Stellate ganglion block
Injection of local anesthetic near the stellate ganglion to block activity of the entire cervical sympathetic chain has been used for nearly a century to treat a variety of sympathetically mediated conditions, including complex regional pain syndrome (CRPS), shingles, and phantom-limb pain. More recently, it has been used in a variety of other conditions, including PTSD, Raynaud’s disease, menopausal hot flashes, and hyperhidrosis.
Insurance companies typically cover it for CRPS, neuropathic upper-extremity pain, hyperhidrosis, and Raynaud’s, said Luke Liu, MD, an anesthesiologist who is founder and chief executive officer of Alaska-based pain management company Neuroversion.
Deborah Duricka, PhD, also with Neuroversion, presented results from a now-published case series of 11 patients with long COVID who underwent stellate ganglion block by a board-certified anesthesiologist, first on one side at the level of C6, then on the contralateral side the following day.
Clinically meaningful benefits were seen in at least five of the patients in fatigue, memory problems, problems concentrating, rapid heartbeat, orthostatic intolerance, sleep problems, postexertional malaise, anxiety, and depression.
The hypothetical mechanism, she said, is that “sympathetic block prevents sympathetically driven vasoconstriction in carotid and vertebral arteries.”
Dr. Liu presented another case series of five patients with ME/CFS who underwent the procedure with ultrasound guidance, again on one side and the other side the next day. All had upper-limb autonomic issues such as Raynaud’s and/or neuropathic pain that had been refractory to more conventional treatments.
All five patients reported improvements in symptoms of ME/CFS, including energy level, cognition, pain, and postexertional malaise. One patient reported “feeling well for the first time in decades.” However, that patient relapsed after a mild viral illness 3.5 months after treatment. Some of the patients have required further treatments.
Dr. Lapp commented that, although the procedure is generally safe when performed by an experienced clinician, “Any time you do an injection like that, there’s a high risk that you could nick an artery or a vein or hit an essential nerve in the neck. That’s why it has to be done under fluoroscopy or ultrasound.”
He said he’s had a few patients undergo the procedure, mostly for CRPS, and they seem to have benefited from it. “It might increase cerebral blood flow and preload to the heart, so it might decrease ME/CFS symptoms and help with POTS as well.”
Nonetheless, Dr. Lapp said he wouldn’t consider stellate ganglion block as first-line treatment for ME/CFS or long COVID. “I think it would be for the treatment-resistant patient, when you’ve gone through all the treatments that we know and addressed all the comorbidities and they’re still not getting better.”
But, he added, it is a standard procedure. “Any pain clinic can do a stellate block.”
Transcutaneous auricular vagus nerve stimulation
Nicola Clague-Baker, PhD, a physiotherapist at the University of Liverpool (England), presented findings from an international survey of people with ME/CFS regarding their experience with transcutaneous auricular vagus nerve stimulation (taVNS) to manage their autonomic symptoms. The technique involves stimulation of the autonomic nervous system via the vagus nerve using electrodes applied to part of the ear. The theory is that the technique stimulates the parasympathetic nervous system and improves autonomic balance.
Two small previous trials showing benefit of vagus nerve stimulation for people with ME/CFS used more invasive and less comfortable methods of applying the stimulation rather than to the ear, Dr. Clague-Baker and colleagues noted in a poster. It has also been used successfully in treating POTS, another conference speaker noted.
A total of 131 people with ME/CFS (called simply “ME” in the United Kingdom) responded to a survey advertised on social media and websites. The majority (60%) were from the United Kingdom while the rest were from Europe, Australia, and North America. Most were female, and slightly more than half had lived with ME for 10 or more years.
The majority (72%) were still using taVNS, while 28% had stopped using it. Only 9% had used the modality for longer than a year. Respondents identified more than 30 benefits in symptoms and activities, with improvements in postexertional malaise (39%) and brain fog (37%) being the most common. One reported significant reduction in constipation.
However, respondents also mentioned more than 20 short- and long-term negatives, including headaches (15%) and long-term irritation at the site (9%). One participant reported a “big improvement in neuropathic pain, but not so much for muscles and joints.”
Overall, 80% reported that they would continue using taVNS and 67% said they would recommend it to others with ME, and 56% said that the system was mildly to very beneficial.
Dr. Lapp noted that several types of transcutaneous electrical nerve stimulation units with ear clips are sold online, and he’s seen them work well for migraine treatment. However, he cautioned that some patients have had side effects from the treatment, such as headaches and dizziness. “It’s putting an electrical current through your brain. In my mind, it’s another last-ditch measure.”
Dr. Lapp reported no financial disclosures.
A version of this article first appeared on Medscape.com.