Cognitive deficits four decades after traumatic brain injury in Australian Vietnam war veterans

Objective: Since 2000, over 350,000 US military personnel have been diagnosed with a traumatic brain injury (TBI) (VA, 2010). Whilst epidemiological studies report up to a fourfold increased risk for dementia associated with brain injury amongst veterans there is limited controlled research into the long-term neuropsychological burden of injury.
Main aim: The study aimed to determine whether Australian Vietnam war veterans with service-related TBI were more likely to exhibit cognitive deficits, 30-50 years after injury when compared to healthy veteran controls.
Materials and methods: 69 male veterans 60-85 years old, underwent psychiatric and neuropsychological assessment; 40 with a TBI (mean age = 68.0 ± 2.5) and 29 without (mean age = 70.1 ± 5.3). The TBI cohort included 15 mild, 16 moderate and nine severe TBI.
Results: After adjustment for identified covariates, veterans with moderate-to-severe TBI performed significantly worse than controls on composite measures of memory and learning (M = -0.55 ± 0.69, t(67) = 2.86, p=0.006, d=0.70) and attention and processing speed (M = -0.71 ± 1.08, t(52) = 2.53, p=0.014, d=0.69). There were no differences in cognitive performance between veterans with mild TBI (mTBI) and controls.
Conclusion: Results from this study suggest that amongst ageing veterans, a moderate-to-severe TBI sustained during early adulthood is associated with later-life cognitive deficits in memory and learning, attention and processing speed.