title: Complexity of Multi-Channel Electroencephalogram Signal Analysis in Childhood Absence Epilepsy.
abstract: Absence epilepsy is an important epileptic syndrome in children. Multiscale entropy (MSE), an entropy-based method to measure dynamic complexity at multiple temporal scales, is helpful to disclose the information of brain connectivity. This study investigated the complexity of electroencephalogram (EEG) signals using MSE in children with absence epilepsy. In this research, EEG signals from 19 channels of the entire brain in 21 children aged 5-12 years with absence epilepsy were analyzed. The EEG signals of pre-ictal (before seizure) and ictal states (during seizure) were analyzed by sample entropy (SamEn) and MSE methods. Variations of complexity index (CI), which was calculated from MSE, from the pre-ictal to the ictal states were also analyzed. The entropy values in the pre-ictal state were significantly higher than those in the ictal state. The MSE revealed more differences in analysis compared to the SamEn. The occurrence of absence seizures decreased the CI in all channels. Changes in CI were also significantly greater in the frontal and central parts of the brain, indicating fronto-central cortical involvement of "cortico-thalamo-cortical network" in the occurrence of generalized spike and wave discharges during absence seizures. Moreover, higher sampling frequency was more sensitive in detecting functional changes in the ictal state. There was significantly higher correlation in ictal states in the same patient in different seizures but there were great differences in CI among different patients, indicating that CI changes were consistent in different absence seizures in the same patient but not from patient to patient. This implies that the brain stays in a homogeneous activation state during the absence seizures. In conclusion, MSE analysis is better than SamEn analysis to analyze complexity of EEG, and CI can be used to investigate the functional brain changes during absence seizures.
authors.affiliation: Department of Life Science, National Taiwan University, Taipei, Taiwan; Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan; Department of Pediatrics, College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Pediatric Neurology, National Taiwan University Children's Hospital, Taipei, Taiwan.
authors.forename: Wen-Chin
authors.initials: WC
authors.lastname: Weng
authors.affiliation: Department of Mechanical Engineering, Yuan Ze University, Taoyuan, Chung-Li, Taiwan.
authors.forename: George J A
authors.initials: GJ
authors.lastname: Jiang
authors.affiliation: Department of Mechanical Engineering, Yuan Ze University, Taoyuan, Chung-Li, Taiwan.
authors.forename: Chi-Feng
authors.initials: CF
authors.lastname: Chang
authors.affiliation: Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Wen-Yu
authors.initials: WY
authors.lastname: Lu
authors.affiliation: Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Chun-Yen
authors.initials: CY
authors.lastname: Lin
authors.affiliation: Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan; Department of Pediatrics, College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Pediatric Neurology, National Taiwan University Children's Hospital, Taipei, Taiwan; Graduate Institute of Brain and Mind Sciences, National Taiwan University, Taipei, Taiwan.
authors.forename: Wang-Tso
authors.initials: WT
authors.lastname: Lee
authors.affiliation: Department of Mechanical Engineering, Yuan Ze University, Taoyuan, Chung-Li, Taiwan; Center for Dynamical Biomarkers and Translational Medicine, National Central University, Chung-Li, Taiwan; Innovation Center for Big Data and Digital Convergence, Yuan Ze University, Taoyuan, Chung-Li, Taiwan.
authors.forename: Jiann-Shing
authors.initials: JS
authors.lastname: Shieh
mesh_terms: D001921:Brain / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography / Q000379:methods*; D019277:Entropy; D004832:Epilepsy, Absence / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012640:Seizures / Q000175:diagnosis / Q000503:physiopathology; D012680:Sensitivity and Specificity; D013997:Time Factors