Postconcussion symptom reporting is not associated with diffusion tensor imaging findings in the subacute to chronic phase of recovery in military service members following mild traumatic brain injury

ABSTRACT

Introduction: The purpose of this study was to examine the relation between white matter integrity of the brain and postconcussion symptom reporting following mild traumatic brain injury (MTBI).

Method: Participants were 109 U.S. military service members (91.7% male) who had sustained a MTBI (n = 88) or orthopedic injury without TBI (trauma controls, TC, n = 21), enrolled from the Walter Reed National Military Medical Center, Bethesda, Maryland. Participants completed a battery of neurobehavioral symptom measures and underwent diffusion tensor imaging (DTI; General Electric 3T) of the whole brain, on average 44.9 months post injury (SD = 42.3). Measures of fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were generated for 18 regions of interest (ROIs). Participants in the MTBI group were divided into two subgroups based on International Classification of Diseases–10th Revision (ICD–10) Category C criteria for postconcussion syndrome (PCS): PCS-present (n = 41) and PCS-absent (n = 47).

Results: The PCS-present group had significantly worse scores on all 13 neurobehavioral measures than the PCS-absent group (p < .001, d = 0.87–2.50) and TC group (p < .003, d = 0.84–2.06). For all ROIs, there were no significant main effects across the three groups for FA, MD, AD, and RD (all ps >.03). Pairwise comparisons revealed no significant differences for all ROIs when using FA and RD, and only two significant pairwise differences were found between PCS-present and PCS-absent groups when using MD and AD [i.e., anterior thalamic radiation and cingulate gyrus (supracallosal) bundle].

Conclusions: Consistent with past research, but not all studies, postconcussion symptom reporting was not associated with white matter integrity in the subacute to chronic phase of recovery following MTBI.

KEYWORDS:

• Military
• white matter integrity
• postconcussion symptoms
• traumatic brain injury

Acknowledgments

The authors would like to acknowledge the efforts of the larger team of Research Coordinators, Research Associates, Research Assistants, Program Managers, and senior management, who contribute to the success of the Defense and Veterans Brain Injury Center 15-Year Longitudinal TBI Study (Sec721 NDAA FY2007).

The views, opinions, and/or findings contained in this article are those of the authors and should not be construed as an official Department of Defense position, policy, or decision unless so designated by other official documentation.

Disclosure statement

No potential conflict of interest was reported by the authors.