Shared and distinct global signal topography disturbances in subcortical and cortical networks in human epilepsy

• Main Authors: Chen, H. (Author), Li, R. (Author), Liao, W. (Author), Lu, G. (Author), Wang, H. (Author), Wang, L. (Author), Wang, X. (Author), Zhang, L. (Author), Zhang, Z. (Author), Zou, T. (Author)
• Format: Article
• Language: English
• Published: John Wiley and Sons Inc 2021
• Subjects: adolescent; Adolescent; adult; Adult; Article; beta rhythm; brain cortex; cerebellum; Cerebellum; Cerebral Cortex; cerebrospinal fluid; controlled study; diagnostic imaging; disease duration; electroencephalography; Electroencephalography; epilepsy; Epilepsy; epileptic patient; female; Female; fluctuations; frontal cortex; functional magnetic resonance imaging; generalized epilepsy; generalized tonic clonic seizure; global signal; global signal topography; gray matter; head movement; human; Humans; idiopathic generalized epilepsy; Magnetic Resonance Imaging; major clinical study; male; Male; medial frontal cortex; mesencephalon; Mesencephalon; middle temporal gyrus; nerve cell network; Nerve Net; nervous system parameters; nuclear magnetic resonance imaging; orbital cortex; parahippocampal gyrus; pathophysiology; pons; prefrontal cortex; priority journal; procedures; resting-state fMRI; sensorimotor network; subcortical–cortical network; superior temporal gyrus; tegmentum; temporal lobe epilepsy; tonic clonic seizure; visual cortex; white matter; young adult; Young Adult
• Online Access: View Fulltext in Publisher

 Epilepsy is a common brain network disorder associated with disrupted large-scale excitatory and inhibitory neural interactions. Recent resting-state fMRI evidence indicates that global signal (GS) fluctuations that have commonly been ignored are linked to neural activity. However, the mechanisms underlying the altered global pattern of fMRI spontaneous fluctuations in epilepsy remain unclear. Here, we quantified GS topography using beta weights obtained from a multiple regression model in a large group of epilepsy with different subtypes (98 focal temporal epilepsy; 116 generalized epilepsy) and healthy population (n = 151). We revealed that the nonuniformly distributed GS topography across association and sensory areas in healthy controls was significantly shifted in patients. Particularly, such shifts of GS topography disturbances were more widespread and bilaterally distributed in the midbrain, cerebellum, visual cortex, and medial and orbital cortex in generalized epilepsy, whereas in focal temporal epilepsy, these networks spread beyond the temporal areas but mainly remain lateralized. Moreover, we found that these abnormal GS topography patterns were likely to evolve over the course of a longer epilepsy disease. Our study demonstrates that epileptic processes can potentially affect global excitation/inhibition balance and shift the normal GS topological distribution. These progressive topographical GS disturbances in subcortical–cortical networks may underlie pathophysiological mechanisms of global fluctuations in human epilepsy. © 2020 The Authors. Human Brain Mapping published by Wiley Periodicals LLC.