Concussions Cause Greater Cognitive Declines in Later Life
DURHAM, N.C. – A study in twins found that even a single traumatic brain injury at any age was associated with worse cognitive function in later life, independent of genes and environmental factors.
The study, led by Duke Health researchers, provides further evidence that traumatic brain injuries (TBIs) such as concussions can lead to a faster rate of cognitive decline later in life, particularly if the injury occurs after the age of 24, or results in a loss of consciousness. The findings appear online Sept. 6 in the journal Neurology.
“Understanding how a traumatic brain injury affects cognitive decline later in life could lead to earlier interventions that could potentially delay or prevent the onset of dementia,” said lead author Marianne Chanti-Ketterl, Ph.D., assistant professor in the Duke’s Department of Psychiatry & Behavioral Sciences.
Chanti-Ketterl and colleagues analyzed data from a cache of 8,662 white male twins who served during World War II; the registry of twin veterans formed the basis of a long-running Duke Twins Study.
Between 1990-2002, the Duke Twins Study conducted telephone screenings of the participants for cognitive status every three to four years, providing 12 years of follow-up that included a cognitive score measuring function over time.
TBI data included the history of occurrence of a brain injury severe enough to require medical attention or cause a black-out; the presence and duration of the loss of consciousness; the number of TBIs; and the person’s age when the injury occurred.
Among the study participants, 25% reported having had a TBI.
In the current analysis, the researchers found that a twin who had any history of a TBI or suffered a concussion registered lower cognitive status than his non-concussed brother at age 70.
The cognitive declines were especially steeper and occurred faster in twins with more than one concussion, a TBI after the age of 24, and/or whose TBI resulted in a black-out.
Chanti-Ketterl said the findings in twins provide unique insights because they inherently rule out genetic risk factors or many early life exposures that confound non-related study participants. The researchers further controlled for alcohol overuse, smoking, and additional factors that could account for cognitive differences within twin pairs.
“This study highlights the importance of treating concussions and TBIs appropriately when they occur,” Chanti-Ketterl said. “Our knowledge and understanding of these injuries has greatly increased. This study demonstrates the importance of treatments for head injuries and the need to minimize or prevent these injuries.”
In addition to Chanti-Ketterl, study authors include Carl F. Pieper, Kristine Yaffe, and Brenda L. Plassman.
The study received funding support from the National Institutes of Health (AG08549, AG071916, P30AG028716), and the Department of Defense (W81XWH-18-1-0692).