Toronto researchers are trying to crack one of COVID’s biggest mysteries: its impact on the brain

McIntyre is leading a double-blind study that is recruiting people from across the province to test an antidepressant called vortioxetine, with the hope that it may help those still struggling with COVID’s brain effects. Half of the participants will receive the antidepressant, and the other half a placebo, without knowing which one they have been given.

When people are depressed and suffering from brain fog, he said, there is often something wrong with their immune system. So his theory is that this anti-inflammatory drug can also help long-term COVID patients with brain problems.

There is precedent, he said, for a viral infection that triggers a “cascade of events” that affect the nervous system and the brain. A recent Harvard study, for example, made headlines for finding a higher risk of multiple sclerosis in people who had the Epstein-Barr virus, which can cause mononucleosis.


There is also some evidence of a link between sore throat and obsessive-compulsive disorder.

Normally, research would come first before potential treatments, McIntyre said. But with so many people suffering from persistent COVID influences and so little insight into what is wrong with them, that changes the game.

“Yes, the horse has to be in front of the carriage, but sometimes they have to go in tandem,” he said.

“We really do not have enough studies right now that generally aim to help people with this condition. We need to go and chew gum at the same time, we need to understand what this problem is, but we also need to find out of ways to treat it. “

As the pandemic drags on, more pieces of the puzzle begin to fall into place. One theory is that the virus can enter through the nose. There is also some evidence that it can damage the brain by reducing its blood flow.

A recent pre-print study led by researchers at Stanford and Yale universities, which has not yet been peer-reviewed, suggests that even mild COVID can cause cognitive impairment. The study examined the brains of nine people who were positive for the virus after they died (not all of the disease) and found signs of inflammation in the brain, similar to what some patients report after chemotherapy treatments for cancer.

Closer to home, researchers at Sunnybrook and CAMH look at brain scans of people who are still alive but who are dealing with the effects of the disease.

Simon Graham, a senior researcher at the Sunnybrook Research Institute, is leading an ongoing Canadian Institutes of Health Research-funded neuroimaging study examining the impact of long-distance COVID on brain function over time.

“We know that the impact on the brain of COVID and the long-term COVID state is very complex,” he said. “So there are several mechanisms by which the brain can become infected.”

This is an important area of ​​research, he added, as long-distance carriers will still be there even if new infections are brought under control.

“We’re going to be left with people who have this long-term illness.”

Dr. Jeffrey Meyer, head of the Neurochemical Imaging Program in Mood and Anxiety Disorders at CAMH, is leading another study that performs brain scans of people who have chronic COVID and depression.

“We suspect they’re getting a lot of encephalitis, and there are some cells in the brain that, when inflamed, make some changes,” said Meyer, who is also Canada Research Chair in Neurochemistry of Severe Depression.

“We are trying to get the right grip on the scale of the problem,” he said, adding that people who volunteer for the study can contribute to new treatments for long-distance carriers.

Our understanding of COVID has come a long way since March 2020, but many people still think of COVID as a respiratory disease, McIntyre said. And they are surprised that it can have such an impact, months or even years later, even though their case was technically mild, like Gouldings, and they did not end up being hospitalized.

“They come to us and say, ‘You know, I used to be that, I used to be that, I got COVID, it was not even that serious, and now I can not even function, I have got no energy, my mind is completely foggy and I can do nothing ‘, and in many cases these are high-functioning people. ”

Goulding, who plans to take part in McIntyre’s study, used to be an avid skier and worked as a floral designer. Her cerebral palsy symptoms subsided within about eight weeks after she thought she was first infected.

She suffered from a number of symptoms, including tinnitus and heart problems. But for her, what happened to her brain was the worst.

She was nervous about driving for months, putting stickers around the house to remind herself of simple everyday tasks, once she left a kettle and smashed the glass plate on her stove. She could not work.

Goulding was helped tremendously, she said, by an interdisciplinary rehabilitation program at an integrated clinic in Burlington, which included physiotherapy and exercises such as word puzzles to practice her mental skills.

She works again, but in a new career as a filmmaker because she can not bear to return to her old job as a floral designer.

As for skiing, she is not back on the slopes yet and she still needs to work up a little strength and endurance. Maybe for next season.

“I’m hopeful,” she said.

May Warren is a Toronto-based breaking news reporter for Star. Follow her on Twitter: @ maywarren11

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