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Neuroradiology

, Volume 60, Issue 10, pp 1019–1033 | Cite as

White matter microstructural abnormalities in blast-exposed combat veterans: accounting for potential pre-injury factors using consanguineous controls

  • Andrew C. McClelland
  • Roman Fleysher
  • Weiya Mu
  • Namhee Kim
  • Michael L. Lipton
Diagnostic Neuroradiology

Abstract

Purpose

Assess the prevalence of white matter microstructural changes in combat veterans, within the context of a highly matched control group comprising unexposed close relatives.

Methods

This prospective study had institutional review board approval, included written informed consent, and is HIPAA-compliant. Diffusion tensor imaging was analyzed in 16 male blast-exposed combat veterans of Operation Iraqi Freedom/Operation Enduring Freedom (mean age 31.0 years) and 18 unexposed males (mean age 30.4 years) chosen on the basis of a consanguineous relationship to a member of the subject group. Whole-brain voxel-based comparison of fractional anisotropy (FA) was performed using both group and individual analyses. Areas where effects on FA were detected were subsequently characterized by extracting radial diffusivity (RD), axial diffusivity (AD), and mean diffusivity (MD) from the regions of abnormal FA.

Results

Controls did not differ from veterans on any background demographic factor. In voxel-based group comparison, we identify high fractional anisotropy (FA) in veterans compared to controls (p < 0.01). Within individual veterans, we find multiple areas of both abnormally high and low FA (p < 0.01) in a heterogeneous distribution, consistent with multifocal traumatic axonal injury. In individualized analyses, low FA areas demonstrate high radial diffusivity, whereas high FA areas demonstrate low RD in both group and individual analyses.

Conclusions

Combat-related blast exposure is associated with microstructural white matter abnormalities, and the nature of the control group decreases the likelihood that the findings reflect underlying background differences. Abnormalities are heterogeneously distributed across patients, consistent with TAI, and include areas of low and high FA.

Keywords

Mild traumatic brain injury (mTBI) Diffusion tensor imaging (DTI) Blast exposure 

Notes

Compliance with ethical standards

Funding

This study was funded by the Resurrecting Lives Foundation.

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from all individual participants included in the study.

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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.The Gruss Magnetic Resonance Research CenterAlbert Einstein College of Medicine and Montefiore Medical CenterBronxUSA
  2. 2.Department of RadiologyAlbert Einstein College of Medicine and Montefiore Medical CenterBronxUSA
  3. 3.Department of Psychiatry and Behavioral SciencesAlbert Einstein College of Medicine and Montefiore Medical CenterBronxUSA

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