cognitive decline and behavioral disturbances, can result in reduced QOL for both the child and their family. Frontal and prefrontal lobe growth disturbances can be present during active-phase epilepsy in some children with neuropsychological impairments. Recovery from prefrontal lobe growth disturbances may depend on the active seizure period. Children with a shorter active seizure period can recover from disturbances in prefrontal lobe growth more rapidly. In contrast, recovery may be delayed in children with a longer active seizure period. Moreover, frequent seizures can lead to seizure-associated headaches, perceptions of self-stigma and parental stigma, and fatigue. Accordingly, severe seizures can lead to neuropsychological impairments in association with prefrontal lobe growth disturbances in children with epilepsy. EEG abnormalities as QOL-related factors: IEDs on EEG, representing persistent pathological neuronal discharges, may be associated with several pathological aspects. Frontal IEDs can be a risk factor for recurrent seizures, cognitive decline, and behavioral disturbances, and they may also play a role as emotional mediators similar to stigma. In addition, behavioral disturbances may result in the presence of secondary bilateral synchrony (SBS) on EEG. Behavioral disturbances can be improved in association with a reduction in IEDs in children with frontal IEDs and SBS. Therefore, EEG abnormalities, such as frontal IEDs and SBS, can also lead to neuropsychological impairments in children with epilepsy. Therapeutic strategies in children with epilepsy: Seizure severity and IEDs on EEG may be associated with neuropsychological impairments, leading to QOL reduction. Therapeutic management may be desirable to reduce seizures and EEG abnormalities, such as frontal IEDs and SBS, as early as possible to improve QOL in children with epilepsy. During antiseizure medication (ASM) selection and adjustment, physicians should strategize the therapeutic approach to controlling seizures and suppressing EEG abnormalities in children with epilepsy. Among various ASMs, novel ASMs, such as levetiracetam and perampanel, may suppress both clinical seizures and IEDs on EEG; thus, these novel ASMs may represent an important addition to the treatments available for epileptic children presenting with frontal IEDs and SBS.

Structural networking of the developing brain: from maturation to neurosurgical implications

Modern neuroscience agrees that neurological processing emerges from the multimodal interaction among multiple cortical and subcortical neuronal hubs, connected at short and long distance by white matter, to form a largely integrated and dynamic network, called the brain "connectome." The final architecture of these circuits results from a complex, continuous, and highly protracted development process of several axonal pathways that constitute the anatomical substrate of neuronal interactions. Awareness of the network organization of the central nervous system is crucial not only to understand the basis of children's neurological development, but also it may be of special interest to improve the quality of neurosurgical treatments of many pediatric diseases. Although there are a flourishing number of neuroimaging studies of the connectome, a comprehensive vision linking this research to neurosurgical practice is still lacking in the current pediatric literature. The goal of this review is to contribute to bridging this gap. In the first part, we summarize the main current knowledge concerning brain network maturation and its involvement in different aspects of normal neurocognitive development as well as in the pathophysiology of specific diseases. The final section is devoted to identifying possible implications of this knowledge in the neurosurgical field, especially in epilepsy and tumor surgery, and to discuss promising perspectives for future investigations.

Seizure enhances SUMOylation and zinc-finger transcriptional repression in neuronal nuclei

A single episode of pilocarpine-induced status epilepticus can trigger the development of spontaneous recurrent seizures in a rodent model for epilepsy. The initial seizure-induced events in neuronal nuclei that lead to long-term changes in gene expression and cellular responses likely contribute toward epileptogenesis. Using a transgenic mouse model to specifically isolate excitatory neuronal nuclei, we profiled the seizure-induced nuclear proteome via tandem mass tag mass spectrometry and observed robust enrichment of nuclear proteins associated with the SUMOylation pathway. In parallel with nuclear proteome, we characterized nuclear gene expression by RNA sequencing which provided insights into seizure-driven transcriptional regulation and dynamics. Strikingly, we saw widespread downregulation of zinc-finger transcription factors, specifically proteins that harbor Krüppel-associated box (KRAB) domains. Our results provide a detailed snapshot of nuclear events induced by seizure activity and demonstrate a robust method for cell-type-specific nuclear profiling that can be applied to other cell types and models.

Whole exome sequencing identified five novel variants in CNTN2, CARS2, ARSA, and CLCN4 leading to epilepsy in consanguineous families

Introduction: Epilepsy is a group of neurological disorders characterized by recurring seizures and fits. The Epilepsy genes can be classified into four distinct groups, based on involvement of these genes in different pathways leading to Epilepsy as a phenotype. Genetically the disease has been associated with various pathways, leading to pure epilepsy-related disorders caused by CNTN2 variations, or involving physical or systemic issues along with epilepsy caused by CARS2 and ARSA, or developed by genes that are putatively involved in epilepsy lead by CLCN4 variations. Methods: In this study, five families of Pakistani origin (EP-01, EP-02, EP-04, EP-09, and EP-11) were included for molecular diagnosis. Results: Clinical presentations of these patients included neurological symptoms such as delayed development, seizures, regression, myoclonic epilepsy, progressive spastic tetraparesis, vision and hearing impairment, speech problems, muscle fibrillation, tremors, and cognitive decline. Whole exome sequencing in index patients and Sanger sequencing in all available individuals in each family identified four novel homozygous variants in genes CARS2: c.655G>A p.Ala219Thr (EP-01), ARSA: c.338T>C: p.Leu113Pro (EP-02), c.938G>T p.Arg313Leu (EP-11), CNTN2: c.1699G>T p.Glu567Ter (EP-04), and one novel hemizygous variant in gene CLCN4: c.2167C>T p.Arg723Trp (EP-09). Conclusion: To the best of our knowledge these variants were novel and had not been reported in familial epilepsy. These variants were absent in 200 ethnically matched healthy control chromosomes. Three dimensional protein analyses revealed drastic changes in the normal functions of the variant proteins. Furthermore, these variants were designated as "pathogenic" as per guidelines of American College of Medical Genetics 2015. Due to overlapping phenotypes, among the patients, clinical subtyping was not possible. However, whole exome sequencing successfully pinpointed the molecular diagnosis which could be helpful for better management of these patients. Therefore, we recommend that exome sequencing be performed as a first-line molecular diagnostic test in familial cases.

