Echoes of the Battlefield: Five-Year Longitudinal Cognitive Trajectories Show Trend of Recovery for Deployment-Related Mild TBI in the LIMBIC-CENC Cohort.

OBJECTIVE

To evaluate the association between deployment-related mild traumatic brain injury (TBI) and longitudinal changes in cognitive performance in the Long-term Impact of Military-relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium (LIMBIC-CENC) Prospective Longitudinal Study (PLS) cohort.

DESIGN

Longitudinal observational study.

SETTING

United States Veteran Affairs and Department of Defense Medical Centers.

PARTICIPANTS

Active duty service members and Veterans who completed at least 3 annual Brief Test of Adult Cognition by Telephone (BTACT) assessments (N=1012).

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Both BTACT composite and individual test scores were evaluated as outcomes. Effect of deployment-related mild TBI on changes in cognitive function was evaluated using multilevel modeling. Probable PTSD diagnosis, time since PLS-derived index event, and demographic characteristics were evaluated as confounding factors.

RESULTS

Veterans with a history of deployment-related mild TBI consistently performed worse on the BTACT over the observation period than those without such history. In addition, participants with deployment TBI history demonstrated a slower rate of improvement in the domain of executive function.

CONCLUSIONS

The findings suggest that deployment-related mild TBI and PTSD are associated with cognitive performance over time. However, results more importantly demonstrate general improvement of cognitive function in individuals with PTSD or TBI history. This is encouraging and supports an overall trajectory of recovery, rather than brain health decline.