Epileptogenesis in the immature brain: emerging mechanisms. Nat Rev Neurol. 2009;5:380-391. [PMID: 19578345 DOI: 10.1038/nrneurol.2009.80]

Epilepsy after acute central nervous system complications of pediatric hematopoietic cell transplantation: A retrospective, multicenter study

BACKGROUND

Acute central nervous system (CNS) complications are common and well described among pediatric patients undergoing haematopoietic cell transplantation (HCT). However, their long-term outcomes are not known. The aim of this study is to describe the incidence, characteristics, and risk factors of long-term epilepsy in pediatric patients with acute CNS complications of HCT.

METHODS

This retrospective study included pediatric patients who developed acute CNS complications from autologous or allogeneic HCT between 2000 and 2022. Clinical, therapeutic and prognostic data including long-term outcomes were analyzed. A diagnosis of epilepsy was provided if unprovoked seizures occurred during follow-up.

RESULTS

Ninety-four patients (63 males, 31 females, median age 10 years, range 1-21 years) were included. The most common acute CNS complications were posterior reversible encephalopathy syndrome (n = 43, 46 %) and infections (n = 15, 16 %). Sixty-five patients (69 %) had acute symptomatic seizures, with 14 (16 %) having one or more episodes of status epilepticus (SE). Nine patients (9.6 %) were diagnosed with long-term focal epilepsy during the follow-up (5-year cumulative incidence from the acute complication, 13.3 %). Acute symptomatic SE during neurological complications of HCT was associated with an increased risk of long-term epilepsy (OR=14, 95 % CI 2.87-68.97).

CONCLUSIONS

A higher occurrence of epilepsy has been observed in our cohort compared to the general population. Acute symptomatic SE during HCT was associated with a higher risk of long-term epilepsy. Pediatric patients with CNS complications during HCT could benefit from specific neurological follow-up. Further studies are needed to characterize mechanisms of epileptogenesis in pediatric patients undergoing HCT.

Drug-resistant epilepsy in Morocco: description, prevalence and predictive factors in Casablanca-Settat region

Drug-resistant epilepsy (DRE) affects about one-third of people with epilepsy (PWE). Our study aims to estimate the DRE prevalence and its predictive factors in Morocco. A cross-sectional study was conducted over 18 months. PWE with clinical diagnosis of epilepsy, and with an antiseizure treatment duration >12 months were examined in the neurology, neurosurgery, psychiatry, and pediatrics departments, of different sampled clinical sectors for the Casablanca-Settat region. Sociodemographic and clinical data were collected using a questionnaire during consultations. Antiseizure multi-therapy, a seizure freedom duration <12 months, compliance, and adequate posology were the determining factors for classifying DRE. Data were analyzed using Statistical Package for Social Sciences (SPSS) software, version 21.0. Statistical significance was set at p < 0.05 and logistic regression was performed to determine the predictive factors. In our sample of 446 PWE, the median age is 25 years (IQR: 11.75-44.00). The DRE estimated prevalence was 29.4 %. Pseudo-resistant epilepsy (PRE) was 18.0 %. Multivariate logistic regression analysis reports that single marital status (ORa = 1.94; CI95%: 1.02-3.71), comorbidities and concomitant affections (ORa = 2.14; CI95%: 1.27-3.59), structural etiology (ORa = 1.96; CI95%: 1.16-3.30), pre-ictal aura (ORa = 1.90; CI95%: 1.09-3.29), inter-ictal EEG abnormalities (ORa = 2.45; CI95%: 1.24-4.84) and allopathic treatment use (ORa = 2.10; CI95%: 1.30-3.39) are the predictive factors for DRE. We report an alarming DRE prevalence. Associated factors found may contribute to the prognosis and early management. PWE awareness, facilitating healthcare access and the development of epilepsy surgery are the key points to limit DRE in Morocco and prevent its various complications, especially for the pediatric population.

Cervical spinal cord stimulation exerts anti-epileptic effects in a rat model of epileptic seizure through the suppression of CCL2-mediated cascades

Epidural spinal cord stimulation (SCS) is indicated for the treatment of intractable pain and is widely used in clinical practice. In previous basic research, the therapeutic effects of SCS have been demonstrated for epileptic seizure. However, the mechanism has not yet been elucidated. In this study, we investigated the therapeutic effect of SCS and the influence of epileptic seizure. First, SCS in the cervical spine was performed. The rats were divided into four groups: control group and treatment groups with SCS conducted at 2, 50, and 300 Hz frequency. Two days later, convulsions were induced by the intraperitoneal administration of kainic acid, followed by video monitoring to assess seizures. We also evaluated glial cells in the hippocampus by fluorescent immunostaining, electroencephalogram measurements, and inflammatory cytokines such as C-C motif chemokine ligand 2 (CCL2) by quantitative real-time polymerase chain reaction. Seizure frequency and the number of glial cells were significantly lower in the 300 Hz group than in the control group. SCS at 300 Hz decreased gene expression level of CCL2, which induces monocyte migration. SCS has anti-seizure effects by inhibiting CCL2-mediated cascades. The suppression of CCL2 and glial cells may be associated with the suppression of epileptic seizure.

The multifaceted role of Wnt canonical signalling in neurogenesis, neuroinflammation, and hyperexcitability in mesial temporal lobe epilepsy

Epilepsy is a neurological disorder characterised by unprovoked, repetitive seizures caused by abnormal neuronal firing. The Wnt/β-Catenin signalling pathway is involved in seizure-induced neurogenesis, aberrant neurogenesis, neuroinflammation, and hyperexcitability associated with epileptic disorder. Wnt/β-Catenin signalling is crucial for early brain development processes including neuronal patterning, synapse formation, and N-methyl-d-aspartate receptor (NMDAR) regulation. Disruption of molecular networks such as Wnt/β-catenin signalling in epilepsy could offer encouraging anti-epileptogenic targets. So, with a better understanding of the canonical Wnt/-Catenin pathway, we highlight in this review the important elements of Wnt/-Catenin signalling specifically in Mesial Temporal Lobe Epilepsy (MTLE) for potential therapeutic targets.

Seizures exacerbate excitatory: inhibitory imbalance in Alzheimer's disease and 5XFAD mice

Approximately 22% of Alzheimer's disease (AD) patients suffer from seizures, and the co-occurrence of seizures and epileptiform activity exacerbates AD pathology and related cognitive deficits, suggesting that seizures may be a targetable component of AD progression. Given that alterations in neuronal excitatory:inhibitory (E:I) balance occur in epilepsy, we hypothesized that decreased markers of inhibition relative to those of excitation would be present in AD patients. We similarly hypothesized that in 5XFAD mice, the E:I imbalance would progress from an early stage (prodromal) to later symptomatic stages and be further exacerbated by pentylenetetrazol (PTZ) kindling. Post-mortem AD temporal cortical tissues from patients with or without seizure history were examined for changes in several markers of E:I balance, including levels of the inhibitory GABAA receptor, the sodium potassium chloride cotransporter 1 (NKCC1) and potassium chloride cotransporter 2 (KCC2) and the excitatory NMDA and AMPA type glutamate receptors. We performed patch-clamp electrophysiological recordings from CA1 neurons in hippocampal slices and examined the same markers of E:I balance in prodromal 5XFAD mice. We next examined 5XFAD mice at chronic stages, after PTZ or control protocols, and in response to chronic mTORC1 inhibitor rapamycin, administered following kindled seizures, for markers of E:I balance. We found that AD patients with comorbid seizures had worsened cognitive and functional scores and decreased GABAA receptor subunit expression, as well as increased NKCC1/KCC2 ratios, indicative of depolarizing GABA responses. Patch clamp recordings of prodromal 5XFAD CA1 neurons showed increased intrinsic excitability, along with decreased GABAergic inhibitory transmission and altered glutamatergic neurotransmission, indicating that E:I imbalance may occur in early disease stages. Furthermore, seizure induction in prodromal 5XFAD mice led to later dysregulation of NKCC1/KCC2 and a reduction in GluA2 AMPA glutamate receptor subunit expression, indicative of depolarizing GABA receptors and calcium permeable AMPA receptors. Finally, we found that chronic treatment with the mTORC1 inhibitor, rapamycin, at doses we have previously shown to attenuate seizure-induced amyloid-β pathology and cognitive deficits, could also reverse elevations of the NKCC1/KCC2 ratio in these mice. Our data demonstrate novel mechanisms of interaction between AD and epilepsy and indicate that targeting E:I balance, potentially with US Food and Drug Administration-approved mTOR inhibitors, hold therapeutic promise for AD patients with a seizure history.

