Older adults who experience injurious falls are more likely to develop dementia within a year of their accident compared to people of the same age who have other kinds of physical injuries, according to a large new study.

The findings from a team of researchers in the US do not prove falls contribute to dementia (although this can't yet be ruled out either), but they do suggest that falls could be an early indicator of deteriorating brain conditions that lead to Alzheimer's disease and other dementias.

"It is possible that falls serve as a sentinel event that marks a future risk for dementia," explain physician Alexander Ordoobadi from Brigham and Women's Hospital and colleagues in their paper.

"This study's findings suggest support for the implementation of cognitive screening in older adults who experience an injurious fall."

Falls are the most common way adults over 65 are injured. Nearly one-third of this age group experiences injury from a fall each year.

'One of the biggest challenges we face is the lack of ownership in the process of follow-up screening for cognitive impairment," Ordoobadi says. "Because there may not be adequate time for these screenings in an emergency department or trauma center setting.

Each year, almost 10 million new cases of dementia are diagnosed, leaving more of us to confront frightening cognitive decline either personally or in our loved ones. Despite decades of effort, we're still without a cure, leaving patients only with strategies to stall the debilitating conditions' progression, so the earlier dementia can be identified, the better.

Ordoobadi and team analyzed a year's worth of US Medicare claims from those who had experienced a traumatic injury. They identified 2 453 655 patients over the age of 65 who sought medical assistance for an injury in 2014 or 2015.

After excluding people with known dementia diagnoses, the researchers then compared patients that had injured themselves in a fall with those who had experienced other types of physical injuries.

They found older adults who experience injury from a fall were over 20 percent more likely to develop dementia within a year of their accident, compared to the other sorts of physical injuries the patients attended a medical clinic for.

"The relationship between falls and dementia appears to be a two-way street," says injury epidemiologist Molly Jarman from Brigham and Women's Hospital.

"Cognitive decline can increase the likelihood of falls, but trauma from those falls may also accelerate dementia's progression and make a diagnosis more likely down the line."

This study can only determine if one factor follows the same pattern as another, so it can't tell if falls and dementia are directly related. Due to a lack of prescription data, the researchers could not account for medication effects, which may have skewed their results.

However, previous studies have found people with known cognitive impairments are at increased risk of experiencing falls, also supporting the idea that falls may be an early indicator of these devastating brain conditions.

Other potential earlier warning signs of the cognitive impairments that lead to dementia include loss of visual sensitivity, poor mental health, and increased nightmares.

But cognitive declines can be an indication of other treatable conditions too, so it is critical that potential dementia patients are thoroughly assessed.

"Our study highlights the opportunity to intervene early," says Jarman.

"If we can establish that falls serve as early indicators of dementia, we could identify other precursors and early events that we could intervene on, which would significantly improve our approach to managing cognitive health in older adults."

This research was published in JAMA.