Stellate Ganglion Block treatment

[Hutan]

It seems like, another season, and another hyped ME/CFS/Long Covid treatment appears. The first day of Autumn in Australia and I've become aware of Stellate Ganglion Block Treatment.

Bye-Bye Fight or Flight? Hello Better Blood Flows? Stellate Ganglion Blocks, Long COVID, and ME/CFS/FM/POTS
Cort Johnson wrote an article about it in late December 2021.
That article suggests that the fight or flight response is on high alert in ME/CFS, FM and POTS.

Various drugs and mindfulness/meditation techniques have been used in an attempt to calm the fight or flight response down in these diseases. One intriguing technique, though, called stellate ganglion block (SGB) has almost never popped up in the ME/CFS, FM, or POTS medical literature. Demonstrating again, long COVID’s ability to shake things up and get investigators peering into all sorts of corners, it just showed up in a case series report for long COVID.

This old technique – developed in the 1930s – essentially jams a central waypoint for sympathetic nervous system activity called the stellate ganglion. These nerve bodies transport fight or flight messages to the upper spinal cord and brain. The technique consists of injecting an anesthetic near this big nerve body to temporarily block the fight or flight messages and hopefully reset the system.

One side of the neck is usually done in one day and the other side the other day. The procedure usually takes about 30 minutes after which the patient can return home. Different patients require different protocols. From 2 to 10 injections can be done, and the risks are described as “very low”.

The evidence for the technique in ME/CFS/Long Covid appears to be a single paper written by the owner of a company, Neuroversion, that offers the treatment. It consists of case studies, reporting reduced levels of symptoms following treatment in two women with Long Covid who underwent the procedure.

That paper is discussed on the forum here:
Stellate ganglion block reduces symptoms of Long COVID: A case series (2021) Liu et al
It has the usual problems of case studies, notably open label treatment with a very small and selected sample (in this case, 2 people), compounded by the conflict of interest created by the author's ownership of a company selling the treatment.

 

[Wonko]

I find the hypothesis confusing.

Where, in the body below the 7th spinal vertebra, do they think the fight or flight 'reflex' comes from?

Coz they must think it's somewhere other than the brain, or blocking its path to the brain would be pointless.

 

[shak8]

https://paincenterhouston.com/stellate-ganglion-blockade/

Edit to add: quote from above link:

"What does the procedure do?
When you block the stellate ganglion, you are blocking the sympathetic nervous system, thus providing relief in neuropathic pain. In a sense, SGB “reboots” the sympathetic nervous system to its pre-trauma state, similar to a computer reboot.
It is useful to:

• Diagnose the cause of pain in the face and head, arms and chest
• Manage pain in the head, neck, chest or arm caused by nerve injuries.
• Reduce sweating in the face, head, arms and hands
• Treat reflex sympathetic dystrophy, sympathetic maintained pain or complex regional pain syndrome, including phantom limb pain
• Relieve symptoms of PTSD."

bolding mine.

 

[Hutan]

Not only that @Wonko, but briefly blocking the flight or flight reflex's path to the brain just a couple of times seemed to do the trick for the two women in the case study.

I'm presuming the anaesthetic lasts roughly as long as a dental anaesthetic. So, stopping the 'fight or flight reflex' getting to the brain for the half hour or whatever seems to have this miraculous permanent effect in a way that relaxing in a nice warm bath with a box of chocolates to hand does not.

It is possible the hand-wavy fight or flight explanation could be wrong but the treatment actually does work in some other way. Cort provides this diagram ( ) with the suggestion that blood flow to the upper body is increased - although again, if it does occur, it is presumably just a temporary effect.

 

[Wonko]

Even assuming that the brain plays absolutely no part in initiating the fight or flight 'reflex' then surely this 'reflex' isn't entirely composed/contained in the nervous system but also has other components, like hormones.

I think that the hypothesis and it's proposed mechanism is 'unlikely'.

 

[Hutan]

A recent review of stellate ganglion block studies focused on reducing sympathetic nervous system-driven pain disorders (which may include fibromyalgia) reported that the pain reduction achieved was “highly significant” and that the procedure was “safe and effective”.

That review is
Effectiveness, Safety, and Predictive Potential in Ultrasound-Guided Stellate Ganglion Blockades for the Treatment of Sympathetically Maintained Pain
Aleanakian et al 2020


This was not actually a 'review of studies'. They retrospectively analysed the clinical records of 105 patients who, between them had 809 ultrasound guided SGBs at the authors' institution. The patients had 'complex regional pain syndrome (CRPS) and neuropathic pain syndromes (all potentially including sympathetically maintained pain)'.