Neonatal Seizures

Neonatal seizures are common among patients with acute brain injury or critical illness and can be difficult to diagnose and treat. The most common etiology of neonatal seizures is hypoxic-ischemic encephalopathy, with other common causes including ischemic stroke and intracranial hemorrhage. Neonatal clinicians can use a standardized approach to patients with suspected or confirmed neonatal seizures that entails laboratory testing, neuromonitoring, and brain imaging. The primary goals of management of neonatal seizures are to identify the underlying cause, correct it if possible, and prevent further brain injury. This article reviews recent evidence-based guidelines for the treatment of neonatal seizures and discusses the long-term outcomes of patients with neonatal seizures.

TARC and Septin 7 can be better monitoring biomarkers than CX3CL1, sICAM5, and IRF5 in children with seizure-free epilepsy with monotherapy and drug-resistant epilepsy

Aim: To evaluate i) the relationship between epilepsy and inflammation by analyzing the levels of thymus activation-regulated chemokine (TARC), and interferon regulatory factor 5 (IRF5) in healthy controls, patients with epilepsy on monotherapy and polytherapy, ii) the levels of sICAM5, chemokine (c-x3-c motif) ligand 1 (CX3CL1), and septin 7 (SEPT7) which are important in both inflammation and synaptic formation. Methods: Patients who were seizure-free with monotherapy (epilepsy group-1), patients with drug-resistant epilepsy (epilepsy group-2), and healthy controls were included. Demographical data, disease durations, and medications were noted. Measurements were made by commercial ELISA kits. Results: The numbers of epilepsy group-1, epilepsy group-2, and healthy controls were 23, 20, and 21, respectively. TARC levels were significantly lower in healthy controls than in both epilepsy groups. Higher TARC levels than 0.58 pg/ml indicated epilepsy with a sensitivity of 81.8% and specificity of 84.0%. SEPT7 levels were significantly higher in epilepsy group-1 than in those epilepsy group-2. A negative correlation was found between SEPT7 levels and disease duration as is the case for the correlation between SEPT7 and average seizure duration. A positive correlation was found between IRF5 and CX3CL1 levels, SEPT7 and IRF5 levels, and IRF5 and sICAM5 levels. Conclusions: We suggest that TARC is a promising biomarker, even in a heterogeneous epilepsy group not only for drug-resistance epilepsy but also for seizure-free epilepsy with monotherapy. Additionally, drug resistance, longer disease, and longer seizure durations are related to lower levels of SEPT7, which has an essential role in immunological functions and dendritic morphology.

Neonatal hypoxia impairs serotonin release and cognitive functions in adult mice

Children who experienced moderate perinatal asphyxia (MPA) are at risk of developing long lasting subtle cognitive and behavioral deficits, including learning disabilities and emotional problems. The prefrontal cortex (PFC) regulates cognitive flexibility and emotional behavior. Neurons that release serotonin (5-HT) project to the PFC, and compounds modulating 5-HT activity influence emotion and cognition. Whether 5-HT dysregulations contribute to MPA-induced cognitive problems is unknown. We established a MPA mouse model, which displays recognition and spatial memory impairments and dysfunctional cognitive flexibility. We found that 5-HT expression levels, quantified by immunohistochemistry, and 5-HT release, quantified by in vivo microdialysis in awake mice, are reduced in PFC of adult MPA mice. MPA mice also show impaired body temperature regulation following injection of the 5-HT1A receptor agonist 8-OH-DPAT, suggesting the presence of deficits in 5-HT auto-receptor function on raphe neurons. Finally, chronic treatment of adult MPA mice with fluoxetine, an inhibitor of 5-HT reuptake transporter, or the 5-HT1A receptor agonist tandospirone rescues cognitive flexibility and memory impairments. All together, these data demonstrate that the development of 5-HT system function is vulnerable to moderate perinatal asphyxia. 5-HT hypofunction might in turn contribute to long-term cognitive impairment in adulthood, indicating a potential target for pharmacological therapies.

Role of non-receptor tyrosine kinases in epilepsy: significance and potential as therapeutic targets

INTRODUCTION

Epilepsy is a chronic neurological condition characterized by a persistent propensity for seizure generation. About one-third of patients do not achieve seizure control with the first-line treatment options, which include >20 antiseizure medications. It is therefore imperative that new medications with novel targets and mechanisms of action are developed.

AREAS COVERED

Clinical studies and preclinical research increasingly implicate Non-receptor tyrosine kinases (nRTKs) in the pathogenesis of epilepsy. To date, several nRTK members have been linked to processes relevant to the development of epilepsy. Therefore, in this review, we provide insight into the molecular mechanisms by which the various nRTK subfamilies can contribute to the pathogenesis of epilepsy. We further highlight the prospective use of specific nRTK inhibitors in the treatment of epilepsy deriving evidence from existing literature providing a rationale for their use as therapeutic targets.

EXPERT OPINION

Specific small-molecule inhibitors of NRTKs can be employed for the targeted therapy as already seen in other diseases by examining the precise molecular pathways regulated by them contributing to the development of epilepsy. However, the evidence supporting NRTKs as therapeutic targets are limiting in nature thus, necessitating more research to fully comprehend their function in the development and propagation of seizures.

Reversible synaptic adaptations in a subpopulation of murine hippocampal neurons following early-life seizures

Early-life seizures (ELSs) can cause permanent cognitive deficits and network hyperexcitability, but it is unclear whether ELSs induce persistent changes in specific neuronal populations and whether these changes can be targeted to mitigate network dysfunction. We used the targeted recombination of activated populations (TRAP) approach to genetically label neurons activated by kainate-induced ELSs in immature mice. The ELS-TRAPed neurons were mainly found in hippocampal CA1, remained uniquely susceptible to reactivation by later-life seizures, and displayed sustained enhancement in α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor-mediated (AMPAR-mediated) excitatory synaptic transmission and inward rectification. ELS-TRAPed neurons, but not non-TRAPed surrounding neurons, exhibited enduring decreases in Gria2 mRNA, responsible for encoding the GluA2 subunit of the AMPARs. This was paralleled by decreased synaptic GluA2 protein expression and heightened phosphorylated GluA2 at Ser880 in dendrites, indicative of GluA2 internalization. Consistent with increased GluA2-lacking AMPARs, ELS-TRAPed neurons showed premature silent synapse depletion, impaired long-term potentiation, and impaired long-term depression. In vivo postseizure treatment with IEM-1460, an inhibitor of GluA2-lacking AMPARs, markedly mitigated ELS-induced changes in TRAPed neurons. These findings show that enduring modifications of AMPARs occur in a subpopulation of ELS-activated neurons, contributing to synaptic dysplasticity and network hyperexcitability, but are reversible with early IEM-1460 intervention.

Enhancement of K+ channel permeation by selective terahertz excitation

The optical excitation effects offer an opportunity to gain insights into the structure and the function of K+ channel, contributing to the prediction of possible targets for drug design and precision therapy. Although there has been increasing research attention on the modulation of ion permeation in K+ channel by terahertz electromagnetic (THz-EM) stimuli, little exploration has been conducted regarding the dependence of ion permeation on frequencies. By using two-dimensional (2D) infrared excitation spectrum calculation for the K+ channel, we have discovered that the frequency of 53.60 THz serves as an optimal excitation modulation mode. This mode leads to an almost twofold enhancement in the rate of K+ ion permeation and a tenfold increase in selectivity efficiency. These improvements can be attributed to the coupling mode matching of the excited properties of CO groups in the K+ channel. Our findings propose a promising application of terahertz technology to improve the performance of ion channels, nanomembrane sieves, nanodevices, as well as neural therapy.

