The Impact of Traumatic Brain Injury on Neuropsychological Functioning and Tau Accumulation Later in Life in Military Veterans

Abstract The following study examines aging veterans that experience a TBI while in service and compares to older veteran without a history of TBI. The objective is to look at cognitive profile later in life for military veterans with moderate to severe TBI different and compared to older veterans with no history of TBI. Is there a difference in tau accumulations on neuroimaging in military veterans with moderate to severe TBI compared to older veterans without a history of TBI? What is the relationship between the cognitive profile and tau imaging correlates for military veterans with moderate to severe TBI later in life? There were 39 participants in the TBI group and 65 participants in the non-TBI group that participated in neuropsychological testing. Out of the above participants 8 in the TBI group and 19 in the non-TBI group participated inPET 18F-AV1451 imaging to compare Braak regions. The Mann-Whitney U test was used for analysis of neuropsychological tests (Clock score, BNT, TMT-A, & TMT-B). T-test was used for analysis of neuropsychological test category fluency animals and one-way ANOVA was used for the analysis of Auditory Verbal Learning test. Additionally, Mann-Whitney U test was used for the analysis of PET imaging: BRAAK regions 1-2, 3-4, and 5-6. The results suggest no statistically significant differences between TBI and non-TBI groups in neuropsychological tests and Braak regions (all p’s \u3e .05). However, there was a trend noticed with TBI group having higher levels of tau in all Braak regions. Ultimately, this study showed that the TBI group and non-TBI did not differ in neuropsychological performance and tau accumulation in BRAAK regions