Summarized by Caleb Lee, BA
June 2026
Every year around 70 million people worldwide suffer from traumatic brain injuries (TBI). Common causes of TBI are due to car collisions, falls, sports injuries, or direct blows to the head among many other reasons. A new study published in Neurology, the journal from the American Academy of Neurology, suggests that there might be a bidirectional relationship between what happens before and after TBI. Research at the San Francisco VA Health Care system posed the question of whether certain brain conditions actually increase a person’s risk of suffering TBI in the first place. To further explore this question, they evaluated 14,000 older veterans, averaging around 78 years of age, who had recently suffered a TBI and compared them to 41,000 veterans without a TBI.
The findings were enlightening. Veterans who had a recent TBI were 3-4 times more likely to have already been diagnosed with stroke, dementia, epilepsy, or Parkinson’s disease in the year before their injury compared to veterans without TBI. For every 1,000 person-years that were evaluated, stroke occurred in 64 people with TBI vs just 20 without a TBI. Dementia showed similar patterns (58 vs 19) as did epilepsy (14 vs 4) and Parkinson’s (10 vs 3). These differences were consistent even with diabetes, smoking, and heart attack taken into consideration.
So why would having any of these conditions increase risk for TBI? The researchers point to a common culprit: falls. Conditions like stroke, dementia, epilepsy, and Parkinson’s disease often affect balance, coordination, gait, and thinking. These factors make patients more susceptible to falling and potential TBI in older adults. On the other hand, the study also found that after a TBI, people were twice as likely to go on to develop stroke or epilepsy, and 24% more likely to develop dementia compared to before their injury. Interestingly, the same wasn’t true for those with Parkinson’s disease. Researchers believe this could be simply because these patients were not tracked long enough to see any significant changes.
Altogether the takeaways that researchers gathered were that diagnoses of stroke, dementia, epilepsy, or Parkinson’s disease should be addressed with fall prevention strategies, not just the isolated diagnosis to manage on its own. The study’s lead author recommends screening older adults for fall risk right when they’re diagnosed with one of these conditions and refer them quickly to physical or occupational therapy. Simple steps like strength/balance training, removing tripping hazards, installing grab bars, and reviewing medications can all meaningfully reduce fall risk. It’s worth noting that the study only included military veterans so the results may not entirely reflect the general population. Still, the findings highlight that protecting the brain after neurological diagnosis may be just as important as treating the condition itself.
For more information: https://www.neurology.org/doi/10.1212/WNL.0000000000218214
