Diagnostic Value of Developmental Atlases of Intracranial EEG Biomarkers for Localizing the Epileptogenic Zone
Abstract number :
3.289
Submission category :
3. Neurophysiology / 3G. Computational Analysis & Modeling of EEG
Year :
2024
Submission ID :
53
Source :
www.aesnet.org
Presentation date :
12/9/2024 12:00:00 AM
Published date :
Authors :
Presenting Author: Keisuke Hatano, MD/PhD – Wayne State University
Naoto Kuroda, MD – Wayne State University
Kazuki Sakakura, MD, PhD – Rush University
Hiroshi Uda, MD/PhD – Wayne State University
Michael Cools, MD – Children's Hospital of Michigan
Aimee F. Luat, MD – Central Michigan University
Eishi Asano, MD/PhD – Wayne State University
Rationale: Interictal high frequency oscillation (HFO) and modulation index (MI: a quantified measure of phase amplitude coupling between HFO and slow waves) are promising intracranial EEG biomarkers for localizing the epileptogenic zone. We hypothesized that excessive upward deviations from the normative range at a given age and cortical site would reflect increased epileptogenicity. Utilizing the developmental normative atlases of intracranial EEG biomarkers (Sakakura et al., Nature Communications 2023), we assessed whether statistical deviations of HFO rate and MI from the age- and anatomy-specific normative ranges could localize the epileptogenic zone more accurately than uncorrected values.
Methods: We studied 79 patients with drug-resistant epilepsy, aged between 4 and 41 years, who had a continuous ≥20-minute intracranial electroencephalography (iEEG) epoch during stage-2 or slow-wave sleep and achieved an ILAE class-1 outcome following focal resection. Electrode sites within the resection were defined as epileptogenic, and those outside as non-epileptogenic. The evaluated biomarkers included the HFO80-300 Hz rate, quantified with a Hilbert detector. We also evaluated MIf Hz, quantifying the coupling between HFOf Hz and the phase of slow waves at 3-4 Hz; thereby, f was either 80-300 or 150-300, and both MI80-300 Hz and MI150-300 Hz are considered to reflect the severity of interictal spike-and-wave discharges. We computed the z-score-normalized HFO and MI at each electrode site using the normative mean and standard deviation derived from the developmental normative atlas. We estimated the localization performance based on Cohen’s D effect size, reflecting the difference in biomarker values between epileptogenic and non-epileptogenic sites. We determined whether the z-score normalized biomarker values produced a higher Cohen’s D compared to uncorrected values using a paired t-test.
Results: Compared to uncorrected values, z-score normalized HFO80-300 Hz, MI80-300 Hz, and MI150-300 Hz produced higher Cohen’s D by 0.14, 0.15, and 0.13, with p-values of 0.026, 0.015, and 0.015, respectively.
Conclusions: Statistical deviations of HFO and MI from the age- and anatomy-specific normative ranges can localize the epileptogenic zone more accurately than uncorrected values. Our developmental normative atlases may improve the diagnostic value of HFO-related biomarkers in epilepsy presurgical evaluations.
Funding: JSPS JP22J23281 and JP22KJ0323 (N.K.), NIH NS064033 (E.A.).
Neurophysiology