Seizure Burden and Neurologic Outcomes After Neonatal Encephalopathy

BACKGROUND AND OBJECTIVES

Seizures are common during neonatal encephalopathy (NE), but the contribution of seizure burden (SB) to outcomes remains controversial. This study aims to examine the relationship between electrographic SB and neurologic outcomes after NE.

METHODS

This prospective cohort study recruited newborns ≥36 weeks postmenstrual age around 6 hours of life between August 2014 and November 2019 from a neonatal intensive care unit (NICU). Participants underwent continuous electroencephalography for at least 48 hours, brain MRI within 3-5 days of life, and structured follow-up at 18 months. Electrographic seizures were identified by board-certified neurophysiologists and quantified as total SB and maximum hourly SB. A medication exposure score was calculated based on all antiseizure medications given during NICU admission. Brain MRI injury severity was classified based on basal ganglia and watershed scores. Developmental outcomes were measured using the Bayley Scales of Infant Development, Third Edition. Multivariable regression analyses were performed, adjusting for significant potential confounders.

RESULTS

Of 108 enrolled infants, 98 had continuous EEG (cEEG) and MRI data collected, of which 5 were lost to follow-up, and 6 died before age 18 months. All infants with moderate-severe encephalopathy completed therapeutic hypothermia. cEEG-confirmed neonatal seizures occurred in 21 (24%) newborns, with a total SB mean of 12.5 ± 36.4 minutes and a maximum hourly SB mean of 4 ± 10 min/h. After adjusting for MRI brain injury severity and medication exposure, total SB was significantly associated with lower cognitive (-0.21, 95% CI -0.33 to -0.08, p = 0.002) and language (-0.25, 95% CI -0.39 to -0.11, p = 0.001) scores at 18 months. Total SB of 60 minutes was associated with 15-point decline in language scores and 70 minutes for cognitive scores. However, SB was not significantly associated with epilepsy, neuromotor score, or cerebral palsy (p > 0.1).

DISCUSSION

Higher SB during NE was independently associated with worse cognitive and language scores at 18 months, even after adjusting for exposure to antiseizure medications and severity of brain injury. These observations support the hypothesis that neonatal seizures occurring during NE independently contribute to long-term outcomes.

1400 W, a selective inducible nitric oxide synthase inhibitor, mitigates early neuroinflammation and nitrooxidative stress in diisopropylfluorophosphate-induced short-term neurotoxicity rat model

Organophosphate nerve agent (OPNA) exposure induces acute and long-term neurological deficits. OPNA exposure at sub-lethal concentrations induces irreversible inhibition of acetylcholinesterase and cholinergic toxidrome and develops status epilepticus (SE). Persistent seizures have been associated with increased production of ROS/RNS, neuroinflammation, and neurodegeneration. A total of 1400W is a novel small molecule, which irreversibly inhibits inducible nitric oxide synthase (iNOS) and has been shown to effectively reduce ROS/RNS generation. In this study, we investigated the effects of 1400W treatment for a week or two weeks at 10 mg/kg or 15 mg/kg per day in the rat diisopropylfluorophosphate (DFP) model. 1400W significantly reduced the number of microglia, astroglia, and NeuN+FJB positive cells compared to the vehicle in different regions of the brain. 1400W also significantly reduced nitrooxidative stress markers and proinflammatory cytokines in the serum. However, neither of the two concentrations of 1400W for two weeks of treatment had any significant effect on epileptiform spike rate and spontaneous seizures during the treatment period in mixed sex cohorts, males, or females. No significant sex differences were found in response to DFP exposure or 1400W treatment. In conclusion, 1400W treatment at 15 mg/kg per day for two weeks was more effective in significantly reducing DFP-induced nitrooxidative stress, neuroinflammatory and neurodegenerative changes.

Association of Hospital Resource Utilization With Neurodevelopmental Outcomes in Neonates With Hypoxic-Ischemic Encephalopathy

IMPORTANCE

Intercenter variation exists in the management of hypoxic-ischemic encephalopathy (HIE). It is unclear whether increased resource utilization translates into improved neurodevelopmental outcomes.

OBJECTIVE

To determine if higher resource utilization during the first 4 days of age, quantified by hospital costs, is associated with survival without neurodevelopmental impairment (NDI) among infants with HIE.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort analysis of neonates with HIE who underwent therapeutic hypothermia (TH) at US children's hospitals participating in the Children's Hospitals Neonatal Database between 2010 and 2016. Data were analyzed from December 2021 to December 2022.

EXPOSURES

Infants who survived to 4 days of age and had neurodevelopmental outcomes assessed at greater than 11 months of age were divided into 2 groups: (1) death or NDI and (2) survived without NDI. Resource utilization was defined as costs of hospitalization including neonatal neurocritical care (NNCC). Data were linked with Pediatric Health Information Systems to quantify standardized costs by terciles.

MAIN OUTCOMES AND MEASURES

The main outcome was death or NDI. Characteristics, outcomes, hospitalization, and NNCC costs were compared.

RESULTS

Among the 381 patients who were included, median (IQR) gestational age was 39 (38-40) weeks; maternal race included 79 (20.7%) Black mothers, 237 (62.2%) White mothers, and 58 (15.2%) mothers with other race; 80 (21%) died, 64 (17%) survived with NDI (combined death or NDI group: 144 patients [38%]), and 237 (62%) survived without NDI. The combined death or NDI group had a higher rate of infants with Apgar score at 10 minutes less than or equal to 5 (65.3% [94 of 144] vs 39.7% [94 of 237]; P < .001) and a lower rate of infants with mild or moderate HIE (36.1% [52 of 144] vs 82.3% [195 of 237]; P < .001) compared with the survived without NDI group. Compared with low-cost centers, there was no association between high- or medium-hospitalization cost centers and death or NDI. High- and medium-EEG cost centers had lower odds of death or NDI compared with low-cost centers (high vs low: OR, 0.30 [95% CI, 0.16-0.57]; medium vs low: OR, 0.29 [95% CI, 0.13-0.62]). High- and medium-laboratory cost centers had higher odds of death or NDI compared with low-cost centers (high vs low: OR, 2.35 [95% CI, 1.19-4.66]; medium vs low: OR, 1.93 [95% CI, 1.07-3.47]). High-antiseizure medication cost centers had higher odds of death or NDI compared with low-cost centers (high vs. low: OR, 3.72 [95% CI, 1.51-9.18]; medium vs low: OR, 1.56 [95% CI, 0.71-3.42]).

