Affiliations: [a] Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| [b] Department of Neurological Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA
| [c] School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA
| [d] Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
Correspondence:
[*]
Correspondence to: Christian LoBue, PhD, 5323 Harry Hines Blvd, Dallas, TX: 75208 8564, USA. Tel.: +1 214 648 4604; Fax: +1 214 648 4660; E-mail: [email protected].
Abstract: Traumatic brain injuries (TBI) have received widespread media attention in recent years as being a risk factor for the development of dementia and chronic traumatic encephalopathy (CTE). This has sparked fears about the potential long-term effects of TBI of any severity on cognitive aging, leading to a public health concern. This article reviews the evidence surrounding TBI as a risk factor for the later development of changes in brain structure and function, and an increased risk of neurodegenerative disorders. A number of studies have shown evidence of long-term brain changes and accumulation of pathological biomarkers (e.g., amyloid and tau proteins) related to a history of moderate-to-severe TBI, and research has also demonstrated that individuals with moderate-to-severe injuries have an increased risk of dementia. While milder injuries have been found to be associated with an increased risk for dementia in some recent studies, reports on long-term brain changes have been mixed and often are complicated by factors related to injury exposure (i.e., number of injuries) and severity/complications, psychiatric conditions, and opioid use disorder. CTE, although often described as a neurodegenerative disorder, remains a neuropathological condition that is poorly understood. Future research is needed to clarify the significance of CTE pathology and determine whether that can explain any clinical symptoms. Overall, it is clear that most individuals who sustain a TBI (particularly milder injuries) do not experience worse outcomes with aging, as the incidence for dementia is found to be less than 7% across the literature.
