By Medical Discovery News
March 17, 2012
A common story among soldiers coming home from Afghanistan is that outwardly they look fine. Yet soon, it’s apparent their memories aren’t as good as they used to be. They have headaches, can’t concentrate, and are irritable and often depressed. Soon, their symptoms put stress on their relationships and their lives begin to fall apart.
This is the picture of someone with traumatic brain injury or TBI, and it’s known as the signature injury of soldiers returning from Afghanistan and Iraq. But what’s even more troubling is that a new study shows these soldiers face over twice the risk of early on-set dementia and other diseases that attack the brain.
The study, led by Dr. Kristine Yaffe of the University of California San Francisco, analyzed the records of 281,540 veterans 55 or older. Of the vets who reported a TBI sometime between 1997 and 2000, 15 percent ended up with dementia seven years later. Compare that to just 6.8 percent of non-TBI vets who ended up with dementia.
The implications are enormous. According to the Pentagon, over 200,000 soldiers have suffered a brain injury over the past 10 years. Other sources put that number higher. In fact, consider the American public, of which 1.7 million suffer from some form of TBI each year.
Traumatic brain injury occurs when a sudden trauma causes damage to the brain. It happens when the head suddenly and violently hits an object, or when something pierces the skull and enters the brain. Soldiers are getting TBIs from roadside bombs and explosions, which account for 59 percent of injuries sustained in these attacks.
An increasing number of studies show head injuries are a risk factor for Alzheimer’s and other forms of dementia. For example, a single severe brain injury from a car accident or fall doubles the risk of Alzheimer’s. Within hours of the injury, a protein called amyloid-beta starts accumulating in the brain, creating a plaque characteristic of the disease. In autopsies of soldiers who suffered from their catastrophic brain injuries, one-third showed this build-up.
On the other hand, repeated, mild TBI leads to the build-up of a different protein called tau. This abnormal protein accumulates in nerve cells, clogging them up and eventually killing the cells. Over time, they destroy the brain’s ability to function normally, and this form of dementia is called chronic traumatic encephalopathy or CTE. Just recently, a star NFL football player who suffered from CTE committed suicide because of his symptoms.
In the latest study with vets, soldiers with TBI may be at risk for developing both types of dementia. Only in the past two years has the U.S. military become responsive to addressing and treating TBIs. Up until then, soldiers have shared stories of not being believed, and not getting the treatment they needed. Already, many with TBI are showing memory loss.
Yaffe’s study can spur scientists to investigate whether early treatment after a TBI can prevent the on-set of dementia in the future. They can also study why brain injuries prompt a build-up of damaging proteins. The study fills one other important purpose: creating more awareness of TBI so that returning soldiers don’t have to fight for the treatment they need.
Pamela K. Bond 