A new study of 55,204 older veterans reveals a dangerous two-way relationship between traumatic brain injury (TBI) and common neurological conditions. Having a TBI increases your risk of developing stroke, dementia, epilepsy, or Parkinson's disease — but the reverse is also true: being diagnosed with one of these conditions makes you three to four times more likely to suffer a TBI within the next year.
The Research
The study, published on June 17, 2026, in Neurology, was led by Carrie Peltz, PhD, of San Francisco Veterans Affairs Health Care System. The team analyzed health records from 13,801 veterans (average age 78) who had a recent TBI and compared them with 41,403 age-matched veterans who had not. They tracked diagnoses of stroke, dementia, epilepsy, and Parkinson's disease one year before and one year after the TBI (or an equivalent time period for controls).
Results were striking. In the year before the TBI, rates of new neurological diagnoses were dramatically higher among those who later had a TBI. For stroke: 64 cases per 1,000 person-years in the TBI group versus 20 in controls. Dementia: 58 versus 19. Epilepsy: 14 versus 4. Parkinson's: 10 versus 3. After adjusting for factors like diabetes, smoking, and heart attack history, people who had a TBI were four times more likely to have been recently diagnosed with epilepsy and three times more likely to have been diagnosed with stroke, dementia, or Parkinson's disease.
The effect also went the other way: experiencing a TBI doubled the risk of later stroke and epilepsy and increased dementia risk by 24%. This creates a feedback loop where neurological impairment leads to falls, causing TBI, which then accelerates further neurological decline.
Why It Matters
These findings have immediate practical implications. As Dr. Peltz explains, “Neurological diseases often impair motor control, balance, gait, coordination and thinking skills — all of which make people more likely to fall, which is the main cause of TBI in older adults.” The study identifies a critical window: right after someone is diagnosed with a neurological condition, preventive steps could break the loop.
For anyone concerned about brain health — especially older adults or those caring for aging relatives — this research underscores that preventing falls isn't just about avoiding injury; it's about protecting future cognitive function. A TBI doesn't just damage the brain in the moment; it can set the stage for more serious neurological disease down the road.
What You Can Do
- If you or a loved one is diagnosed with a neurological condition (stroke, dementia, epilepsy, Parkinson's), ask your doctor about fall prevention strategies, including physical therapy and occupational therapy.
- Remove tripping hazards in the home (loose rugs, clutter, poor lighting) and consider grab bars in bathrooms.
- Maintain strength and balance through regular exercise like walking, tai chi, or yoga.
Source: Neuroscience News
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