One of the principle qualities of pain is that it demands an explanation.
Plainwater, by Anne Carson

published 12/19/06

Pain Is an Opinion

What recent discoveries in neurology can do for you now

by Paul Ingraham, Vancouver, Canada (qualifications)

The only time I have “flare-ups” seems to be when I'm in a very “stressed-out” period. For instance, just this weekend, I was trying to film a short film that I helped write. However, I am no actor. On the first “shoot,” I was super anxious, lots of adrenaline pumping through me, and it was like I could actually feel the nerve endings in my wrists and hands becoming ultra-sensitive … like they were going to flare up if I did anything. And … they did. Just from lifting some light equipment that day, it pushed me over the edge. That experience alone made me more interested in the “nervous system” aspect of my problem.
Jamie Vance, musician struggling with tendinitis

Not-so-recent discoveries about the physiology of pain have been — pun intended — painfully slow to reach the public, or even general practitioners and physical therapists. This knowledge is useful, and needs to be shared. Health care professionals need it so that they can beat a hasty retreat from some particularly unfortunate old attitudes about pain problems (“if I don’t understand it, it must be all in your head”). Patients need it so they can get some truly comforting perspective … not to mention relief!

I can hardly imagine a better argument that we need a more biologically literate society.1

Ramachandran’s excellent phrase

Ramachandran said, “pain is an opinion” — which sounds like a flaky New Age mind-over-matter theory. But Ramachandran is no mystic or guru. He is a medical scientist, a neurologist. The passage below, from his book, Phantoms in the Brain, is mainly known for the first handful of words, a brilliantly concise statement of the modern understanding of how pain works.

Pain is an opinion on the organism’s state of health …

But the passage continues, referring to an extraordinary cure Ramachandran achieved treating a man with phantom limb pain. The man was tortured by agony in a clenched fist that was not there. With a clever arrangement of mirrors, Ramachandran created the illusion that the man’s amputated arm was restored — a sort of “virtual” limb. The mere appearance of his phantom hand opening and closing normally cured the agonizing “spasms.” It is one of the most curious anecdotes in all of pain science.

Pain is an opinion on the organism’s state of health rather than a mere reflective response to an injury. There is no direct hotline from pain receptors to ‘pain centers’ in the brain. There is so much interaction between different brain centers, like those concerned with vision and touch, that even the mere visual appearance of an opening fist can actually feed all the way back into the patient’s motor and touch pathways, allowing him to feel the fist opening, thereby killing an illusory pain in a nonexistent hand.
Phantoms in the Brain, by VS Ramachandran and Sandra Blakeslee

Since then, “mirror therapy” has been studied and applied in many ways2 — although a 2006 study did not show that it was effective at reducing phantom limb pain, as Ramachandran claimed to have seen.3

Pain in the old days

For most of the history of medical science, pain was believed to work like this:4

Something bad happens to the body.
Nerves send a message to the brain about the problem, and the intensity of the message is directly proportionate to the severity of the injury.
The brain interprets the message at face value — that is, if the message says, “There’s some bad damage here,” we believe it.

But it’s just not that simple. For several decades now, it’s been clear to pain scientists and most health care professionals that this model is hopelessly inaccurate. The real situation is much more complicated … and interesting!

What goes up, must come down

It turns out that the brain is not just a passive, gullible receiver for whatever pain messages the peripheral nerves send upstairs. And, if you think about, it’s kind of strange that we would think of it that way. This is, after all, the brain we’re talking about: seat of consciousness, the generator of your reality.

The brain is not just a passive, gullible receiver for whatever pain messages the peripheral nerves send upstairs.

Not only does the brain critically evaluate every pain message it receives, considering it in context, checking it out like a piece of fruit at the grocery before deciding whether or not to buy it, it also sends messages downwards that affect the sensitivity and behaviour of nerve endings.5

Everything that hurts involves a conversation, a sort of debate, between the central and peripheral nervous system. It could be dramatized like this:

NERVES	Got problems here! Bad problems! Red alert!
BRAIN	Yeah? Hmm. Okay, so noted. But you know what? I have access to information — sorry, it’s classified, you’ll just have to take my word for it — that suggests that we don’t have to worry about this much.
NERVES	I’m telling you, this is serious!
BRAIN	Nope, I don’t buy it.
NERVES	Look, I may not have access to this “information” you’re always talking about, but I know tissue damage, and I am not kidding around, this is a credible threat, and I am going to keep telling you about it.
BRAIN	Actually, you’re having trouble remembering what the problem is. You’re going to send me fewer messages for a while.
NERVES	Uh, right. What was I saying? Gosh, it seems like just a second ago I had something important to say, and it’s just gone. I’ll get back to you later I guess …

The brain can boss nerves around, tell them how sensitive to be. When anxious, the brain might request “more information” from the peripheral nerves, ordering them to produce more signals in response to smaller stimuli. Or it might do exactly the opposite. In short, messages about pain don’t just go up to the brain, they go down. This two-way functionality in the pain system is the main difference between modern and old pain science. But there’s more.

The brain can boss nerves around, tell them how sensitive to be.

There is extensive recent evidence that the peripheral nerves can even physically, chemically change, perhaps in response to brain requests, tissue conditions, or both. To extend the analogy, this isn’t just twiddling the volume knob, but changing the equipment, changing the signal before it even gets to the “amplifier.”