The paper notes that the evidence base for the treatment has been regarded as unsatisfactory:

Despite numerous studies demonstrating the potential of SGBs to reduce pain in CRPS2-5 and herpes zoster,6, 7 clinical guidelines remain conservative in recommending SGBs,8 implying that available published data are unsatisfactory.

The paper's approach to deciding if the treatment is successful is if pain reduction is reported: (umm, controls, blinding, placebo effect, natural healing over time...)

Data summarized here present a pragmatic approach assigning success of the SGB to pain reduction retrospectively, ie, if pain reduction is present, the preceding SGB is considered successful.

In addition to the SGB series, all patients underwent standard treatment consisting of physiotherapy, occupational therapy, and individually adjusted medication, including non-opioid analgesics (ibuprofen, metamizole, paracetamol), opioid analgesics, anticonvulsants (carbamazepine, gabapentin, pregabalin), antidepressants (amitriptyline, citalopram, doxepin, sertraline), and (for patients with CRPS only) corticosteroids. ...Additional treatment of underlying diseases beyond pain management, especially in the case of AHZ, was performed when indicated according to current guidelines.

So, there's the potential for not just the passage of time to impact on the pain the patients report. For goodness sake, they were giving some of the patients opioids and gabapentin, as well as this treatment. That surely is a fatal flaw.

Patients underwent a variable number of separate blockades during individual series. Series were ended when no further pain reduction was seen in the clinical setting.

And so they took the estimate of pain change from the baseline until the pain level reported stopped reducing. So, if the pain was 9 out of 10 to start with, and the pain reduced down to 8 out of 10 and then 7 out of 10 and then went back up to 9 out of 10, they would assume the level of pain had reduced from 9 to 7.

This is a really rubbish study - there is no point in looking at the results. It certainly does not present evidence that the procedure is useful in treating neuropathic pain.

And, not a risk-free procedure.

Additionally, there is only scarce literature analyzing the safety and incidence of complications of SGBs.12-14 Common complications range from transient hoarseness and dysphagia13, 15 to more severe retropharyngeal or cervicomediastinal hematoma,16, 17 or life-threatening convulsions.12, 18

This is the report on side effects relating to the 809 procedures. Note that 3 were categorised as potentially life-threatening. 'Aspiration of blood' probably wasn't a fun time either.

 

[Hutan]

It’s reported, though, to be quite safe

A recent review of stellate ganglion block studies focused on reducing sympathetic nervous system-driven pain disorders (which may include fibromyalgia) reported that the pain reduction achieved was “highly significant” and that the procedure was “safe and effective”.

Clinical studies report that the procedure is safe and takes about 30 minutes.

Sorry to hammer home the point. Cort's reporting on that Aleanakian study was inaccurate in terms of it being evidence of efficacy, as was the impression he gives of the safety profile of the treatment. Cort should have done better when it came to reporting on SGB treatment.

 

[Milo]

Sorry to hammer home the point. Cort's reporting on that Aleanakian study was inaccurate in terms of it being evidence of efficacy, as was the impression he gives of the safety profile of the treatment. Cort should have done better when it came to reporting on SGB treatment.

Very honestly, nothing is gained by reading his interpretations of “science”.

 

[Hutan]

There seems to be an industry built around providing SGB treatment to people with PTSD. See for example the Stella network of clinics in Australia. It seems that these treatments are covered by private health insurers.

So, what's the evidence of SGB for PTSD? It's actually pretty minimal, and unconvincing.


Stellate Ganglion Block for the Treatment of Posttraumatic Stress Disorder: A Randomized, Double-Blind, Controlled Trial
Hanling et al, 2016
I can't see the whole study and the abstract does not report sample size or quantify outcomes. It's a military study. It concludes

Although previous case series have suggested that SGB offers an effective intervention for PTSD, this study did not demonstrate any appreciable difference between SGB and sham treatment on psychological or pain outcomes. Future studies should examine if differences in treatment methods or patient population could allow individuals with PTSD to benefit from SGB, but current evidence does not support widespread or indiscriminant clinical use of the procedure for PTSD.

Effect of Stellate Ganglion Block Treatment on Posttraumatic Stress Disorder SymptomsA Randomized Clinical Trial
Olmsted et al, 2019

Multiple other case series showed promising results with anxiety symptoms associated with PTSD.11-13 However, the first pilot, randomized clinical trial (RCT) of SGB for combat-associated PTSD14 did not find a significant difference between the SGB group and the saline-injection control group. There have been procedural and methodologic criticisms of this study.15 The mechanism by which temporary interruption of the cervical sympathetic chain could improve PTSD symptoms is not well understood. In the absence of level 1 evidence, we designed and conducted this RCT.

