title: Disrupted Intrinsic Connectivity among Default, Dorsal Attention, and Frontoparietal Control Networks in Individuals with Chronic Traumatic Brain Injury.
abstract: OBJECTIVE
  Individuals with chronic traumatic brain injury (TBI) often show detrimental deficits in higher order cognitive functions requiring coordination of multiple brain networks. Although assessing TBI-related deficits in higher order cognition in the context of network dysfunction is promising, few studies have systematically investigated altered interactions among multiple networks in chronic TBI.
  
  
  METHODS
  We characterized disrupted resting-state functional connectivity of the default mode network (DMN), dorsal attention network (DAN), and frontoparietal control network (FPCN) whose interactions are required for internally and externally focused goal-directed cognition in chronic TBI. Specifically, we compared the network interactions of 40 chronic TBI individuals (8 years post-injury on average) with those of 17 healthy individuals matched for gender, age, and years of education.
  
  
  RESULTS
  The network-based statistic (NBS) on DMN-DAN-FPCN connectivity of these groups revealed statistically significant (p NBS2.58) reductions in within-DMN, within-FPCN, DMN-DAN, and DMN-FPCN connectivity of the TBI group over healthy controls. Importantly, such disruptions occurred prominently in between-network connectivity. Subsequent analyses further exhibited the disrupted connectivity patterns of the chronic TBI group occurring preferentially in long-range and inter-hemispheric connectivity of DMN-DAN-FPCN. Most importantly, graph-theoretic analysis demonstrated relative reductions in global, local and cost efficiency (p<.05) as a consequence of the network disruption patterns in the TBI group.
  
  
  CONCLUSIONS
  Our findings suggest that assessing multiple networks-of-interest simultaneously will allow us to better understand deficits in goal-directed cognition and other higher order cognitive phenomena in chronic TBI. Future research will be needed to better understand the behavioral consequences related to these network disruptions.
authors.affiliation: 1Center for BrainHealth,School of Behavioral and Brain Sciences,The University of Texas at Dallas,Dallas,Texas.
authors.forename: Kihwan
authors.identifier: http://orcid.org/0000-0002-4574-7306
authors.initials: K
authors.lastname: Han
authors.affiliation: 1Center for BrainHealth,School of Behavioral and Brain Sciences,The University of Texas at Dallas,Dallas,Texas.
authors.forename: Sandra B
authors.initials: SB
authors.lastname: Chapman
authors.affiliation: 1Center for BrainHealth,School of Behavioral and Brain Sciences,The University of Texas at Dallas,Dallas,Texas.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Krawczyk
mesh_terms: D000293:Adolescent; D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology; D000070642:Brain Injuries, Traumatic / Q000150:complications*; D001931:Brain Mapping; D002908:Chronic Disease; D005260:Female; D005625:Frontal Lobe / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008959:Models, Neurological; D009415:Nerve Net / Q000000981:diagnostic imaging / Q000473:pathology*; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000000981:diagnostic imaging / Q000473:pathology*; D011569:Psychiatric Status Rating Scales; D018709:Statistics, Nonparametric; D055815:Young Adult
keywords: Attention network; Default network; Fronto-parietal control network; Functional connectivity; Goal-directed cognition; Graph theory; TBI; fMRI