Vagus Nerve Stimulation for ME/CFS, POTS, & Long-Haul COVID
What Is the Vagus Nerve and Why Does It Matter?
The vagus nerve is one of the longest and most influential nerves in the body. Stretching from the brainstem to the abdomen, it acts as a superhighway for communication between the brain and many organs, including the heart, lungs, and digestive system. The vagus nerve plays a vital role in:
Regulating heart rate.
Supporting digestion.
Modulating the immune system.
Because of its far-reaching influence, treatments targeting the vagus nerve show promise for conditions like ME/CFS, long-haul COVID, fibromyalgia, and postural orthostatic tachycardia syndrome (POTS).
How Viruses Affect the Vagus Nerve
During acute infections, the vagus nerve prompts the body to rest and recover. However, some neurotropic viruses—viruses that infect nerve tissue—can invade the vagus nerve directly. These include:
Epstein-Barr virus (EBV).
HHV6.
SARS-CoV-2.
Enterovirus and Coxsackie virus.
When the vagus nerve becomes infected, it may over-amplify signals for rest, leading to:
Severe fatigue.
Persistent postviral symptoms like those seen in ME/CFS.
This is why antiviral drugs often fail to alleviate symptoms: they can’t effectively penetrate nerve tissues to target lingering infections.
What Is External Vagus Nerve Stimulation (tVNS)?
Vagus nerve stimulation (VNS) has been used since 1997 to treat conditions like epilepsy and depression. Traditional VNS requires surgical implantation of a device. Newer external transcutaneous vagus nerve stimulators (tVNS) offer a non-invasive alternative. These devices:
Deliver mild electrical pulses to the vagus nerve via the tragus (the small flap of cartilage at the front of the ear).
Are approved for pain management and refractory epilepsy in the EU.
How tVNS Reduces Inflammation
Chronic inflammation is central to conditions like ME/CFS, fibromyalgia, and long-haul COVID. By stimulating the vagus nerve, tVNS helps reduce inflammation through several mechanisms:
1. Activating Anti-Inflammatory Pathways
Stimulates the inflammatory reflex, which reduces the production of pro-inflammatory cytokines like IL-8 and TNF-alpha.
2. Modulating the HPA Axis
Enhances adrenal gland activity, leading to the release of glucocorticoids, powerful anti-inflammatory hormones.
3. Supporting Immune System Balance
Helps balance pro-inflammatory and anti-inflammatory signals, providing a “reset” for an overactive immune system.
4. Improving Blood Flow and Oxygen Delivery
Regular tVNS use increases blood flow and oxygen delivery, addressing hallmark issues in ME/CFS and long-haul COVID.
5. Monitoring the Gut Environment
Sensory fibers of the vagus nerve detect gut microbiota imbalances, contributing to reduced systemic inflammation.
Research on Vagus Nerve Stimulation for Postviral Conditions
Although research is still in early stages, clinical trials show promising results for tVNS in postviral conditions:
1. ME/CFS
A 2023 study of 31 ME/CFS patients found that 1 month of tVNS reduced inflammatory cytokines (e.g., IL-17A, IL-12B, and CCL28). While fatigue improvements were limited, logistical challenges may have impacted results.
A Sjogren’s syndrome study of 40 individuals using tVNS for 56 days showed improvements in fatigue, cognitive tests, and brain activity (measured by EEG).
2. POTS
tVNS helps regulate autonomic function, reducing dizziness and fatigue by improving heart rate variability and blood flow.
A 2-month study showed lower levels of autoantibodies to autonomic nervous system receptors (alpha-1 and beta-1-adrenergic).
3. Long-Haul COVID
Early research suggests tVNS may improve symptoms like fatigue, brain fog, and heart palpitations by restoring autonomic balance and reducing inflammation.
In a 2022 study, 6 weeks of daily tVNS improved quality-of-life scores for long-haul COVID patients.
Benefits and Limitations of tVNS
Benefits
Non-invasive and generally well-tolerated.
Reduces systemic inflammation, potentially alleviating fatigue, pain, and brain fog.
Offers a multi-faceted approach by targeting the autonomic nervous system, immune response, and inflammation.
Limitations
Clinical trials with larger cohorts are needed to confirm efficacy.
Devices vary in electrical frequencies and vagus nerve targeting, and standardized protocols (e.g., treatment duration) are lacking.
Contraindicated for certain individuals, including pregnant women and those with pacemakers or implanted electrical devices.
Final Thoughts: A Promising Tool for Postviral Conditions
Of all emerging treatments for postviral syndromes like ME/CFS, POTS, and long-haul COVID, vagus nerve stimulation holds great promise. While more research is needed, current studies suggest that tVNS could provide symptom relief by reducing inflammation, improving autonomic regulation, and supporting immune system balance.
If you’re exploring treatment options for chronic fatigue, pain, or postviral symptoms, vagus nerve stimulation is worth discussing with your healthcare provider. As research progresses, tVNS may become a key tool in managing these complex conditions. Dr. Craig has been trialing the Nurosym device. Stay tuned for updates on social media.
References
1. Linnhoff S, Koehler L, Haghikia A, Zaehle T. The therapeutic potential of non-invasive brain stimulation for the treatment of Long-COVID-related cognitive fatigue. Front Immunol. 2023 Jan 9;13:935614. doi: 10.3389/fimmu.2022.935614. PMID: 36700201; PMCID: PMC9869163. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9869163/
2. Sant'Anna FM, Resende RCL, Sant'Anna LB, et al. Auricular vagus nerve stimulation: a new option to treat inflammation in COVID-19?. Rev Assoc Med Bras (1992). 2023;69(6):e20230345. Published 2023 Jun 2. doi:10.1590/1806-9282.20230345
3. VanElzakker MB. Chronic fatigue syndrome from vagus nerve infection: A psychoneuroimmunological hypothesis. Med. Hypotheses (2013), http://dx.doi.org/10.1016/j.mehy.2013.05.034
4. Tarn J, Evans E, Traianos E, et al. The Effects of Noninvasive Vagus Nerve Stimulation on Fatigue in Participants With Primary Sjögren's Syndrome. Neuromodulation. 2023;26(3):681-689. doi:10.1016/j.neurom.2022.08.461
5. Rodriguez L, Pou C, Lakshmikanth T, Zhang J, Mugabo CH, Wang J, Mikes J, Olin A, Chen Y, Rorbach J, Juto JE, Li TQ, Julin P, Brodin P. Achieving symptom relief in patients with myalgic encephalomyelitis by targeting the neuro-immune interface and optimizing disease tolerance. Oxf Open Immunol. 2023 Apr 17;4(1):iqad003. doi: 10.1093/oxfimm/iqad003. PMID: 37255930; PMCID: PMC10148714.
6. Stavrakis S, Chakraborty P, Farhat K, et al. Noninvasive Vagus Nerve Stimulation in Postural Tachycardia Syndrome: A Randomized Clinical Trial. JACC Clin Electrophysiol. 2024;10(2):346-355. doi:10.1016/j.jacep.2023.10.015 https://pubmed.ncbi.nlm.nih.gov/37999672/
7. Natelson, B., Blate, M. & Soto, T. Transcutaneous Vagus Nerve Stimulation in the Treatment of Long COVID-Chronic Fatigue Syndrome. Preprint at https://doi.org/10.1101/2022.11.08.22281807.
