Understanding long-term effects of concussion

By Crystal Mackay, MA’05

Take a look at these words. Now quickly say out loud what colour they are written in.

Adrian Owen, PhD, and his team hypothesize that if you’ve had a concussion at some point in your life, you are going to be much slower at completing this task than someone who hasn’t. The task, which measures the Stroop Effect, is one of a battery of tests as part of a new study looking at the long-term cognitive effects of concussion.

For most people who suffer a concussion, symptoms will resolve within days of the incident, but for about 10 to 30 per cent of patients, symptoms persist for months and even years after the injury.

Owen, a Professor at Schulich Medicine & Dentistry, and his team at the Brain and Mind Institute are looking to recruit 1,000 participants to complete an online survey with the aim of investigating whether sustaining a concussion leads to long-term adverse effects on general cognitive abilities.

“The only way you can treat a problem is to really understand that problem,” said Owen. “By identifying the problems that people are having more specifically, we can start to think about rehabilitation or targeted programs that can improve those difficulties. At the moment, we have to rely on anecdotal accounts from people who have been concussed.”

Supported by Western’s BrainsCAN, this concussion study was spurred by an interesting result that the team saw when they conducted the world’s largest sleep study. There was a question on the online survey about whether or not participants had suffered a past concussion. When they looked at the data more closely, it turned out that those that answered ‘yes’ to that question also scored poorly on the Stroop task. They were cognitively comparable to their peers on all the other tests except this one.

While very little of his research to date has focused on concussion, Owen says this result really piqued his interest because it fits with what concussed patients report anecdotally – that long-term they have trouble concentrating on a given task or reading a book without distraction. Owen says the Stroop task measures selective attention, which is the ability to filter out distracting or irrelevant information.

While the result on the sleep study was interesting, it only provided very narrow information that the team now hopes to expand on.

“The problem is, that based on a single question on that survey, we don’t have enough information about the concussions – where did they occur, how long ago did they happen, how severe were they, or whether it involved time in hospital,” said Owen. “We’re looking at getting as much information as we can based on this interesting finding from the sleep study.”

Interestingly, Owen says when they gave the same battery of cognitive tests to varsity football players, they also showed deficits in the same Stroop task. “That result didn’t come from looking for players who had been concussed, it was purely based on our assumption that as a group, these players bang their heads together a lot,” he said.

“So there are a few things out there that indicate we are on the right track, but we’d really like to nail this down, so that we can be more specific about the problems and challenges that people who have had a concussion are experiencing.”

The team will be recruiting participants and collecting data during the next year.

“I’ve really come to this study serendipitously by studying sleep and it has now produced a whole new theme in my lab,” he said. “I’m really pleased about it, because Western University has an established strength in concussion research that we can draw upon.”