Long-Term Neurobehavioral Symptoms and Return to Productivity in Operation Enduring Freedom/Operation Iraqi Freedom Veterans With and Without Traumatic Brain Injury.

OBJECTIVE: To describe Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) veterans who underwent the Comprehensive Traumatic Brain Injury Evaluation (CTBIE), differences between the traumatic brain injury (TBI) and non-TBI subgroups, and factors associated with return to productivity (RTP). DESIGN: Retrospective medical record review. SETTING: Medical center. PARTICIPANTS: Medical records of OEF/OIF veterans (N=236) who underwent the CTBIE between 2009 and 2013. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Demographic characteristics, injury history, clinical presentation, and factors associated with RTP. RESULTS: Veteran sample included 90.7% men, was 45.3% white and 34.7% black, with half of Hispanic origin, and had a mean age of 33 years. The mean time since injury was approximately 4 years. Reported symptoms were high, with >90% reporting anxiousness, irritability, sleep difficulty, forgetfulness, and headaches. TBI diagnosis was found in 163 veterans (69%). The TBI subgroup was younger (TBI: 32.5y vs non-TBI: 34.9y; P=.02), reported a greater number of injuries (P<.001), and had significantly higher rates of half of the reported symptoms. Greatest differences were noted with forgetfulness (TBI: 95.7% vs non-TBI: 79.5%; P<.001), poor concentration (TBI: 90.2% vs non-TBI: 76.7%; P=.007), and headaches (TBI: 93.9% vs non-TBI: 83.6%; P=.014). RTP was 60.6% for the total veteran population. Factors associated with RTP were race (white) (odds ratio [OR], 2.00; 95% confidence interval [CI], 1.13-3.55; P=.018), sensitivity to light (OR, 2.58; 95% CI, 1.17-5.66; P=.018), and fatigue (OR, 3.68; 95% CI, 1.51-8.95; P=.004). Veterans that did RTP were 3 times less likely to report depression (OR, .32; 95% CI, .12-.85; P=.022). CONCLUSIONS: Veterans reported a substantial number of lingering symptoms, with a higher prevalence in veterans with TBI. Veterans with reported depression were less likely to RTP. Future research should focus on the relation between depression and non-RTP and the effectiveness of Department of Veterans Affairs services.

Blast Exposure, White Matter Integrity, and Cognitive Function in Iraq and Afghanistan Combat Veterans.

The long-term effects of blast exposure are a major health concern for combat veterans returning from the recent conflicts in Iraq and Afghanistan. We used an optimized diffusion tensor imaging tractography algorithm to assess white matter (WM) fractional anisotropy (FA) in blast-exposed Iraq and Afghanistan veterans (n = 40) scanned on average 3.7 years after deployment/trauma exposure. Veterans diagnosed with a blast-related mild traumatic brain injury (mTBI) were compared to combat veterans with blast exposure but no TBI diagnosis. Blast exposure was associated with decreased FA in several WM tracts. However, total blast exposure did not correlate well with neuropsychological testing performance and there were no differences in FA based on mTBI diagnosis. Yet, veterans with mTBI performed worse on every neurocognitive test administered. Multiple linear regression across all blast-exposed veterans using a six-factor prediction model indicated that the amount of blast exposure accounted for 11-15% of the variability in composite FA scores such that as blast exposure increased, FA decreased. Education accounted for 10% of the variability in composite FA scores and 25-32% of FA variability in the right cingulum, such that as level of education increased, FA increased. Total blast exposure, age, and education were significant predictors of FA in the left cingulum. We did not find any effect of post-traumatic stress disorder on cognition or composite FA. In summary, our findings suggest that greater total blast exposure is a contributing factor to poor WM integrity. While FA was not associated with neurocognitive performance, we hypothesize that FA changes in the cingulum in veterans with multiple combat exposures and no head trauma prior to deployment may represent a marker of vulnerability for future deficits. Future work needs to examine this longitudinally.