How Traumatic Brain Injury History Relates to Brain Health MRI Markers and Dementia Risk: Findings from the 3C Dijon Cohort

J Alzheimers Dis. 2023;92(1):183-193. doi: 10.3233/JAD-220658.


Background: The long-term effects of traumatic brain injury (TBI) with loss of consciousness (LOC) on magnetic resonance imaging (MRI) markers of brain health and on dementia risk are still debated.

Objective: To investigate the associations of history of TBI with LOC with incident dementia and neuroimaging markers of brain structure and small vessel disease lesions.

Methods: The analytical sample consisted in 4,144 participants aged 65 and older who were dementia-free at baseline from the Three City -Dijon study. History of TBI with LOC was self-reported at baseline. Clinical Dementia was assessed every two to three years, up to 12 years of follow-up. A subsample of 1,675 participants <80 years old underwent a brain MRI at baseline. We investigated the associations between history of TBI with LOC and 1) incident all cause and Alzheimer's disease (AD) dementia using illness-death models, and 2) neuroimaging markers at baseline.

Results: At baseline, 8.3% of the participants reported a history of TBI with LOC. In fully-adjusted models, participants with a history of TBI with LOC had no statistically significant differences in dementia risk (HR = 0.90, 95% CI = 0.60-1.36) or AD risk (HR = 1.03, 95% CI = 0.69-1.52), compared to participants without TBI history. History of TBI with LOC was associated with lower white matter volume (β= -4.58, p = 0.048), but not with other brain volumes, white matter hyperintensities volume, nor covert brain infarct.

Conclusion: This study did not find evidence of an association between history of TBI with LOC and dementia or AD dementia risks over 12-year follow-up, brain atrophy, or markers of small vessel disease.

Keywords: Alzheimer’s disease; brain MRI; dementia; traumatic brain injury.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged, 80 and over
  • Alzheimer Disease* / pathology
  • Brain / pathology
  • Brain Injuries, Traumatic* / complications
  • Humans
  • Magnetic Resonance Imaging
  • Unconsciousness / complications