What do we know about the risks of developing dementia after traumatic brain injury?

Abstract

Traumatic brain injury (TBI) is considered to be a risk factor for the later development of dementia, but although the evidence dates back to the early 20 th century, the nature of any association and its mechanistic pathways remain unclear. There has been greater focus on this subject over recent years, in part because of increasing reports around sports-related TBIs, especially in the US. Differences in research methods and clinical sampling remain the primary reason for the variable findings, although there is clearly increased prevalence of neurodegenerative disorders in general. Duration of follow up, definition of both TBI and dementia, and differences in the extent to which other dementia risk factors are controlled, as well as concerns about medical record accuracy are all issues yet to be resolved in TBI research, Running title: Traumatic brain injuries and dementias 2 as is an absence pathological evidence. In addition, TBI has been reported to initiate a cascade of pathological processes related to several neurodegenerative disorders, and as such, it is likely that the risks vary between individuals. Given the evidence that dementia risk may increase with injury severity and frequency, a detailed account of age and type of injury, as well as lifetime TBI exposure is essential to document in future studies, and further longitudinal research with biomarker assessments are needed.

Traumatic Brain Injury and Secondary Neurodegenerative Disease

“…Secondary neurodegeneration can manifest in many ways depending on specific etiology and affected neuroanatomy. Chronic traumatic encephalopathy (CTE) is a well-known disease closely associated with repeated traumatic brain injuries (TBI) [ 1 , 2 ]. Parkinson’s disease (PD), frontotemporal dementia (FTD), and other neurodegenerative diseases are less common but can also be induced as a consequence of TBI [ 3 – 5 ].…”