Examining Microstructural White Matter in Active Duty Soldiers with a History of Mild Traumatic Brain Injury and Traumatic Stress
Michael N. Dretsch1, *, Rael T. Lange2, Jeffery S. Katz3, 4, 5, Adam Goodman3, Thomas A. Daniel3, Gopikrishna Deshpande3, 4, 5, Thomas S. Denney3, 4, 5, Grant L. Iverson6, Jennifer L. Robinson3, 4, 5
Identifiers and Pagination:Year: 2017
First Page: 46
Last Page: 57
Publisher Id: TONIJ-11-46
Article History:Received Date: 15/06/2017
Revision Received Date: 20/06/2017
Acceptance Date: 10/08/2017
Collection year: 06/09/2017
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
There is a high comorbidity of posttraumatic stress (PTS) and mild traumatic brain injury (mTBI), with largely overlapping symptomatology, in military service members.
To examine white matter integrity associated with PTS and mTBI as assessed using diffusion tensor imaging (DTI).
Seventy-four active-duty U.S. soldiers with PTS (n = 16) and PTS with co-morbid history of mTBI (PTS/mTBI; n = 28) were compared to a military control group (n = 30). Participants received a battery of neurocognitive and clinical symptom measures. The number of abnormal DTI values was determined (>2 SDs from the mean of the control group) for fractional anisotropy (FA) and mean diffusivity (MD), and then compared between groups. In addition, mean DTI values from white matter tracts falling into three categories were compared between groups: (i) projection tracts: superior, middle, and inferior cerebellar peduncles, pontine crossing tract, and corticospinal tract; (ii) association tracts: superior longitudinal fasciculus; and (iii) commissure tracts: cingulum bundle (cingulum-cingulate gyrus and cingulum-hippocampus), and corpus callosum.
The comorbid PTS/mTBI group had significantly greater traumatic stress, depression, anxiety, and post-concussive symptoms, and they performed worse on neurocognitive testing than those with PTS alone and controls. The groups differed greatly on several clinical variables, but contrary to what we hypothesized, they did not differ greatly on primary and exploratory analytic approaches of hetero-spatial whole brain DTI analyses.
The findings suggest that psychological health conditions rather than pathoanatomical changes may be contributing to symptom presentation in this population.