Hundreds of thousands of Canadians get concussions each year — many don't recover

This is an excerpt from Second Opinion, a weekly analysis of health and medical science news emailed to subscribers Saturday mornings. If you haven't subscribed yet, you can do that by clicking here.

After Michelle Tobin-Forgrave fell and hit her head more than five years ago, she developed a constellation of symptoms that began to derail her day-to-day life.

The Miramichi, N.B., resident knew she had a concussion — her second one — and expected to have a quick recovery, just like her first experience years earlier. But this round felt different. 

Tobin-Forgrave went back to her job in the education sector after taking two months off work, then realized she needed to take hourly breaks from her computer. Sometimes she'd just lay on a yoga mat in her office, wracked by fatigue. The busy mother of two also started experiencing insomnia, couldn't remember basic words like the names of household appliances, and developed issues with her vision and depth perception.

"The symptoms just never, ever went away," she said, "and got worse — much worse — over time."

The latest available data suggests hundreds of thousands of Canadians get concussions every year, and federal guidance last updated in 2021 suggests while recovery times can vary, most people get better in "10 days to 4 weeks."

Yet a growing body of research indicates that many take much longer to recover than previously thought — or don't ever fully recover at all. 

A study published in the journal Brain in February found that almost half of people with concussions still show symptoms of brain injury six months later, likely due to damage in an area of the brain called the thalamus, which relays information from the senses. 

Researchers analyzed the brain scans of 108 patients in Europe who had recently had a concussion to look for structural changes in the brain, and found a marked increase in the activity between the thalamus and the rest of the brain shortly after a concussion. 

"It's almost like they were doing more work than those areas normally do. They were trying to communicate harder," said Emmanuel Stamatakis, lead author of the study and head of the Cognition and Consciousness Imaging Group at the University of Cambridge in England. 

"We found that the more hyper-connected those areas were, the more likely it is that you will have one of the symptoms that are associated with concussion — such as headaches, fatigue and sleep disturbances." 

The researchers used a less-common type of scan called a resting-state functional MRI — which isn't widely available to patients — to analyze structural changes in the brain. Stamatakis said he hoped the findings would better inform patient care in the future and potentially lead to new concussion treatments.

"What I hope this study will achieve is to have clinicians think twice or three times before they send somebody with a concussion home and tell them: 'You're healthy,'" he said. 

Dr. Charles Tator, an internationally renowned neurosurgeon and head of the Canadian Concussion Centre at Toronto Western Hospital's Krembil Brain Institute, said the study points to the thalamus as an important area for concussion research for the first time.