Acupuncture at GV20 (Bai-Hui) for Sedation

I was recently asked about a specific acupuncture technique which pops up from time to time– needling or injecting medications at the location known as GV20 for calming or sedating effects.

It is always problematic to evaluate specific claims in acupuncture because-

• The underlying theories behind acupuncture are pseudoscientific nonsense.
  
• Almost no one understands this, and acupuncturists have invented many complex and scientific-sounding ad hoc explanations for how acupuncture is supposed to work. These explanations are typically unproven, and while they explain some of the effects of needling and electrostimulation (and any other minor local trauma), they don’t support the broad, system effects proponents claim for acupuncture
  
• Acupuncture points don’t exist. (a, b, c)
  
• Almost no one understands this, and acupuncturists are always identifying special characteristics for particular locations they claim as treatment points. Unfortunately, you can find something “special” (nerves, blood vessels, tendons, etc.) at nearly every point on the body, but again there is no convincing, consistent evidence that the collection of locations used for acupuncture is real.
  
• There are many clinical studies of acupuncture treatment. Some look like they show meaningful benefits. This is mostly an illusion made out of placebo effects, bias and error in study design and reporting, tooth-fairy science, and minor non-specific effects from sticking needles in things. The bottom line is that acupuncture is mostly placebo, non-specific local effects of minor trauma, and the effects of other interventions credited to acupuncture.
  
• Almost no one understands this, and the sheer size of the acupuncture literature is enough to convince a lot of people despite the fatal flaws in it.

All of this makes any attempt to challenge claims about specific acupuncture treatments challenging, and probably pointless. A thorough critical evaluation of studies around the use of GV20 is arguably meaningless if GV20 doesn’t exist and no one who believes in acupuncture will change their mind no matter what the results are. Despite that, shouting science into the void is arguably a majority of the content of this blog, so here goes….

What is GV20?
The short answer is that it is an imaginary construct that acupuncturists claim as a functional and anatomically specific treatment location. 

Traditionally, the governing vessel has been said to “connect all yang vessels in the body and functions to regulate local qi and blood, and modulate the balance between yin and yang”¹ as well as to regulate “liver fire” and “internal wind.” This, of course, is all meaningless nonsense, but despite claims to the contrary it is how this and other acupuncture treatments are determined. Attempts to find “scientific” explanations for specific points and how they work are all post hoc rationalizations for a system still founded in this kind of pseudo-religious folk mythology.

Consistent with the general trend in acupuncture to look in an area that pre-scientific folk medicine claims is special and then report whatever is found there to be the reason for why the location is special and therapeutically relevant, many papers have characterized the anatomic and physiologic features of location of “Governing Vessel 20” or “Baihui.” It has been identified by anatomic landmarks relative to the skull, ears, or hairline, the purported presence of cranial or peripheral nerves, the presence of connective tissue, proximity to the central or precentral sulcus of the frontal lobe, and other criteria.^1–4 Somewhat circularly, it has also been identified in terms of the supposed clinical effects of doing acupuncture there.

The purported uses for acupuncture at GV20 include^3,d  brain and bone marrow disorders, palpitation, stroke, loss of consciousness, chronic or acute infantile convulsion, sunstroke, irregular menstruation due to deficiency and cold in the lower jiao, dysmenorrhea…brain

disorder and mental disorder, such as heaviness of head, dizziness., vertigo, manic-depressive disorder, epilepsy, palpitation and poor memory; headache, dizziness, eye pain and redness, irritability, hypertension, anal, uterine, and vaginal prolapse and hemorrhoids; nasal obstruction and allergic rhinitis and insomnia.

This broad list is typical of claims for acupuncture, and other folk medicine traditions, which are often a hodgepodge of unrelated symptoms and conditions reflecting the foundations of these methods in vague theory and the accumulation of trial-and-error anecdotes. Most commonly, GV20 is used with the intention of sedating or calming pets for veterinary treatment, including potentially to reduce the dosage needed for sedative and anesthetic drugs. 

