Concussions and traumatic brain injuries (TBI) have long been recognized as significant health concerns, particularly for athletes and military personnel. However, a groundbreaking study published in the September 6, 2023, online issue of Neurology®, the medical journal of the American Academy of Neurology, has shed new light on the enduring consequences of concussions, especially when experienced early in life.
This comprehensive study, conducted by Marianne Chanti-Ketterl, PhD, MSPH, of Duke University in Durham, North Carolina, has revealed that individuals who sustain concussions during their youth may face lower cognitive scores on thinking and memory tests even decades later, as well as a more rapid decline in cognitive function compared to their counterparts who never experienced a concussion.
The study delved into the lives of 8,662 World War II veterans, offering a unique perspective into the long-term consequences of concussions in a population known for their shared experiences and similarities. The research not only highlights the lingering cognitive impact of concussions but also underscores the importance of early interventions for those at risk.
The Impact of Concussions on Cognitive Function
The participants, with an average age of 67 at the study’s commencement, were assessed using a test of thinking skills. This test evaluated various cognitive domains and assigned scores ranging from zero to 50, with a baseline average score of 32.5 points among all participants. Remarkably, a quarter of the veterans had experienced a concussion during their lifetime, setting the stage for an in-depth exploration of the long-term consequences.
- Lower Test Scores at Age 70: Twins who had experienced a concussion, especially those who lost consciousness during the incident or were older than 24 at the time of the injury, were more likely to exhibit lower test scores at age 70. This suggests that the cognitive impact of concussions can persist for decades.
- Accelerated Cognitive Decline: Twins with a history of traumatic brain injury with loss of consciousness, multiple traumatic brain injuries, or injuries occurring after the age of 24 exhibited a more rapid cognitive decline than their uninjured counterparts. For instance, a twin who suffered a traumatic brain injury after age 24 scored 0.59 points lower on the cognitive test at age 70 compared to their uninjured twin. Moreover, their cognitive skills declined faster, at a rate of 0.05 points per year.
- Consideration of Other Factors: The study accounted for various factors that could influence cognitive function, such as high blood pressure, alcohol use, smoking status, and education, thus strengthening the association between concussions and cognitive decline.
Implications and Future Considerations
While the effect sizes observed in this study may be considered modest, the cumulative impact of traumatic brain injuries on late-life cognition cannot be underestimated. The findings suggest that even individuals who appear to have fully recovered from concussions may still be at risk of cognitive problems and an increased susceptibility to dementia in their later years.
Dr. Chanti-Ketterl underscores the significance of these findings, especially in light of the growing trend of emergency room visits due to sports or recreational injuries and the substantial number of military personnel who have experienced TBIs. Early interventions may offer a promising avenue to slow cognitive decline or potentially delay or prevent dementia in those at risk.
Limitations of the Study
It is important to acknowledge the limitations of this study. Traumatic brain injuries were self-reported by the participants, which may introduce recall bias and result in underreporting of injuries. Additionally, not all injuries may have been accurately remembered or reported, which could influence the study’s findings.
Funding and Acknowledgments
The study was made possible through the support of the National Institute on Aging and the U.S. Department of Defense, highlighting the collaborative effort to uncover the long-term consequences of concussions and traumatic brain injuries.
In conclusion, the study conducted by Dr. Marianne Chanti-Ketterl and her team at Duke University underscores the lasting impact of concussions on cognitive function, even in individuals who seem to have recovered fully.
The findings emphasize the importance of recognizing the potential for cognitive problems and dementia in those with a history of traumatic brain injuries, particularly in light of the rising prevalence of such injuries in recent years. Early interventions and support may offer hope in mitigating the cognitive decline associated with concussions and TBIs, improving the quality of life for those affected by these injuries.