New perspectives on amyloid-β dynamics after acute brain injury: Moving between experimental approaches and studies in the human brain

The links between traumatic brain injury and Alzheimer disease have been of great interest for many years. However, the importance of amyloid-β- related neurodegenerative pathophysiologic processes after traumatic brain injury is still unknown. In this review, we present a brief overview of the scientific evidence regarding traumatic brain injury as a contributor to Alzheimer disease and describe recent results showing significant changes in brain extracellular amyloid-β dynamics in patients with severe brain injury. We then discuss the clinical significance of these findings with their implications for translational neurobiology and conclude with further directions for traumatic brain injury and Alzheimer disease research.