The ongoing COVID-19 pandemic has brought to light various lingering effects, with long-COVID patients experiencing symptoms that persist well beyond the acute phase of the infection. Among these lingering effects, parosmia, a distortion in the sense of smell, has emerged as a significant concern affecting a considerable percentage of COVID-19 survivors.
A recent study led by Dr. Adam C. Zoga, M.D., M.B.A., Professor of Musculoskeletal Radiology at Jefferson Health in Philadelphia, Pennsylvania, presents a potentially groundbreaking intervention for long-COVID patients with parosmia. The study, set to be presented at the annual meeting of the Radiological Society of North America (RSNA), explores the use of CT-guided stellate ganglion block to restore the sense of smell in affected individuals.
Background: Parosmia, characterized by an incorrect functioning of the sense of smell, has been identified as a known symptom of COVID-19, impacting up to 60% of COVID-19 patients. While most individuals recover their sense of smell over time, a subset of long-COVID patients experiences persistent parosmia for months or even years post-infection. This enduring condition significantly affects the patients’ appetite for food and their overall quality of life.
The Study: The research team, led by Dr. Zoga, investigated the potential benefits of CT-guided stellate ganglion block as a treatment for long-term post-COVID parosmia. Stellate ganglia, part of the autonomic nervous system, play a role in regulating involuntary processes such as heart rate, blood pressure, breathing, and digestion. The team hypothesized that stimulating the regional autonomic nervous system through a minimally invasive procedure could alleviate parosmia symptoms.
Methodology: The study included 54 patients referred from ear, nose, and throat specialists after enduring at least six months of post-COVID parosmia resistant to pharmaceutical and topical therapies. CT guidance was employed to position a spinal needle at the base of the neck for injection into the stellate ganglion. The researchers combined a small dose of corticosteroid with the anesthetic to address potential nerve inflammation caused by the COVID virus.
Results: The initial patient showed a remarkably positive outcome, with rapid improvement and eventual resolution of symptoms within four weeks. Follow-up data was obtained for 65% of the patients, with 59% reporting improved symptoms one week post-injection. Of these, 82% experienced significant progressive improvement by one month post-procedure. At three months, there was a mean 49% improvement in symptoms among the 22 patients.
Twenty-six patients received a second injection on the contralateral side of their neck after a six-week interval. While the second injection did not benefit non-responders to the first injection, 86% of patients reporting some improvement after the first injection experienced additional improvement after the contralateral injection. Notably, no complications or adverse events were reported.
Conclusion: The study suggests that CT-guided stellate ganglion block is a promising intervention for restoring the sense of smell in long-COVID patients with persistent parosmia. The procedure, taking less than 10 minutes and requiring no sedation or intravenous analgesia, demonstrated significant improvements in symptoms for a majority of the treated patients. With further research and validation, this minimally invasive approach could offer hope and relief to individuals grappling with the enduring effects of COVID-19 on their sense of smell.
Reference: Zoga, A. C., Kamel, S. I., Moriarty, T. R., Roedl, J. B., Desai, V., & Belair, J. A. (Year). CT-guided stellate ganglion block for the treatment of long-COVID parosmia: A prospective study. Radiological Society of North America Annual Meeting,