TORONTO — A few years ago on his second tour of duty in Afghanistan, a vehicle commanded by Master Cpl. Michael Blois was struck multiple times by rocket-propelled grenades.
Although he wasn’t hit by shrapnel, Blois has endured symptoms ever since.
“When I got back to Canada, I did what a lot of soldiers do — I lied about how bad my injuries were,” he said, describing his symptoms.
“I was getting dizzy, a lot of fatigue, I was getting sick, I would throw up if I did any exercise, but because I wanted to go back overseas I just pretended like nothing happened.”
Blois described his traumatic brain injury as St. Michael’s Hospital in Toronto unveiled research on blast injuries, and the discovery of broken neurons and broken axons in the white matter of the brain of rats — even when there’s no other obvious physical damage.
Dr. Andrew Baker, who works in intensive care at the hospital, said he meets people with brain injuries like this every weekend.
“We wanted to understand what was going on with blast injury,” he said, relating how a short intense burst of energy causes a high- followed by a low-pressure wave.
“It has impact where it intersects with tissue of different density, so most of the time when people are close to a blast injury, they either get severe injuries which you hear about on the news all the time or, relatively near, it will impact their lung or their bowel or eardrum because of the intersection between air and tissue.”
Most of these people are aware of their injuries. Others — soldiers such as Blois, for instance — will maintain they’re fine even though they’ve been exposed to a blast injury, but they ultimately have symptoms and problems, Baker said.
In the lab research, published recently in the Journal of Neurotrauma, rats were subjected to one-quarter the intensity of a blast that would cause a lung or bowel problem, and scientists looked at the function of the brains using sophisticated electrophysiology techniques.
“What we found was very surprising,” Baker said.
“We found under a microscope, broken neurons, broken axons in the white matter.
“Not only that, but we found that these breakages were happening 12, 24 and 72 hours later.”
The cells were still showing signs of injury seven, 14 and 30 days later, he added.
By way of background, he explained that white matter is the part of the brain which contains long axons and links parts of the grey matter. People think with the grey matter, but white matter connects different parts of the brain.
“It’s when the white matter is injured that we have problems with concentration, memory, headache and dizziness.”
The new findings indicate the brain is more sensitive than the rest of the body to these blast waves, Baker said, and that the injury persists and actually develops over time.
“So it’s worse on Day 3 than on Day 1, and the exciting thing about this is it opens up the opportunity to look for drugs to stop this process, especially now that we’re describing the physiology.”