Citation

Ewing-Cobbs L, DeMaster DM, Watson CG, Prasad MR, Cox CS, Kramer LA, Fischer JT, Duque GA, Swank PR. J. Neurotrauma 2019; 36(11): 1738-1751.

Affiliation

UT Health Sciences Center Houston, Developmental Pediatrics, Houston, Texas, United States ; paul_r_swank@yahoo.com.

Copyright

(Copyright © 2019, Mary Ann Liebert Publishers)

DOI

10.1089/neu.2018.6071

PMID

30672379

Abstract

Prefrontal-limbic circuitry is vulnerable to effects of stress and injury. We examined microstructure of prefrontal-limbic circuitry following traumatic brain (TBI) or extracranial injury (EI) and its relation to post-traumatic stress symptoms (PTSS). Participants aged 8 to 15 who sustained mild to severe TBI (n=53) or EI (n=26) in motor vehicle incidents were compared to healthy children (n=38) in a prospective longitudinal study. At the 7-week follow-up, diffusion tensor imaging was obtained in all groups; injured children completed PTSS ratings using a validated scale. Using probabilistic diffusion tensor tractography, pathways were seeded from bilateral amygdalae and hippocampi to estimate the trajectory of white matter connecting them to each other and to targeted prefrontal cortical (PFC) regions. Microstructure was estimated using fractional anisotropy (FA) in white matter and mean diffusivity (MD) in gray matter. Prefrontal-limbic microstructure was similar across groups, except for reduced FA in the right hippocampus to orbital PFC pathway in the injured versus healthy group. We examined microstructure of components of prefrontal-limbic circuitry with concurrently obtained PTSS cluster scores in the injured children. Neither microstructure nor PTSS scores differed significantly in the TBI and EI groups. Across PTSS factors, specific symptom clusters were positively related to higher FA and MD. Higher hyperarousal, avoidance, and re-experiencing symptoms were associated with higher FA in amygdala to prefrontal and hippocampus to amygdala pathways. Higher hippocampal MD had a central role in hyperarousal and emotional numbing symptoms. Age moderated the relation of white and gray matter microstructure with hyperarousal scores. Our findings are consistent with models of traumatic stress that implicate disrupted top-down PFC and hippocampal moderation of overreactive subcortical threat arousal systems. Alterations in limbic-prefrontal circuitry and PTSS place children with either brain or bodily injuries at elevated risk for both current and future psychological health problems.

Language: en

Keywords

Diffusion Tensor Imaging; OUTCOME MEASURES; PEDIATRIC BRAIN INJURY