Open AccessHigh-Fidelity Measures of Whole-Brain Functional Connectivity and White Matter Integrity Mediate Relationships between Traumatic Brain Injury and Post-Traumatic Stress Disorder Symptoms
Author(s) -
Evan M. Gordon,
Randall S. Scheibel,
Laura Zambrano-Vazquez,
Meilin Jia-Richards,
Geoffrey May,
Éric Meyer,
Steven M. Nelson
Publication year - 2018
Publication title -
journal of neurotrauma
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.653
H-Index - 149
eISSN - 1557-9042
pISSN - 0897-7151
DOI - 10.1089/neu.2017.5428
Subject(s) - traumatic brain injury , fractional anisotropy , white matter , diffusion mri , resting state fmri , psychology , functional connectivity , neuroscience , traumatic stress , neuroimaging , brain activity and meditation , clinical psychology , medicine , psychiatry , magnetic resonance imaging , electroencephalography , radiology
Traumatic brain injury (TBI) disrupts brain communication and increases risk for post-traumatic stress disorder (PTSD). However, mechanisms by which TBI-related disruption of brain communication confers PTSD risk have not been successfully elucidated in humans. This may be in part because functional MRI (fMRI), the most common technique for measuring functional brain communication, is unreliable for characterizing individual patients. However, this unreliability can be overcome with sufficient within-individual data. Here, we examined whether relationships could be observed among TBI, structural and functional brain connectivity, and PTSD severity by collecting ∼3.5 hours of resting-state fMRI and diffusion tensor imaging (DTI) data in each of 26 United States military veterans. We observed that a TBI history was associated with decreased whole-brain resting-state functional connectivity (RSFC), while the number of lifetime TBIs was associated with reduced whole-brain fractional anisotropy (FA). Both RSFC and FA explained independent variance in PTSD severity, with RSFC mediating the TBI-PTSD relationship. Finally, we showed that large amounts of per-individual data produced highly reliable RSFC measures, and that relationships among TBI, RSFC/FA, and PTSD could not be observed with typical data quantities. These results demonstrate links among TBI, brain connectivity, and PTSD severity, and illustrate the need for precise characterization of individual patients using high-data fMRI scanning.