title: Multi-frequency analysis of brain connectivity networks in migraineurs: a magnetoencephalography study.
abstract: BACKGROUND
  Although alterations in resting-state neural network have been previously reported in migraine using functional MRI, whether this atypical neural network is frequency dependent remains unknown. The aim of this study was to investigate the alterations of the functional connectivity of neural network and their frequency specificity in migraineurs as compared with healthy controls by using magnetoencephalography (MEG) and concepts from graph theory.
  
  
  METHODS
  Twenty-three episodic migraine patients with and without aura, during the interictal period, and 23 age- and gender-matched healthy controls at resting state with eye-closed were studied with MEG. Functional connectivity of neural network from low (0.1-1 Hz) to high (80-250 Hz) frequency ranges was analyzed with topographic patterns and quantified with graph theory.
  
  
  RESULTS
  The topographic patterns of neural network showed that the migraineurs had significantly increased functional connectivity in the slow wave (0.1-1 Hz) band in the frontal area as compared with controls. Compared with the migraineurs without aura (MwoA), the migraineurs with aura (MwA) had significantly increased functional connectivity in the theta (4-8 Hz) band in the occipital area. Graph theory analysis revealed that the migraineurs had significantly increased connection strength in the slow wave (0.1-1 Hz) band, increased path length in the theta (4-8 Hz) and ripple (80-250 Hz) bands, and increased clustering coefficient in the slow wave (0.1-1 Hz) and theta (4-8 Hz) bands. The clinical characteristics had no significant correlation with interictal MEG parameters.
  
  
  CONCLUSIONS
  Results indicate that functional connectivity of neural network in migraine is significantly impaired in both low- and high-frequency ranges. The alteration of neural network may imply that migraine is associated with functional brain reorganization.
authors.affiliation: Department of Neurology, Nanjing Brain Hospital, Nanjing Medical University, 264 Guangzhou Road, Nanjing, Jiangsu, 210029, China.
authors.forename: Di
authors.initials: D
authors.lastname: Wu
authors.affiliation: Department of Neurology, Nanjing Brain Hospital, Nanjing Medical University, 264 Guangzhou Road, Nanjing, Jiangsu, 210029, China.
authors.forename: Yuchen
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: MEG Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH, 45220, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Xiang
authors.affiliation: Department of Neurology, Nanjing Brain Hospital, Nanjing Medical University, 264 Guangzhou Road, Nanjing, Jiangsu, 210029, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Tang
authors.affiliation: Department of Neurology, Nanjing Brain Hospital, Nanjing Medical University, 264 Guangzhou Road, Nanjing, Jiangsu, 210029, China.
authors.forename: Hongxing
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Neurology, Nanjing Brain Hospital, Nanjing Medical University, 264 Guangzhou Road, Nanjing, Jiangsu, 210029, China.
authors.forename: Shuyang
authors.initials: S
authors.lastname: Huang
authors.affiliation: MEG Center, Nanjing Brain Hospital, Nanjing, Jiangsu, 210029, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Wu
authors.affiliation: MEG Center, Nanjing Brain Hospital, Nanjing, Jiangsu, 210029, China.
authors.forename: Qiqi
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Neurology, Nanjing Brain Hospital, Nanjing Medical University, 264 Guangzhou Road, Nanjing, Jiangsu, 210029, China. lidou2005@126.com.
authors.forename: Xiaoshan
authors.initials: X
authors.lastname: Wang
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D008881:Migraine Disorders / Q000503:physiopathology*; D009415:Nerve Net / Q000503:physiopathology*; D055815:Young Adult
keywords: Functional connectivity; Graph theory; Magnetoencephalography (MEG); Migraine; Multi-frequency; Neural network