Although the coronavirus infection has subsided, patients faced a harsh reality. What was once a pleasant scent suddenly became rancid. The sautéed garlic and onions smelled like rotting garbage, and the coffee was no longer palatable.
This distorted sense of smell, known as parosmia, is a part of long-term coronavirus infections.
At the beginning of the pandemic, we saw changes in our sense of smell and taste. considered to be an important symptom About coronavirus infection.a Study abroad in UK Approximately 43% of people who reported losing their sense of smell in March 2020 were found to have anosmia six months later.
But doctors have struggled to understand why parosmia develops after a viral infection, much less figure out how to treat it.
A new study from Jefferson Health in Philadelphia shows that a procedure called a stellate ganglion block can reduce parosmia in patients who have suffered from the condition for at least six months after the onset of COVID-19 and have not responded to medications or topical treatments. This suggests that it is effective to some extent in reducing
Treatment involves injecting an anesthetic into the stellate ganglion, a tangle of nerves in the neck that transmit signals to the head, neck, arms, and upper chest. It has been used for decades to treat chronic pain.
Of the 37 patients who underwent the procedure at Jefferson Health and subsequently followed up with a physician, 22 reported improvement in odor distortion one week after the injection. Additionally, 18 out of 22 people said their symptoms had significantly improved after one month.
After the first injection, 26 people returned for a second injection on the other side of the neck at least six weeks later. Most people who responded to the first treatment reported further improvement after the second treatment, but the injections remained ineffective for those who saw no change the first time.
The findings will be presented Monday afternoon at the annual meeting of the Radiological Society of North America.
Dr. Adam Zoga, a professor of musculoskeletal radiology at Jefferson Health who conducted the study, said the treatment is life-changing for patients whose parosmia has severely affected their physical and mental health. He said that it became.
“I had a patient who had a young daughter, and she said, ‘I can’t bathe my 3-year-old daughter because she can’t stand the smell of soap,'” he said. “Other patients did not find any food enjoyable and had lost significant weight.”
What is required for the procedure?
A stellate ganglion block is a 10-minute outpatient procedure that does not require the patient to be sedated. The doctor uses CT or ultrasound images to locate the nerve bundles at the base of the neck and then injects the injections at those precise locations.
Zoga said that while some doctors simply inject an anesthetic, his team “usually uses the typical mixture that we use for nerve injections: a small amount of corticosteroid, a small amount of short-acting “We are injecting a type anesthetic, a small amount of a long-acting anesthetic.” ”
This procedure requires technical skill because the stellate ganglion is located near two major blood vessels that carry blood to and from the brain. But Zoga said it is relatively harmless if administered by trained personnel.
However, this injection comes with side effects. Most patients experience drooping eyelids, dilated pupils, and some vision loss for about 10 minutes, but the symptoms quickly subside.
Zoga said the first patient’s parosmia symptoms completely disappeared within a few weeks.
“She couldn’t eat her favorite cold meats and had been eating them since the surgery,” he said. “I continue to keep in touch with her. It has now been 18 months since she was discharged from the hospital and she is still making a full recovery.”
The battle for parosmia treatment
Dr. Christine Smith, assistant professor of otorhinolaryngology at the University of Utah Health, said doctors don’t know why stellate ganglion blocks are effective in some people with long-term COVID-19 infections. .
“The hypothesis is that these injections cause some kind of reset to our nervous system,” said Smith, who was not involved in the study. “I don’t know if there’s a clear answer as to why it works or doesn’t work.”
Smith says many people find that their odor problems resolve on their own without medical intervention. Some people find relief with steroid nasal sprays, salt water gargles, or olfactory retraining, in which the person smells the same scent every day for several months in hopes of regaining their old sense of smell.
“Things like stellate ganglion blocks are really reserved for patients who have failed less aggressive medical therapies,” Smith said.
But Dr. Nyssa Farrell, assistant professor of otorhinolaryngology at Washington University School of Medicine in St. Louis, said there is little evidence that first-line treatments such as steroids or olfactory training are effective for anosmia.
Mr. Farrell is looking for volunteers. clinical trial It will examine whether stellate ganglion blocks can improve severe olfactory abnormalities. She wants to find out whether the procedure has a placebo effect, as some patients report that their symptoms return after a short break following treatment.
“Since this is a placebo, will it only last a month for these patients, or will this have an actual effect and perhaps need some kind of boost over time, or will the dose need to be changed?” ‘Is there a case?’ It’s too early to tell from these limited case reports,” Farrell said.
in one study Using stellate ganglion blocks to treat 195 people in Texas with long-term coronavirus symptoms, 87% saw improvement in odor problems after the injection.another Case Study They found that five out of six patients in Florida felt relief from the treatment.
Farrell’s previous the study They also showed that stellate ganglion blocks improved symptoms in about half of the 20 participants with complete or partial loss of smell. Participants viewed the treatment favorably, she added.
“At the end of the study we asked people, even if we didn’t see such a large effect, would you recommend this to others? And they said ‘yes,'” Farrell said. Told.