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

ABSTRACT:

Background

Localization 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.

Methods

Seventy 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 analys

SUBMITTER: Hu L 

PROVIDER: S-EPMC12924499 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature