Promising CT-Guided Stellate Ganglion Block Treatment Restores Sense of Smell in Long-COVID Patients with Parosmia–Potential Breakthrough Indicates Early Study Results
At the annual meeting of the Radiological Society of North America (RSNA), it was revealed that researchers are exploring the possibility of restoring the sense of smell for long-COVID patients using an image-guided minimally invasive procedure.
Understanding Parosmia
Parosmia, resulting in disordered smelling, is a well-known symptom of COVID-19. Studies showed that approximately 60% of COVID-19 patients displayed this condition with some experiencing long-term symptoms, even after recovery, which negatively impacted the quality of their lives through distorted taste perception and smell.
Lead author of the study, Adam C. Zoga, M.D., M.B.A., explained, “Post-COVID parosmia is common and increasingly recognized. Patients can develop a distaste for foods and drinks they used to enjoy.” Other patients may start to perceive phantom smells that are not present in their surroundings.
New Treatment Restores Sense of Smell in Patients With Long COVID Infographic. Credit: RSNA
Potential Treatment
Through a CT-guided stellate ganglion block, researchers aimed to treat long-term post-COVID parosmia. This procedure involves injecting an anesthetic into the stellate ganglion located in the neck, hence stimulating the autonomic nervous system which regulates various involuntary functions such as heart rate, blood pressure, and digestion.
“Other treatments have failed to date. This injection is working.” — Dr. Adam C. Zoga
Dr. Zoga emphasized, “Parosmia has previously been reported as a rare disorder occurring after brain trauma, brain surgery, stroke, viral syndromes, and with some head and neck tumors. We were not entirely confident that the procedure would work for parosmia.”
Study and Outcomes
A total of 54 patients, exhibiting post-COVID parosmia for at least six months, took part in the study to assess the efficacy of the intervention. The team employed CT guidance to administer the spinal needle for the injection into the stellate ganglion and added a small dose of corticosteroid to the anesthetic to mitigate potential nerve inflammation caused by the virus.
Dr. Zoga advocated, “The initial patient experienced tremendous improvement and continued to show progress until total symptom resolution at four weeks.” Notably, 18 of 22 patients reported significant progressive improvement at one month post-procedure, with a 49% mean improvement in symptoms after three months. Moreover, 86% of patients reported further improvement after a second injection on the other side of their neck.
Dr. Zoga concluded, “Other treatments have failed to date. This injection is working.” The study was carried out in collaboration with researchers Sarah I. Kamel, M.D., T. Rohan, M. A. Moriarty, Johannes B. Roedl, Ph.D., M.D., Vishal Desai, M.D., and Jeffrey A. Belair, M.D.
