Higher cerebrospinal fluid tau is associated with history of traumatic brain injury and reduced processing speed in Vietnam-era veterans: A Department of Defense Alzheimer's Disease Neuroimaging Initiative (DOD-ADNI) study.

Introduction:  Our goal was to determine whether cognitive and cerebrospinal fluid (CSF) markers of tau and amyloid beta 1-42 (Aβ ₄₂ ) differ between Vietnam-era veterans with and without history of traumatic brain injury (TBI) and whether TBI moderates the association between CSF markers and neurocognitive functioning.
Methods:  A total of 102 male participants (52 TBI, 50 military controls [MCs]; mean age = 68) were included. Levels of CSF Aβ ₄₂ , tau phosphorylated at the threonine 181 position (p-tau), and total tau (t-tau) were quantified. Group differences in CSF markers and cognition as well as the moderating effect of TBI on CSF and cognition associations were explored.
Results:  Relative to MCs, the TBI group showed significantly higher p-tau ( P  = .01) and t-tau ( P  = .02), but no differences in amyloid ( P  = .09). TBI history moderated the association between CSF tau and performance on a measure of processing speed (t-tau:  P   = .04; p-tau:  P   = .02).
Discussion:  Tau accumulation may represent a mechanism of dementia risk in older veterans with remote TBI.
(© 2021 The Authors. Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring published by Wiley Periodicals, LLC on behalf of Alzheimer's Association.)