Counter-stimulation, Acupuncture & Pain Relief

[See video above] New technologies for Virtual Reality, as evidenced by Snow World, add fuller dimension to the evolving idea of pain relief.

The idea of counter stimulation – where sensory stimulation reduces our perception of pain, either locally or distally – is not new. We do it all the time, clenching our faces in pain or wriggling our toes when the masseur presses down hard at one spot. It’s instinctive for most of us to rub our bruises as if that act of rubbing takes the pain away. But it does – most of the time – until we stop rubbing or putting pressure on the spot. And remember how you would slap that itch away.

Today, we understand it as a crowding out of pain, where we interfere with the sensation of pain by creating other sensations that our sensory nerves detect and send to the brain. These sensations may include different types of touch (rubbing, pressing, slapping) or different temperatures (hot, cold). That’s how it works, but let’s move on to review some approaches developed through the centuries.

Traditional approaches: Massage and Acupuncture as Counter-stimulation

One would postulate that massage and acupuncture probably came about as described above, when parts of the body that were painful were rubbed to ease the pain. These points – called A-shi points – are still indicated in massage or acupuncture treatment, and we understand intuitively that most times it makes sense to stimulate the spot that is painful. The pricking of the skin with a needle is understood to give this effect.

But I think it’s often more than this. Rubbing your bruised arm is not just counter-stimulation – it may also relax the muscles by creating warmth, or help disperse chemical mediators in the area. In a similar way, the effect of acupuncture is much more. Some say it causes the brain to release enkaphalins (endorphins) or regulates the release of neurotransmitters as serotonin, dopamine et al. Some points certainly have more marked endocrine effect, and may cause a variety of changes in our body chemistry, dilating vessels and bringing in the healing salvation of blood to the area, or boosting the production of hormones that the body is in need of but not making. It runs a large gamut, and may not be as easy to pin down as we’d like.

Gate theories are also used to explain the effect of acupuncture on pain perception and on motor function.

  • Gate control theory sees pain perception as controlled by a gate between the place you’ve been pricked (locatin of impulse generation) and the brain. We know that pain travels via sensory nerve fibers to be relayed to the brain. But this gate closes up and blocks off the transmission of pain IF the pain impulses are getting through too much too quickly. The thin C fibers have been found to exhibit such a “gate” function.
  • Gates may not just exist in sensory fibers. When implicated in motor fibers, stimulation of the fibers – whether by massage, acupuncture or exercise – reopens a closed gate, hence enabling motor impulses from the brain to reach muscles or internal organs. This is not just useful for treating impaired muscle function, but may also be helpful when we think that nerves leading to certain organs are “blocked.”

Traditional Approaches: Counter-irritants

I put counter-irritants in a different category, because whether correct or otherwise, I think of counter-irritants as liniments or ointment that are rubbed on painful parts of the body.

In general, application of a counter-irritant will not only crowd out the primary course of pain (e.g. arthritis) but will also induce inflammation. Inflammation involves vasodilation, blood moving in with oxygen to nurture the local area and with neutrophils and macrophages to get rid of any byproducts, and perhaps other chemical mediators that will assist in healing.

So, the idea here is that inflammation inadequate with chronic pain. We may thus need to induce inflammation – in moderation – to aid healing.

This may be over-simplifying it, but counter-irritants are:

  • analgesic: by crowding out the primary source of pain.
  • vasodilating: by inducing benevolent inflammation.

This would be a good explanation for why moxibustion, baguan and gusha are TCM treatments that may be both analgesic and beneficial to the healing process.