If you’re living with parosmia – where familiar smells become distorted or unpleasant after COVID-19 – you’ve probably heard about various treatments being explored. Recently, researchers looked into whether a procedure called Stellate Ganglion Block might help people with parosmia. Here’s what they found and what it might mean for you.
What Is Stellate Ganglion Block?
Stellate Ganglion Block (SGB) is a medical procedure where doctors inject medication near a cluster of nerves in your neck called the stellate ganglion. This nerve cluster is part of your body’s sympathetic nervous system, which controls things like heart rate and blood flow, both of which are involved in the body’s response to stress. There is at this time no known link between the stellate ganglion and olfactory function.
During the procedure, doctors use ultrasound to guide a needle to the right spot and inject either an anaesthetic medication (mepivacaine) or, in the case of this study, sometimes just saline solution as a comparison.
What the Researchers Studied
The research team at Washington University wanted to know if SGB could genuinely help people with COVID-related parosmia. They designed their study carefully to get reliable answers:
- They recruited 57 people who had been dealing with parosmia for at least 6 months after COVID-19
- Participants were randomly assigned to receive either the active treatment (mepivacaine) or a placebo (saline solution)
- Neither the patients nor the researchers knew who got which treatment until after the study ended
- They measured improvements using a specialised questionnaire called the DisODOR scale, which tracks how parosmia affects daily life
What They Found
The results were clear but perhaps not what people hoped for. After following participants for three months:
- 43% of people who received the active treatment showed meaningful improvement
- 38% of people who received the placebo also showed meaningful improvement
- The difference between the two groups was so small that it could easily be due to chance
Importantly, both groups saw some people improve, but the active treatment didn’t work better than the placebo injection in a way that was statistically significant.
Did the Study Have Any Limitations?
The researchers made up their mind about how good this treatment was by looking at the scores of their specialised questionnaire. They did not ask the participants about their feelings, and how much parosmia affected their mental health. Future studies might consider this, as it is a major factor for people with parosmia.
What This Means for You
This study provides valuable information about SGB for parosmia, even if the news isn’t what we might have hoped for. Here’s what to take from these findings:
- SGB isn’t a proven treatment for parosmia at this time. Based on this research, the procedure doesn’t offer benefits beyond what might happen naturally or through the placebo effect.
- Some people did improve in both groups. This reminds us that parosmia can get better over time for some people, even without specific treatments. Your symptoms aren’t necessarily permanent.
- Good research takes time and careful design. This study was done carefully, with a control group and people not knowing which treatment they received. This gives us reliable information.
- It’s okay to feel disappointed. If you were considering or hoping for SGB as a treatment option, it’s natural to feel let down by these results.
Why Some People Might Have Felt Better
Both groups in this study had some people who improved, which highlights something important: our bodies are often working on healing in ways we can’t see or feel day to day. Some possible explanations for the improvement in both groups include:
- Natural recovery is happening over time
- The SGB treatment might be affecting the autonomous nervous system in some way that makes people feel less stressed
- The focused attention and care that comes with participating in a medical study
- The hope and expectation that treatment might help
- Other factors in people’s lives that support recovery
Moving Forward
While this study did not find SGB to be a recommended treatment for parosmia, it doesn’t close the door on your recovery journey. Research into parosmia treatments continues, and it’s possible that other research institutions will look at SGB, perhaps in a different way. It’s important to keep an open mind on what might, and might not help.
The study also reinforces that parosmia recovery is possible – nearly 40-43% of people in both groups saw meaningful improvements over just three months. Your experience with parosmia is valid, your symptoms matter, and improvement remains possible.
If you’ve been considering SGB specifically, this research suggests your time and resources might be better spent on other approaches. Talk with your healthcare provider about other options, including smell training, which continues to have research support.
Key Takeaway
A carefully designed study of 57 people with COVID-related parosmia found that stellate ganglion block didn’t work better than a placebo injection. While this means SGB isn’t recommended as a treatment, the study also showed that about 40% of people experienced meaningful improvement over three months regardless of which treatment they received, offering hope that recovery can happen naturally over time.
Want to dive deeper?
This blog is based on findings from a recent review:
“Stellate Ganglion Block for the Treatment of COVID-19−Induced Parosmia”
– Nyssa Fox Farrell, MD; Lara W. Crock, MD, PhD, MSCI; Aseeyah Islam, BSE; et al
