Thursday, February 15, 2018 by Rhonda Johansson
A traumatic brain injury (TBI) increases the risk of a person developing dementia by 80 percent, even 15 to 30 years after the incident. In the largest study observing the connection between TBI and dementia risk, scientists from Umea University have concluded that victims of a traumatic brain injury should take special care in preserving their brain health. It is apparent that the effects of TBI are long-lasting and can manifest themselves decades after the initial injury, particularly in the development of dementia.
The Swedish researchers analyzed the data of nearly a million people via nationwide databases between 1964 to 2012. Three cohorts were studied: The first examined people who have had a TBI and who were then compared to an equal-sized control group; the second had patients diagnosed with dementia who were compared to a similar-sized control group; and the last looked at pairs of siblings, where one had received a TBI. Results invariably showed that suffering from a TBI increased a person’s risk of developing dementia.
The first year following a TBI is the most dangerous; the risk of developing dementia in the first year is six times that of a normal person. The risk does decline after that, but it still remains 25 percent higher even three decades after the blow to the head was received. The risk becomes higher the more severe the TBI and if several TBIs have been recorded. This holds true for both men and women.
Lead author of the study, Professor Peter Nordstrom said, “The findings of this study suggest an existence of a time and dose dependent risk of developing dementia more than 30 years after TBI. To our knowledge, no previous prospective study with similar power and follow-up has been reported.”
The results of this study, while conclusive, are not new. Previous research has stated that receiving a blow to the head dramatically increases the risk of developing neurological disorders, not least of which is dementia. (Related: The brain-gut connection: A new study finds that traumatic brain injury also causes intestinal damage.)
These conclusions have highlighted the potential dangers many contact sports have. Several athletes have been noted to have suffered quite dearly in terms of mental health due to the repeated abuse their heads had received over their professional career. The most talked about athlete is England’s striker Jeff Astle who died in 2002. Astle was only 59 years old at the time of his death but was reviewed to have the brain of a 90-year-old. Brain scans showed that Astle suffered from chronic traumatic encephalopathy (CTE) which is a progressive brain disease typically found in people who have a history of head injury. Months before Astle passed away, he was unable to recognize his own children and had difficulties performing everyday tasks.
More recently, 27-year old former New England Patriots player Aaron Hernandez killed himself in April 2017 while serving life in prison for murder. Hernandez’ autopsy revealed that the former athlete had a severe case of CTE. The disease is associated with TBI, dementia, and aggression. Doctors who worked on Hernandez’ case are unsure whether his career in football caused his CTE or if other factors came into play, especially in his crime. That said, doctors have stated that Hernandez’ CTE was the “worst” they’ve ever seen in such a young person and do speculate that his repeated head injuries may have played a role in the rapid decline of his mental health.
Controversies aside, those who have had a TBI should not panic. Receiving a head injury does not doom you to developing dementia. Doctors say that this new research should just emphasize the importance of regular screening and being particularly careful in noticing slight symptoms of a neurological disorder such as persistent forgetfulness and changes in mood, thoughts, and behavior.