Stable Yet Destabilised: Towards Understanding Brain Network Dynamics in Psychogenic Disorders

Journal of Clinical Medicine, Journal Year: 2025, Volume and Issue: 14(3), P. 666 - 666

Published: Jan. 21, 2025

Background: Psychogenic non-epileptic seizures (PNES) are seizure-like episodes that resemble behavioral aspects observed for epileptic but without the abnormal electrical activity typically seen in epilepsy. The lack of an etiologic model PNES as well limitations available diagnostic methods largely hinders a clear-cut distinction from epilepsy and normal functioning brain. Methods: In this study, we investigate brain dynamics people with during phases far-off events control group. Probing differences between these groups, utilise network ansatz explore local global characteristics time-evolving functional networks. We observe subject-specific across highlighting physiological specific regions. Furthermore, significant characteristics—relating to communication, robustness, stability Conclusions: Our findings may provide new insights into mechanisms underlying offer promising approach differentiate them

Language: Английский

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EEG signal dimension is an index of seizure propensity and antiseizure medication effects in a mouse model of acquired epilepsy

Epilepsia, Journal Year: 2025, Volume and Issue: unknown

Published: April 9, 2025

Abstract Objective Variability in the frequency, timing, and pattern of seizures may influence assessment effect antiseizure medications (ASMs) when measuring seizure especially patients with infrequent seizures. A low rate is an exclusion criterion for enrollment epilepsy clinical trials requires prolonged periods monitoring, thus delaying appropriate treatment interventions. We investigated whether electroencephalogram (EEG)–based complexity measure susceptibility epileptic mice provides a reliable alternative to frequency evaluating efficacy ASMs. Methods used mouse model acquired characterized by variability over time among mice, as observed humans. analyzed EEG recordings from chronic ( n = 106) at baseline during phenobarbital, valproate, carbamazepine, or phenytoin. recurrence quantification analysis detect increased autocorrelation critical slowing‐down, two signatures criticality that together contribute estimate dimension phase–space signals. The measurements were compared proxies correlation tests evaluation ASM efficacy. Results Dimension provided statistically robust (inverse) including no observation periods. In contrast, only high rate. Consistently, using variations accurately reproduced responsiveness patterns this model. Significance EEG‐based propensity experience well efficacy, regardless rates. Measuring variation should facilitate inclusion subjects preclinical while also shortening monitoring. This could accelerate both development new treatments therapeutic decisions medical field.

Language: Английский

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Preictal connectivity dynamics: Exploring inflow and outflow in iEEG networks

Frontiers in Network Physiology, Journal Year: 2025, Volume and Issue: 5

Published: April 28, 2025

Introduction: Focal resective surgery can be an effective treatment option for patients with refractory epilepsy if the seizure onset zone is accurately identied through intracranial EEG recordings. The traditional concept of epileptogenic has expanded to notion network, emphasizing role interconnected brain regions in generation. Precise delineation this network essential optimizing surgical outcomes. Over past 3 decades, several quantitative connectivity methods have been developed study interactions between and non-involved regions. Despite these advances, mechanisms governing transition from interictal ictal periods remain poorly understood. In study, we investigated preictal broader using directed measures. Methods: We evaluated their effectiveness identifying zones a multicenter dataset, encompassing 243 seizures 61 patients. Directed transfer function partial coherence were used extract matrices during 28-seconds period good Inflow outflow metrics computed iEEG electrode contact annotated as performance each metric assessed disentangling electrodes rest network. Results: observed two distinct patterns preceding onset. While there was increase inflow information one subset patients, other subset, prominent suggesting associated across Further analyses showed that who underwent grid/strip/depth implantation approach exhibited significantly higher area under curve (AUC) than those electrocorticography (ECoG) or stereo-electroencephalography (sEEG) alone. Finally, examining influence lesional vs non-lesional neuroimaging status demonstrated greater proportion high-inflow high-outflow lesional. Conclusion: Our findings reinforce generation driven by dynamic shifts flow within brain's functional --either increased high it --underscore reorganization involved epileptic transitions. These results emphasize network-level phenomenon, supporting use concepts better understanding dynamics improving localization strategies.

Language: Английский

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Emergence of a tipping subnetwork during a critical transition in networked systems: A new avenue to extreme events

Physical Review Research, Journal Year: 2025, Volume and Issue: 7(2)

Published: May 1, 2025

Unexpected and often irreversible shifts in the state or dynamics of a complex system accumulate extreme events with likely disastrous impact on its environment. Detection, understanding, possible prediction such critical transitions are thus paramount importance across variety scientific fields. The rather modest improvement achieved so far may be due previous research mostly concentrating either particular subsystems, considered to vital for generating mechanism transition, as whole. These approaches only rarely take into account intricate, time-dependent interrelatedness subsystems that can essentially determine emerging behaviors underlying transitions. We uncover network vertices, certain edges, tipping elements networked dynamical system, forming time-evolving subnetwork. demonstrate existence subnetworks excitable networks human epileptic brains. systems repeatedly undergo result events. Our findings reveal encapsulate key properties mechanisms involved Published by American Physical Society 2025