CONCLUSIONS AND RELEVANCE

Hospitalization costs during the first 4 days of age in neonates with HIE treated with TH were not associated with neurodevelopmental outcomes. Higher EEG costs were associated with lower odds of death or NDI yet higher laboratory and antiseizure medication costs were not. These findings serve as first steps toward identifying aspects of NNCC that are associated with outcomes.

Seizure Burden, EEG, and Outcome in Neonates With Acute Intracranial Infections: A Prospective Multicenter Cohort Study

BACKGROUND

Limited data exist regarding seizure burden, electroencephalogram (EEG) background, and associated outcomes in neonates with acute intracranial infections.

METHODS

This secondary analysis was from a prospective, multicenter study of neonates enrolled in the Neonatal Seizure Registry with seizures due to intracranial infection. Sites used continuous EEG monitoring per American Clinical Neurophysiology Society guidelines. High seizure burden was defined a priori as seven or more EEG-confirmed seizures. EEG background was categorized using standardized terminology. Primary outcome was neurodevelopment at 24-months corrected age using Warner Initial Developmental Evaluation of Adaptive and Functional Skills (WIDEA-FS). Secondary outcomes were postneonatal epilepsy and motor disability.

RESULTS

Twenty-seven of 303 neonates (8.9%) had seizures due to intracranial infection, including 16 (59.3%) bacterial, 5 (18.5%) viral, and 6 (22.2%) unknown. Twenty-three neonates (85%) had at least one subclinical seizure. Among 23 children with 24-month follow-up, the WIDEA-FS score was, on average, 23 points lower in children with high compared with low seizure burden (95% confidence interval, [-48.4, 2.1]; P = 0.07). After adjusting for gestational age, infection etiology, and presence of an additional potential acute seizure etiology, the effect size remained unchanged (β = -23.8, P = 0.09). EEG background was not significantly associated with WIDEA-FS score. All children with postneonatal epilepsy (n = 4) and motor disability (n = 5) had high seizure burden, although associations were not significant.

CONCLUSION

High seizure burden may be associated with worse neurodevelopment in neonates with intracranial infection and seizures. EEG monitoring can provide useful management and prognostic information in this population.

Optical Monitoring in Neonatal Seizures

BACKGROUND

Neonatal seizures remain a significant cause of morbidity and mortality worldwide. The past decade has resulted in substantial progress in seizure detection and understanding the impact seizures have on the developing brain. Optical monitoring such as cerebral near-infrared spectroscopy (NIRS) and broadband NIRS can provide non-invasive continuous real-time monitoring of the changes in brain metabolism and haemodynamics.

AIM

To perform a systematic review of optical biomarkers to identify changes in cerebral haemodynamics and metabolism during the pre-ictal, ictal, and post-ictal phases of neonatal seizures.

METHOD

A systematic search was performed in eight databases. The search combined the three broad categories: (neonates) AND (NIRS) AND (seizures) using the stepwise approach following PRISMA guidance.

RESULTS

Fifteen papers described the haemodynamic and/or metabolic changes observed with NIRS during neonatal seizures. No randomised controlled trials were identified during the search. Studies reported various changes occurring in the pre-ictal, ictal, and post-ictal phases of seizures.

CONCLUSION

Clear changes in cerebral haemodynamics and metabolism were noted during the pre-ictal, ictal, and post-ictal phases of seizures in neonates. Further studies are necessary to determine whether NIRS-based methods can be used at the cot-side to provide clear pathophysiological data in real-time during neonatal seizures.

Development and validation of a nomogram for the early prediction of drug resistance in children with epilepsy

BACKGROUND AND PURPOSE

This study aimed to effectively identify children with drug-resistant epilepsy (DRE) in the early stage of epilepsy, and take personalized interventions, to improve patients' prognosis, reduce serious comorbidity, and save social resources. Herein, we developed and validated a nomogram prediction model for children with DRE.

METHODS

The training set was patients with epilepsy who visited the Children's Hospital of Soochow University (Suzhou Industrial Park, Jiangsu Province, China) between January 2015 and December 2017. The independent risk factors for DRE were screened by univariate and multivariate logistic regression analyses using SPSS21 software. The nomogram was designed according to the regression coefficient. The nomogram was validated in the training and validation sets. Internal validation was conducted using bootstrapping analyses. We also externally validated this instrument in patients with epilepsy from the Children's Hospital of Soochow University (Gusu District, Jiangsu Province, China) and Yancheng Maternal and Child Health Hospital between January 2018 and December 2018. The nomogram's performance was assessed by concordance (C-index), calibration curves, as well as GiViTI calibration belts.

RESULTS

Multivariate logistic regression analysis of 679 children with epilepsy from the Children's Hospital of Soochow University (Suzhou Industrial Park, Jiangsu Province, China) showed that onset age<1, status epilepticus (SE), focal seizure, > 20 pre-treatment seizures, clear etiology (caused by genetic, structural, metabolic, or infectious), development and epileptic encephalopathy (DEE), and neurological abnormalities were all independent risk factors for DRE. The AUC of 0.92 for the training set compared to that of 0.91 for the validation set suggested a good discrimination ability of the prediction model. The C-index was 0.92 and 0.91 in the training and validation sets. Additionally, both good calibration curves and GiViTI calibration belts (P-value: 0.849 and 0.291, respectively) demonstrated that the predicted risks had strong consistency with the observed outcomes, suggesting that the prediction model in both groups was perfectly calibrated.

CONCLUSION

A nomogram prediction model for DRE was developed, with good discrimination and calibration in the training set and the validation set. Furthermore, the model demonstrated great accuracy, consistency, and prediction ability. Therefore, the nomogram prediction model can aid in the timely identification of DRE in children.

