Pain and chronic mild traumatic brain injury in the US military population: a Chronic Effects of Neurotrauma Consortium study

ABSTRACT

Primary objectives: To describe the association between mild traumatic brain injury (mTBI) and pain intensity and pain interference outcomes while accounting for potential confounders and mediators including environmental factors and comorbidities in a cohort of US Veterans of the Iraq and Afghanistan wars.

Research design:Cross-sectional snapshot of baseline data from a prospective, longitudinal study.

Methods: Effects of mTBI on pain intensity and pain interference were compared between participants with or without mTBI exposure. Data were analysed using covariate-adjusted regression analyses as well as structural equation modelling (SEM) methods to assess the robustness of findings across different modelling assumptions. As results of the two approaches were consistent with respect to the overall association between mTBI exposure and pain, the results focus primarily on the SEM findings.

Results: The mTBI exposed group reported significantly greater indices of post-traumatic stress disorder (PTSD), depression, anxiety and sleep disturbance. After accounting for other factors, mTBI exposure was significantly, but indirectly associated with the pain interference and pain intensity outcomes.

Conclusions: mTBI is strongly associated with pain intensity and pain interference in this sample. However, the effect appears to be mediated by other common mTBI comorbidities: PTSD, depression, anxiety and sleep disturbance.

KEYWORDS:

• Anxiety
• concussion
• depression
• post-traumatic stress disorder
• sleep disturbance
• structural equation modelling

Acknowledgements

The CENC Observational Study Group members include Study leadership: William C. Walker MD (CENC Observational Study Chairman), David X. Cifu MD (consortium PI); Site PIs or co-PIs: Heather G. Belanger PhD (Tampa), Randall Scheibel PhD (Houston), Blessen C. Eapen MD (San Antonio), Carlos Jaramillo MD (San Antonio), Ajit Pai MD (Richmond), Melissa Geurra MD (Fort Belvoir), Terri Pogoda PhD (Boston), Scott Sponheim PhD (Minneapolis) and Kathleen Carlson PhD (Portland). We also acknowledge the efforts of the entire CENC Observational Study Leadership Working Group and Core Team members who also include Justin Alicea, Jessica Berumen, Cody Blankenship, Jennifer Boyce, Linda Brunson, Katrina Burson, William Carne, Julia Christensen, Margaret Clarke, Sureyya Dikmen, Esra Doud, Connie Duncan, Stephanie Edmunds, Robyn Endsley, Elizabeth Fogleman, Cheryl Ford-Smith, Laura M. Franke, George Gitchel, Katelyn Gormley, Brenda Hair, Jim Henry, Sidney R. Hinds (consortium co-PI), Shawn Hirsch, Nancy Hsu, Caitlin Jones, Kimbra Kenney, Sunchai Khemalaap, Valerie Larson, Henry Lew, Tiffany Lewis, Scott McDonald, Tamara McKenzie-Hartman, Frank Mierzwa, Alison Molitor, Joe Montanari, Johnnie Mortenson, Lauren Nagusuki, Nicholas Pastorek, Judy Pulliam, Risa Richardson, Callie Riggs, Rachel Rosenfield, Sara Salkind, Robert Shin, James K. Sickinger, Taylor Swankie, Nancy Temkin, Doug Theriaque, Maya Troyanskaya, Rodney Vanderploeg, Carmen Vasquez and Rick Williams (consortium Co-PI).

This material is based upon work supported with resources and the use of facilities at: Hunter Holmes McGuire Veterans Affairs Medical Center (VAMC) in Richmond, VA; James A. Haley Veterans Hospital (VH), Tampa, FL; Audie L. Murphy Memorial VH, San Antonio, TX and Michael E. DeBakey VA Medical Center, Houston, TX and is based upon work supported in part by the Defense and Veterans Brain Injury Center, US Army Medical Research and Material Command (USAMRMC).

Declaration of interest

This work was supported by grant funding from: Department of Defense, CENC Award W81XWH-13-2-0095 and Department of Veterans Affairs CENC Award I01 CX001135. The authors report no conflicts of interest. Any opinions, findings, conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the US Government, Department of Defense or the US Department of Veterans Affairs, and no official endorsement should be inferred.

Additional information

Funding

This work was supported by the US Department of Defense [W81XWH-13-2-0095];US Department of Veterans Affairs [I01 CX001135].