Disruption in the functional integrity of large-scale neural networks following traumatic brain injury (TBI) has been well documented, in particular using static resting state functional magnetic resonance imaging (fMRI), which examines the temporal correlations between spatially remote brain regions. However, to date no work has investigated whether moderate-to-severe TBI disrupts the way functional connectivity changes over short periods of time (i.e., dynamic functional connectivity, dFC), and how different large-scale systems interact with each other. 
The aim of the current study was to use resting state fMRI to examine dFC in a moderate-to-severe TBI population, in order to add to our knowledge of how TBI disrupts brain functionality, and to uncover new possible biomarkers of cognitive dysfunction caused by TBI. We used a sliding window approach to examine resting state dFC in a sample of 32 individuals with moderate-severe TBI and 21 healthy comparison (HC) participants. In particular, we focused on seven brain networks: Visual, Somatomotor, Dorsal Attention, Ventral Attention, Limbic, Frontoparietal, and Default, and found that individuals with TBI displayed significantly lower dFC (i.e., fewer oscillations of functional connectivity between these brain networks and the rest of the brain) than HCs. Further inspection of the topographical data revealed that it was predominantly network hubs (i.e., regions that are habitually rich in connections, such as the precuneus, anterior insula, and dorsal anterior cingulate cortex) that were less dynamically connected to large-scale brain networks in TBI.
This work reveals that moderate-severe TBI disrupts the dynamic functional integrity of large-scale neural systems, and provides evidence that TBI is associated with abnormal patterns of fluctuating communication between brain networks that underlie different cognitive, affective, and behavioral functioning.

DYNAMIC RESTING STATE FUNCTIONAL CONNECTIVITY IN MODERATE-SEVERE TRAUMATIC BRAIN INJURY