Experiencing a traumatic brain injury (TBI) increases the chances of an older adult having cognitive decline, a new study shows.
The report was published in Alzheimer’s & Dementia on July 5. Researchers used diagnostic codes and self-reporting to define who had TBIs and how many injuries they had. The team performed cognitive testing on 11,701 people in the Atherosclerosis Risk in Communities (ARIC) Study during five visits over 30 years, putting scores into a combined cognition factor score. The average age of participants when the study began was 58 years.
During the 30-year follow-up period, 18% of participants experienced TBIs.
The adjusted average decline in cognition per decade was more than twice as fast in people with two or more TBIs, but not in people who only had one compared to those who didn’t have any brain injury.
The difference in cognitive decline was about the same as those with two or more TBIs being about 9.7 years older at the start of the study period, the authors noted.
“This study provides robust evidence that TBIs fundamentally alter the trajectories of cognitive decline,” the authors wrote.
“Overall, these findings support the designation of TBI as a potentially modifiable risk factor for dementia by providing robust evidence that TBI events fundamentally alter trajectories of cognitive decline,” the authors wrote. “Not only do our findings underscore the importance of interventions focused on the primary prevention of TBI, but they also suggest the importance of future research that investigates mechanisms underlying long-term cognitive decline to inform interventions aimed to address TBI-related neurodegeneration.”
Some previous research has found a link between TBI and cognitive decline; studies have found a higher risk of dementia in those with TBIs, the authors wrote. But some studies haven’t found associations between TBI and TBI severity with dementia and cognitive decline, the authors noted.
