Karon Law Blog

Study Finds Sustaining a Concussion Increases Risk of Dementia

By Jonathan A. Karon

A study published on April 10th in the journal The Lancet Psychiatry concluded that sustaining even a mild traumatic brain injury increases the risk of developing dementia later in life. The study, entitled “Long-term risk of dementia among people with traumatic brain injury in Denmark: a population based cohort study” followed a group of over 2.7 million people for an average of almost ten years. The researchers used detailed data from Denmark’s national registries.

Their analysis concluded that sustaining a concussion increases the risk of dementia by 17%. Traumatic brain injuries classified as “severe” increased the risk of dementia by 35%. Professor Jesse Fann, of the University of Washington, who was the lead author of the study, quoted in the UK Telegraph, stated, “Individuals with a history of traumatic brain injury, including those with less severe injuries have an increased risk of developing dementia, even decades after the injury.”

Other important findings included that the younger a person was when they sustained a traumatic brain injury the higher their risk of developing dementia and that the risk of dementia also increased with the number of traumatic brain injuries sustained.

These results are consistent with the findings of Boston University researchers published last fall (“Age of first exposure to American football and long-term neuropsychiatric and cognitive outcomes” published on September 19, 2017 in the journal Translational Psychiatry) indicating that playing tackle football before age 12 may substantially increase the risk of developing significant cognitive problems. They also suggest that we may need to revise our thinking about the consequences of sustaining a concussion or mild traumatic brain injury. For years, it’s been widely accepted that approximately 15% of persons with a mild traumatic brain injury (MTBI) will continue to experience significant symptoms more than a year after their injury. The implication is usually that the remaining 85% will make a full recovery. Not only has recent research (See my prior blog post of April 22, 2017 “Persistent Post-Concussion Syndrome May Be More Widespread Than Previously Thought” http://www.karonlaw.net/blog?id=390 ) suggested that the 15% figure grossly underestimates the percentage of persons suffering long term effects from an MTBI, but this study indicates that persons sustaining an MTBI must also deal with the increased risk of dementia.

Accordingly, these findings raise important questions for further study regarding the safety of contact sports and prevention of increased risk of dementia. It also suggests that full compensation for negligently caused traumatic brain injuries should include having to live with a significantly increased risk of dementia.