title: Localization of epileptogenic zone based on graph analysis of stereo-EEG.
abstract: Localization of the epileptogenic zone (EZ) is essential for the successful surgical treatment of medically intractable epilepsy. In the present study, stereo-EEG (SEEG) recordings were obtained from seven patients underwent presurgical evaluation for treatment of intractable epilepsy. Partial directed coherence (PDC) analysis was applied to construct peri-ictal effective connectivity networks. The graphic measures, in-degree, out-degree and betweenness centrality, were evaluated to localize the EZ. A receiver operating characteristic (ROC) analysis was used to quantify the localization accuracy. We found that the in-degree coincided well with the EZ identified by epileptologists' visual inspection in all seven patients who had a significant improvement in seizure outcomes, however, the other two measures were effective only in some cases. Furthermore, in all seven patients the electrode contact with the highest in-degree was always located within the EZ identified by epileptologists' visual inspection. These results indicate that the graph theory is an effective method to localize the EZ when suitable graphic measures were chosen. Furthermore, the in-degree was the most effective measure among the three graphic measures in localizing the EZ when the PDC method was used.
authors.affiliation: School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: qsylj@126.com.
authors.forename: Yong-Hua
authors.initials: YH
authors.lastname: Li
authors.affiliation: Department of Functional Neurosurgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200001, China. Electronic address: xiao-lai.ye@hotmail.com.
authors.forename: Xiao-Lai
authors.initials: XL
authors.lastname: Ye
authors.affiliation: Department of Functional Neurosurgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200001, China. Electronic address: windsto@163.com.
authors.forename: Qiang-Qiang
authors.initials: QQ
authors.lastname: Liu
authors.affiliation: School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: junw.mao@gmail.com.
authors.forename: Jun-Wei
authors.initials: JW
authors.lastname: Mao
authors.affiliation: School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: pjliang@sjtu.edu.cn.
authors.forename: Pei-Ji
authors.initials: PJ
authors.lastname: Liang
authors.affiliation: Department of Functional Neurosurgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200001, China. Electronic address: xjw88@vip.163.com.
authors.forename: Ji-Wen
authors.initials: JW
authors.lastname: Xu
authors.affiliation: School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: pmzhang@sjtu.edu.cn.
authors.forename: Pu-Ming
authors.initials: PM
authors.lastname: Zhang
mesh_terms: D000328:Adult; D019540:Area Under Curve; D001931:Brain Mapping; D000069279:Drug Resistant Epilepsy / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D000069280:Electrocorticography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011300:Preoperative Care; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012815:Signal Processing, Computer-Assisted; D016896:Treatment Outcome; D055815:Young Adult
keywords: Epileptogenic zone; Focal epilepsy; Graph theory; Partial directed coherence; Stereo-EEG