Evidence map›Paper›PMID 41804684›Full record

ArticleEpilepsia2026

Sleep magnetoencephalography enhances detection and source imaging of seizures and fast oscillations in focal cortical dysplasia.

Marcel Heers, Jawata Afnan, Christoph Braun, Christophe Grova, Dirk-Matthias Altenmüller, Bernhard J Steinhoff, Matthias Dümpelmann, Theo Demerath, Horst Urbach, Silke Ethofer and 4 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 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing 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

1 citing paper in PubMed.

  1. 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

14 authors.

Marcel HeersEpilepsy Center, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.ORCID https://orcid.org/0000-0001-5545-7014
Jawata AfnanMultimodal Functional Imaging Lab, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.ORCID https://orcid.org/0000-0003-3206-9873
Christoph BraunMagnetoencephalography Center, University of Tübingen, Tübingen, Germany.
Christophe GrovaMultimodal Functional Imaging Lab, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.ORCID https://orcid.org/0000-0003-2775-9968
Dirk-Matthias AltenmüllerEpilepsy Center, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.ORCID https://orcid.org/0000-0001-8610-2216
Bernhard J SteinhoffEpilepsy Center Kork, Kehl-Kork, Germany.ORCID https://orcid.org/0000-0001-5995-5862
Matthias DümpelmannEpilepsy Center, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.ORCID https://orcid.org/0000-0002-1476-7777
Theo DemerathDepartment of Neuroradiology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.ORCID https://orcid.org/0000-0002-5869-1110
Horst UrbachDepartment of Neuroradiology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.ORCID https://orcid.org/0000-0001-7264-4807
Silke EthoferDepartment of Neurosurgery, University Hospital Tübingen, Tübingen, Germany.ORCID https://orcid.org/0000-0002-6726-0531
Markus SiegelMagnetoencephalography Center, University of Tübingen, Tübingen, Germany.ORCID https://orcid.org/0000-0001-5115-936X
Andreas Schulze-BonhageEpilepsy Center, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.ORCID https://orcid.org/0000-0003-2382-0506
Holger LercheDepartment of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.ORCID https://orcid.org/0000-0002-1783-8710
Yiwen Li HegnerMagnetoencephalography Center, University of Tübingen, Tübingen, Germany.ORCID https://orcid.org/0000-0001-9960-6958

Funding

Deutsche Forschungsgemeinschaft HE6844/3-1Deutsche Forschungsgemeinschaft LI1904/2-1Deutsche Forschungsgemeinschaft Project ID: 468174690
6 · The paper itself

Abstract

objectiveFocal cortical dysplasia (FCD) causes drug-resistant epilepsy requiring presurgical evaluation. Invasive electroencephalographic (EEG) studies demonstrate that sleep modulates epileptic activity, including interictal epileptiform discharges (IEDs), fast oscillations (FOs) in the beta (14-40 Hz) and gamma (40-80 Hz) frequency bands, and seizures. This study aimed to quantify sleep-associated changes in IEDs, FOs, and seizures in FCD patients using noninvasive magnetoencephalography (MEG).

methodsNineteen patients with FCD were prospectively recruited and underwent simultaneous MEG/EEG recordings lasting 89 ± 19 min during daytime sleep. Sleep stages were classified from the EEG. Beamformer source signals were computed from the MEG signal to enhance sensitivity for visual detection of IEDs, FOs in the beta and gamma frequency bands, and seizures. Magnetic source imaging (MSI) was performed using the Maximum Entropy on the Mean (MEM) method, which is particularly sensitive to the spatial extent of sources, enabling accurate localization of epileptic activity.

resultsN1 sleep was reached in 17 of 19 patients and N2 sleep in 14 of 19 patients. Compared to wakefulness, sleep recordings showed significantly higher rates of FOs and seizures (both p < .05), whereas IED rates showed nonsignificant trends. Ten patients demonstrated FOs or seizures, and 12 showed IEDs. MSI of IEDs demonstrated consistent accuracy across vigilance states, with median Euclidean distances of 12.74 mm (interquartile range [IQR] = 22.74) in wake and 8.34 mm (IQR = 27.58) in sleep, and no systematic amplitude or spatial extent changes. Wavelet-MEM enabled frequency-specific source imaging, with FOs and seizures localizing concordantly to FCD lesions in five of seven and seven of eight patients, respectively. SIGNIFICANCE: Daytime sleep MEG recordings are clinically feasible and significantly enhance the detection of seizures (37% of patients) and FOs compared to wakefulness. Sleep protocols enable noninvasive capture of ictal patterns-the gold standard for epileptogenic zone localization-alongside increased FO rates. These findings support incorporating sleep into standard MEG protocols for presurgical epilepsy evaluation.

Indexed as

Focal Cortical DysplasiaMagnetoencephalographySeizuresSleepAdolescentAdultDrug Resistant EpilepsyElectroencephalographyFemaleHumansMaleMiddle AgedProspective StudiesYoung Adultfocal cortical dysplasiafocal epilepsymagnetic source imagingseizuressleep

Identifiers

PMID41804684
PMCPMC13285261

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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.