title: Altered Effective Connectivity among Core Neurocognitive Networks in Idiopathic Generalized Epilepsy: An fMRI Evidence.
abstract: Idiopathic generalized epilepsy (IGE) patients with generalized tonic-clonic seizures (GTCS) suffer long-term cognitive impairments, and present a higher incidence of psychosocial and psychiatric disturbances than healthy people. It is possible that the cognitive dysfunctions and higher psychopathological risk in IGE-GTCS derive from disturbed causal relationship among core neurocognitive brain networks. To test this hypothesis, we examined the effective connectivity across the salience network (SN), default mode network (DMN), and central executive network (CEN) using resting-state functional magnetic resonance imaging (fMRI) data collected from 27 IGE-GTCS patients and 29 healthy controls. In the study, a combination framework of time domain and frequency domain multivariate Granger causality analysis was firstly proposed, and proved to be valid and accurate by simulation experiments. Using this method, we then observed significant differences in the effective connectivity graphs between the patient and control groups. Specifically, between-group statistical analysis revealed that relative to the healthy controls, the patients established significantly enhanced Granger causal influence from the dorsolateral prefrontal cortex to the dorsal anterior cingulate cortex, which is coherent both in the time and frequency domains analyses. Meanwhile, time domain analysis also revealed decreased Granger causal influence from the right fronto-insular cortex to the posterior cingulate cortex in the patients. These findings may provide new evidence for functional brain organization disruption underlying cognitive dysfunctions and psychopathological risk in IGE-GTCS.
authors.affiliation: Department of Automatic Control, College of Mechatronics and Automation, National University of Defense Technology Changsha, China.
authors.forename: Huilin
authors.initials: H
authors.lastname: Wei
authors.affiliation: Department of Medical Imaging, The First Affiliated Hospital of Guangzhou University of Chinese Medicine Guangzhou, China.
authors.forename: Jie
authors.initials: J
authors.lastname: An
authors.affiliation: Department of Automatic Control, College of Mechatronics and Automation, National University of Defense Technology Changsha, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Shen
authors.affiliation: Department of Automatic Control, College of Mechatronics and Automation, National University of Defense Technology Changsha, China.
authors.forename: Ling-Li
authors.initials: LL
authors.lastname: Zeng
authors.affiliation: Department of Medical Imaging, The First Affiliated Hospital of Guangzhou University of Chinese Medicine Guangzhou, China.
authors.forename: Shijun
authors.initials: S
authors.lastname: Qiu
authors.affiliation: Department of Automatic Control, College of Mechatronics and Automation, National University of Defense Technology Changsha, China.
authors.forename: Dewen
authors.initials: D
authors.lastname: Hu
keywords: core neurocognitive networks; effective connectivity; idiopathic generalized epilepsy; multivariate Granger causality; resting-state fMRI