title: Neuromagnetic coherence of epileptic activity: an MEG study.
abstract: OBJECTIVE
  This study was undertaken to test the hypothesis that patients with epilepsy have abnormal imaginary coherence compared with control subjects.
  
  
  METHODS
  Thirty patients with seizures underwent magnetoencephalography (MEG) recording using a whole cortex MEG system. Conventional equivalent current dipoles (ECDs) and synthetic aperture magnetometry (SAM) were used to analyze MEG data. Neural synchronization was studied using imaginary coherence to analyze resting-state MEG data. The ECDs, SAM, and MEG results were then compared with intra/extra-operative EEG.
  
  
  RESULTS
  Abnormal imaginary coherence was identified in all patients (30/30, 100%). The locations of abnormal imaginary coherence were in agreement with the ECDs locations of spikes in 23 patients (23/30, 76.7%). The ECD locations in 5 patients were scattered or located bilaterally. The locations of abnormal imaginary coherence were in agreement with SAM locations in 26 patients (26/30, 86.7%). One case of imaginary coherence was located in two lobes. The ECDs fit locations were in agreement with SAM locations in 21 patients (21/30, 70.0%). The locations of abnormal imaginary coherence, ECDs, and SAM were in agreement with intra/extra-operative EEG in 23 patients (23/30, 76.7%), 17 patients (17/30, 56.7%), and 20 patients (20/30, 66.7%), respectively. The results of ECDs location, SAM location, imaginary coherence, and intracranial EEG (iEEG) were consistent in 15 patients (15/30, 50%).
  
  
  CONCLUSIONS
  The results show that patients with epilepsy have abnormal imaginary coherence, and suggest that the location and coherence of epileptic activity could be quantitatively identified and analyzed using neuromagnetic signals.
authors.affiliation: Key Laboratory for NeuroInformation of the Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China; Department of Magnetoencephalography, Nanjing Brain Hospital, Affiliated to Nanjing Medical University, Nanjing 210029, China. Electronic address: lvwu123@163.com.
authors.forename: Ting
authors.initials: T
authors.lastname: Wu
authors.affiliation: Key Laboratory of Child Development and Learning Science, Ministry of Education, Southeast University, Nanjing 210096, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Ge
authors.affiliation: Department of Magnetoencephalography, Nanjing Brain Hospital, Affiliated to Nanjing Medical University, Nanjing 210029, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Department of Magnetoencephalography, Nanjing Brain Hospital, Affiliated to Nanjing Medical University, Nanjing 210029, China.
authors.forename: Hongyi
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Magnetoencephalography, Nanjing Brain Hospital, Affiliated to Nanjing Medical University, Nanjing 210029, China.
authors.forename: Qiqi
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Key Laboratory for NeuroInformation of the Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China.
authors.forename: Ruirui
authors.initials: R
authors.lastname: Zhao
authors.affiliation: Key Laboratory for NeuroInformation of the Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yin
authors.affiliation: Key Laboratory for NeuroInformation of the Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China.
authors.forename: Xiuxiu
authors.initials: X
authors.lastname: Lv
authors.affiliation: Key Laboratory for NeuroInformation of the Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China.
authors.forename: Tianzi
authors.initials: T
authors.lastname: Jiang
mesh_terms: D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000503:physiopathology*; D002648:Child; D004569:Electroencephalography; D004827:Epilepsy / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D060306:Magnetometry; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000503:physiopathology; D012146:Rest; D012640:Seizures / Q000503:physiopathology; D055815:Young Adult
keywords: Coherence; Epilepsy; Functional connectivity; Magnetoencephalography; Resting state