Classifying epileptic phase-amplitude coupling in SEEG using complex-valued convolutional neural network

EEG phase-amplitude coupling (PAC), the amplitude of high-frequency oscillations modulated by the phase of low-frequency oscillations (LFOs), is a useful biomarker to localize epileptogenic tissue. It is commonly represented in a comodulogram of coupling strength but without coupled phase informatio...

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Main Authors: Chunsheng Li, Shiyue Liu, Zeyu Wang, Guanqian Yuan
Format: Article
Language:English
Published: Frontiers Media S.A. 2023-01-01
Series:Frontiers in Physiology
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fphys.2022.1085530/full
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author Chunsheng Li
Shiyue Liu
Zeyu Wang
Zeyu Wang
Guanqian Yuan
author_facet Chunsheng Li
Shiyue Liu
Zeyu Wang
Zeyu Wang
Guanqian Yuan
author_sort Chunsheng Li
collection DOAJ
description EEG phase-amplitude coupling (PAC), the amplitude of high-frequency oscillations modulated by the phase of low-frequency oscillations (LFOs), is a useful biomarker to localize epileptogenic tissue. It is commonly represented in a comodulogram of coupling strength but without coupled phase information. The phase-amplitude coupling is also found in the normal brain, and it is difficult to discriminate pathological phase-amplitude couplings from normal ones. This study proposes a novel approach based on complex-valued phase-amplitude coupling (CV-PAC) for classifying epileptic phase-amplitude coupling. The CV-PAC combines both the coupling strengths and the coupled phases of low-frequency oscillations. The complex-valued convolutional neural network (CV-CNN) is then used to classify epileptic CV-PAC. Stereo-electroencephalography (SEEG) recordings from nine intractable epilepsy patients were analyzed. The leave-one-out cross-validation is performed, and the area-under-curve (AUC) value is used as the indicator of the performance of different measures. Our result shows that the area-under-curve value is .92 for classifying epileptic CV-PAC using CV-CNN. The area-under-curve value decreases to .89, .80, and .88 while using traditional convolutional neural networks, support vector machine, and random forest, respectively. The phases of delta (1–4 Hz) and alpha (8–10 Hz) bands are different between epileptic and normal CV-PAC. The phase information of CV-PAC is important for improving classification performance. The proposed approach of CV-PAC/CV-CNN promises to identify more accurate epileptic brain activities for potential surgical intervention.
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spelling doaj.art-a14fd09fb1194a8eb98c55eaa065ba302023-01-05T09:13:16ZengFrontiers Media S.A.Frontiers in Physiology1664-042X2023-01-011310.3389/fphys.2022.10855301085530Classifying epileptic phase-amplitude coupling in SEEG using complex-valued convolutional neural networkChunsheng Li0Shiyue Liu1Zeyu Wang2Zeyu Wang3Guanqian Yuan4Department of Biomedical Engineering, School of Electrical Engineering, Shenyang University of Technology, Shenyang, ChinaDepartment of Biomedical Engineering, School of Electrical Engineering, Shenyang University of Technology, Shenyang, ChinaDepartment of Biomedical Engineering, School of Electrical Engineering, Shenyang University of Technology, Shenyang, ChinaDepartment of Electrical Engineering and Information Systems, University of Pannonia, Veszprem, HungaryDepartment of Neurosurgery, General Hospital of Northern Theater Command, Shenyang, ChinaEEG phase-amplitude coupling (PAC), the amplitude of high-frequency oscillations modulated by the phase of low-frequency oscillations (LFOs), is a useful biomarker to localize epileptogenic tissue. It is commonly represented in a comodulogram of coupling strength but without coupled phase information. The phase-amplitude coupling is also found in the normal brain, and it is difficult to discriminate pathological phase-amplitude couplings from normal ones. This study proposes a novel approach based on complex-valued phase-amplitude coupling (CV-PAC) for classifying epileptic phase-amplitude coupling. The CV-PAC combines both the coupling strengths and the coupled phases of low-frequency oscillations. The complex-valued convolutional neural network (CV-CNN) is then used to classify epileptic CV-PAC. Stereo-electroencephalography (SEEG) recordings from nine intractable epilepsy patients were analyzed. The leave-one-out cross-validation is performed, and the area-under-curve (AUC) value is used as the indicator of the performance of different measures. Our result shows that the area-under-curve value is .92 for classifying epileptic CV-PAC using CV-CNN. The area-under-curve value decreases to .89, .80, and .88 while using traditional convolutional neural networks, support vector machine, and random forest, respectively. The phases of delta (1–4 Hz) and alpha (8–10 Hz) bands are different between epileptic and normal CV-PAC. The phase information of CV-PAC is important for improving classification performance. The proposed approach of CV-PAC/CV-CNN promises to identify more accurate epileptic brain activities for potential surgical intervention.https://www.frontiersin.org/articles/10.3389/fphys.2022.1085530/fullepilepsySEEGcomplex-valued phase-amplitude couplingcomplex-valued convolutional neural networkepileptogenic zone
spellingShingle Chunsheng Li
Shiyue Liu
Zeyu Wang
Zeyu Wang
Guanqian Yuan
Classifying epileptic phase-amplitude coupling in SEEG using complex-valued convolutional neural network
Frontiers in Physiology
epilepsy
SEEG
complex-valued phase-amplitude coupling
complex-valued convolutional neural network
epileptogenic zone
title Classifying epileptic phase-amplitude coupling in SEEG using complex-valued convolutional neural network
title_full Classifying epileptic phase-amplitude coupling in SEEG using complex-valued convolutional neural network
title_fullStr Classifying epileptic phase-amplitude coupling in SEEG using complex-valued convolutional neural network
title_full_unstemmed Classifying epileptic phase-amplitude coupling in SEEG using complex-valued convolutional neural network
title_short Classifying epileptic phase-amplitude coupling in SEEG using complex-valued convolutional neural network
title_sort classifying epileptic phase amplitude coupling in seeg using complex valued convolutional neural network
topic epilepsy
SEEG
complex-valued phase-amplitude coupling
complex-valued convolutional neural network
epileptogenic zone
url https://www.frontiersin.org/articles/10.3389/fphys.2022.1085530/full
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AT zeyuwang classifyingepilepticphaseamplitudecouplinginseegusingcomplexvaluedconvolutionalneuralnetwork
AT zeyuwang classifyingepilepticphaseamplitudecouplinginseegusingcomplexvaluedconvolutionalneuralnetwork
AT guanqianyuan classifyingepilepticphaseamplitudecouplinginseegusingcomplexvaluedconvolutionalneuralnetwork