Early endocannabinoid-mediated depolarization-induced suppression of excitation delays the appearance of the epileptic phenotype in synapsin II knockout mice

The mechanism underlying the transition from the pre-symptomatic to the symptomatic state is a crucial aspect of epileptogenesis. SYN2 is a member of a multigene family of synaptic vesicle phosphoproteins playing a fundamental role in controlling neurotransmitter release. Human SYN2 gene mutations are associated with epilepsy and autism spectrum disorder. Mice knocked out for synapsin II (SynII KO) are prone to epileptic seizures that appear after 2 months of age. However, the involvement of the endocannabinoid system, known to regulate seizure development and propagation, in the modulation of the excitatory/inhibitory balance in the epileptic hippocampal network of SynII KO mice has not been explored. In this study, we investigated the impact of endocannabinoids on glutamatergic and GABAergic synapses at hippocampal dentate gyrus granule cells in young pre-symptomatic (1-2 months old) and adult symptomatic (5-8 months old) SynII KO mice. We observed an increase in endocannabinoid-mediated depolarization-induced suppression of excitation in young SynII KO mice, compared to age-matched wild-type controls. In contrast, the endocannabinoid-mediated depolarization-induced suppression of inhibition remained unchanged in SynII KO mice at both ages. This selective alteration of excitatory synaptic transmission was accompanied by changes in hippocampal endocannabinoid levels and cannabinoid receptor type 1 distribution among glutamatergic and GABAergic synaptic terminals contacting the granule cells of the dentate gyrus. Finally, inhibition of type-1 cannabinoid receptors in young pre-symptomatic SynII KO mice induced seizures during a tail suspension test. Our results suggest that endocannabinoids contribute to maintaining network stability in a genetic mouse model of human epilepsy.

Pharmacokinetic and pharmacodynamic principles: unique considerations for optimal design of neonatal clinical trials

Core clinical pharmacology principles must be considered when designing and executing neonatal clinical trials. In this review, the authors discuss important aspects of drug dose selection, pharmacokinetics, pharmacogenetics and pharmacodynamics that stakeholders may consider when undertaking a neonatal or infant clinical trial.

Fluorescence probe for real-time malonaldehyde detection in epilepsy model

Oxidative stress, a condition involving an imbalance between reactive oxygen species (ROS) and antioxidants, is closely linked to epilepsy, contributing to abnormal neuronal excitability. This study introduces a novel fluorescent probe, the MDP probe, designed for the efficient detection of malondialdehyde (MDA), a critical biomarker associated with oxidative stress. The MDP probe offers several key advantages, including high sensitivity with a low detection limit of 0.08 μM for MDA, excellent selectivity for MDA even in the presence of interfering substances, and biocompatibility, making it suitable for cell-based experiments. The probe allows for real-time monitoring of MDA levels, enabling dynamic studies of oxidative stress. In vivo experiments in mice demonstrate its potential for monitoring MDA levels, particularly in epilepsy models, which could have implications for disease research and diagnosis. Overall, the MDP probe represents a promising tool for studying oxidative stress, offering sensitivity and specificity in cellular and in vivo settings. Its development opens new avenues for exploring the role of oxidative stress in various biological processes and diseases, contributing to advancements in healthcare and biomedical research.

A Comprehensive Review of Emerging Trends and Innovative Therapies in Epilepsy Management

Epilepsy is a complex neurological disorder affecting millions worldwide, with a substantial number of patients facing drug-resistant epilepsy. This comprehensive review explores innovative therapies for epilepsy management, focusing on their principles, clinical evidence, and potential applications. Traditional antiseizure medications (ASMs) form the cornerstone of epilepsy treatment, but their limitations necessitate alternative approaches. The review delves into cutting-edge therapies such as responsive neurostimulation (RNS), vagus nerve stimulation (VNS), and deep brain stimulation (DBS), highlighting their mechanisms of action and promising clinical outcomes. Additionally, the potential of gene therapies and optogenetics in epilepsy research is discussed, revealing groundbreaking findings that shed light on seizure mechanisms. Insights into cannabidiol (CBD) and the ketogenic diet as adjunctive therapies further broaden the spectrum of epilepsy management. Challenges in achieving seizure control with traditional therapies, including treatment resistance and individual variability, are addressed. The importance of staying updated with emerging trends in epilepsy management is emphasized, along with the hope for improved therapeutic options. Future research directions, such as combining therapies, AI applications, and non-invasive optogenetics, hold promise for personalized and effective epilepsy treatment. As the field advances, collaboration among researchers of natural and synthetic biochemistry, clinicians from different streams and various forms of medicine, and patients will drive progress toward better seizure control and a higher quality of life for individuals living with epilepsy.

Don't Give Me Lip: A Role for Lipid-Accumulated Reactive Astrocytes in Temporal Lobe Epilepsy

Lipid-Accumulated Reactive Astrocytes Promote Disease Progression in Epilepsy Chen ZP, Wang S, Zhao X, Fang W, Wang Z, Ye H, Wang MJ, Ke L, Huang T, Lv P, Jiang X, Zhang Q, Li L, Xie ST, Zhu JN, Hang C, Chen D, Liu X, Yan C. Nat Neurosci . 2023;26(4). doi:10.1038/s41593-023-01288-6 Reactive astrocytes play an important role in neurological diseases, but their molecular and functional phenotypes in epilepsy are unclear. Here, we show that in patients with temporal lobe epilepsy (TLE) and mouse models of epilepsy, excessive lipid accumulation in astrocytes leads to the formation of lipid-accumulated reactive astrocytes (LARAs), a new reactive astrocyte subtype characterized by elevated APOE expression. Genetic knockout of APOE inhibited LARA formation and seizure activities in epileptic mice. Single-nucleus RNA sequencing in TLE patients confirmed the existence of a LARA subpopulation with a distinct molecular signature. Functional studies in epilepsy mouse models and human brain slices showed that LARAs promote neuronal hyperactivity and disease progression. Targeting LARAs by intervention with lipid transport and metabolism could thus provide new therapeutic options for drug-resistant TLE.

Principal neurons in the olfactory cortex mediate bidirectional modulation of seizures

Although the piriform cortex (PC) has been previously implicated as a critical node for seizure generation and propagation, the underlying neural mechanism has remained unclear. Here, we found increased excitability in PC neurons during amygdala kindling acquisition. Optogenetic or chemogenetic activation of PC pyramidal neurons promoted kindling progression, whereas inhibition of these neurons retarded seizure activities induced by electrical kindling in the amygdala. Furthermore, chemogenetic inhibition of PC pyramidal neurons alleviated the severity of kainic acid-induced acute seizures. These results demonstrate that PC pyramidal neurons bidirectionally modulate seizures in temporal lobe epilepsy, providing evidence for the efficacy of PC pyramidal neurons as a potential therapeutic target for epileptogenesis. KEY POINTS: While the piriform cortex (PC) is an important olfactory centre critically involved in olfactory processing and plays a crucial role in epilepsy due to its close connection with the limbic system, how the PC regulates epileptogenesis is largely unknown. In this study, we evaluated the neuronal activity and the role of pyramidal neurons in the PC in the mouse amygdala kindling model of epilepsy. PC pyramidal neurons are hyperexcited during epileptogenesis. Optogenetic and chemogenetic activation of PC pyramidal neurons significantly promoted seizures in the amygdala kindling model, whereas selective inhibition of these neurons produced an anti-epileptic effect for both electrical kindling and kainic acid-induced acute seizures. The results of the present study indicate that PC pyramidal neurons bidirectionally modulate seizure activity.

