Generalisability of epileptiform patterns across time and patients

Scientific Reports, Journal Year: 2024, Volume and Issue: 14(1)

Published: March 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.

Language: Английский

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A library of quantitative markers of seizure severity

Epilepsia, Journal Year: 2023, Volume and Issue: 64(4), P. 1074 - 1086

Published: Feb. 2, 2023

Abstract Objective Understanding fluctuations in seizure severity within individuals is important for determining treatment outcomes and responses to therapy, as well assessing novel treatments epilepsy. Current methods grading rely on qualitative interpretations from patients clinicians. Quantitative measures of would complement existing approaches electroencephalographic (EEG) monitoring, outcome prediction. Therefore, we developed a library quantitative EEG markers that assess the spread intensity abnormal electrical activity during after seizures. Methods We analyzed intracranial (iEEG) recordings 1009 seizures 63 patients. For each seizure, computed 16 capture signal magnitude, spread, duration, postictal suppression Results distinguished focal versus subclinical across In individual patients, 53% had moderate large difference (rank sum , ) between three or more markers. Circadian longer term changes were found majority Significance demonstrate feasibility using iEEG measure severity. Our distinguish types are therefore sensitive established differences results also suggest modulated over different timescales. envisage our proposed will be expanded updated collaboration with epilepsy research community include modalities.

Language: Английский

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Temporal stability of intracranial electroencephalographic abnormality maps for localizing epileptogenic tissue

Epilepsia, Journal Year: 2023, Volume and Issue: 64(8), P. 2070 - 2080

Published: May 25, 2023

Abstract Objective Identifying abnormalities on interictal intracranial electroencephalogram (iEEG), by comparing patient data to a normative map, has shown promise for the localization of epileptogenic tissue and prediction outcome. The approach typically uses short segments approximately 1 min. However, temporal stability findings not been established. Methods Here, we generated map iEEG in nonpathological brain from 249 patients. We computed regional band power separate cohort 39 patients duration their monitoring period (.92–8.62 days data, mean = 4.58 per patient, >4800 hours recording). To assess localizing value abnormality, —a measure how different surgically resected spared was terms abnormalities—over time. Results In each relatively consistent over median entire recording separated seizure‐free (International League Against Epilepsy [ILAE] 1) not‐seizure‐free (ILAE well (area under curve [AUC] .69). This effect similar interictally (AUC .69) peri‐ictally .71). Significance Our results suggest that abnormality D_RS, as predictor outcomes epilepsy surgery, is robust metric These add further support mapping neurophysiology during presurgical evaluation.

Language: Английский

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Incomplete resection of the intracranial electroencephalographic seizure onset zone is not associated with postsurgical outcomes

Epilepsia, Journal Year: 2024, Volume and Issue: 65(9)

Published: July 11, 2024

Delineation of seizure onset regions using intracranial electroencephalography (icEEG) is vital in the surgical workup drug-resistant epilepsy cases. However, it unknown whether complete resection these necessary for freedom, or postsurgical recurrence can be attributed to incomplete removal regions. To address this gap, we retrospectively analyzed icEEG recordings from 63 subjects, identifying visually and algorithmically. We assessed region correlated with control. The majority subjects had more than half their resected (82.46% 80.65% visual algorithmic methods, respectively). There was no association between proportion zone (SOZ) that subsequently better outcomes (area under receiver operating characteristic curve [AUC] < .7). Investigating spatial extent regions, found substantial evidence an control (all AUC Although are typically completely large part, not associated worse outcomes. conclude cannot SOZ alone. Other network mechanisms beyond likely contribute.

Language: Английский

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Diminished circadian and ultradian rhythms of human brain activity in pathological tissue in vivo

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Oct. 2, 2024

Language: Английский

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More variable circadian rhythms in epilepsy captured by long‐term heart rate recordings from wearable sensors

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

Published: April 26, 2025

Abstract Objective The circadian rhythm synchronizes physiological and behavioral patterns with the 24‐h light–dark cycle. Disruption to is linked various health conditions, although optimal methods describe these disruptions remain unclear. An emerging approach examine intraindividual variability in measurable properties of over extended periods. Epileptic seizures are modulated by rhythms, but relevance disruption epilepsy remains unexplored. Our study investigates its relationship seizures. Methods We retrospectively analyzed >70 000 h wearable smartwatch data (Fitbit) from 143 people (PWE) 31 healthy controls. Circadian oscillations heart rate time series were extracted, daily estimates period, acrophase, amplitude produced, an entire recording calculated. Results PWE exhibited greater period (76 vs. 57 min, d = .66, p < .001) acrophase (64 48 .49, .004) compared controls, not (2 beats per minute, −.15, .49). Variability showed no correlation seizure frequency nor any differences between weeks without Significance For first time, we show that rhythms more variable PWE, detectable via consumer devices. However, association or occurrence was found, suggesting this might be underpinned etiology rather than being a seizure‐driven effect.

