Military personnel who suffered traumatic brain injuries from explosions on the battlefields of Iraq and Afghanistan are at risk for long-term conditions including Alzheimer's-like dementia, says a report released Thursday for the U.S. Department of Veterans Affairs.

Researchers at the Institute of Medicine, which offers evidence-based advice to the U.S. government, wrote the report. It calls on the Defence and Veterans departments to step up research on helping troops to recover from or cope with brain injuries after they survive explosions.

People who sustain severe or moderate brain injuries may go on to develop Alzheimer's-like dementia, aggression, memory loss, depression and symptoms similar to those of Parkinson's disease, the report's authors said.

In most traumatic brain injuries, the skull isn't penetrated by a direct strike to the head, but the pressure wave from an explosion causes hidden damage — ranging from a mild concussion to a severe injury — inside the skull.

"For mild brain injuries, which is a much bigger group of injuries and it has a much broader scope, what we can say is for those kinds of injuries that there's a probable association between having one of those — especially with loss of consciousness — and having depression, having aggressive behaviour or having persistent post-concussive symptoms," said Dr. George Rutherford of the University of California, San Francisco, the report's lead researcher.

Post-concussive symptoms include memory loss, headaches and dizziness.

It is important to understand any long-term health effects of these injuries to help wounded service members to gain therapy and rehabilitation promptly, he noted.

The panel looked at decades of studies on mostly civilian injuries. They recommended that every soldier exposed to even a low-intensity blast should be screened for brain injury, and take brain function tests before and after deployment, which the U.S. military said it has started to do.

Screening for Canadian troops

As of January, more than 5,500 U.S. military personnel had suffered traumatic brain injuries in Iraq and Afghanistan as a result of improvised explosive devices, or IEDs, according to the U.S. Department of Defence.

A similar Canadian figure for troops deployed to Afghanistan is not available, Maj. Andre Berdais, a senior public affairs officer with the Canadian Forces Health Services Group, said via e-mail to the Canadian Press.

The Department of National Defence does not track the data, which isn't "essential in supporting our primary responsibility of patient care," Berdais said.

Canadian troops who experience explosions are screened for traumatic brain injury and are removed from active duty while showing symptoms to prevent the risk of a repeated injury, Berdais said.

Intuitively, and based on anecdotal evidence, injury rates are increasing among Canadian soldiers as well, said New Democrat MP Dawn Black, who has raised the issue as a member of the House of Commons defence committee and has talked to soldiers and their families.

Figuring out the best treatments for traumatic brain injuries remains a challenge since researchers lack a clear understanding of their long-term effects, said Dr. Greg Passey, a psychiatrist with Vancouver Coastal Health Services who spent 22 years in the Canadian Forces and who now specializes in treating post-traumatic stress disorder.

Teaching strategies to improve memory and attention problems can help people who are suffering lingering problems from traumatic brain injuries, said psychologist Gerrit Groeneweg, executive director of Calgary's Brain Injury Rehabilitation Centre.

With files from the Associated Press and the Canadian Press