GFAP and dementia: Lastly, because participants with dementia were excluded from this study, it is unknown whether our findings will generalize to this important geriatric TBI sub-population who may comprise 11–24% of older adults presenting to trauma centres with acute TBI.19,41 One of the prior studies of S100b elevations in geriatric TBI mentioned above identified significantly higher acute elevations in S100b among older adults presenting with mTBI who had dementia versus those without dementia.19 The relationship between age, dementia, TBI, and blood-based GFAP may prove particularly complex.