Clinical spectrum of pediatric drug refractory epilepsy secondary to parieto-occipital gliosis

BACKGROUND

Parieto-occipital (PO) gliosis secondary to perinatal insult, is often associated with neurologic sequelae such as epilepsy, which can be drug resistant.

OBJECTIVE

To evaluate the spectrum of epilepsy among patients presenting with seizures in association with PO gliosis and to determine factors that influence the development of epileptic encephalopathy (EE) in these patients.

METHODS

We retrospectively evaluated patients aged < 16 years with drug refractory epilepsy and PO gliosis who underwent video electroencephalography (Video EEG). We evaluated the clinical, electrophysiological and radiological profile including treatment responsiveness of subjects with EE.

RESULTS

One hundred one patients (M: F=3:1) with mean age of onset of epilepsy at 28.9 ± 33.1 months were recruited into the study. Based on video EEG findings, Based on video EEG findings, the commonest type of focal onset ictus was tonic seizures with impaired awareness (n = 26, 29.9%). Myoclonic jerks (n = 20, 23%) were the commonest type of generalised onset seizures. Ictal onset from parieto occipital region were observed in 28 patients. Ictal onset from frontal, temporal and fronto temporal region were observed in 6 (6.8%), 7(7.9%) and 9 (8.9%) patients, respectively. Comparison of the seizure types and ictal onset among subgroups of patients with occipital gliosis, parieto-occipital gliosis and parieto-occipital with frontal gliosis revealed that the extent of gliosis did not significantly affect seizure semiology or ictal onset. EE was significantly associated with presence of neonatal seizures (p = 0.04), hypoglycaemia (p = 0.005), longer duration of ICU stay (Z score = -3.55, p < 0.001) and younger age of onset of seizures (Z score = - 2.97, p = 0.03). Eleven out of eighteen (64.7%) subjects with EE showed greater than 50% improvement in seizure frequency following three months of pulse intravenous methylprednisolone therapy.

CONCLUSIONS

Among subjects with PO gliosis on MRI, the seizure semiology is unaffected by laterality, radiologic extension beyond the occipital cortex or presence of ulegyria. Patients with PO gliosis can have florid interictal epileptiform discharges anteriorly and can have seizures with ictal onset from frontal and temporal region. Development of EE is strongly related to the age of onset of seizures, neonatal seizures, prolonged NICU admission, rather than the radiological findings. Subjects with EE and PO gliosis show good response to intravenous pulse methylprednisolone.

Sensitivity, specificity and limitation of in vitro hippocampal slice and neuron-based assays for assessment of drug-induced seizure liability

An effective in vitro screening assay to detect seizure liability in preclinical development can contribute to better lead molecule optimization prior to candidate selection, providing higher throughput and overcoming potential brain exposure limitations in animal studies. This study explored effects of 26 positive and 14 negative reference pharmacological agents acting through different mechanisms, including 18 reference agents acting on glutamate signaling pathways, in a brain slice assay (BSA) of adult rat to define the assay's sensitivity, specificity, and limitations. Evoked population spikes (PS) were recorded from CA1 pyramidal neurons of hippocampus (HPC) in the BSA. Endpoints for analysis were PS area and PS number. Most positive references (24/26) elicited a concentration-dependent increase in PS area and/or PS number. The negative references (14/14) had little effect on the PS. Moreover, we studied the effects of 15 reference agents testing positive in the BSA on spontaneous activity in E18 rat HPC neurons monitored with microelectrode arrays (MEA), and compared these effects to the BSA results. From these in vitro studies we conclude that the BSA provides 93% sensitivity and 100% specificity in prediction of drug-induced seizure liability, including detecting seizurogenicity by 3 groups of metabotropic glutamate receptor (mGluR) ligands. The MEA results seemed more variable, both quantitatively and directionally, particularly for endpoints capturing synchronized electrical activity. We discuss these results from the two models, comparing each with published results, and provide potential explanations for differences and future directions.

Navigated transcranial magnetic stimulation mapping of the motor cortex for preoperative diagnostics in pediatric epilepsy

OBJECTIVE

Navigated transcranial magnetic stimulation (nTMS) is a noninvasive technique often used for localization of the functional motor cortex via induction of motor evoked potentials (MEPs) in neurosurgical patients. There has, however, been no published record of its application in pediatric epilepsy surgery. In this study, the authors aimed to investigate the feasibility of nTMS-based motor mapping in the preoperative diagnostic workup within a population of children with medically refractory epilepsy.

METHODS

A single-institution database was screened for preoperative nTMS motor mappings obtained in pediatric patients (aged 0 to 18 years, 2012 to present) with medically refractory epilepsy. Patient clinical data, demographic information, and mapping results were extracted and used in statistical analyses.

RESULTS

Sixteen patients met the inclusion criteria, 15 of whom underwent resection. The median age was 9 years (range 0-17 years). No adverse effects were recorded during mapping. Specifically, no epileptic seizures were provoked via nTMS. Recordings of valid MEPs induced by nTMS were obtained in 10 patients. In the remaining patients, no MEPs could be elicited. Failure to generate MEPs was associated significantly with younger patient age (r = 0.8020, p = 0.0001863). The most frequent seizure control outcome was Engel Epilepsy Surgery Outcome Scale class I (9 patients).

CONCLUSIONS

Navigated TMS is a feasible, effective, and well-tolerated method for mapping the motor cortex of the upper and lower extremities in pediatric patients with epilepsy. Patient age modulates elicitability of MEPs, potentially reflecting various stages of myelination. Successful motor mapping has the potential to add to the existing presurgical diagnostic workup in this population, and further research is warranted.

