A new study involving twins finds that the twin who has experienced concussions or traumatic brain injuries (TBIs) early in life showed a more rapid decline in cognition, memory and thinking in later years than the twin sibling.
“These findings indicate that even people with traumatic brain injuries in earlier life who appear to have fully recovered from them may still be at increased risk of cognitive problems and dementia later in life,” Marianne Chanti-Ketterl, author of the study and a medical instructor at the Division of Behavioral Medicine & Neurosciences at Duke University, USA, says in a statement.
The study was published on September 6 in the journal Neurology, the medical journal of the American Academy of Neurology.
An early trauma
When there is any kind of hit or injury to the head, it can cause damage to the brain depending on the force of the impact, potentially leading to TBIs.
Read more: Understanding traumatic brain injuries
This study supports several previous studies that examined how people who had TBIs earlier in their lives were more prone to Alzheimer’s disease and dementia later in life. These previous studies fell short in not tracking the TBI-affected individuals over a long period. They were unable to assess how TBI-related damage leads to cognitive decline.
The current study fills this gap. The researchers examined data of twins from the National Academy of Science – National Research Centre Twin Registry of male WW II veterans. They assessed around 7,188 individuals who were part of twin pairs, of which approximately 25 per cent % had a history of a TBI after turning 24 years of age.
The researchers then assessed the cognitive status of these twins over telephonic interviews. In the interviews, they did a modified version of the mini-mental state examination test, which helps identify cognitive impairment in older adults.
Post-injury monitoring is essential
They looked at various cognition-related aspects, such as attention, language, memory, orientation, the ability to recall words in a specific order and visuospatial awareness. They did these interviews once every three to four years, with the participants completing up to four sessions of cognitive screening.
“Among identical twins, who share the same genes and many of the same exposures early in life, we found that the twin who had a concussion had lower test scores and faster [memory] decline than [the other] twin who had never had a concussion,” according to Dr Chanti-Ketterl.
The researchers saw that twins with TBI had cognitive test scores 0.56 points lower at age 70 and declined 0.02 points more per year than twins without TBI. This study highlights the need to monitor people with TBI continuously.
“With the trend we are seeing [of] increased emergency room visits due to sports, recreation activity injuries and sustained military injuries, the potential long-term impact of TBI cannot be overlooked,” Dr Chati-Ketterl says.
She hopes that understanding the lifelong result of concussions or a traumatic brain injury on cognitive decline can help in giving the person early intervention, with the aim of delaying or preventing the onset of dementia.
Read more: Study finds Alzheimer’s risk from frequent exposure to blasts