While this sounds like a worthy goal, given that such drugs do have risks and unwanted effects, it is critical to establish that this treatment actually works and doesn’t have its own unwanted effects before using it as a substitute for well-established and thoroughly studies science-based treatments. We do not benefit our patients by believing we have made them more comfortable and withholding necessary drugs if that belief is false.

GV20 and the Evidence
Acupuncture research inevitably raises the issue of Tooth Fairy Science. It is possible to generate extensive and impressive data and statistics evaluating imaginary treatments, and these data mislead rather than enlighten us. If Qi and Yin/Yang and meridians and points don’t exist, if they are just folk medicine metaphors unconnected with physiological reality, then clinical trials studying them can never give us reliable evidence about the value of treating them.

Acupuncture, of course, is an especially challenging practice to tests scientifically. While the folk-medicine theories behind it are nonsense, sticking needles in tissue actually does something, and it is fair to ask whether this something might have some value anyway. However, studies of acupuncture are nearly always designed, conducted, and analyzed by people who believe deeply in the power of acupuncture, so the potential for bias to influence the results is pretty great. This is seen in the consistently unreliable data about acupuncture coming from countries with a cultural bias in favor of the practice.^5–9

Of course, clinical research incorporates multiple methods for mitigating the impact of such bias, and these can be helpful. Some of them, unfortunately, are very difficult to use in acupuncture studies. Blinding, for example, is difficult to achieve with patients (who can often tell if they are really being stuck with needles or not), and it is impossible to achieve for therapists, who will always know whether they are giving “real” acupuncture treatment or a sham. Since it the demeanor of the therapist can have a significant impact on the patient’s perception of their condition, it can be difficult to trust seemingly positive results from such studies, especially when the outcome measure is something very subjective like pain, nausea, etc.

That said, we do the best we can with the evidence we have, so let’s take a look at an example of the type of research cited to support using acupuncture at GV20.

One study involved giving the common sedative dexmedetomidine, and its reversal agent, under the skin (SQ) at the GV20 location compared with giving these drugs by other routes and in other locations for the purposes of sedating dogs for x-rays.¹⁰ This is sometimes called “pharmacoacupuncture,” which seems a bit of a bait-and-switch.

Dogs were randomly assigned to get the sedative, and the reversal agent, in a vein IV), a muscle IM), or under the skin (SQ) at the GV20 point. Sedation was measured by numerous techniques and lots of comparisons were made between the various injection locations. 

There were many statistical tests done, most showing no difference form chance and some appearing to. The most consistent finding was that sedation given into a muscle was slower and less effective than sedation given into a vein. Sedation at GV20 appeared to be intermediate between the two, and generally more like IV than IM administration. 

The differences were sometimes statistically significant but it is not clear that they were clinically meaningful. The goal (taking orthopedic x-rays) was achievable for all groups, and the adverse effects were minor and not different between the IM and SQ groups (they were greater for the IV group, though none were serious or a reason not to give the sedative by this route if needed). 

So what does this have to do with acupuncture? Not much, honestly. 

The authors themselves point out that no sedative was given at a SQ spot on the head, or anywhere else, that wasn’t deemed an “acupuncture point.” Perhaps the differences had to do with giving the drug under the skin compared to in a vein or muscle. Or perhaps the head has a particularly good blood supply (scalp wounds are notorious for bleeding profusely), so drugs given SQ here absorb well. There is, in fact, another study comparing administration of sedatives at GV20 and another SQ spot on the head that found not meaningful difference between the locations, so this is quite likely the case.¹¹

There are many plausible explanations for the findings that have nothing to do with the theoretical rationale for acupuncture or the issue of whether or not it works as a general approach. This study doesn’t even convincingly justify the supposed effects of needle stimulation at GV20, much less the larger practice of acupuncture. 