More simply, and probably more importantly, we only feel what our brains allow us to feel. Incredibly “loud” sensory messages can be filtered down to almost nothing by the central nervous system … or, conversely, “quiet” sensory messages can be amplified. The quality and intensity of the final experience is clearly the product of an elaborate set of neurological filters.

Pain is less painful when we are confident that we are safe. This was demonstrated quite early in the history of pain research by a famous paper about wounded soldiers in WWII, which showed that they experienced surprisingly little pain considering the severity of their injuries — probably because they were so glad to be off the battlefield.6 Ever since, researchers have been trying to understand just how that actually works. Although many questions remain to be answered, we do seem to have a rough outline.

What can you do with this?

This is all very interesting — and it really is! — but it would be nice if there were some practical applications for it. And there are. Here are several useful implications of things that scientists have learned about pain neurology over the last few decades …

Treat stubborn pain early

Early intervention is critical to prevent acute pain from turning into chronic pain.7 It is clear that chronic pain involves significant neurological changes, both in nerves and in how pain is processed in the brain. Once those changes occur, recovery is much more difficult, at an incredible cost in suffering and medical expense. Persistent pain should not be ignored.

Don’t panic, and educate yourself

Knowledge and reassurance are crucial factors in recovery from pain problems — obviously because (at least) a confident, happy brain amplifies pain signals less than an anxious, miserable brain. This explains lots of interesting results in research (not to mention clinical observations), such as the fact that the single most important factor predicting how soon people return to work after back pain is whether or not they expect to return to work,8 or the fact that education alone helps to resolve neck pain.9

a confident, happy brain amplifies pain signals less than an anxious, miserable brain

Do not let doctors scare you. Seek out as much information as you can find. Nothing causes more anxiety than uncertainty. These are real defenses against pain.

It’s really, really not “all in your head”

The doctorly idea that a pain problem might be “all in your head” has always been disrespectful, but now it is also scientifically obsolete and can be thrown out with yesterday’s trash. Any doctor or therapist caught talking like that should probably be ignored. There is simply no such thing. We know better: if you believe that you have a problem, you will have one. It is also clearer every year that incredibly problematic, misunderstood conditions like fibromyalgia are probably diseases of the central nervous system. There is simply no such thing as an entirely psychological pain problem. It is time for health care professionals to err on the side of the patient, and assume that pain indicates a real problem.

Stress relief is not just “nice,” it’s therapy

Likewise, there is no such thing as a problem that is only physical. Even the pain of terrible war wounds have been shown to yield to the brain’s influence. The brain mediates the experience of all pain and injury — without implying that you have a psychological problem. The classic easy example of this is the common stomach ulcer, now known to be caused by a bacteria, Helicobacter pylori,10 but also known to be strongly aggravated by emotional stress, which produces additional hydrochloric acid in the stomach, irritating the lesion and giving the infection greater opportunity.

There is no such thing as a problem that is only physical.

Respect the fact that your mental does affect pain experiences significantly — and exploit it. Know that stress relief, for instance, is not just a coping mechanism, it’s therapy.

Don’t be afraid of narcotic medication

A more enlightened, progressive approach to medicating pain is required.11 Patients and doctors alike shy away from pain medications. Due to simplistic, obsolete views of how pain works, a widespread attitude that pain should be tolerated instead of treated, and a fear of drug addiction that verges on the hysterical — and is irrelevant to rational, medical treatment of serious pain — countless people are deprived of medication that could not only relieve enormous suffering, but actually serve to treat serious chronic pain conditions.

Notes

An Introduction to Biological Literacy Return to text.
Mirror therapy for pain. BoingBoing.net. 2005. Return to text.
McCabe et al. Novartis Found Symp. 2004. Return to text.
This is basically how the French philosopher René Descartes described it. Return to text.
Jackson. Pain. 2002. Return to text.
Beecher. Journal of the American Medical Association. 1956. Return to text.
Muscle Pain Return to text.
Schultz et al. Pain. 2004. This study identified factors affecting return-to-work time after an episode of low-back pain. From the abstract: “The key psychosocial predictors identified were expectations of recovery and perception of health change.” Return to text.
Brison et al. Spine. 2005. This is one of a few studies showing a benefit to education for neck pain. The researchers showed a reassuring educational video to more than 200 patients with “whiplash associated disorders” (i.e. whiplash injuries that become chronic neck cricks), and found that they had less severe symptoms than about the same number of patients who received no educational intervention. The effectiveness of education probably depends a lot on the type of neck pain and the type of education, making it very hard to study. A recent review of the scientific literature found that most such studies are negative, but I believe that there are many reasons to be optimistic about education for pain problems: see Haig for more information. Return to text.
In the early 1980's, Drs. Barry Marshall and Robin Warren of Australia discovered bacteria in the stomach lining of patients with chronic gastritis and peptic ulcers. The flagellated corkscrew-shaped bacterium, Helicobacter pylori, apparently survives in the forbidding acid environment of the stomach and duodenum by hiding in the mucus and neutralizing stomach acid in its local environment. Long thought precipitated by stress and stomach acidity, ulcers are increasingly believed to be caused by Helicobacter infection. See Helicobacter Foundation. Return to text.
Jackson. Pain, pp283–296. A standout chapter in an otherwise only average book, Jackson thoroughly reports on the case of Dr. Frank Adams, a credible and earnest American physician who moved to Canada in the hopes of finding a more enlightened political environment for the treatment of pain ... only to find his new home just as problematic as his old one. A fascinating look at our culture’s puritancial, head-in-the-sand attitude towards narcotics. Return to text.