Altered functional connectivity and network excitability in a model of cortical dysplasia

Focal cortical dysplasias (FCDs) are malformations of cortical development that often result in medically refractory epilepsy, with a greater incidence in the pediatric population. The relationship between the disturbed cortical morphology and epileptogenic activity of FCDs remains unclear. We used the BCNU (carmustine 1-3-bis-chloroethyl-nitrosourea) animal model of cortical dysplasia to evaluate neuronal and laminar alterations and how these result in altered activity of intracortical networks in early life. We corroborated the previously reported morphological anomalies characteristic of the BCNU model, comprising slightly larger and rounder neurons and abnormal cortical lamination. Next, the neuronal activity of live cortical slices was evaluated through large field-of-view calcium imaging as well as the neuronal response to a stimulus that leads to cortical hyperexcitability (pilocarpine). Examination of the joint activity of neuronal calcium time series allowed us to identify intracortical communication patterns and their response to pilocarpine. The baseline power density distribution of neurons in the cortex of BCNU-treated animals was different from that of control animals, with the former showing no modulation after stimulus. Moreover, the intracortical communication pattern differed between the two groups, with cortexes from BCNU-treated animals displaying decreased inter-layer connectivity as compared to control animals. Our results indicate that the altered anatomical organization of the cortex of BCNU-treated rats translates into altered functional networks that respond abnormally to a hyperexcitable stimulus and highlight the role of network dysfunction in the pathophysiology of cortical dysplasia.

Feature separation and adversarial training for the patient-independent detection of epileptic seizures

An epileptic seizure is the external manifestation of abnormal neuronal discharges, which seriously affecting physical health. The pathogenesis of epilepsy is complex, and the types of epileptic seizures are diverse, resulting in significant variation in epileptic seizure data between subjects. If we feed epilepsy data from multiple patients directly into the model for training, it will lead to underfitting of the model. To overcome this problem, we propose a robust epileptic seizure detection model that effectively learns from multiple patients while eliminating the negative impact of the data distribution shift between patients. The model adopts a multi-level temporal-spectral feature extraction network to achieve feature extraction, a feature separation network to separate features into category-related and patient-related components, and an invariant feature extraction network to extract essential feature information related to categories. The proposed model is evaluated on the TUH dataset using leave-one-out cross-validation and achieves an average accuracy of 85.7%. The experimental results show that the proposed model is superior to the related literature and provides a valuable reference for the clinical application of epilepsy detection.

The maturation of aperiodic EEG activity across development reveals a progressive differentiation of wakefulness from sleep

During development, the brain undergoes radical structural and functional changes following a posterior-to-anterior gradient, associated with profound changes of cortical electrical activity during both wakefulness and sleep. However, a systematic assessment of the developmental effects on aperiodic EEG activity maturation across vigilance states is lacking, particularly regarding its topographical aspects. Here, in a population of 160 healthy infants, children and teenagers (from 2 to 17 years, 10 subjects for each year), we investigated the development of aperiodic EEG activity in wakefulness and sleep. Specifically, we parameterized the shape of the aperiodic background of the EEG Power Spectral Density (PSD) by means of the spectral exponent and offset; the exponent reflects the rate of exponential decay of power over increasing frequencies and the offset reflects an estimate of the y-intercept of the PSD. We found that sleep and development caused the EEG-PSD to rotate over opposite directions: during wakefulness the PSD showed a flatter decay and reduced offset over development, while during sleep it showed a steeper decay and a higher offset as sleep becomes deeper. During deep sleep (N2, N3) only the spectral offset decreased over age, indexing a broad-band voltage reduction. As a result, the difference between values in deep sleep and those in both light sleep (N1) and wakefulness increased with age, suggesting a progressive differentiation of wakefulness from sleep EEG activity, most prominent over the frontal regions, the latest to complete maturation. Notably, the broad-band spectral exponent values during deep sleep stages were entirely separated from wakefulness values, consistently across developmental ages and in line with previous findings in adults. Concerning topographical development, the location showing the steepest PSD decay and largest offset shifted from posterior to anterior regions with age. This shift, particularly evident during deep sleep, paralleled the migration of sleep slow wave activity and was consistent with neuroanatomical and cognitive development. Overall, aperiodic EEG activity distinguishes wakefulness from sleep regardless of age; while, during development, it reveals a postero-anterior topographical maturation and a progressive differentiation of wakefulness from sleep. Our study could help to interpret changes due to pathological conditions and may elucidate the neurophysiological processes underlying the development of wakefulness and sleep.

Efficacy and safety of ketamine for neonatal refractory status epilepticus: case report and systematic review

Background

Evidence-based data on treatment of neonatal status epilepticus (SE) are scarce. We aimed to collect data on the efficacy and safety of ketamine for the treatment of neonatal SE and to assess its possible role in the treatment of neonatal SE.

Methods

We described a novel case and conducted a systematic literature review on neonatal SE treated with ketamine. The search was carried out in Pubmed, Cochrane, Clinical Trial Gov, Scopus and Web of Science.

Results

Seven published cases of neonatal SE treated with ketamine were identified and analyzed together with our novel case. Seizures typically presented during the first 24 h of life (6/8). Seizures were resistant to a mean of five antiseizure medications. Ketamine, a NMDA receptor antagonist, appeared to be safe and effective in all neonates treated. Neurologic sequelae including hypotonia and spasticity were reported for 4/5 of the surviving children (5/8). 3/5 of them were seizure free at 1-17 months of life.

Discussion

Neonatal brain is more susceptible to seizures due to a shift towards increased excitation because of a paradoxical excitatory effect of GABA, a greater density of NMDA receptors and higher extracellular concentrations of glutamate. Status epilepticus and neonatal encephalopathy could further enhance these mechanisms, providing a rationale for the use of ketamine in this setting.

Conclusions

Ketamine in the treatment of neonatal SE showed a promising efficacy and safety profile. However, further in-depth studies and clinical trials on larger populations are needed.

Effects of altered excitation-inhibition imbalance by repetitive transcranial magnetic stimulation for self-limited epilepsy with centrotemporal spikes

Objectives

Patients with self-limited epilepsy with centrotemporal spikes (SeLECTS) with electrical status epilepticus in sleep (ESES) have generalized cognitive impairment, yet treatment options are limited. Our study aimed to examine the therapeutic effects of repetitive transcranial magnetic stimulation (rTMS) on SeLECTS with ESES. In addition, we applied electroencephalography (EEG) aperiodic components (offset and slope) to investigate the improvement of rTMS on the excitation-inhibition imbalance (E-I imbalance) in the brain of this group of children.

Methods

Eight SeLECTS patients with ESES were included in this study. Low-frequency rTMS (≤1 Hz) was applied for 10 weekdays in each patient. To assess the clinical efficacy and changes in E-I imbalance, EEG recordings were performed both before and after rTMS. Seizure-reduction rate and spike-wave index (SWI) were measured to investigate the clinical effects of rTMS. The aperiodic offset and slope were calculated to explore the effect of rTMS on E-I imbalance.

Results

Five of the eight patients (62.5%) were seizure-free within 3 months after stimulation, with treatment effects decreasing with longer follow-ups. The SWI decreased significantly at 3 and 6 months after rTMS compared with the baseline (P = 0.0157 and P = 0.0060, respectively). The offset and slope were compared before rTMS and within 3 months after stimulation. The results showed a significant reduction in the offset after stimulation (P < 0.0001). There was a remarkable increase in slope after the stimulation (P < 0.0001).

Conclusion

Patients achieved favorable outcomes in the first 3 months after rTMS. The ameliorative effect of rTMS on SWI may last up to 6 months. Low-frequency rTMS could reduce firing rates in neuronal populations throughout the brain, which was most pronounced at the site of stimulation. A significant reduction in the slope after rTMS treatment suggested an improvement in the E-I imbalance in the SeLECTS.

Patient-specific approach using data fusion and adversarial training for epileptic seizure prediction

Epilepsy is the second common neurological disorder after headache, accurate and reliable prediction of seizures is of great clinical value. Most epileptic seizure prediction methods consider only the EEG signal or extract and classify the features of EEG and ECG signals separately, the improvement of prediction performance from multimodal data is not fully considered. In addition, epilepsy data are time-varying, with differences between each episode in a patient, making it difficult for traditional curve-fitting models to achieve high accuracy and reliability. In order to improve the accuracy and reliability of the prediction system, we propose a novel personalized approach based on data fusion and domain adversarial training to predict epileptic seizures using leave-one-out cross-validation, which achieves an average accuracy, sensitivity and specificity of 99.70, 99.76, and 99.61%, respectively, with an average error alarm rate (FAR) of 0.001. Finally, the advantage of this approach is demonstrated by comparison with recent relevant literature. This method will be incorporated into clinical practice to provide personalized reference information for epileptic seizure prediction.

