Association of self-reported traumatic brain injury with risk factors and brain MRI markers in the Multi-Ethnic Study of Atherosclerosis

Background: This study sought to characterize patterns of traumatic brain injury (TBI) prevalence in a diverse community-based cohort of older adults, and to evaluate associations of TBI with five measures of interest on magnetic resonance imaging (MRI) of the brain. Methods and Results: In 2000-2002, the Multi-Ethnic Study of Atherosclerosis enrolled 6814 participants from four race/ethnic groups who were 45-84 years of age and free of clinical cardiovascular disease. In a follow-up examination in 2018-2019 at a mean age of 73 years, 989 participants completed a head injury questionnaire and underwent brain magnetic resonance imaging (MRI). A total of 8.3% reported a history of TBI, defined as a head injury with loss of consciousness or feeling dazed or confused, with higher prevalence for men than for women. TBI prevalence was highest among Hispanic participants (11.6%), and lowest among Chinese-American participants (4.0%). In multivariable models, compared with those with no self-reported head injury, no significant associations were found between TBI and any of five brain MRI measures we evaluated (total white matter volume, total gray matter volume, white matter hyperintensity volume, white matter fractional anisotropy, and presence of microbleeds) after adjusting for relevant demographic and cardiovascular risk factors. Conclusions: Patterns of TBI prevalence in this diverse cohort of older adults are similar to those previously reported for White, and Black Americans, though overall prevalence was somewhat lower. The prevalence of reported TBI in Chinese-American participants was low, at 4%. This study did not find evidence of associations between TBI history and the five brain MRI measures of interest.