Bottom Line
Nearly all the studies purporting to validate the benefits of acupuncture at GV20 use injections of drugs or electrical simulation, and none that I have seen effectively control for bias while comparing needling alone at this spot to an appropriate control. Given the implausibility of the traditional explanations for acupuncture, the lack of consistent and convincing evidence that “acupuncture points” exist as a discrete, consistent, identifiable functional entity, and the lack of solid scientific evidence to support the specific claims made about GV20, it is not appropriate to rely on needling at this point as primary component of sedation or pain control for dogs. 

As I have said in the past, acupuncture is pretty low-risk in itself, and most of the danger associated with it lies in substituting an ineffective practice for treatments that actually work. If vets want to stick a needle in the head while they also give appropriate science-based treatments for pain, anxiety, and sedation, this is unlikely to do any direct harm. But the belief that this is an “ancient,” Powerful,” or “proven” treatment method is unjustified, and it can lead to unnecessary suffering if we rely on it in place of therapies with better supporting scientific evidence.

References
1.         Yang Y, Deng P, Si Y, Xu H, Zhang J, Sun H. Acupuncture at GV20 and ST36 Improves the Recovery of Behavioral Activity in Rats Subjected to Cerebral Ischemia/Reperfusion Injury. Front Behav Neurosci. 2022;16. doi:10.3389/fnbeh.2022.909512

2.         Shen EY, Chen FJ, Chen YY, Lin MF. Locating the Acupoint Baihui (GV20) Beneath the Cerebral Cortex with MRI Reconstructed 3D Neuroimages. Evid-Based Complement Altern Med ECAM. 2011;2011:362494. doi:10.1093/ecam/neq047

3.         Qian L, Jiang Y, Lin F. Mechanism of the acupoints of the governor vessel in treatment of post-stroke depression on the base of the specificity of meridian points. World J Acupunct – Moxibustion. 2019;29(3):244-248. doi:10.1016/j.wjam.2019.07.004

4.         Martha A. Littlefield DVM MS. Anatomic Review of Ten Important Canine Acupuncture Points Located on the Head: Part I. Am J Tradit Chin Vet Med. 2019;14(2):55-66.

5.         Wang Y, Wang L, Chai Q, Liu J. Positive Results in Randomized Controlled Trials on Acupuncture Published in Chinese Journals: A Systematic Literature Review. J Altern Complement Med. 2014;20(5):A129-A129. doi:10.1089/acm.2014.5346.abstract

6.         Vickers A, Goyal N, Harland R, Rees R. Do certain countries produce only positive results? A systematic review of controlled trials. Control Clin Trials. 1998;19(2):159-166. doi:10.1016/s0197-2456(97)00150-5

7.         Masuyama S, Yamashita H. Trends and quality of randomized controlled trials on acupuncture conducted in Japan by decade from the 1960s to the 2010s: a systematic review. BMC Complement Med Ther. 2023;23:91. doi:10.1186/s12906-023-03910-3

8.         Ma B, Qi G qing, Lin X ting, Wang T, Chen Z min, Yang K hu. Epidemiology, Quality, and Reporting Characteristics of Systematic Reviews of Acupuncture Interventions Published in Chinese Journals. J Altern Complement Med. 2012;18(9):813-817. doi:10.1089/acm.2011.0274

9.         Li J, Hui X, Yao L, et al. The relationship of publication language, study population, risk of bias, and treatment effects in acupuncture related systematic reviews: a meta-epidemiologic study. BMC Med Res Methodol. 2023;23:96. doi:10.1186/s12874-023-01904-w

10.       Leriquier C, Freire M, Llido M, et al. Comparison of sedation with dexmedetomidine/atipamezole administered subcutaneously at GV20 acupuncture point with usual routes of administration in dogs presented for orthopaedic radiographs. J Small Anim Pract. 2023;64(12):759-768. doi:10.1111/jsap.13668

11.       Llido M, Leriquier C, Juette T, Benito J, Freire M. Comparison of sedation with dexmedetomidine administered subcutaneously at 2 different locations on the head in dogs. Can Vet J. 2024;65(4):351-358.