​​Dr. Robin Green and Master’s student Alex Terpstra
(L to R): Dr. Robin Green and Master’s student Alex Terpstra found anxiety plays a role in long-term brain shrinkage for people who have experienced a traumatic brain injury. (Photo: UHN)

Researchers at Toronto Rehab are one-step closer to understanding what may lead to chronic brain shrinkage in patients who suffer a moderate to severe traumatic brain injury (TBI).

Their findings reveal anxiety symptoms present within the first year of injury may be an early sign of long-term deterioration.

This research raises the possibility that treating anxiety early could help protect the brain from ongoing shrinkage after injury.

 "This is important because it's something we can treat," says team lead Dr. Robin Green, Senior Scientist and Canada Research Chair (tier2). "Our group has been heavily focused on identifying post-injury factors implicated in neurodegeneration after TBI. Pre-injury factors, like age and education, cannot be modified. But elevated anxiety after injury is treatable."

To help put these findings into context, a moderate to severe TBI may result in enduring alternations to consciousness, such as coma, that can last for days, weeks, or even months. A mild TBI or concussion may involve only momentary alterations to consciousness.

How a TBI affects the brain

Within the first few months of a moderate to severe TBI patients will experience rapid recovery as their thinking, motor, and emotional functions start to improve.

By the end of the first year, recovery will have started to plateau with less obvious signs of ongoing improvements there over.

But somewhere in the midst of this recovery trajectory, the brain will actually start to deteriorate again.

"Our research shows that the brain injury sets in motion an accelerated aging process or degeneration" says Dr. Green. "We used to think of a brain injury as very stable once the initial damages resolved. But that's not the case."

What Dr. Green's team found when they looked at what factors cause this other process to begin is that anxiety plays a role.

Specifically, after analyzing the magnetic resonance imaging (MRI) and behaviour of 80 patients over the course of 30 months post-injury, data revealed higher anxiety symptoms early on predicted significant later shrinkage in the brain.

"The most exciting implication of these findings is that treating anxiety symptoms – which are often increased after brain injury and compromise well-being and everyday functioning - may also reduce the brain's physical decline after injury," says Alex Terpstra, a Master's student and the study's first author.

Therefore, this discovery has the potential to minimize the risk of brain deterioration, by calling for the detection and treatment of anxiety in the early stages of injury.

"It sounds gloomy to say we're excited that elevated anxiety is associated with brain deterioration, but anxiety isn't that hard to treat," says Dr. Green.

"There are medications, psychological treatments like cognitive behavioural therapy and mindful meditation, and physical exercise. So these are very encouraging findings for improving outcomes from brain injury."

Best Publication Award Winner

The study, which was published in the journal Neurorehabilitation and Neural Repair, was recently recognized at Toronto Rehabilitation Institute's annual Research Day, where first author Alex Terpstra was honoured with one of two Best Publication awards.

"This year, the focus of Research Day was impact," says Dr. Susan Jaglal, Associate Academic Director of Research at Toronto Rehabilitation Institute. "The selection committee chose this as the best paper because there are huge implications for impact in the field of brain injury research and treatment."

"Another factor in the decision was that this study involved very complex data analysis that was well beyond what you would expect from a Master's student," she says.​

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