Multiscale neuro-inspired models for interpretation of EEG signals in patients with epilepsy

Clinical Neurophysiology, Год журнала: 2024, Номер 161, С. 198 - 210

Опубликована: Март 16, 2024

The aim is to gain insight into the pathophysiological mechanisms underlying interictal epileptiform discharges observed in electroencephalographic (EEG) and stereo-EEG (SEEG, depth electrodes) recordings performed during pre-surgical evaluation of patients with drug-resistant epilepsy.

Язык: Английский

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Generalisability of epileptiform patterns across time and patients

Scientific Reports, Год журнала: 2024, Номер 14(1)

Опубликована: Март 15, 2024

Abstract The complexity of localising the epileptogenic zone (EZ) contributes to surgical resection failures in achieving seizure freedom. distinct patterns epileptiform activity during interictal and ictal phases, varying across patients, often lead suboptimal localisation using electroencephalography (EEG) features. We posed two key questions: whether neural signals reflecting epileptogenicity generalise from time windows within each patient, patients. Utilising an intracranial EEG dataset 55 we extracted a large battery simple complex features stereo-EEG (SEEG) electrocorticographic (ECoG) windows. Our (n = 34) quantified many aspects including statistical moments, complexities, frequency-domain cross-channel network attributes. Decision tree classifiers were then trained tested on patients evaluate generalisability respectively. Evidence strongly supported particularly signal power high-frequency network-based Consistent observed most regions generalised with higher window. Signal contributory cross-patient generalisation These findings offer insights into generalisable epileptic implications for future automated approaches supplement other EZ methods.

Язык: Английский

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Focal seizures are organized by feedback between neural activity and ion concentration changes

eLife, Год журнала: 2022, Номер 11

Опубликована: Авг. 2, 2022

Human and animal EEG data demonstrate that focal seizures start with low-voltage fast activity, evolve into rhythmic burst discharges are followed by a period of suppressed background activity. This suggests processes dynamics in the range tens seconds govern seizure evolution. We investigate associated complementing Hodgkin-Huxley mathematical model physical laws dictate ion movement maintain ionic gradients. Our biophysically realistic computational closely replicates electrographic pattern typical human characterized low voltage activity onset, tonic phase, clonic phase postictal suppression. study demonstrates, for first time silico, potential mechanism initiation inhibitory interneurons via initial build-up extracellular K + due to intense interneuronal spiking. The also identifies mechanisms may underlie key feature dynamics, is, progressive slowing down ictal towards end seizure. prediction specific scaling inter-burst intervals is confirmed recorded whole guinea pig brain vitro humans, suggesting observed termination hold across different species. results emphasize as elementary behind generation indicate targets new therapeutic strategies.

Язык: Английский

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Chloride ion dysregulation in epileptogenic neuronal networks

Neurobiology of Disease, Год журнала: 2023, Номер 177, С. 106000 - 106000

Опубликована: Янв. 10, 2023

GABA is the major inhibitory neurotransmitter in mature CNS. When GABAA receptors are activated membrane potential driven towards hyperpolarization due to chloride entry into neuron. However, ion dysregulation that alters ionic gradient can result depolarizing GABAergic post-synaptic potentials instead. In this review, we highlight inhibition prevents and restrains focal seizures but then reexamine notion context of evidence a static and/or dynamic dysregulation, increases intracellular concentrations, promotes epileptiform activity seizures. To reconcile these findings, hypothesize epileptogenic pathologically interconnected neuron (PIN) microcircuits, representing small minority neurons, exhibit should (IPSPs). We speculate PIN cluster activation may generate fast ripples spikes as well initiate hypersynchronous seizure onset pattern microseizures. Also, discuss genetic, molecular, cellular players important which regulate epileptogenesis low-voltage pattern. conclude neuronal networks appears be critical for genesis, feed-back feed-forward neurotransmission plays an role preventing restraining well.

Язык: Английский

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From phenomenological to biophysical models of seizures

Neurobiology of Disease, Год журнала: 2023, Номер 182, С. 106131 - 106131

Опубликована: Апрель 21, 2023

Epilepsy is a complex disease that requires various approaches for its study. This short review discusses the contribution of theoretical and computational models. The presents frameworks underlie understanding certain seizure properties their classification based on dynamical at onset offset seizures. Dynamical system tools are valuable resources in study These can provide insights into mechanisms offer framework classification, by analyzing complex, dynamic behavior Additionally, models have high potential clinical applications, as they be used to develop more accurate diagnostic personalized medicine tools. We discuss modeling span different scales levels, while also questioning neurocentric view, emphasizing importance considering glial cells. Finally, we explore epistemic value provided this type approach.

