September: Pain Awareness Month – What is Pain in TCVM?

Emily Mangan, DVM, CTCVMP, CCRV, CVMMP

The use of acupuncture for analgesia is one of the best-supported and widely-studied benefits of acupuncture. From the early 1970s, when scientific inquiry started investigating acupuncture in the West, early studies identified that acupuncture had analgesic effects. Over the last 50 years, as the scientific method matured, so did our understanding of the complex cascades and neuromodulatory effects that resulted in diminished pain in animals.

The Gate Control Theory of Pain, popularized by Ronald Melzack and Patrick Wall in 1965, is one of the fundamental theories of pain suppression.^1,2 While we know acupuncture has various mechanisms within the body, the Gate Control Theory explains how stimulation of A-β fibers by acupuncture needles leads to stimulation of an inhibitory interneuron within the spinal cord. This interneuron inhibits transmission of C nociceptive fibers, which classically transmit pain signals. Thus, inhibition of C nociceptive fibers decreases pain.

Beyond the Gate Theory, we now know there are also a host of other local, segmental (spinal cord), and suprasegmental (brain) effects of acupuncture that function to decrease nociceptive signaling and pain perception in the body.² These effects include mast cell degranulation, ATP release, release of endogenous opioids, suppression of NMDA receptors and inhibition of substance P release, all of which have well-documented analgesic effects.^2,3

While the World Health Organization identified acupuncture as a useful modality for management of post-operative pain in humans in 2002, recent studies have identified efficacy for pre-, intra-, and post-operative pain relief for dogs undergoing ovariohysterectomy,⁴ hemilaminectomy,^5,6 and a variety of other surgical interventions. Acupuncture has also been recognized as pain management for naturally-occurring orthopedic or musculoskeletal disease, including coxofemoral osteoarthritis in dogs and thoracolumbar and gluteal pain in horses.

With all this information, it is no surprise that acupuncture is quickly being integrated into multimodal pain management plans in veterinary medicine.

What is pain from a TCVM perspective?

In the simplest terms, pain is felt when there is Stagnation of Qi or Blood. There can be a variety of causes of Qi and/or Blood Stagnation, but the end result is often pain.

The treatment principle of pain in TCVM is therefore straightforward: Clear Stagnation and the pain will be resolved. It’s important to remember that Stagnation is often not the primary diagnosis and that there are frequently underlying pattern diagnoses that predispose the animal to developing areas of Stagnation. Treatment of the Stagnation as well as the underlying patterns are paramount to success.

Pain of any type is debilitating. Chronic pain not only impacts quality of life, but also results in central sensitization or “wind up” pain that can become intractable and even more difficult to manage. Creating a multi-modal pain management plan is therefore vital for ethical and conscientious care of our companions and patients.

Pain Management Case Study

History

Connie, a 12-year-old black Labrador Retriever, presented for progressive hindlimb weakness and difficulty rising. She was previously diagnosed with hip dysplasia as a young dog and she had been receiving carprofen daily for the last several years. A few days before presentation, after a midmorning nap, she had been unable to rise without assistance, which prompted her visit.

TCVM Evaluation

Connie was a balanced Earth constitution. Her tongue was red and wet, and her pulses were thready, choppy, and weaker on the right. Her head and back were warm and she panted constantly. She was sensitive to palpation of BL-54 bilaterally, and resented hip extension. Coxofemoral crepitus was appreciated on hip range of motion. She was also sensitive to palpation of iliopsoas and other hip flexors and she had bilateral hind limb atrophy with a local muscle condition score of 1/3.

Pattern Diagnosis: Kidney Qi and Yin Deficiency Bony Bi Syndrome with Local Qi/Blood Stagnation at bilateral coxofemoral joints.

TCVM Treatment Principles: Clear Local Qi/Blood Stagnation and tonify Kidney Qi and Kidney Yin

Acupuncture Point Prescription

GV-20, GV-14, Bai-hui, Shen-shu, LIV-4, LIV-3, ST-36, SP-6, KID-3, BL-11, BL-23, BL-40, BL-54, GB-29, GB-30

GV-20 – Permission, calming

GV-14 – Clear Heat

Bai-hui – Permission point, local to hind end

Shen-shu– Tonify Kidney, local to the hind end

LI-4 and LIV-3 – The Four Gates to clear Stagnation

ST-36 – Tonify Qi

SP-6 – Tonify Yin

KID-3 – Yuan source point for the Kidney

BL-11 – Influential for Bone

BL-23 – Back-shu Association for Kidney

BL-40 – Master point for hips and low back

BL-54 – Master point of the hind limb

GB-29 and GB-30 – Local to the hip to clear Stagnation

Herbal Formula prescription

Di Gu Pi^†

• Tonify Kidney Qi and Yin
• Clear Deficient Heat
• Dispel Wind-Damp
• Dose at 100mg/kg by mouth twice daily

Treatment Outcome

After the first treatment, Connie slept most the day. The second day, she was able to rise on her own and navigate the steps from the porch to the lawn and back. She was also prescribed therapeutic exercises to strengthen the hind limbs. After her 2^nd treatment, she was more comfortable and her tongue was less red and began to show more purple. At the 3^rd treatment, she was panting less and seemed more comfortable and content, and was able to consistently navigate around her home environment and the steps to the yard. Her owners remarked that she was acting like her younger self.

Summary

Connie’s case is a good example of underlying pattern diagnoses of Kidney Qi and Yin Deficiency contributing to the formation of Bony Bi Syndrome, Local Qi/Blood Stagnation and ultimately, pain. Connie also had a component of Kidney Jing Deficiency (early onset of hip dysplasia predisposing her to Bony Bi), as well as Spleen Qi Deficiency, and both of these diagnoses did become apparent in her TCVM exam after the initial Stagnation and False Heat had been cleared. She was initially brought for TCVM consultation due to weakness in the hind end, but it turns out that her weakness was actually secondary to severe osteoarthritis pain due to hip dysplasia. Once her pain was adequately managed, she was able to strengthen her hind limbs and regain the ability to rise.

^†Dr. Xie's Jing Tang Herbal

References

1. Mendell LM. Constructing and Deconstructing the Gate Theory of Pain. Pain 2014;155:210–216.

2. Huntingford JL, Petty MC. Evidence-Based Application of Acupuncture for Pain Management in Companion Animal Medicine. Vet Sci 2022;9:252.

3. Dewey CW, Xie H. The scientific basis of acupuncture for veterinary pain management: A review based on relevant literature from the last two decades. Open Vet J 2021;11:203–209.

4. Luna SPL, Martino ID, Lorena SER de S, et al. Acupuncture and pharmacopuncture are as effective as morphine or carprofen for postoperative analgesia in bitches undergoing ovariohysterectomy. Acta Cir Bras 2015;30:831–837.

5. Machin H, Taylor-Brown F, Adami C. Use of acupuncture as adjuvant analgesic technique in dogs undergoing thoracolumbar hemilaminectomy. Vet J 2020;264:105536.

6. Laim A, Jaggy A, Forterre F, et al. Effects of adjunct electroacupuncture on severity of postoperative pain in dogs undergoing hemilaminectomy because of acute thoracolumbar intervertebral disk disease. J Am Vet Med Assoc 2009;234:1141–1146.