On the Origin of Paroxysmal Depolarization Shifts: The Contribution of Cav1.x Channels as the Common Denominator of a Polymorphous Neuronal Discharge Pattern

Since their discovery in the 1960s, the term paroxysmal depolarization shift (PDS) has been applied to a wide variety of reinforced neuronal discharge patterns. Occurrence of PDS as cellular correlates of electrographic spikes during latent phases of insult-induced rodent epilepsy models and their resemblance to giant depolarizing potentials (GDPs) nourished the idea that PDS may be involved in epileptogenesis. Both GDPs and - in analogy - PDS may lead to progressive changes of neuronal properties by generation of pulsatile intracellular Ca2+ elevations. Herein, a key element is the gating of L-type voltage gated Ca2+ channels (LTCCs, Cav1.x family), which may convey Ca2+ signals to the nucleus. Accordingly, the present study investigates various insult-associated neuronal challenges for their propensities to trigger PDS in a LTCC-dependent manner. Our data demonstrate that diverse disturbances of neuronal function are variably suited to induce PDS-like events, and the contribution of LTCCs is essential to evoke PDS in rat hippocampal neurons that closely resemble GDPs. These PDS appear to be initiated in the dendritic sub-compartment. Their morphology critically depends on the position of recording electrodes and on their rate of occurrence. These results provide novel insight into induction mechanisms, origin, variability, and co-existence of PDS with other discharge patterns and thereby pave the way for future investigations regarding the role of PDS in epileptogenesis.

Down syndrome cell adhesion molecule like-1 (DSCAML1) links the GABA system and seizure susceptibility

The Ihara epileptic rat (IER) is a mutant model with limbic-like seizures whose pathology and causative gene remain elusive. In this report, via linkage analysis, we identified Down syndrome cell adhesion molecule-like 1(Dscaml1) as the responsible gene for IER. A single base mutation in Dscaml1 causes abnormal splicing, leading to lack of DSCAML1. IERs have enhanced seizure susceptibility and accelerated kindling establishment. Furthermore, GABAergic neurons are severely reduced in the entorhinal cortex (ECx) of these animals. Voltage-sensitive dye imaging that directly presents the excitation status of brain slices revealed abnormally persistent excitability in IER ECx. This suggests that reduced GABAergic neurons may cause weak sustained entorhinal cortex activations, leading to natural kindling via the perforant path that could cause dentate gyrus hypertrophy and epileptogenesis. Furthermore, we identified a single nucleotide substitution in a human epilepsy that would result in one amino acid change in DSCAML1 (A2105T mutation). The mutant DSCAML1A2105T protein is not presented on the cell surface, losing its homophilic cell adhesion ability. We generated knock-in mice (Dscaml1A2105T) carrying the corresponding mutation and observed reduced GABAergic neurons in the ECx as well as spike-and-wave electrocorticogram. We conclude that DSCAML1 is required for GABAergic neuron placement in the ECx and suppression of seizure susceptibility in rodents. Our findings suggest that mutations in DSCAML1 may affect seizure susceptibility in humans.

Dynamic Transitions of Epilepsy Waveforms Induced by Astrocyte Dysfunction and Electrical Stimulation

Experimental studies have shown that astrocytes participate in epilepsy through inducing the release of glutamate. Meanwhile, considering the disinhibition circuit among inhibitory neuronal populations with different time scales and the feedforward inhibition connection from thalamic relay nucleus to cortical inhibitory neuronal population, here, we propose a modified thalamocortical field model to systematically investigate the mechanism of epilepsy. Firstly, our results show that rich firing activities can be induced by astrocyte dysfunction, including high or low saturated state, high- or low-frequency clonic, spike-wave discharge (SWD), and tonic. More importantly, with the enhancement of feedforward inhibition connection, SWD and tonic oscillations will disappear. In other words, all these pathological waveforms can be suppressed or eliminated. Then, we explore the control effects after different external stimulations applying to thalamic neuronal population. We find that single-pulse stimulation can not only suppress but also induce pathological firing patterns, such as SWD, tonic, and clonic oscillations. And we further verify that deep brain stimulation can control absence epilepsy by regulating the amplitude and pulse width of stimulation. In addition, based on our modified model, 3 : 2 coordinated reset stimulation strategies with different intensities are compared and a more effective and safer stimulation mode is proposed. Our conclusions are expected to give more theoretical insights into the treatment of epilepsy.

Dietary omega-3 fatty acids prevent neonatal seizure-induced early alterations in the hippocampal glutamatergic system and memory deficits in adulthood

OBJECTIVE

We investigated the influence of dietary omega-3 polyunsaturated fatty acids (n-3 PUFAs) on glutamatergic system modulation after a single episode of neonatal seizures and their possible effects on seizure-induced long-lasting behavioral deficits.

METHODS

Male Wistar rats receiving an omega-3 diet (n-3) or an n-3 deficient diet (D) from the prenatal period were subjected to a kainate-induced seizure model at P7. Glutamate transporter activity and immunocontents (GLT-1 and GLAST) were assessed in the hippocampus at 12, 24, and 48 h after the seizure episode. Fluorescence intensity for glial cells (GFAP) and neurons (NeuN) was assessed 24 h after seizure in the hippocampus. Behavioral analysis (elevated-plus maze and inhibitory avoidance memory task) was performed at 60 days of age.

RESULTS

The D group showed a decrease in glutamate uptake 24 h after seizure. In this group only, the GLT1 content increased at 12 h, followed by a decrease at 24 h. GLAST increased up to 24 h after seizure. GFAP fluorescence was higher, and NeuN fluorescence decreased, in the D group independent of seizures. In adulthood, the D group presented memory deficits independent of seizures, but short-term memory (1.5 h after a training session) was abolished in the D group treated with kainate.

SIGNIFICANCE

N-3 PUFA positively influenced the glutamatergic system during seizure and prevented seizure-related memory deficits in adulthood.

Self-injurious and suicidal behavior in young adults, teens, and children with epilepsy: A population-based study

OBJECTIVE

Whereas studies in adult epilepsy patients have shown higher rates of suicidal ideation and attempt, such studies in children are limited. Using the Rochester Epidemiology Project database, we compared the risk of self-injurious behavior and suicidal ideation in a population-based cohort of childhood epilepsy to controls.

METHODS

We studied 339 cases with epilepsy and 678 age- and sex-matched controls followed to a median age of 24.7 and 23.4 years, and identified 98 subjects with self-injurious behavior or suicidal ideation (43 with epilepsy and 55 controls). All behaviors were categorized using the Columbia Suicide Severity Rating Scale.