Anti-seizure efficacy of perampanel in two established rodent models of early-life epilepsy

Early-life seizures can be refractory to conventional antiseizure medications (ASMs) and can also result in chronic epilepsy and long-term behavioral and cognitive deficits. Treatments targeting age-specific mechanisms contributing to epilepsy would be of clinical benefit. One such target is the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) subtype of excitatory glutamate receptor, which is upregulated in the developing brain. Perampanel is a non-competitive, selective AMPAR antagonist that is FDA-approved for focal onset seizures (FOS) or primary generalized tonic-clonic seizures (PGTC) in children and adults. However, the efficacy of perampanel treatment in epilepsy patients younger than 4 years has been less documented. We thus tested the efficacy of perampanel in two early-life seizure models: (1) a rat model of hypoxia-induced neonatal seizures and (2) a mouse model of Dravet syndrome with hyperthermia-induced seizures. Pretreatment with perampanel conferred dose-dependent protection against early-life seizures in both experimental models. These findings suggest that AMPAR-mediated hyperexcitability could be involved in the pathophysiology of early-life seizures, which may be amenable to treatment with perampanel.

Association of Cystic Periventricular Leukomalacia and Postnatal Epilepsy in Very Preterm Infants

INTRODUCTION

Cystic periventricular leukomalacia (PVL) is the most common white matter injury and a common cause of cerebral palsy in preterm infants. Postnatal epilepsy may occur after cystic PVL, but their causal relationship remains uncertain. Our aim was to validate the contribution of cystic PVL to postnatal epilepsy in very preterm infants and demonstrate their seizure characteristics.

METHODS

This prospective cohort study enrolled 1,342 preterm infants (birth weight <1,500 g and gestational age <32 weeks) from 2003 to 2015. Cystic PVL was diagnosed by serial cerebral ultrasound, and other comorbidities were recorded during hospitalization. Neurological developments and consequences, including epilepsy, were serially accessed until the age of 5.

RESULTS

A total of 976 preterm infants completed a 5-year neurological follow-up; 47 (4.8%) had cystic PVL. Preterm infants with cystic PVL were commonly associated with other comorbidities, including necrotizing enterocolitis stage III, neonatal seizures, and intraventricular hemorrhage during hospitalization. At age 5, 14 of the 47 (29.8%) preterm infants with cystic PVL had postnatal epilepsy. After adjusting for gender, gestational age, and three common comorbidities, cystic PVL was an independent risk factor for postnatal epilepsy (adjust OR: 16.2; 95% CI: 6.8-38.4; p < 0.001). Postnatal epilepsy after cystic PVL was commonly the generalized type (13 of 14, 92.9%), not intractable and most occurred after 1 year of age.

DISCUSSION/CONCLUSION

Cystic PVL would independently lead to postnatal epilepsy. Preterm infants with cystic PVL are at risk of postnatal epilepsy after age 1 in addition to cerebral palsy.

Acceleration of GABA-switch after early life stress changes mouse prefrontal glutamatergic transmission

Early life stress (ELS) alters the excitation-inhibition-balance (EI-balance) in various rodent brain areas and may be responsible for behavioral impairment later in life. The EI-balance is (amongst others) influenced by the switch of GABAergic transmission from excitatory to inhibitory, the so-called "GABA-switch". Here, we investigated how ELS affects the GABA-switch in mouse infralimbic Prefrontal Cortex layer 2/3 neurons, using the limited-nesting-and-bedding model. In ELS mice, the GABA-switch occurred already between postnatal day (P) 6 and P9, as opposed to P15-P21 in controls. This was associated with increased expression of the inward chloride transporter NKCC1, compared to the outward chloride transporter KCC2, both of which are important for the intracellular chloride concentration and, hence, the GABA reversal potential (Erev). Chloride transporters are not only important for regulating chloride concentration postsynaptically, but also presynaptically. Depending on the Erev of GABA, presynaptic GABA_A receptor stimulation causes a depolarization or hyperpolarization, and thereby enhanced or reduced fusion of glutamate vesicles respectively, in turn changing the frequency of miniature postsynaptic currents (mEPSCs). In accordance, bumetanide, a blocker of NKCC1, shifted the Erev GABA towards more hyperpolarized levels in P9 control mice and reduced the mEPSC frequency. Other modulators of chloride transporters, e.g. VU0463271 (a KCC2 antagonist) and aldosterone -which increases NKCC1 expression-did not affect postsynaptic Erev in ELS P9 mice, but did increase the mEPSC frequency. We conclude that the mouse GABA-switch is accelerated after ELS, affecting both the pre- and postsynaptic chloride homeostasis, the former altering glutamatergic transmission. This may considerably affect brain development.

Transcranial Direct Current Stimulation (tDCS) in Pediatric Populations—– Voices from Typically Developing Children and Adolescents and their Parents

Background

Transcranial direct current stimulation (tDCS) is a brain stimulation technique currently being researched as an alternative or complimentary treatment for various neurological disorders. There is little knowledge about experiences of the participants of tDCS clinical research, especially from pediatric studies.

Methods

An interview study with typically developing minors (n = 19, mean age 13,66 years) participating in a tDCS study, and their parents (n = 18) was conducted to explore their views and experiences and inform the ethical analysis.

Results

Children (10–13 years old) and adolescents (14–18 years old) reported good experiences with the stimulation. Next to financial incentives, main motives to participate in the study were curiosity and the possibility to help develop treatments for children affected by neurological disorders. They could also see a potential of using tDCS in a non-medical setting, especially regarding the provision of equal opportunity, e.g. in education. Parents also presented a positive attitude towards tDCS and their children participation in the basic research study. Nevertheless, their understanding of tDCS was rather poor. Even though many of them understood the techniques, they often did not see the link between the (current) lack of side effects and an absence of longitudinal studies. Parents were also cautious about using tDCS for non-medical/enhancement purposes.

Conclusions

The study findings show a need for more transparent information about the state of the art of tDCS, its function and what it might be able to offer, especially considering the good acceptability of tDCS.

Continuous electroencephalography in the intensive care unit: A critical review and position statement from an Australian and New Zealand perspective

Objectives

This article aims to critically review the literature on continuous electroencephalography (cEEG) monitoring in the intensive care unit (ICU) from an Australian and New Zealand perspective and provide recommendations for clinicians.

Design and review methods

A taskforce of adult and paediatric neurologists, selected by the Epilepsy Society of Australia, reviewed the literature on cEEG for seizure detection in critically ill neonates, children, and adults in the ICU. The literature on routine EEG and cEEG for other indications was not reviewed. Following an evaluation of the evidence and discussion of controversial issues, consensus was reached, and a document that highlighted important clinical, practical, and economic considerations regarding cEEG in Australia and New Zealand was drafted.

Results

This review represents a summary of the literature and consensus opinion regarding the use of cEEG in the ICU for detection of seizures, highlighting gaps in evidence, practical problems with implementation, funding shortfalls, and areas for future research.

Conclusion

While cEEG detects electrographic seizures in a significant proportion of at-risk neonates, children, and adults in the ICU, conferring poorer neurological outcomes and guiding treatment in many settings, the health economic benefits of treating such seizures remain to be proven. Presently, cEEG in Australian and New Zealand ICUs is a largely unfunded clinical resource that is subsequently reserved for the highest-impact patient groups. Wider adoption of cEEG requires further research into impact on functional and health economic outcomes, education and training of the neurology and ICU teams involved, and securement of the necessary resources and funding to support the service.

