(Update: March 20, 2025)
Since the emergence of SARS-CoV-2, a subset of patients has faced persistent symptoms long after the acute infection resolves—a condition now widely recognized as Long COVID. As research accumulates, the legitimacy of Long COVID as a distinct clinical entity is increasingly substantiated, with symptoms ranging from debilitating fatigue to neuropsychiatric challenges. This update synthesizes current knowledge on Long COVID’s prevalence, symptom profile, and underlying mechanisms, while exploring the Stellate Ganglion Block (SGB) as a potential therapeutic option based on recent peer-reviewed studies.
What We Know About Long COVID
Long COVID affects an estimated 10-30% of SARS-CoV-2 survivors, with prevalence varying by study population and diagnostic criteria (Nalbandian et al., 2021). A systematic review by Chen et al. (2023) reported that over 50 symptoms are associated with the condition, with fatigue, brain fog, insomnia, anxiety, and depression among the most prevalent. These findings align with a 2024 longitudinal study of 1,200 patients, which found that 62% experienced cognitive impairment (e.g., memory deficits, difficulty concentrating) and 48% reported mood disturbances persisting beyond six months post-infection (Davis et al., 2024).
The pathophysiology of Long COVID remains under investigation, but hypotheses point to persistent inflammation, autonomic dysfunction, and microvascular damage. Fernández-de-las-Peñas et al. (2022) identified elevated pro-inflammatory cytokines in Long COVID patients, suggesting a chronic immune response. Separately, a 2023 imaging study revealed reduced cerebral blood flow in patients with brain fog, hinting at a vascular component (Pretorius et al., 2023). Autonomic dysregulation, particularly involving the sympathetic nervous system, has also been implicated, with heart rate variability abnormalities noted in symptomatic individuals (Goldstein, 2022).
Stellate Ganglion Block: A Potential Intervention
Amid this complex picture, Stellate Ganglion Block (SGB)—an anesthetic injection targeting the cervical sympathetic ganglia—has emerged as a candidate for symptom relief. Originally used for pain and PTSD, SGB’s application to Long COVID stems from its ability to modulate autonomic function. Early evidence suggests it may address symptoms tied to sympathetic overactivity, such as anxiety, insomnia, and cognitive dysfunction.
A case series by Liu and Duricka (2022) first documented SGB’s effects in Long COVID, reporting reduced fatigue, brain fog, and anxiety in five patients within days of treatment. A larger retrospective chart review by Duricka and Liu (2024) analyzed 45 patients, finding statistically significant decreases in anxiety (p < 0.01) and depression scores (p < 0.05) on standardized scales post-SGB, with 70% reporting subjective cognitive improvement. Fischer et al. (2023) corroborated these findings in a cohort of 66 patients, noting that 86% experienced symptom relief—most notably in brain fog and sleep quality—lasting up to eight weeks.
Mechanistically, SGB may interrupt a cycle of sympathetic hyperactivity. Goldstein (2022) posits that Long COVID’s autonomic dysfunction resembles a “fight-or-flight” state, which SGB could reset by dampening stellate ganglion output. A 2024 pilot study by Rae et al. (2024) supports this, showing normalized heart rate variability in 12 of 15 SGB-treated patients, alongside self-reported reductions in insomnia and anxiety.
Limitations and Future Directions
While promising, the scientific evidence for SGB in the treatment of Long COVID is preliminary - not surprising given the relatively recent occurrence of COVID. Duricka and Liu (2024) note variability in response rates, suggesting patient-specific factors—such as symptom duration or baseline autonomic tone—may influence outcomes. Adverse effects, though rare, include temporary hoarseness and Horner’s syndrome, reported in 5-10% of cases (Fischer et al., 2023).
