When you swing your racquet, there will be friction in places where your hand grips the racquet. Over time, your fingers will develop tears and abrasions in these areas of greater than normal friction. Eventually, protective calluses will form over these areas. Thus, injury, pain, and healing lead to further protection through the adaptive process.
Pain helps us grow in awareness of our environment. Darwin would agree that children with CIP are at a significant survival disadvantage. They can’t help but repeatedly hurt themselves, causing tissue injury, and they typically die prematurely.
As much as I would like to be able to turn their pain off in order to end their suffering altogether, patients with chronic pain need their capacity for pain as much as ever. I have had numerous patients discover serious illness or injury thanks to pain, whether jaw pain from a tooth infection, abdominal pain from appendicitis, or flank pain from a kidney stone. Even though they had long wished they could turn off the alarm system, when these conditions were found and treated promptly, they were able to be thankful that they’d had it on.
The Cartesian Model of Pain
Let’s consider simple, anatomic reasons for pain, like a stubbed toe or a paper cut. In his Treatise of Man, 17th-century French philosopher René Descartes proposed the existence of a “hollow tube” transmitting the pain sensation from the location of the injury to the brain. Fundamentally speaking, today’s pain specialists concur with Descartes in that they believe:
1 Nerves detect a painful sensation.
2 Those nerves transmit a pain signal to the brain.
3 By interrupting that signal we can stop the perception of pain.
Thus, we inject substances or prescribe medications that reduce a nerve’s ability to transmit pain to achieve pain reduction.
This model works quite well for physical pain, or pain “with a cause.” It leads us to seek out a focal, physical source of pain and treat it. However, the Cartesian model fails miserably when dealing with the psychological aspects of pain. For example, a person on a battlefield can sustain a horrific injury and perceive little or no pain and then experience agony in the hospital afterward during a simple needle injection. (We’ll cover this idea more in Chapter 4.)
If we identify a physical pain generator, like an area of inflammation, we can treat it through a combination of techniques with the goal of improving the patient’s functionality and reducing the level of pain with the lowest-risk intervention. When we can’t find a clear pain generator, we come to the conclusion that the nervous system is sending a false alarm and we attempt to tone down the general sensitivity of the pain signaling system.
While Descartes was in many ways a visionary when it comes to pain, our ideas on the subject have evolved substantially since the 1600s. Patrick Wall, mentioned earlier, and Canadian psychologist Ronald Melzack proposed the gate control theory of pain in 1965. They described a series of nerve pathways (peripheral, spinal cord, and brain) that allow us to perceive pain. According to their theory, while a pain signal is transmitted, there is potential for gates to be opened along these pathways, allowing for modulation of the intensity of the pain signal.
Although there are shortcomings in the gate control theory of pain, there are some benefits to this conceptual model over the simple Cartesian view of simple circuits that are either on or off. More recently, others have proposed a multidimensional model of pain in which three distinct areas combine to form one perception of pain: sensory (what we physically feel as pain), affective (how we feel emotionally about that pain), and cognitive (what we ultimately think about the pain based on our value system, cultural context, and so on).
None of these models perfectly describe how we perceive pain, but each sheds some light on a phenomenally complex area of human experience.
The Expectations and Goals of Pain Treatment
Like detectives searching for clues, pain specialists study diagnostic results and perform clinical exams to solve the mystery of a patient’s pain. We ask ourselves, “Is the pain adaptive or maladaptive?” Pain is anything but simple. For one thing, we know that the mind can amplify or reduce pain. For example, anxiety about pain or depression because of pain can amplify the perception of that pain. This suggests that developing mental resilience to anxiety and depression might reduce the sensation of pain and, in fact, this has proven to be the case. In fact, simply by engaging ourselves in other activities—work, sports, reading—we occupy more of our brain’s bandwidth and measurably reduce the severity of the pain we experience.
We must be careful not to treat pain in isolation unless we’ve already looked for the underlying cause. We must remember that pain is first and foremost a symptom, an adaptive quality, and to listen to it. Our job is to search for an underlying cause in treating pain. To treat pain as an isolated entity is to risk missing a warning sign that our body is trying to send us.
It’s true that once an acute injury has healed or stabilized, the pain may become chronic. In many cases, we are treating the chronic pain as a separate entity from acute pain. But I would argue that even when pain is chronic, we can achieve success with a multi-modal strategy to manage it as well as to attack the focal source of pain.
The Process of Reversing Pain
In 2004, I was completing my pain fellowship at Brigham and Women’s Hospital in Boston. The Red Sox hadn’t won the World Series since 1918. Fans believed that Babe Ruth, nicknamed “The Great Bambino,” had cursed their team when he was traded to the Yankees. As a result, the Sox would never win the World Series. That October, they defied the curse of the Bambino.
While the city was still buzzing with excitement from the win, I was walking along the Charles River and saw that someone had vandalized a sign on Storrow Drive. The sign had said “Reverse Curve” but someone had changed it to say “Reverse the Curse.” This got me thinking. In some ways, we have been conditioned to view pain as a curse, as something to avoid. If we find ourselves cursed with pain, there is a systematic process to try to reverse it.
Pain is both a positive and a negative. Pain starts with a positive (P), specifically the absence of pain. Then, through an accident (A) or injury (I), it ends up being a negative (N). This negative state has two dimensions, the injury and the unpleasantness of the pain.
Once you have P.A.I.N.2, you can literally turn the word around to use it as a model to grow from the painful experience and build resilience. By doing so, you turn a negative into a positive:
N. Define the negative experience by identifying the source of the pain.
I. Intervene by addressing the source of the pain.
A. Assess the response.
P. Attain a positive result.
You may not know it, but you already use this model on a daily basis. For example, when you touch a hot object, you instantly withdraw your hand because of the pain. The feeling of an ankle sprain is your body’s way of telling you not to run until the pain has decreased, signifying that the injury has healed. This phenomenon is a form of adjustment to the painful experience so you can protect yourself from re-injury.
Let’s walk through the steps of reversing the pain of an ankle sprain:
N: The negative is the painful sprained