Modelling hyperexcitability in human cerebral cortical organoids: Oxygen/glucose deprivation most effective stimulant

Epilepsy is a common neurological disorder that affects 1% of the global population. The neonatal period constitutes the highest incidence of seizures. Despite the continual developments in seizure modelling and anti-epileptic drug development, the mechanisms involved in neonatal seizures remain poorly understood. This leaves infants with neonatal seizures at a high risk of death, poor prognosis of recovery and risk of developing neurological disorders later in life. Current in vitro platforms for modelling adult and neonatal epilepsies - namely acute cerebral brain slices or cell-derived cultures, both derived from animals-either lack a complex cytoarchitecture, high-throughput capabilities or physiological similarities to the neonatal human brain. Cerebral organoids, derived from human embryonic stem cells (hESCs), are an emerging technology that could better model neurodevelopmental disorders in the developing human brain. Herein, we study induced hyperexcitability in human cerebral cortical organoids - setting the groundwork for neonatal seizure modelling - using electrophysiological techniques and pharmacological manipulations. In neonatal seizures, energy failure - specifically due to deprivation of oxygen and glucose - is a consistent and reliable seizure induction method that has been used to study the underlying cellular and molecular mechanisms. Here, we applied oxygen-glucose deprivation (OGD) as well as common chemoconvulsants in 3-7-month-old cerebral organoids. Remarkably, OGD resulted in hyperexcitability, with increased power and spontaneous events compared to other common convulsants tested at the population level. These findings characterize OGD as the stimulus most capable of inducing hyperexcitable changes in cerebral organoid tissue, which could be extended to future modelling of neonatal epilepsies in cerebral organoids.

Long-Interval Intracortical Inhibition and the Cortical Silent Period in Youth

BACKGROUND

The cortical silent period (CSP) and long-interval intracortical inhibition (LICI) are putative markers of γ-aminobutyric acid receptor type B (GABA_B)-mediated inhibitory neurotransmission. We aimed to assess the association between LICI and CSP in youths.

METHODS

We analyzed data from three previous studies of youth who underwent CSP and LICI measurements with transcranial magnetic stimulation and electromyography. We assessed CSP and LICI association using Spearman rank correlation tests and multiple linear regression analyses adjusted for demographic and clinical covariates.

RESULTS

The sample included 16 healthy participants and 45 participants with depression. The general mean (SD) age was 15.5 (1.7), 14.3 (1.7) for healthy participants, and 15.9 (1.6) years for participants with depression. Measures were nonnormally distributed (Shapiro-Wilk, p < 0.001). CSP and LICI were not correlated at 100-millisecond (ρ = -0.2421, p = 0.06), 150-millisecond (ρ = -0.1612, p = 0.21), or 200-millisecond (ρ = -0.0507, p = 0.70) interstimulus intervals using Spearman rank correlation test. No correlations were found in the multiple regression analysis (p = 0.35).

CONCLUSIONS

Although previous studies suggest that cortical silent period and long-interval intracortical inhibition measure GABA_B receptor-mediated activity, these biomarkers were not associated in our sample of youths. Future studies should focus on the specific physiologic and pharmacodynamic properties assessed by CSP and LICI in younger populations.

Dopamine, Immunity, and Disease

The neurotransmitter dopamine is a key factor in central nervous system (CNS) function, regulating many processes including reward, movement, and cognition. Dopamine also regulates critical functions in peripheral organs, such as blood pressure, renal activity, and intestinal motility. Beyond these functions, a growing body of evidence indicates that dopamine is an important immunoregulatory factor. Most types of immune cells express dopamine receptors and other dopaminergic proteins, and many immune cells take up, produce, store, and/or release dopamine, suggesting that dopaminergic immunomodulation is important for immune function. Targeting these pathways could be a promising avenue for the treatment of inflammation and disease, but despite increasing research in this area, data on the specific effects of dopamine on many immune cells and disease processes remain inconsistent and poorly understood. Therefore, this review integrates the current knowledge of the role of dopamine in immune cell function and inflammatory signaling across systems. We also discuss the current understanding of dopaminergic regulation of immune signaling in the CNS and peripheral tissues, highlighting the role of dopaminergic immunomodulation in diseases such as Parkinson's disease, several neuropsychiatric conditions, neurologic human immunodeficiency virus, inflammatory bowel disease, rheumatoid arthritis, and others. Careful consideration is given to the influence of experimental design on results, and we note a number of areas in need of further research. Overall, this review integrates our knowledge of dopaminergic immunology at the cellular, tissue, and disease level and prompts the development of therapeutics and strategies targeted toward ameliorating disease through dopaminergic regulation of immunity. SIGNIFICANCE STATEMENT: Canonically, dopamine is recognized as a neurotransmitter involved in the regulation of movement, cognition, and reward. However, dopamine also acts as an immune modulator in the central nervous system and periphery. This review comprehensively assesses the current knowledge of dopaminergic immunomodulation and the role of dopamine in disease pathogenesis at the cellular and tissue level. This will provide broad access to this information across fields, identify areas in need of further investigation, and drive the development of dopaminergic therapeutic strategies.

Intracranial electrophysiological recordings on a swine model of mesial temporal lobe epilepsy

Objective

To test the feasibility and reliability of intracranial electrophysiological recordings in an acute status epilepticus model on laboratory swine.

Method

Intrahippocampal injection of kainic acid (KA) was performed on 17 male Bama pigs (Sus scrofa domestica) weighing between 25 and 35 kg. Two stereoelectroencephalography (SEEG) electrodes with a total of 16 channels were implanted bilaterally along the sensorimotor cortex to the hippocampus. Brain electrical activity was recorded 2 h daily for 9-28 days. Three KA dosages were tested to evaluate the quantities capable of evoking status epilepticus. Local field potentials (LFPs) were recorded and compared before and after the KA injection. We quantified the epileptic patterns, including the interictal spikes, seizures, and high-frequency oscillations (HFOs), up to 4 weeks after the KA injection. Test-retest reliability using intraclass correlation coefficients (ICCs) were performed on interictal HFO rates to evaluate the recording stability of this model.

Results

The KA dosage test suggested that a 10 μl (1.0 μg/μl) intrahippocampal injection could successfully evoke status epilepticus lasting from 4 to 12 h. At this dosage, eight pigs (50% of total) had prolonged epileptic events (tonic-chronic seizures + interictal spikes n = 5, interictal spikes alone n = 3) in the later 4 weeks of the video-SEEG recording period. Four pigs (25% of total) had no epileptic activities, and another four (25%) had lost the cap or did not complete the experiments. Animals that showed epileptiform events were grouped as E + (n = 8) and the four animals showing no signs of epileptic events were grouped as E- (n = 4). A total of 46 electrophysiological seizures were captured in the 4-week post-KA period from 4 E + animals, with the earliest onset on day 9. The seizure durations ranged from 12 to 45 s. A significant increase of hippocampal HFOs rate (num/min) was observed in the E+ group during the post-KA period (weeks 1, 2,4, p < 0.05) compared to the baseline. But the E-showed no change or a decrease (in week 2, p = 0.43) compared to their baseline rate. The between-group comparison showed much higher HFO rates in E + vs. E - (F = 35, p < 0.01). The high ICC value [ICC (1, k) = 0.81, p < 0.05] quantified from the HFO rate suggested that this model had a stable measurement of HFOs during the four-week post-KA periods.

Significance

This study measured intracranial electrophysiological activity in a swine model of KA-induced mesial temporal lobe epilepsy (mTLE). Using the clinical SEEG electrode, we distinguished abnormal EEG patterns in the swine brain. The high test-retest reliability of HFO rates in the post-KA period suggests the utility of this model for studying mechanisms of epileptogenesis. The use of swine may provide satisfactory translational value for clinical epilepsy research.

Endocytosis of AMPA receptors: Role in neurological conditions

AMPA receptors are glutamate-gated ion channels, present in a wide range of neuron types and in glial cells. Their main role is to mediate fast excitatory synaptic transmission, and therefore, they are critical for normal brain function. In neurons, AMPA receptors undergo constitutive and activity-dependent trafficking between the synaptic, extrasynaptic and intracellular pools. The kinetics of AMPA receptor trafficking is crucial for the precise functioning of both individual neurons and neural networks involved in information processing and learning. Many of the neurological diseases evoked by neurodevelopmental and neurodegenerative malfunctions or traumatic injuries are caused by impaired synaptic function in the central nervous system. For example, attention-deficit/hyperactivity disorder (ADHD), Alzheimer's disease (AD), tumors, seizures, ischemic strokes, and traumatic brain injury are all characterized by impaired glutamate homeostasis and associated neuronal death, typically caused by excitotoxicity. Given the important role of AMPA receptors in neuronal function, it is not surprising that perturbations in AMPA receptor trafficking are associated with these neurological disorders. In this book chapter, we will first introduce the structure, physiology and synthesis of AMPA receptors, followed by an in-depth description of the molecular mechanisms that control AMPA receptor endocytosis and surface levels under basal conditions or synaptic plasticity. Finally, we will discuss how impairments in AMPA receptor trafficking, particularly endocytosis, contribute to the pathophysiology of various neurological disorders and what efforts are being made to therapeutically target this process.