RESULTS

Those with epilepsy had a significantly higher rate of any self-injurious behavior and suicidal ideation (hazard ratio [HR] = 1.56, 95% confidence interval [CI] = 1.04-2.35) and tended to have an increased risk of suicidal ideation and attempt (HR = 1.48, 95% CI = 0.93-2.37). The prevalence of preceding mood and substance abuse disorders was similarly high in both cases and controls with self-injurious behavior or suicidal ideation; however, preceding attention-deficit/hyperactivity disorder was more than twice as common in the epilepsy cases. Among cases with epilepsy, we did not identify any specific epilepsy-related variable that was significantly correlated with risk of self-injurious behavior or suicidal ideation.

SIGNIFICANCE

Children, teens, and young adults with a history of childhood epilepsy are at greater risk of self-injurious behavior, highlighting the need for careful screening of mental health concerns as part of routine epilepsy care.

Felbamate for infantile spasms syndrome resistant to first-line treatments

AIM

To analyse the effects of felbamate in refractory infantile spasms/West syndrome.

METHOD

We conducted a 10-year retrospective study of infants (including all infants younger than 18mo) treated with felbamate for electroencephalography-recorded epileptic spasms persisting after first-line treatment.

RESULTS

In total, 29 infants (17 males, 12 females) were included in the study. Felbamate was initiated at a mean age of 13.8 months (range 4.5-66mo) after sequential administration or combination of vigabatrin and oral steroids; a ketogenic diet was implemented in 23 infants. Eight infants became spasm-free at a mean dose of 34.6mg/kg/day felbamate (range 26-45mg/kg/day). Mean duration of felbamate use was 19 months (range 1-67mo) for the 19 infants whose treatment was terminated. No severe side effects were observed. Reversible neutropenia led to withdrawal of felbamate in six patients. One spasm-free patient demonstrated recurrence when felbamate was withdrawn.

INTERPRETATION

N-methyl-d-aspartate receptors with felbamate controlled epileptic spasms in eight infants resistant to first-line treatment should be targeted.

Children with epilepsy demonstrate macro- and microstructural changes in the thalamus, putamen, and amygdala

PURPOSE

Despite evidence for macrostructural alteration in epilepsy patients later in life, little is known about the underlying pathological or compensatory mechanisms at younger ages causing these alterations. The aim of this work was to investigate the impact of pediatric epilepsy on the central nervous system, including gray matter volume, cerebral blood flow, and water diffusion, compared with neurologically normal children.

METHODS

Inter-ictal magnetic resonance imaging data was obtained from 30 children with epilepsy ages 1-16 (73% F, 27% M). An atlas-based approach was used to determine values for volume, cerebral blood flow, and apparent diffusion coefficient in the cerebral cortex, hippocampus, thalamus, caudate, putamen, globus pallidus, amygdala, and nucleus accumbens. These values were then compared with previously published values from 100 neurologically normal children using a MANCOVA analysis.

RESULTS

Most brain volumes of children with epilepsy followed a pattern similar to typically developing children, except for significantly larger putamen and amygdala. Cerebral blood flow was also comparable between the groups, except for the putamen, which demonstrated decreased blood flow in children with epilepsy. Diffusion (apparent diffusion coefficient) showed a trend towards higher values in children with epilepsy, with significantly elevated diffusion within the thalamus in children with epilepsy compared with neurologically normal children.

CONCLUSION

Children with epilepsy show statistically significant differences in volume, diffusion, and cerebral blood flow within their thalamus, putamen, and amygdala, suggesting that epilepsy is associated with structural changes of the central nervous system influencing brain development and potentially leading to poorer neurocognitive outcomes.

Mechanistic insights into autocrine and paracrine roles of endothelial GABA signaling in the embryonic forebrain

The developing cerebral cortex uses a complex developmental plan involving angiogenesis, neurogenesis and neuronal migration. Our recent studies have highlighted the importance of endothelial cell secreted GABA signaling in the embryonic forebrain and established novel autonomous links between blood vessels and the origin of neuropsychiatric diseases. A GABA pathway operates in both endothelial cells and GABAergic neurons of the embryonic telencephalon; however, while the neuronal GABA pathway has been extensively studied, little is known about the endothelial GABA pathway. Our recently generated Vgat endothelial cell knockout mouse model that blocks GABA release from endothelial cells, serves as a new tool to study how endothelial GABA signaling shapes angiogenesis and neurovascular interactions during prenatal development. Quantitative gene expression profiling reveals that the endothelial GABA signaling pathway influences genes connected to specific processes like endothelial cell proliferation, differentiation, migration, tight junction formation, vascular sprouting and integrity. It also shows how components of the neuronal GABA pathway, for instance receptor mediated signaling, cell cycle related components and transcription factors are affected in the absence of endothelial GABA release. Taken together, our findings delineate the close relationship between vascular and nervous systems that begin early in embryogenesis establishing their future interactions and interdependence.

Home Videos as a Cost-Effective Tool for the Diagnosis of Paroxysmal Events in Infants: Prospective Study

Background

The diagnosis of paroxysmal events in infants is often challenging. Reasons include the child’s inability to express discomfort and the inability to record video electroencephalography at home. The prevalence of mobile phones, which can record videos, may be beneficial to these patients. In China, this advantage may be even more significant given the vast population and the uneven distribution of medical resources.

Objective

The aim of this study is to investigate the value of mobile phone videos in increasing the diagnostic accuracy and cost savings of paroxysmal events in infants.

Methods

Clinical data, including descriptions and home videos of episodes, from 12 patients with paroxysmal events were collected. The investigation was conducted in six centers during pediatric academic conferences. All 452 practitioners present were asked to make their diagnoses by just the descriptions of the events, and then remake their diagnoses after watching the corresponding home videos of the episodes. The doctor’s information, including educational background, profession, working years, and working hospital level, was also recorded. The cost savings from accurate diagnoses were measured on the basis of using online consultation, which can also be done easily by mobile phone. All data were recorded in the form of questionnaires designed for this study.

Results

We collected 452 questionnaires, 301 of which met the criteria (66.6%) and were analyzed. The mean correct diagnoses with and without videos was 8.4 (SD 1.7) of 12 and 7.5 (SD 1.7) of 12, respectively. For epileptic seizures, mobile phone videos increased the mean accurate diagnoses by 3.9%; for nonepileptic events, it was 11.5% and both were statistically different (P=.006 for epileptic events; P<.001 for nonepileptic events). Pediatric neurologists with longer working years had higher diagnostic accuracy; whereas, their working hospital level and educational background made no difference. For patients with paroxysmal events, at least US $673.90 per capita and US $128 million nationwide could be saved annually, which is 12.02% of the total cost for correct diagnosis.