Language: Английский

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Chronic intracranial EEG recordings and interictal spike rate reveal multiscale temporal modulations in seizure states

Brain Communications, Journal Year: 2023, Volume and Issue: 5(5)

Published: Jan. 1, 2023

Many biological processes are modulated by rhythms on circadian and multidien timescales. In focal epilepsy, various seizure features, such as spread duration, can change from one to the next within same patient. However, specific timescales of this variability, well characteristics that over time, unclear. Here, in a cross-sectional observational study, we analysed within-patient variability 10 patients with chronic intracranial EEG recordings (185-767 days recording 57-452 seizures/patient). We characterized evolutions sequences finite number patient-specific functional network states. then compared state occurrence duration (1) time since implantation (2) cycles interictal spike rate. most patients, or at least was associated implantation. Some had more states were phases and/or rate cycles. A given state's usually not timescale. Our results suggest different time-varying factors modulate multiple timescales, separate modulating duration. These findings imply development time-adaptive treatments epilepsy must account for several properties epileptic seizures similar principles likely apply other neurological conditions.

Language: Английский

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The seizure severity score: a quantitative tool for comparing seizures and their response to therapy

Journal of Neural Engineering, Journal Year: 2023, Volume and Issue: 20(4), P. 046026 - 046026

Published: Aug. 1, 2023

Epilepsy is a neurological disorder characterized by recurrent seizures which vary widely in severity, from clinically silent to prolonged convulsions. Measuring severity crucial for guiding therapy, particularly when complete control not possible. Seizure diaries, the current standard are insensitive duration of events or propagation seizure activity across brain. We present quantitative score that incorporates electroencephalography (EEG) and clinical data demonstrate how it can guide epilepsy therapies.

Language: Английский

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Generalisability of epileptiform patterns across time and patients

medRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: Sept. 1, 2023

Abstract Complexity of epileptogenic zone (EZ) localisation contributes to failure surgical resection produce seizure freedom. This is some extent a result distinct patterns epileptiform activity between (i.e., interictal) and during seizures ictal) their diversity across patients. often leads suboptimal based on inspection electroencephalography (EEG) features. We asked two open questions. First, whether neural signal reflecting epileptogenicity would be generalisable from interictal ictal time window within each patient. critical for patients who are monitored in hospital without having help with EZ localisation, more generally understanding the predictive power resting state (interictal) EEG data determining EZ. Second, generalise patients, if so, which aspects those most generalisable. used an intracranial dataset that included fifty-five lesional non-lesional pathology, had subsequently undergone cortical frontal or temporal lobe different levels extracted large set simple complex features stereo-EEG (SEEG) electrocorticographic (ECoG) signals recorded windows. fed decision tree classifiers quantify through cross-time cross-patient generalisation procedure. observed significant evidence ( Bayes factor >> 10) generalisability windows were dominantly reflected high-frequency network-based Majority showed consistent windows, above-chance area-under-curve (mean AUC = 0.6). regions could both higher than 0.75 vs. 0.59; 10). While moment contributory window, complexity window. These results provide new insights about epileptic interictal-ictal can have implications qualitative quantitative localisation. The explainable machine-learning pipeline developed here guide future developments epilepsy investigations.

Language: Английский

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Diazepam nasal spray administration is effective to control seizure clusters irrespective of time of day

Frontiers in Neurology, Journal Year: 2024, Volume and Issue: 15

Published: May 24, 2024

Introduction Neurologic circadian influences, including sleep/wake transitions, processes (e.g., hormonal variation), and behavioral patterns consumption of food oral medications), may affect seizure patterns. Specific seizures have been reported depending on type, onset location, severity; however, data for patients with clusters effectiveness rescue therapy by time day are limited. Methods We conducted post hoc analyses using patient diary from the phase 3 safety study diazepam nasal spray, which is indicated acute treatment in epilepsy aged ≥6 years. Patients were administered age- weight-based doses; second doses could be if needed to control a cluster. assessed clock timing seizure-cluster along second-dose use as proxy effectiveness. Treatment-emergent adverse events recorded. Results Seizure-cluster was observed generally highest during mornings late evenings lowest early evening middle night. Second-dose not consistently associated specific day. The profile consistent that expected previous studies spray. Conclusion These results suggest spray can effectively at any

Language: Английский

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