Язык: Английский

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Is High‐Frequency Activity at Seizure Onset Inhibitory? A Stereoelectroencephalographic Study of Motor Cortex Seizures

Annals of Neurology, Год журнала: 2024, Номер 95(6), С. 1127 - 1137

Опубликована: Март 13, 2024

Objective In the era of stereoelectroencephalography (SEEG), many studies have been devoted to understanding role interictal high‐frequency oscillations. High‐frequency activity (HFA) at seizure onset has identified as a marker epileptogenic zone. We address physiological significance ictal HFAs and their relation clinical semiology. Methods retrospectively patients with pure focal primary motor epilepsy. selected only in whom SEEG electrodes were optimally placed cortex confirmed by electrical stimulation. Based on these narrow inclusion criteria, we extensively studied 5 (3 males 2 females, mean age = 22.4 years) using time–frequency analysis time correlation signs onset. Results A total 157 analyzable seizures recorded subjects. The first subjects had tonic or clonic semiology rare secondary generalization. Subject 3 atonic followed hand/arm flexion. 4 clusters facial movements. upper extremity median frequency fast extracted from Epileptogenic Zone Fingerprint pipeline was 76 Hz (interquartile range 21.9Hz). Positive did not occur concomitantly high gamma developing cortex. Motor began end HFAs. Interpretation This study supports hypothesis an inhibitory effect band associated direction output effect. Changes excitatory occurred when discharge dropped low beta. ANN NEUROL 2024;95:1127–1137

Язык: Английский

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Cl ⁻ -dependent amplification of excitatory synaptic potentials at distal dendrites revealed by voltage imaging

Science Advances, Год журнала: 2024, Номер 10(35)

Опубликована: Авг. 28, 2024

The processing of synaptic signals in somatodendritic compartments determines neuronal computation. Although the amplification excitatory by local voltage-dependent cation channels has been extensively studied, their spatiotemporal dynamics elaborate dendritic branches remain obscure owing to technical limitations. Using fluorescent voltage imaging throughout arborizations hippocampal pyramidal neurons, we demonstrate a unique chloride ion (Cl

Язык: Английский

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HCN channels promote Na/K‐ATPase activity during slow afterhyperpolarization after seizure‐like events in vitro

The Journal of Physiology, Год журнала: 2025, Номер unknown

Опубликована: Фев. 7, 2025

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are strongly involved in the regulation of neuronal excitability, with their precise role being determined by subcellular localization and interaction other ion transporters. Their causing epileptic seizures is not fully understood. Using whole-cell patch-clamp recordings rat brain slices, we show that HCN constitute a substantial fraction membrane conductance deep entorhinal principal neurons. 4-aminopyridine model vitro, channel blockade ZD-7288 increases frequency seizure-like events (SLEs) alters time course afterhyperpolarization after SLEs (post-SLE AHP), promoting its faster onset making it more transient. Simultaneous K+ ion-selective electrode revealed changes potential extracellular concentration presence differed from control, which can be explained altered Na/K-ATPase [sodium-potassium adenosine triphosphatase (sodium-potassium pump)] activity SLEs. To confirm this hypothesis, demonstrated ouabain sensitivity post-SLE AHP showed loading neurons high intracellular Na+ prevented effect on AHP. Taken together, results obtained suggest during AHP, influx through helps to maintain hyperactivity, resulting longer pauses between Mathematical modelling confirmed feasibility proposed mechanism. Such an interplay may crucial for seizure termination epilepsy. KEY POINTS: significant resting modulate cortex. The reduces duration follows them. affect sodium dynamics, prolonging (sodium-potassium) pump] SLEs, turn

Язык: Английский

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Hippocampal Interneurons Shape Spatial Coding Alterations in Neurological Disorders

Molecular Neurobiology, Год журнала: 2025, Номер unknown

Опубликована: Май 20, 2025

Язык: Английский

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Optogenetic Low-Frequency Stimulation of Principal Neurons, but Not Parvalbumin-Positive Interneurons, Prevents Generation of Ictal Discharges in Rodent Entorhinal Cortex in an In Vitro 4-Aminopyridine Model

International Journal of Molecular Sciences, Год журнала: 2022, Номер 24(1), С. 195 - 195

Опубликована: Дек. 22, 2022

Low-frequency electrical stimulation is used to treat some drug-resistant forms of epilepsy. Despite the effectiveness method in suppressing seizures, there a considerable risk side effects. An optogenetic approach allows targeting specific populations neurons, which can increase and safety low-frequency stimulation. In our study, we tested efficacy suppression ictal activity entorhinal cortex slices 4-aminopyridine model with three variants light (LFLS): (1) activation excitatory inhibitory neurons (on Thy1-ChR2-YFP mice), (2) interneurons only PV-Cre mice after virus injection channelrhodopsin2 gene), (3) hyperpolarization Wistar rats archaerhodopsin gene). Only first variant did simultaneous LFLS replace interictal activity. We suggest that caused changes concentration gradients K+ Na+ cations across neuron membrane, activated Na-K pumping. According mathematical modeling, pump induced by led an antiepileptic effect. Thus, less generalized effect on was more effective model.

Язык: Английский

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