Evidence map›Paper›PMID 41606732›Full record

ArticleBMC medicine2026

Harmonic patterns embedded in ictal EEG signals in focal epilepsy: new insight into the epileptogenic zone.

Lingli Hu, Lingqi Ye, Hongyi Ye, Xiaochen Liu, Kai Xiong, Yuanming Zhang, Zhe Zheng, Hongjie Jiang, Cong Chen, Chunhong Shen and 10 more

Abstract read
In one paragraph

Article in BMC medicine, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing 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

3 citing papers in PubMed.

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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

20 authors.

Lingli HuDepartment of Neurology and Epilepsy Center, School of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, 310009, China.
Lingqi YeDepartment of Neurology and Epilepsy Center, School of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, 310009, China.
Hongyi YeDepartment of Neurology and Epilepsy Center, School of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, 310009, China.
Xiaochen LiuCollege of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, China.
Kai XiongCollege of Computer Science and Technology, Zhejiang University, Hangzhou, China.
Yuanming ZhangCollege of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, China.
Zhe ZhengDepartment of Neurosurgery, School of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China.
Hongjie JiangDepartment of Neurosurgery, School of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, China.
Cong ChenDepartment of Neurology and Epilepsy Center, School of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, 310009, China.
Chunhong ShenDepartment of Neurology and Epilepsy Center, School of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, 310009, China.
Zhongjin WangDepartment of Neurology and Epilepsy Center, School of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, 310009, China.
Jiping ZhouDepartment of Neurology, Wayne State University/Detroit Medical Center, Detroit, MI, USA.
Yingcai WuCollege of Computer Science and Technology, Zhejiang University, Hangzhou, China.
Kejie HuangCollege of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, China.
Junming ZhuNanhu Brain-Computer Interface Institute, Hangzhou, China.
Zhong ChenKey Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China.
Meiping DingDepartment of Neurology and Epilepsy Center, School of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, 310009, China.
Shennan WeissDepartment of Neurology, Stony Brook University, Stony Brook, USA.
Dongping YangDepartment of Neurology and Epilepsy Center, School of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, 310009, China. dpyang@zhejianglab.com.
Shuang WangDepartment of Neurology and Epilepsy Center, School of Medicine, Second Affiliated Hospital, Zhejiang University, Hangzhou, 310009, China. wangs77@zju.edu.cn.

Funding

The National Natural Science Foundation of China 82171437The Natural Science Foundation of Zhejiang Province LD24H090003
6 · The paper itself

Abstract

backgroundLocalization of the epileptogenic zone (EZ) requires further refinement. We identified a unique ictal spectral structure, the "harmonic pattern" (H pattern), which potentially serves as a novel biomarker for localizing the EZ. This study aimed to analyze the clinical significance of the H pattern and to explore its underlying waveform features.

methodsSeventy patients with drug-resistant focal epilepsy, undergoing stereo-EEG (SEEG) evaluation and surgery, were included. Time-frequency maps (TFM) were generated using Morlet wavelet transform analysis. The H pattern was defined as multiple equidistant, high-density bands with varying frequencies on TFM. The upper quartile was employed to confirm contacts expressing dominant H pattern (dH pattern). Bispectral analysis and transfer function modeling were employed to assess nonlinear properties and signal propagation, respectively. The performance of the dH pattern in evaluating the EZ was compared with other ictal biomarkers.

resultsRegardless of seizure onset patterns, the H pattern commonly occurred during early or late seizure propagation among 57 patients (81.4%). It harbored within specific EEG segments characterized by fast activity and irregular polyspikes. The H pattern often appeared simultaneously across different brain regions at a consistent fundamental frequency, highlighting a crucial stage in seizure propagation characterized by inter-regional synchronization. The dH pattern demonstrated greater nonlinearity compared to the non-dH pattern, as evidenced by bispectral analysis. The waveforms associated with the dH pattern were more stereotyped and showed increased skewness and/or asymmetry. Notably, the complete removal of areas exhibiting the dH pattern, but not high epileptogenicity index (≥ 0.3) or seizure onset zone, was independently associated with seizure freedom after surgery.

conclusionsThe H pattern provides unique insights into ictal neural dynamics. Additionally, it is a novel and alternative approach for measuring the EZ over an extended ictal time window.

Indexed as

BrainDrug Resistant EpilepsyElectroencephalographyEpilepsies, PartialAdolescentAdultFemaleHumansMaleYoung AdultEpilepsy surgeryEpileptogenic zoneHarmonic patternIctal EEGNonlinear phenomena

Identifiers

PMID41606732
PMCPMC12924499

What Socratic holds

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LicenceCC BY
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Registered trials

None linked

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 Socratic graph.