A brain injury more than doubles the risk of dementia, according to new research.
A large study of older war veterans suggests those who experienced traumatic brain injury (TBI) during their lives had more than two times the risk of developing dementia, according to scientists from the University of California-San Francisco. The researchers presented their findings today at the Alzheimer's Association's annual International Conference in Paris.
"We're now getting a much better understanding that head injury is an important risk factor for developing dementia down the road," says lead researcher Kristine Yaffe, director of the Memory Disorders Program at the San Francisco VA Medical Center.
Yaffe and colleagues looked at medical records of nearly 300,000 veterans, all 55 or older. None had dementia at the study's start. About 2% had had a TBI. All had at least one inpatient or outpatient visit between 1997 and 2000 and a follow-up sometime between 2001 and 2007.
A diagnosis of a concussion, post-concussion syndrome, a skull fracture or some non-specific head injuries are considered TBIs, she says.
The risk of dementia was 15% in those with a TBI diagnosis, compared with almost 7% in those who had never had a TBI, Yaffe says.
Other studies have shown that TBI can increase the risk of dementia: It might hit earlier, and symptoms could worsen, says Douglas Smith, professor of neurosurgery and director of the Center for Brain Injury and Repair at the University of Pennsylvania in Philadelphia.
About 1.7 million people experience a TBI each year, mostly because of falls and car accidents. TBI also is referred to as the "signature wound" of the wars in Iraq and Afghanistan, where TBI accounts for 22% of casualties overall and 59% of blast-related injuries, Yaffe says.
Smith says that with so many soldiers returning from war affected by blasts, the relationship between TBI and dementia needs to be sorted out.
It's unknown at this point how many soldiers have a history of brain injury, he says. "I'm even worried for people psychologically. People worry a lot about, 'Am I going to get Alzheimer's disease?'"
Yaffe says more research is needed to explore whether early rehabilitation can help reduce the risk for dementia. "If you know you've had a head injury and you are approaching older age, one has to be carefully monitored and screened for cognitive dementia."
To see more of USAToday.com, or to subscribe, go to http://www.usatoday.com
Copyright 2011 USA TODAY, a division of Gannett Co. Inc.