Perinatal hypoxia and thalamus brain region: increased efficiency of antiepileptic drug levetiracetam to inhibit GABA release from nerve terminals

Levetiracetam (LV), 2S-(2-oxo-1-pyrrolidiny1) butanamide, is an antiepileptic drug. The exact mechanisms of anticonvulsant effects of LV remain unclear. In this study, rats (Wistar strain) underwent hypoxia and seizures at the age of 10–12 postnatal days (pd). [3H]GABA release was analysed in isolated from thalamus nerve terminals (synaptosomes) during development at the age of pd 17–19 and pd 24–26 (infantile stage), pd 38–40 (puberty) and pd 66–73 (young adults) in control and after perinatal hypoxia. The extracellular level of [3H]GABA in the preparation of thalamic synaptosomes increased during development at the age of pd 38–40 and pd 66–73 as compared to earlier ones. LV did not influence the extracellular level of [3H]GABA in control and after perinatal hypoxia at all studied ages. Exocytotic [3H]GABA release in control increased at the age of pd 24–26 as compared to pd 17–19. After hypoxia, exocytotic [3H]GABA release from synaptosomes also increased during development. LV elevated [3H]GABA release from thalamic synaptosomes at the age of pd 66–73 after hypoxia and during blockage of GABA uptake by NO-711 only. LV realizes its antiepileptic effects at the presynaptic site through an increase in exocytotic release of [3H]GABA in thalamic synaptosomes after perinatal hypoxia at pd 66–73. LV exhibited a more significant effect in thalamic synaptosomes after perinatal hypoxia than in control ones. The action of LV is age-dependent, and the drug was inert at the infantile stage that can be useful for an LV application strategy in child epilepsy therapy. Keywords: brain development, exocytosis, GABA, levetiracetam, perinatal hypoxia, thalamic synaptosomes

Current knowledge, challenges and innovations in developmental pharmacology: A combined conect4children Expert Group and European Society for Developmental, Perinatal and Paediatric Pharmacology White Paper

Developmental pharmacology describes the impact of maturation on drug disposition (pharmacokinetics, PK) and drug effects (pharmacodynamics, PD) throughout the paediatric age range. This paper, written by a multidisciplinary group of experts, summarizes current knowledge, and provides suggestions to pharmaceutical companies, regulatory agencies and academicians on how to incorporate the latest knowledge regarding developmental pharmacology and innovative techniques into neonatal and paediatric drug development. Biological aspects of drug absorption, distribution, metabolism and excretion throughout development are summarized. Although this area made enormous progress during the last two decades, remaining knowledge gaps were identified. Minimal risk and burden designs allow for optimally informative but minimally invasive PK sampling, while concomitant profiling of drug metabolites may provide additional insight in the unique PK behaviour in children. Furthermore, developmental PD needs to be considered during drug development, which is illustrated by disease- and/or target organ-specific examples. Identifying and testing PD targets and effects in special populations, and application of age- and/or population-specific assessment tools are discussed. Drug development plans also need to incorporate innovative techniques such as preclinical models to study therapeutic strategies, and shift from sequential enrolment of subgroups, to more rational designs. To stimulate appropriate research plans, illustrations of specific PK/PD-related as well as drug safety-related challenges during drug development are provided. The suggestions made in this joint paper of the Innovative Medicines Initiative conect4children Expert group on Developmental Pharmacology and the European Society for Developmental, Perinatal and Paediatric Pharmacology, should facilitate all those involved in drug development.

Structural and functional changes in drug-naïve benign childhood epilepsy with centrotemporal spikes and their associated gene expression profiles

Benign epilepsy with centrotemporal spikes (BECTS) is a common pediatric epilepsy syndrome that has been widely reported to show abnormal brain structure and function. However, the genetic mechanisms underlying structural and functional changes remain largely unknown. Based on the structural and resting-state functional magnetic resonance imaging data of 22 drug-naïve children with BECTS and 33 healthy controls, we conducted voxel-based morphology (VBM) and fractional amplitude of low-frequency fluctuation (fALFF) analyses to compare cortical morphology and spontaneous brain activity between the 2 groups. In combination with the Allen Human Brain Atlas, transcriptome-neuroimaging spatial correlation analyses were applied to explore gene expression profiles associated with gray matter volume (GMV) and fALFF changes in BECTS. VBM analysis demonstrated significantly increased GMV in the right brainstem and right middle cingulate gyrus in BECTS. Moreover, children with BECTS exhibited significantly increased fALFF in left temporal pole, while decreased fALFF in right thalamus and left precuneus. These brain structural and functional alterations were closely related to behavioral and cognitive deficits, and the fALFF-linked gene expression profiles were enriched in voltage-gated ion channel and synaptic activity as well as neuron projection. Our findings suggest that brain morphological and functional abnormalities in children with BECTS involve complex polygenic genetic mechanisms.

Tailoring Materials for Epilepsy Imaging: From Biomarkers to Imaging Probes

Excising epileptic foci (EF) is the most efficient approach for treating drug-resistant epilepsy (DRE). However, owing to the vast heterogeneity of epilepsies, EF in one-third of patients cannot be accurately located, even after exhausting all current diagnostic strategies. Therefore, identifying biomarkers that truly represent the status of epilepsy and fabricating probes with high targeting specificity are prerequisites for identifying the "concealed" EF. However, no systematic summary of this topic has been published. Herein, the potential biomarkers of EF are first summarized and classified into three categories: functional, molecular, and structural aberrances during epileptogenesis, a procedure of nonepileptic brain biasing toward epileptic tissue. The materials used to fabricate these imaging probes and their performance in defining the EF in preclinical and clinical studies are highlighted. Finally, perspectives for developing the next generation of probes and their challenges in clinical translation are discussed. In general, this review can be helpful in guiding the development of imaging probes defining EF with improved accuracy and holds promise for increasing the number of DRE patients who are eligible for surgical intervention.

Sleep architecture in neonatal and infantile onset epilepsies in the first six months of life: A scoping review

AIM

Epilepsy occurs in approximately 80 per 100,000 infants in the first year of life, ranging in severity from self-limited and likely to spontaneously resolve, to severe developmental and epileptic encephalopathies. Sleep plays a key role in early brain development and the reciprocal relationship between sleep and seizures is not yet fully understood, particularly in young children. We conducted a Scoping Review to synthesise current knowledge of sleep architecture in neonates and infants with epilepsy.

METHOD

Peer-reviewed publications from 2005 to 2022 describing sleep architecture in infants up to six months of age with unprovoked seizures were included. The analysis set was derived from EMBASE, Web of Science and PubMED using key terms "sleep, epilepsy and infant" and related descriptors. Inclusion criteria were prospectively described in a Scoping Review protocol. Sleep architecture was assessed as macro- and micro-structural elements.

RESULTS

21 publications were included in the qualitative analysis. In self-limited familial and genetic epilepsy, sleep macrostructure was generally preserved. In DEEs and in epileptic encephalopathies of genetic or structural aetiology, sleep architecture was significantly disrupted.

INTERPRETATION

Early identification of infants with epilepsy is important to ensure early and effective treatment. In the DEE spectrum, sleep architecture is significantly impacted, and abnormal sleep architecture may be associated with compromised developmental outcome. Further research is needed to identify the sequence of events in abnormal brain development, epilepsy and sleep disruption and potentially help to predict the course of epilepsy towards a self-limited epilepsy versus a DEE.

