Dr. Deborah Duricka—affiliate assistant professor at WWAMI School of Medicine and clinical research scientist at Neuroversion—was awarded a Solve M.E. Ramsay Research Grant in 2023 to study whether a procedure called stellate ganglion block (SGB) can help patients with Long Covid,
The stellate ganglion is an oval- or star-shaped bundle of nerves near the voice boxes of most people (although for 2 in 10 people, the proper neck nerves do not fuse into a bundle but remain separate). The stellate ganglion is important for sympathetic signals involving the head, neck, and upper chest—these are signals that control our bodily functions automatically. Examples of sympathetic functions are heart rate, blood pressure, and sweating; our nervous system regulates these functions without us needing to think about them. Injecting an anesthetic into the stellate ganglion (the SGB) can relieve sympathetically mediated pain, regulate sympathetic nervous system activity, or improve circulation or nerve function. SGBs also help patients with Long Covid, helping restore proper sleep, increase cognition, and improve neurological function.
Dr. Duricka’s research, conducted at Neuroversion and just published in the journal Autonomic Neuroscience: Basic and Clinical, now add more evidence that SGB reduces many severe Long Covid symptoms. Dr. Duricka and her co-author Dr. Luke Liu analyzed the medical records of patients at her clinic who reported having Long Covid and who were treated with SGBs. Before and after treatment, patients completed questionnaires about the severity of their symptoms—fatigue, post-exertional malaise (after either mental or physical activities), dizziness when standing, fast heart rate, memory problems, concentration problems, sleeping problems, anxiety, depression, problems with taste, and problems with smell—all common for patients with Long Covid. Most patients found their symptoms went down soon after the SGB treatments. In fact, within 24 hours of treatment, all assessed symptoms were significantly reduced. Especially reduced were post-exertional malaise (after either mental or physical activities), dizziness when standing, and fast heart rate. Treatment effects were long-lasting—one in three participants continued to experience relief one month after treatment—even for patients who long experienced these symptoms (as long as 19 months).
These results support the use of treatments targeting the sympathetic nervous system for reducing severe symptoms of Long Covid in some patients. Dr. Duricka also pointed out that patients who take SGBs for other conditions (like sympathetic pain) usually need several injections before they see long-lasting relief. After each injection, symptoms increasingly go down. But Dr. Duricka found several patients experienced long-lasting relief (lasting at least one month) after only one injection; thus, multiple SGB injections may provide even more long-lasting benefits for these patients.
Dr. Duricka noted some limitations of this study, which she hopes future studies will address. Because she was reviewing patient charts, Dr. Duricka could not consider participants who received placebo treatments. Including placebo-treated patients would have let her more confidently tell whether the SGB-treated patients improved because of the treatment or because their symptoms naturally went down over time. Also, Dr. Duricka had only a few patients for her study. She started with charts of 33 patients but needed to omit almost half because they were from patients whose symptoms increased after being reinfected by SARS-CoV-2 or after being vaccinated, complicating how she interpreted the SGB effects. Also, she needed to omit other patients because although they responded to SGB treatments, they took other treatments for their severe symptoms, also complicating their situations. Dr. Duricka was left with only a dozen patients to assess one month after treatment—too few for strong statistical analyses. Still, considering the original 33 patients, over three in four experienced at least short-term relief after receiving SGB treatment; and one in three experienced long-term relief. Considering these promising results, Dr. Duricka advocates clinical trials with more patients (including patients receiving placebo treatments). In clinical trials, researchers might also more carefully and more objectively measure patients’ sympathetic functions (for example, by measuring blood pressures and by taking 24-hour electrocardiogram readings) than they could by using questionnaires.
Dr. Duricka noted that Solve provided funding to make this journal article open access for the benefit of clinicians and patients who need it most:
“We are grateful that Solve has agreed to contribute to the substantial Article Publication Charge for open access publication of this manuscript. Without open access publishing, information is inaccessible to the very people who need it most: patients. Patients must be empowered to bring peer-reviewed publications from reputable journals to their physicians, especially when the article in question details a promising new treatment avenue. Physicians simply do not have the time to keep up with the avalanche of journal articles published on a weekly basis. The data in this manuscript was used as the basis for my Ramsay Research Project, a prospective pilot study using stellate ganglion blocks to treat ME/CFS (manuscript in preparation). Without the support of Solve M.E., the findings in the current manuscript would have met the same fate as many promising treatment leads for ME/CFS—consigned to the archives of PubMed. Thanks to Solve M.E., we were able to move forward exploring the utility of SGB for ME/CFS patients, and we are working hard to publish the results from our prospective pilot study.”