Conclusions

Home videos made on mobile phones are a cost-effective tool for the diagnosis of paroxysmal events in infants. They can facilitate the diagnosis of paroxysmal events in infants and thereby save costs. The best choice for infants with paroxysmal events on their initial visit is to record their events first and then show the video to a neurologist with longer working years through online consultation.

Neuroprotective Effects of AG490 in Neonatal Hypoxic-Ischemic Brain Injury

In infants and children, neonatal hypoxic-ischemic (HI) brain injury represents a major cause of chronic neurological morbidity. The transient receptor potential melastatin 2 (TRPM2), a non-selective cation channel that conducts calcium, can mediate neuronal death following HI brain injury. An important endogenous activator of TRPM2 is H₂O₂, which has previously been reported to be upregulated in the neonatal brain after hypoxic ischemic injury. Here, incorporating both in vitro (H₂O₂-induced neuronal cell death model) and in vivo (mouse HI brain injury model) approaches, we examined the effects of AG490, which can inhibit the H₂O₂-induced TRPM2 channel. We found that AG490 elicited neuroprotective effects. We confirmed that AG490 reduced H₂O₂-induced TRPM2 currents. Specifically, application of AG490 to neurons ameliorated H₂O₂-induced cell injury in vitro. In addition, AG490 administration reduced brain damage and improved neurobehavioral performance following HI brain injury in vivo. The neuroprotective benefits of AG490 suggest that pharmacological inhibition of H₂O₂-activated TRPM2 currents can be exploited as a potential therapeutic strategy to treat HI-induced neurological complications.

The Paroxysmal Depolarization Shift: Reconsidering Its Role in Epilepsy, Epileptogenesis and Beyond

Paroxysmal depolarization shifts (PDS) have been described by epileptologists for the first time several decades ago, but controversy still exists to date regarding their role in epilepsy. In addition to the initial view of a lack of such a role, seemingly opposing hypotheses on epileptogenic and anti-ictogenic effects of PDS have emerged. Hence, PDS may provide novel targets for epilepsy therapy. Evidence for the roles of PDS has often been obtained from investigations of the multi-unit correlate of PDS, an electrographic spike termed “interictal” because of its occurrence during seizure-free periods of epilepsy patients. Meanwhile, interictal spikes have been found to be associated with neuronal diseases other than epilepsy, e.g., Alzheimer’s disease, which may indicate a broader implication of PDS in neuropathologies. In this article, we give an introduction to PDS and review evidence that links PDS to pro- as well as anti-epileptic mechanisms, and to other types of neuronal dysfunction. The perturbation of neuronal membrane voltage and of intracellular Ca²⁺ that comes with PDS offers many conceivable pathomechanisms of neuronal dysfunction. Out of these, the operation of L-type voltage-gated calcium channels, which play a major role in coupling excitation to long-lasting neuronal changes, is addressed in detail.

In Vitro Models of Brain Disorders

The brain is the most complex organ of the body, and many pathological processes underlying various brain disorders are poorly understood. Limited accessibility hinders observation of such processes in the in vivo brain, and experimental freedom is often insufficient to enable informative manipulations. In vitro preparations (brain slices or cultures of dissociated neurons) offer much better accessibility and reduced complexity and have yielded valuable new insights into various brain disorders. Both types of preparations have their advantages and limitations with regard to lifespan, preservation of in vivo brain structure, composition of cell types, and the link to behavioral outcome is often unclear in in vitro models. While these limitations hamper general usage of in vitro preparations to study, e.g., brain development, in vitro preparations are very useful to study neuronal and synaptic functioning under pathologic conditions. This chapter addresses several brain disorders, focusing on neuronal and synaptic functioning, as well as network aspects. Recent progress in the fields of brain circulation disorders, excitability disorders, and memory disorders will be discussed, as well as limitations of current in vitro models.

Long-Term Effects of Early Life Seizures on Endogenous Local Network Activity of the Mouse Neocortex

Understanding the long term impact of early life seizures (ELS) is of vital importance both for researchers and clinicians. Most experimental studies of how seizures affect the developing brain have drawn their conclusions based on changes detected at the cellular or behavioral level, rather than on intermediate levels of analysis, such as the physiology of neuronal networks. Neurons work as part of networks and network dynamics integrate the function of molecules, cells and synapses in the emergent properties of brain circuits that reflect the balance of excitation and inhibition in the brain. Therefore, studying network dynamics could help bridge the cell-to-behavior gap in our understanding of the neurobiological effects of seizures. To this end we investigated the long-term effects of ELS on local network dynamics in mouse neocortex. By using the pentylenetetrazole (PTZ)-induced animal model of generalized seizures, single or multiple seizures were induced at two different developmental stages (P9-15 or P19-23) in order to examine how seizure severity and brain maturational status interact to affect the brain's vulnerability to ELS. Cortical physiology was assessed by comparing spontaneous network activity (in the form of recurring Up states) in brain slices of adult (>5 mo) mice. In these experiments we examined two distinct cortical regions, the primary motor (M1) and somatosensory (S1) cortex in order to investigate regional differences in vulnerability to ELS. We find that the effects of ELSs vary depending on (i) the severity of the seizures (e.g., single intermittent ELS at P19-23 had no effect on Up state activity, but multiple seizures induced during the same period caused a significant change in the spectral content of spontaneous Up states), (ii) the cortical area examined, and (iii) the developmental stage at which the seizures are administered. These results reveal that even moderate experiences of ELS can have long lasting age- and region-specific effects in local cortical network dynamics.

What is new: Talk about status epilepticus in the neonatal period

Nowadays, no general consensus was achieved regarding neonatal status epilepticus and its definition. Indeed, different criteria (mainly based on seizure duration) were used. Whereas a recent proposal has been developed to define status epilepticus in older ages, it seems that the peculiar characteristics of neonatal seizures and of the immature brain make difficult to find a tailored definition for this period of life. Achieving a consensus on this entity would mean to make the first step toward a targeted therapeutic strategy of intervention.