Cerebral ischemia in the developing brain

Brain ischemia affects all ages, from neonates to the elderly population, and is a leading cause of mortality and morbidity. Multiple preclinical rodent models involving different ages have been developed to investigate the effect of ischemia during different times of key brain maturation events. Traditional models of developmental brain ischemia have focused on rodents at postnatal day 7-10, though emerging models in juvenile rodents (postnatal days 17-25) indicate that there may be fundamental differences in neuronal injury and functional outcomes following focal or global cerebral ischemia at different developmental ages, as well as in adults. Here, we consider the timing of injury in terms of excitation/inhibition balance, oxidative stress, inflammatory responses, blood brain barrier integrity, and white matter injury. Finally, we review translational strategies to improve function after ischemic brain injury, including new ideas regarding neurorestoration, or neural repair strategies that restore plasticity, at delayed time points after ischemia.

Rutin prevents seizures in kainic acid-treated rats: evidence of glutamate levels, inflammation and neuronal loss modulation

Rutin, a naturally derived flavonoid molecule with known neuroprotective properties, has been demonstrated to have anticonvulsive potential, but the mechanism of this effect is still unclear. The current study aimed to investigate the probable antiseizure mechanisms of rutin in rats using the kainic acid (KA) seizure model. Rutin (50 and 100 mg kg^-1) and carbamazepine (100 mg kg^-1) were administered daily by oral gavage for 7 days before KA (15 mg kg^-1) intraperitoneal (i.p.) injection. Seizure behavior, neuronal cell death, glutamate concentration, excitatory amino acid transporters (EAATs), glutamine synthetase (GS), glutaminase, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunits GluA1 and GluA2, N-methyl-D-aspartate (NMDA) receptor subunits GluN2A and GluN2B, activated astrocytes, and inflammatory and anti-inflammatory molecules in the hippocampus were evaluated. Supplementation with rutin attenuated seizure severity in KA-treated rats and reversed KA-induced neuronal loss and glutamate elevation in the hippocampus. Decreased glutaminase and GluN2B, and increased EAATs, GS, GluA1, GluA2 and GluN2A were observed with rutin administration. Rutin pretreatment also suppressed activated astrocytes, downregulated the protein levels of inflammatory molecules [interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), high mobility group Box 1 (HMGB1), interleukin-1 receptor 1 (IL-1R1), and Toll-like receptor-4 (TLR-4)] and upregulated anti-inflammatory molecule interleukin-10 (IL-10) protein expression. Taken together, the results indicate that the preventive treatment of rats with rutin attenuated KA-induced seizures and neuronal loss by decreasing glutamatergic hyperactivity and suppressing the IL-1R1/TLR4-related neuroinflammatory cascade.

Integrated in a systems pharmacology approach, pharmacogenetics holds the promise for personalized medicine in neonates

Tweetable abstract Integrated in a systems pharmacology approach, pharmacogenetics holds the promise for personalized medicine in neonates. This has been illustrated for some diseases specific to neonates.

Neonatal seizures: diagnostic updates based on new definition and classification

Neonatal seizures are the most common neurological symptoms caused by various etiologies in the neonatal period, but their diagnosis and treatment are challenging because their pathophysiology and electroclinical manifestations differ from those of patients in older age groups. Many seizures present as electrographic-only events without clinical signs or as obscure clinical manifestations that are difficult to distinguish from other neonatal behaviors. Accordingly, a new definition and classification of neonatal seizures was recently proposed by the International League Against Epilepsy Task Force on neonatal seizures, highlighting the role of electroencephalography in diagnosing and treating neonatal seizures. Neonatal seizures are defined as electrographic events with sudden, paroxysmal, and abnormal alteration of activity and divided into electroclinical seizures and electrographic-only seizures according to their clinical signs, thus excluding clinical events without an electrographic correlation. Seizure types are described by their predominant clinical features and divided into motor (automatisms, clonic, epileptic spasms, myoclonic, tonic, and sequential), nonmotor (autonomic and behavioral arrest), and unclassified. Although many neonatal seizures are acute reactive events caused by hypoxic-ischemic encephalopathy or vascular insults, structural, genetic, or metabolic etiologies of neonatal-onset epilepsy should also be thoroughly evaluated to determine their appropriate management.

Junctional instability in neuroepithelium and network hyperexcitability in a focal cortical dysplasia human model

Focal cortical dysplasia is a highly epileptogenic cortical malformation with few treatment options. Here, we generated human cortical organoids from patients with focal cortical dysplasia type II. Using this human model, we mimicked some focal cortical dysplasia hallmarks, such as impaired cell proliferation, the presence of dysmorphic neurons and balloon cells, and neuronal network hyperexcitability. Furthermore, we observed alterations in the adherens junctions zonula occludens-1 and partitioning defective 3, reduced polarization of the actin cytoskeleton, and fewer synaptic puncta. Focal cortical dysplasia cortical organoids showed downregulation of the small GTPase RHOA, a finding that was confirmed in brain tissue resected from these patients. Functionally, both spontaneous and optogenetically-evoked electrical activity revealed hyperexcitability and enhanced network connectivity in focal cortical dysplasia organoids. Taken together, our findings suggest a ventricular zone instability in tissue cohesion of neuroepithelial cells, leading to a maturational arrest of progenitors or newborn neurons, which may predispose to cellular and functional immaturity and compromise the formation of neural networks in focal cortical dysplasia.

Early life GABAA blockade alters the synaptic plasticity and cognitive functions in male and female rats

Gamma-aminobutyric acid (GABA), the major inhibitory neurotransmitter in adults, has a critical contribution to balanced excitatory-inhibitory networks in the brain. Alteration in depolarizing action of GABA during early life is connected to a wide variety of neurodevelopmental disorders. Additionally, the effects of postnatal GABA blockade on neuronal synaptic plasticity are not known and therefore, we set out to determine whether postnatal exposure to bicuculline, a competitive antagonist of GABA_A receptors, affects electrophysiologic changes in hippocampal CA1 neurons later on. To this end, male and female Wistar rats received vehicle or bicuculline (300 μg/kg) on postnatal days (PNDs) 7, 9 and 11, and then underwent different behavioral and electrophysiological examinations in adulthood. Postnatal exposure to bicuculline did not affect basic synaptic transmission but led to a pronounced decrease in paired-pulse facilitation (PPF) in CA1 pyramidal neurons. Bicuculline treatment also attenuated the long-term potentiation (LTP) and long-term depression (LTD) of CA1 neurons accompanied by decreased theta-burst responses in male and female adult rats. These electrophysiology findings together with the reduced brain-derived neurotrophic factor (BDNF) levels in the hippocampus and prefrontal cortex reliably explain the disturbance in spatial reference and working memories of bicuculline-treated animals. This study suggests that postnatal GABA_A blockade deteriorates short- and long-term synaptic plasticity of hippocampal CA1 neurons and related encoding of spatial memory in adulthood.

The metabolic basis of epilepsy

The brain is a highly energy-demanding organ and requires bioenergetic adaptability to balance normal activity with pathophysiological fuelling of spontaneous recurrent seizures, the hallmark feature of the epilepsies. Recurrent or prolonged seizures have long been known to permanently alter neuronal circuitry and to cause excitotoxic injury and aberrant inflammation. Furthermore, pathological changes in bioenergetics and metabolism are considered downstream consequences of epileptic seizures that begin at the synaptic level. However, as we highlight in this Review, evidence is also emerging that primary derangements in cellular or mitochondrial metabolism can result in seizure genesis and lead to spontaneous recurrent seizures. Basic and translational research indicates that the relationships between brain metabolism and epileptic seizures are complex and bidirectional, producing a vicious cycle that compounds the deleterious consequences of seizures. Metabolism-based treatments such as the high-fat, antiseizure ketogenic diet have become mainstream, and metabolic substrates and enzymes have become attractive molecular targets for seizure prevention and recovery. Moreover, given that metabolism is crucial for epigenetic as well as inflammatory changes, the idea that epileptogenesis can be both negatively and positively influenced by metabolic changes is rapidly gaining ground. Here, we review evidence that supports both pathophysiological and therapeutic roles for brain metabolism in epilepsy.