Language: Английский

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Oscillatory and nonoscillatory sleep electroencephalographic biomarkers of the epileptic network

Epilepsia, Journal Year: 2024, Volume and Issue: 65(10), P. 3038 - 3051

Published: Aug. 24, 2024

In addition to the oscillatory brain activity, nonoscillatory (scale-free) components of background electroencephalogram (EEG) may provide further information about complexity underlying neuronal network. As epilepsy is considered a network disease, such scale-free metrics might help delineate epileptic Here, we performed an analysis sleep (spindle, slow wave, and rhythmic spectral power) (H exponent) intracranial EEG using multiple interictal features estimate whether how they deviate from normalcy in 38 adults with drug-resistant epilepsy.

Language: Английский

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Resting state connectivity biomarkers of seizure freedom after epilepsy surgery

NeuroImage Clinical, Journal Year: 2024, Volume and Issue: 44, P. 103673 - 103673

Published: Jan. 1, 2024

Alterations in brain networks may cause the lowering of seizure threshold and hypersynchronization that underlie recurrence unprovoked seizures epilepsy. The aim this work is to estimate functional network characteristics, which help predicting outcome epilepsy surgery. Twenty patients were studied (11 females, 9 males, mean age 33 years) with scalp-recorded HD-EEG resting state (eyes closed, no interictal discharges) before intracranial evaluation, allowed precise determination epileptogenic zone. Dipole source time courses estimated using Weighted Minimum Norm Estimate based on signals. Information inflow outflow atlas-based regions computed partial directed connectivity. A set graph measures for pairwise connections standard EEG frequency bands was calculated. After surgery 10 seizure-free (Engel 1a) continued suffering from worse than 1a). Inflow containing zone beta delta significantly lower who achieved seizure-freedom after surgery, compared have (p = 0.012, p 0.026, respectively). Average path length band higher freedom 0.012). In band, local efficiency clustering coefficient (0.033, 0.046). preoperative analysis epileptic exhibited stronger separation region onset zone, less information. contrast, shorter paths within facilitate hypersynchronous neuronal activity thus non-seizure free patients. This study supports hypothesis properties might define suitable candidates

Language: Английский

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Modeling seizure networks in neuron-glia cultures using microelectrode arrays

Frontiers in Network Physiology, Journal Year: 2024, Volume and Issue: 4

Published: Sept. 3, 2024

Epilepsy is a common neurological disorder, affecting over 65 million people worldwide. Unfortunately, despite resective surgery, 30 % of patients with drug-resistant epilepsy continue to experience seizures. Retrospective studies considering connectivity using intracranial electrocorticography (ECoG) obtained during neuromonitoring have shown that treatment failure likely driven by consider critical components the seizure network, an idea first formally introduced in 2002. However, current only capture snapshots time, precluding ability network development. Over past few years, multiwell microelectrode arrays been increasingly used study neuronal networks vitro . As such, we sought develop novel MEA model allow for networks. Specifically, 4-aminopyridine (4-AP) hyperexcitable activity, and then show increased changes after 2 days chronic treatment. We characterize functional measures technique dimensionality reduction. find 4-AP successfully captures persistently elevated mean firing rate significant underlying patterns. believe this affords robust from which longitudinal can be studied, laying groundwork future exploring

Language: Английский

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Brivaracetam and rufinamide combination increased seizure threshold and improved neurobehavioral deficits in corneal kindling model of epilepsy

Animal Models and Experimental Medicine, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 22, 2024

Abstract Background Besides seizures, a myriad of overlapping neuropsychiatric and cognitive comorbidities occur in patients with epilepsy, which further debilitates their quality life. This study provides an in‐depth characterization the impact brivaracetam rufinamide individually combination at 10 20 mg/kg doses, respectively, on corneal kindling‐induced generalized seizures behavioral alterations. Furthermore, observed convulsive frequency changes were correlated to post‐kindling‐induced activity markers oxidative stress. Methods Adult C57BL/6 mice kindled via twice‐daily transcorneal 50‐Hz electrical stimulations (3 mA) for 3 s 12 days until animals reached fully state. After kindling procedure, tested using set tests, neurochemical alterations assessed. Results Corneal‐kindled exhibited intense convulsions, altered phenotypes typified by positive symptoms (hyperlocomotion), negative (anxiety anhedonia), deficits semantic working memory. BRV + RFM dual regime increased threshold propensity toward start stage 4–5 improved phenotypical deficits, that is, anxiety, depression, memory impairments. Moreover, this therapy mitigated redox impairments as evidenced reduced malondialdehyde acetylcholinesterase levels glutathione antioxidant brain subjected repetitive insult. Conclusion Based our outcomes, supporting evidence alleviating epilepsy‐induced neurobehavioral homeostasis.

Language: Английский

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