The study (also a military one) aimed to be blinded, with the SGB treatment and a sham treatment, and it does sound as though they went to quite a bit of effort to ensure the blinding was effective. Even so, I think, and the researchers acknowledge, that some of the participants could probably tell if they actually received the nerve blocker - there are tell-tale symptoms. The sham injection was not in the same place as the real injection.

The clinicians who did the procedure could not be blinded. Probably they had expertise in the procedure, so perhaps they stood to gain prestige if the procedure was found to be useful. So, it's possible that the clinicians did give some hint of whether the person was receiving the real or sham treatments.

The primary outcome was PTSD symptoms measured at baseline and at 8 weeks (CAPS-5 scale). Two SGBs (or shams) were administered. 74 people were allocated to the SGB treatment and 39 were allocated to the sham treatment.

The people receiving the real treatment did show better improvement than the people receiving the sham treatment. There were a few different approaches to analysis (intention to treat, some exclusions), but most of them resulted in the people with the real treatment getting a mean reduction in the PTSD score of around 12 ( on a scale from 0 to 80), whereas the people with the sham treatment had a mean reduction in the PTSD score of around 6. Some of the people knew the intervening physician or received a non-centrally randomised intervention. There were some dropouts (only 31 out of the 39 sham treatment participants were counted).

I don't find the outcome of the trial convincing as there was quite a bit of overlap in results, the numbers of people in the sham treatment was a bit low and the percentage of sham dropouts was high, the previous RCT was negative, the US defence forces seem to offering the treatment to personnel with PTSD so there are people in the system who want the treatment to be found useful, and the common signs of the nerve block mean that complete blinding was impossible. Also, we still don't have any sensible mechanism to explain why this would work, other than as a high quality placebo. Nevertheless, it was a decent trial and it found some benefit.

I think it's reasonable for proponents of the treatment for PTSD to conclude that further trials making an even greater effort to manage the blinding and involve researchers with equipoise could be justified. I don't think it's reasonable for this treatment, which is not risk-free, to be offered to people outside of good trials. Particularly, I don't think private companies should be allowed to suggest the treatment is proven useful. Companies like the Stella Group should absolutely not be allowed to say, as they do on their website:

SGB is a widely studied and highly effective treatment that has shown in most cases to “reset” the brain to its pre-trauma state.

 

[Mij]

They have an ongoing clinical study for post-menopausal women.

Exclusion Criteria:

conditions that preclude SGB or sham intervention (e.g., anatomic abnormalities of the anterior neck or cervical spine ; goiter, cardiac/pulmonary compromise; contralateral (left-sided) phrenic nerve paralysis or diaphragmatic paresis; history of seizure, coma, or stroke; history of neurologic deficit to the brachial plexus or an abnormal brachial plexus neurologic exam; history of Zenker's diverticulum; acute illness/infection; coagulopathy or bleeding abnormalities; INR >1.3; hemoglobin<9.0, platelets <100,000, BUN ≥ 30mg/dl; creatinine ≥ 2 mg/ml; ALT (SGPT), AST (SGOT), Alk Phos ≥ three times the upper limit of normal; serum potassium (K+) ≤ 3.5 or ≥ 5.0 mEq/L allergic reactions or contraindications to a local anesthetic or contrast dye, systolic blood pressure (SBP) >140 mm Hg or diastolic blood pressure (DBP) >90 mm Hg, pregnancy.

https://clinicaltrials.gov/ct2/show/NCT02907983

The exclusion criteria includes acute illness/infection; coagulopathy or bleeding abnormalities. Wouldn't that be an exclusion criteria for LC?

 

[Hutan]

ongoing clinical study for post-menopausal women

Thanks Mij, it does feel as though this is a treatment in search of a disease.

 

[forestglip]

Youtuber Dianna Cowern has apparently received this treatment.

 

[Trish]

It's a one minute video showing the treatment, nothing about effects.

 

[Braganca]

Having this done on Monday. I have neuropathic itch on my arms, and it’s been prescribed for that. Mostly it’s on forearms but can go higher. The itch started with ME onset 11 years ago, but became worse past 2 years. For a year antihistamines helped I think because they have a anticholinergic effect. Now it mostly comes on like clockwork at about midnight or 1am, first on right arm, a few mins later on the left arm. I ice it and it subsides. But it can also happen during daytime. Will post here any result on SGB for itch or for ME symptoms.

 

[Utsikt]

@Braganca Any updates?

 

[Braganca]

@Braganca Any updates?

Hi.. sadly zero effect on neuropathic itch or ME symptoms. The doctor was really expecting it to help with the itch, so it’s a pity.

 

[Utsikt]

Hi.. sadly zero effect on neuropathic itch or ME symptoms. The doctor was really expecting it to help with the itch, so it’s a pity.

That’s a shame.. I hope you get some relief soon!