Is balance performance reduced after mild traumatic brain injury?: Interim analysis from chronic effects of neurotrauma consortium (CENC) multi-centre study

Objectives: Determine if mild traumatic brain injury (mTBI) history is associated with balance disturbances. Setting: Chronic Effects of Neurotrauma Consortium (CENC) centres. Participants: The CENC multi-centre study enrols post-9/11 era Service Members and Veterans with combat exposure. This sample (n = 322) consisted of enrolees completing initial evaluation by September 2016 at the three sites conducting computerized dynamic post-urography (CDP) testing. Design: Observational study with cross-sectional analyses using structural equation modelling. Main Measures: Comprehensive structured interviews were used to diagnose all lifetime mild traumatic brain injuries (mTBIs). The outcome, Sensory Organization Test (SOT), was measured on CDP dual-plate force platform. Other studied variables were measured by structured interviews, record review and questionnaires. Results: The overall positive/negative mTBI classification did not have a significant effect on the composite equilibrium score. However, the repetitive mTBI classification showed lower scores for participants with ≥ 3 mTBI versus 1–2 lifetime mTBIs. For repetitive mTBI, pain interference acted as a mediator for the indirect effect, and a direct effect was evident on some sensory condition equilibrium scores. Conclusion: These findings show that repeated mTBI, partially mediated by pain, may lead to later balance disturbances among military combatants. Further study of CDP outcomes within this accruing cohort is warranted.