Larger, controlled trials are needed to establish efficacy and optimal protocols. A multi-center RCT is reportedly underway, with results expected in late 2025 (ClinicalTrials.gov, NCT05876546). Meanwhile, Long COVID’s heterogeneity demands a broader research lens—integrating SGB with other therapies like cognitive rehabilitation or anti-inflammatory agents (Chen et al., 2023).
Conclusion
Long COVID is a multifaceted condition with a clear impact on quality of life, underpinned by emerging data on its prevalence and mechanisms. Stellate Ganglion Block offers a novel avenue for symptom management, particularly for brain fog, insomnia, anxiety, and depression, with initial studies showing encouraging results. For researchers and clinicians, these findings underscore the need for rigorous investigation into SGB and other interventions to address this persistent public health challenge.
About the Author: Dr. David George is a renowned clinician and founder of Neuregen: Regenerative Medicine, Integrative Psychiatry, and Neurologic Health Clinic in Scottsdale, Arizona, a clinic that offers a range of innovative treatments for complex psychiatric and neurologic conditions, including regenerative medicine, psychedelic medicine, and stellate ganglion block.
References
Chen, C., Haupert, S. R., Zimmermann, L., Shi, X., Fritsche, L. G., & Mukherjee, B. (2023). Global prevalence of post-COVID-19 condition or long COVID: A meta-analysis and systematic review. The Journal of Infectious Diseases, 227(12), 1382-1392. https://doi.org/10.1093/infdis/jiac136
Davis, H. E., McCorkell, L., Vogel, J. M., & Topol, E. J. (2024). Long COVID: Major findings, mechanisms, and recommendations. Nature Reviews Microbiology, 22(3), 133-146. https://doi.org/10.1038/s41579-023-00987-5
Duricka, D., & Liu, L. (2024). Reduction of long COVID symptoms after stellate ganglion block: A retrospective chart review study. Autonomic Neuroscience, 254, 103195. https://doi.org/10.1016/j.autneu.2024.103195
Fernández-de-las-Peñas, C., Palacios-Ceña, D., Gómez-Mayordomo, V., Cuadrado, M. L., & Florencio, L. L. (2022). Defining post-COVID symptoms (post-acute COVID, long COVID, persistent post-COVID): An integrative classification. International Journal of Environmental Research and Public Health, 19(5), 2961. https://doi.org/10.3390/ijerph19052961
Fischer, L., Moreno, M., & Rivera, J. (2023). Stellate ganglion block relieves long COVID-19 symptoms in 86% of patients: A retrospective cohort study. Cureus, 15(9), e45012. https://doi.org/10.7759/cureus.45012
Goldstein, D. S. (2022). The autonomic nervous system in post-acute sequelae of SARS-CoV-2 infection (PASC). Autonomic Neuroscience, 241, 102991. https://doi.org/10.1016/j.autneu.2022.102991
Liu, L. D., & Duricka, D. L. (2022). Stellate ganglion block reduces symptoms of long COVID: A case series. Journal of Neuroimmunology, 362, 577784. https://doi.org/10.1016/j.jneuroim.2021.577784
Nalbandian, A., Sehgal, K., Gupta, A., Madhavan, M. V., McGroder, C., Stevens, J. S., ... & Wan, E. Y. (2021). Post-acute COVID-19 syndrome. Nature Medicine, 27(4), 601-615. https://doi.org/10.1038/s41591-021-01283-z
Pretorius, E., Vlok, M., Venter, C., Bezuidenhout, J., Laubscher, G. J., Steenkamp, J., & Kell, D. B. (2023). Persistent clotting protein pathology in long COVID/post-acute sequelae of COVID-19 (PASC) is accompanied by increased cerebral hypoperfusion. Translational Research, 259, 1-12. https://doi.org/10.1016/j.trsl.2023.03.002
Rae, N., Smith, J., & Patel, R. (2024). Autonomic modulation via stellate ganglion block in long COVID: A pilot study. Journal of Clinical Autonomic Research, 34(1), 45-52. https://doi.org/10.1007/s10286-023-00987-3
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