 This study will evaluate the diagnostic accuracy of two blood-based biomarkers, glylfibrillar acidic protein, GFAP and ubiquitin-carboxyterminal hydrolase L1-UCH-L1 in elderly patients with mild traumatic brain injury, MTBI. The study will also determine reference values for these biomarkers in a non-TBI elderly population. This article was authored by Vincent Sapin, Jean-François Payin and others.