2023 American Academy of Neurology Abstract Website

Shruti Durape¹, Prajakta Joshi², Rebecca Burton³, Kurtis Chien-Young¹, Eden Price³, Kristin Shanabrook⁴, Euky Yhang¹, Yulin Liu³, Ting Fang Alvin Ang², Sherral Devine³, Ashita Gurnani³, Douglas Katz¹, Yorghos Tripodis¹, Michael Alosco¹, Kristen Dams-O'Connor⁵, Rhoda Au², Jesse Mez¹
¹Department of Neurology, ²Department of Anatomy and Neurobiology, Boston University Chobanian & Avedisian School of Medicine, ³Framingham Heart Study, ⁴Boston University, ⁵Department of Rehabilitation Medicine & Department of Neurology, Mount Sinai Icahn School of Medicine

Objective:

To estimate the associations between traumatic brain injury (TBI), mild cognitive impairment (MCI), all-cause dementia, and Alzheimer’s disease (AD) dementia.

Background:

Research on the relationship between TBI, AD and AD related dementias is inconsistent.

Design/Methods:

The Framingham Heart Study (FHS) is a population-based cohort study which recruited its original cohort, ages 30-62, between 1948-1950. Information on TBIs was collected by self-report and comprehensive review of medical records obtained through FHS health history updates until death. TBI occurrence and severity were operationalized using modified American Congress of Rehabilitation Medicine and Veterans Affairs/Department of Defense criteria respectively. MCI, dementia, and AD dementia consensus diagnoses were operationalized using modified Peterson criteria, Diagnostic and Statistical Manual of Mental Disorders, 4^th edition, and National Institute of Neurological and Communicative Diseases and Stroke/AD and Related Disorders Association criteria respectively.

Results:

The study included 715 participants with TBI and 2145 age- and sex-matched participants without TBI who were cognitively normal at time of TBI and followed for an average of 16±17 years. 567 (26.43%), 461 (21.49%) and 373 (17.39%) participants without TBI developed MCI, all cause dementia and AD dementia respectively compared with 271 (37.9%), 218 (30.49%) and 131 (21.12%) of those with TBI. For mild TBI, hazard ratios (HRs) for MCI, all-cause dementia and AD dementia were 1.55 (95%CI 1.14–2.12), 1.47 (95%CI 1.02-2.14), and 1.06 (95%CI 0.68-1.66) respectively. For moderate-to-severe TBI, HRs for MCI, all cause dementia and AD dementia were 3.50 (95%CI 1.10-11.17), 4.61 (95%CI 0.96-22.14), and 6.36 (95%CI 0.72-56.50) respectively.

Conclusions:

In this cohort followed for more than a decade and comprehensively assessed for TBI and dementia-related outcomes, there were small to moderate sized associations of mild TBI and large associations of moderate-severe TBI with MCI and all-cause dementia. Association between mild TBI and dementia may be driven by non-AD etiologies.