Longitudinal evaluation of ventricular volume changes associated with mild traumatic brain injury in military service members

ABSTRACT

Primary objective: To investigate differences in longitudinal trajectories of ventricle-brain ratio (VBR), a general measure of brain atrophy, between Veterans with and without history of mild traumatic brain injury (mTBI).

Research design: Structural magnetic resonance imaging (MRI) was used to calculate VBR in 70 Veterans with a history of mTBI and 34 Veterans without such history at two time points approximately 3 and 8 years after a combat deployment.

Main outcomes and results: Both groups demonstrated a quadratic relationship between VBR and age that is consistent with normal developmental trajectories. Veterans with history of mTBI had larger total brain volume, but no interaction between mTBI and age was observed for brain volume, ventricular volume, or VBR.

Conclusions: In our longitudinal sample of deployed Veterans, mTBI was not associated with gross brain atrophy as reflected by abnormally high VBR or abnormal increases in VBR over time.

KEYWORDS:

• Concussion
• mild brain injury
• military
• neurodegeneration
• MRI

Acknowledgments

The authors would like to thank the participants for generously sharing their time and experiences with us. We would also like to acknowledge the efforts of Lisa Keacher, Ellie Decker, Erin Begnel, Jamie Kiefer, and Cassie Fleming in collecting consistently high quality data, and of Doug Theriaque and Gene Turner in data management.

Declaration of Interest

This work was supported by grant funding from Department of Veterans Affairs (I01RX002171, IK2RX000709, I01RX000622, I01CX001135) and Department of Defense (W81XWH-13-2-0095, W81XWH-08-2-0038) and was conducted as part of the Chronic Effects of Neurotrauma Consortium (CENC). The authors report no conflicts of interest. The views, opinions, and/or findings contained in this manuscript are those of the authors and should not be construed as an official Veterans Affairs or Department of Defense position, policy or decision, unless so designated by other official documentation.