The effects of soy and tamoxifen on apoptosis in the hippocampus and dentate gyrus in a pentylenetetrazole-induced seizure model of ovariectomized rats

The effects of tamoxifen and soy on apoptosis of the hippocampus and dentate gyrus of ovariectomized rats after repeated seizures were investigated. Female rats were divided into: (1) Control, (2) Sham, (3) Sham-Tamoxifen (Sham-T), (4) Ovariectomized (OVX), (5) OVX-Tamoxifen (OVX-T), (6)OVX-Soy(OVX-S) and (7) OVX-S-T. The animals in the OVX-S, OVX-T and OVX-S-T groups received soy extract (60 mg/kg; i.p.), tamoxifen (10 mg/kg) or both for 2 weeks before induction of seizures. The animals in these groups additionally received the mentioned treatments before each injection of pentylenetetrazole (PTZ; 40 mg/kg) for 6 days. The animals in the Sham and OVX groups received a vehicle of tamoxifen and soy. A significant decrease in the seizure score and TUNEL-positive neurons was seen in the OVX group compared to the Sham (P < 0.001). The animals in both the OVX-T and OVX-S groups had a significantly higher seizure score as well as number of TUNEL-positive neurons compared to the OVX group (P < 0.01-P < 0.001). Co-treatment of the OVX rats by the extract and tamoxifen decreased the seizure score and number of TUNEL-positive neurons compared to OVX-S (P < 0.001). Treatment of the OVX rats by either soy or tamoxifen increased the seizure score as well as the number of TUNEL-positive neurons in the hippocampal formation. Co-administration of tamoxifen and soy extract inhibited the effects of the soy extract and tamoxifen when they were administered alone. It might be suggested that both soy and tamoxifen have agonistic effects on estrogen receptors by changing the seizure severity.

Brain responses to auditory oddball task in children with benign childhood epilepsy with centrotemporal spikes: Quantitative analysis and correlation with neuropsychological assessment scores

OBJECTIVE

Variable degrees of cognitive dysfunction have been reported in children with benign childhood epilepsy with centrotemporal spikes (BCECTS). Our aim was to perform quantitative analyses of the brain responses to cognitive tasks using event-related desynchronization (ERD) and event-related synchronization (ERS) and correlating the results with the scores of neuropsychological tests in patients with BCECTS.

METHODS

This case control study included 30 patients with BCECTS and 20 controls. Clinical assessment, neuropsychological tests, the Positive wave at 300 msec (P300) parameters recording, and quantitative electroencephalography (EEG) analysis were carried out for both groups. Alpha power ERD and ERS were measured in six different brain regions during an auditory oddball paradigm.

RESULTS

Children with epilepsy showed a statistically significant poorer performance in verbal intelligence quotient (IQ), performance IQ, and total scale IQ and lower number of correct responses. Moreover, both groups showed diffuse alpha power attenuation in response to the target tones. After summation of the alpha power ERD over all brain regions to get the net diffuse ERD, the patients' group showed a statistically significant smaller net alpha ERD compared with that of the control group (P=0.001). No significant correlations between the alpha ERD percentage, recorded P300 parameters, and neuropsychological tests scores were found.

CONCLUSIONS

Children with BCECTS have subtle cognitive dysfunction proved by significantly lower scores of verbal IQ and performance IQ subtests. The significantly smaller net diffuse alpha power ERD detected in children with epilepsy may be an electrophysiological indicator of disruptive brain activation in relation to cognitive attentional tasks; however, its correlation with neuropsychological tests was insignificant.

BAD and KATP channels regulate neuron excitability and epileptiform activity

Brain metabolism can profoundly influence neuronal excitability. Mice with genetic deletion or alteration of Bad (BCL-2 agonist of cell death) exhibit altered brain-cell fuel metabolism, accompanied by resistance to acutely induced epileptic seizures; this seizure protection is mediated by ATP-sensitive potassium (K_ATP) channels. Here we investigated the effect of BAD manipulation on K_ATP channel activity and excitability in acute brain slices. We found that BAD’s influence on neuronal K_ATP channels was cell-autonomous and directly affected dentate granule neuron (DGN) excitability. To investigate the role of neuronal K_ATP channels in the anticonvulsant effects of BAD, we imaged calcium during picrotoxin-induced epileptiform activity in entorhinal-hippocampal slices. BAD knockout reduced epileptiform activity, and this effect was lost upon knockout or pharmacological inhibition of K_ATP channels. Targeted BAD knockout in DGNs alone was sufficient for the antiseizure effect in slices, consistent with a ‘dentate gate’ function that is reinforced by increased K_ATP channel activity.

Endothelial cell-derived GABA signaling modulates neuronal migration and postnatal behavior

The cerebral cortex is essential for integration and processing of information that is required for most behaviors. The exquisitely precise laminar organization of the cerebral cortex arises during embryonic development when neurons migrate successively from ventricular zones to coalesce into specific cortical layers. While radial glia act as guide rails for projection neuron migration, pre-formed vascular networks provide support and guidance cues for GABAergic interneuron migration. This study provides novel conceptual and mechanistic insights into this paradigm of vascular-neuronal interactions, revealing new mechanisms of GABA and its receptor-mediated signaling via embryonic forebrain endothelial cells. With the use of two new endothelial cell specific conditional mouse models of the GABA pathway (Gabrb3^ΔTie2-Cre and Vgat^ΔTie2-Cre), we show that partial or complete loss of GABA release from endothelial cells during embryogenesis results in vascular defects and impairs long-distance migration and positioning of cortical interneurons. The downstream effects of perturbed endothelial cell-derived GABA signaling are critical, leading to lasting changes to cortical circuits and persistent behavioral deficits. Furthermore, we illustrate new mechanisms of activation of GABA signaling in forebrain endothelial cells that promotes their migration, angiogenesis and acquisition of blood-brain barrier properties. Our findings uncover and elucidate a novel endothelial GABA signaling pathway in the CNS that is distinct from the classical neuronal GABA signaling pathway and shed new light on the etiology and pathophysiology of neuropsychiatric diseases, such as autism spectrum disorders, epilepsy, anxiety, depression and schizophrenia.