Evidence map›Paper›PMID 41553358›Full record

ArticleEpilepsia2026

Spectral entropy variability of intraoperative electrocorticography predicts outcome after epilepsy surgery in people with focal cortical dysplasia.

Eline V Schaft, Sem Hoogteijling, Dongqing Sun, Cyrille H Ferrier, Pieter van Eijsden, Wim M Otte, Galia Anguelova, Nick F Ramsey, Maryse A Van't Klooster, Maeike Zijlmans and 1 more

Abstract read
In one paragraph

Article in Epilepsia, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Entropy of the resting state cortex in epilepsy.Biomedical physics & engineering express · 2026
    Article
  2. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

11 authors.

Eline V SchaftDepartment of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands.ORCID https://orcid.org/0000-0002-6094-6178
Sem HoogteijlingDepartment of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands.ORCID https://orcid.org/0000-0002-4455-6700
Dongqing SunDepartment of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands.
Cyrille H FerrierDepartment of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands.
Pieter van EijsdenDepartment of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands.
Wim M OtteDepartment of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands.ORCID https://orcid.org/0000-0003-1511-6834
Galia AnguelovaStichting Epilepsie Instellingen Nederland, the Netherlands.ORCID https://orcid.org/0000-0001-7633-2018
Nick F RamseyDepartment of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands.
Maryse A Van't KloosterDepartment of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands.
Maeike ZijlmansDepartment of Neurology and Neurosurgery, University Medical Center Utrecht Brain Center, University Medical Center Utrecht, Utrecht, the Netherlands.ORCID https://orcid.org/0000-0003-1258-5678
RESPect database study group

Funding

Anna Teding van Berkhout StichtingDutch Research Coucil NWO division ZonMW 09150172210057EpilepsieNLEuropean Research Council 883880HORIZON EUROPE Framework Programme 101095387
6 · The paper itself

Abstract

objectiveEpilepsy surgery in people with focal cortical dysplasia (FCD) requires accurate removal of all epileptogenic tissue, and outcome is difficult to predict. We explored whether spectral entropy, a fast computable electroencephalographic (EEG) feature, could estimate epileptic activity in intraoperative electrocorticography (ioECoG) and forecast postsurgical outcomes.

methodsWe included people with FCD pathology who underwent ioECoG-assisted resective surgery. We analyzed ioECoG recordings acquired before and after resection. We computed spectral entropy across eight frequency bands (1-500, 1-4, 4-8, 8-12, 12-20, 20-80, 80-250, 250-500 Hz) in 2-s epochs during 1 min, and the mean and SD per electrode. The preresection features were the input for a random forest machine learning model to classify channels covering resected from nonresected tissue. Explainable artificial intelligence was used to select features that positively influenced the model predicting resected tissue. We then related these markers measured after the resection to postsurgical outcome using trend analysis (Jonckheere-Terpstra) across outcome groups Engel IA without medication, Engel IA-D, Engel II, Engel III, and Engel IV.

resultsWe analyzed ioECoG data from 37 patients (age range = 0-61 years, 21 patients were ≤16 years), including 2270 preresection and 1278 postresection channels. The random forest model discriminated between resected and nonresected cortex (validation fold area under the curve = .84, 95% confidence interval =.74-.95). Features with the strongest positive Shapley Additive Explanations values included high spectral entropy variability (SEV) in the 80-500-Hz bands. In postresection recordings, higher mean SEV and greater spatial variability of SEV were associated with poorer Engel outcome across several frequency bands. After multiple comparison correction, the positive relationship of high mean SEV (p = .004) and high spatial variability (p = .001) at 250-500 Hz with poor seizure outcome remained statistically significant. SIGNIFICANCE: SEV is a real-time computable invasive EEG marker that represents persisting epileptic activity after resection. SEV may be used to evaluate resection adequacy directly or may reflect residual epileptic activity. This would enable epilepsy surgery guidance and postsurgical counseling and decision-making.

Indexed as

ElectrocorticographyEpilepsyFocal Cortical DysplasiaIntraoperative Neurophysiological MonitoringAdolescentAdultChildChild, PreschoolEntropyFemaleHumansMachine LearningMaleMiddle AgedTreatment OutcomeYoung Adultfocal epilepsyhigh‐frequency oscillationsintracranial EEGmachine learningseizure freedomtailoring

Identifiers

PMID41553358
PMCPMC13179649

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.