Disrupted Structural Connectome Is Associated with Both Psychometric and Real-World Neuropsychological Impairment in Diffuse Traumatic Brain Injury

Abstract

Traumatic brain injury (TBI) is likely to disrupt structural network properties due to diffuse white matter pathology. The present study aimed to detect alterations in structural network topology in TBI and relate them to cognitive and real-world behavioral impairment. Twenty-two people with moderate to severe TBI with mostly diffuse pathology and 18 demographically matched healthy controls were included in the final analysis. Graph theoretical network analysis was applied to diffusion tensor imaging (DTI) data to characterize structural connectivity in both groups. Neuropsychological functions were assessed by a battery of psychometric tests and the Frontal Systems Behavior Scale (FrSBe). Local connection-wise analysis demonstrated reduced structural connectivity in TBI arising from subcortical areas including thalamus, caudate, and hippocampus. Global network metrics revealed that shortest path length in participants with TBI was longer compared to controls, and that this reduced network efficiency was associated with worse performance in executive function and verbal learning. The shortest path length measure was also correlated with family-reported FrSBe scores. These findings support the notion that the diffuse form of neuropathology caused by TBI results in alterations in structural connectivity that contribute to cognitive and real-world behavioral impairment.

Impaired rich club and increased local connectivity in children with traumatic brain injury: Local support for the rich?

“…First, we found a reduced density and an increased normalized characteristic path length in TBI patients compared with healthy controls. This finding concurs with previous research reporting reduced density and/or increased path length in both children with TBI (Caeyenberghs et al, ; Konigs et al, 2017; Yuan, Treble‐Barna, Sohlberg, Harn, & Wade, ) and adults with TBI (Caeyenberghs et al, ; Kim et al, ) in the chronic stage of recovery. Furthermore, our findings suggest an increase in normalized clustering coefficient in children with TBI.…”

The structural connectome of children with traumatic brain injury

“…When compared to the TC group, children with moderate/severe TBI had higher characteristic path length indicative of decreased structural integration. The current findings converge with previous studies reporting increased path length in the connectivity probability network after moderate/severe TBI in adults [Caeyenberghs et al, 2012a, 2012b, 2014; Kim et al, ] and a pilot study in children with complicated to severe TBI [Yuan et al, ]. We further extend these findings by showing that longer characteristic path length is associated with poorer neurocognitive outcome of pediatric TBI in terms of intelligence and working memory.…”

Longitudinal increases in structural connectome segregation and functional connectome integration are associated with better recovery after mild TBI

“…The discrepancy between their findings and our results could be due to the difference in populations, that is, moderate to severe versus mTBI. Kim et al () showed no differences in transitivity and modularity between mTBI and controls, but showed longer SC characteristic path lengths were moderately correlated with worse performance on executive function and verbal learning tasks in the mTBI group. However, multiple comparisons corrections were not performed in this cross‐sectional, preliminary study.…”