London clinical trial targets lingering COVID toll on patients – smell distortion

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Haunted for more than a year by phantom smells she couldn’t explain, Rebecca Bruzzese said she worried about her safety and mental health.

She could smell burning cigarettes in her living room, but no one was smoking. Beef frying on the stove smelled like “excrement in a pan.” Coffee was even worse.

“It smelled like hot garbage,” the 32-year-old said.

Unable to eat, Bruzzese lost 30 pounds and developed other health problems.

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What she didn’t know was she had developed parosmia, a disorder triggered by COVID-19 that distorts the sense of smell. Thanks to a novel trial treatment program at St. Joseph’s Health Care in London, the Toronto woman now knows about the disorder and is enrolled in the program.

“It’s really hopeful not just for myself, but for other people dealing with this,” she said.

Things looked very different not long ago for the marketing professional.

Normal odours had become repulsive to Bruzzese, and there were the disturbing and frightening phantom smells.

Bruzzese had recovered from COVID, or at least thought she had, after being hard hit by the virus in 2023. She’d been stuck on the couch for two weeks, coughing non-stop, she recalled.

But the “scent hallucinations” remained, even after her other COVID symptoms passed, Bruzzese said. “The effect that it had on my mental health was something that I really hadn’t expected.”

At one point, she even asked her building manager to investigate what she thought was a gas leak, only there wasn’t one.

From nasal sprays to old wives’ tales, the 32-year-old said she tried everything to regain her sense of smell, but nothing worked and “desperation” set in.

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That’s when she found out about the treatment program at St. Joe’s, for people with smell distortions triggered by COVID.

Still in its trial phase, the treatment is known as stellate ganglion block (SGB). It involves injecting a local anesthetic into the stellate ganglion, a collection of nerves in the neck that controls signals to the head, neck, arms and part of the chest. The randomized trial is being run by Dr. Leigh Sowerby, a head and neck surgeon and a scientist at the Lawson Health Research Institute in London.

When the stellate ganglion is “overworked,” the injection resets the nerves by blocking them temporarily.

Neither the participants in the double-blind clinical trial, including Bruzzese, nor its investigators know which patients are receiving the anesthetic and which ones the placebo, saline.

The nerves in the neck where the injection is made aren’t responsible for the sense of smell, but Sowerby said they have much to do with how the brain interprets the signals it receives.

A diagnosis of parosmia considers the patient’s COVID-19 history, including a smell test, but other health problems such as chronic infection can also trigger the disorder, Sowerby said.

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Early on in the pandemic, about half of COVID-19 patients reported a loss of smell. Most recovered, but a “significant number” never got it back, Sowerby said.

The loss of smell happens when an organ inside the nose, filled with cells responsible for smelling, is injured by COVID. It can take a long time to regenerate, Sowerby said, and even when the sense of smell returns, patients sometimes report symptoms of parosmia.

Bruzzese, who began her treatment in March, said she’s thrilled to have regained her normal sense of smell. An added benefit was receiving support and validation through social media from others dealing with the same issue, she said. 

“I’m not going insane, and other people are experiencing this (disorder) too. It was really validating,” she said.

The next step in the trial is a follow-up with 44 patients to determine the effectiveness of the treatment in post-COVID parosmia.

bbaleeiro@postmedia.com

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