This is the fourth part in a series about an amazing new approach to physical therapy for chronic pain patients.  To start from the beginning, check out Part One, Two, and Three.

For the first few visits, all Tim and I did was talk.  He didn’t have me in the gym doing exercises like all the other patients I walked by on the way in.  Instead, we sat in a quiet area and talked about what I had learned from Neil Pearson’s lectures.

What I learned is that pain is so much more complicated than we think.  When I first learned about the nervous system in high school biology, I was taught that nerve impulses travel through the spinal cord to the brain, where they are interpreted.

This is a very simple model, and on a basic level it’s true.  That is how nerve impulses get to the brain.  But when it comes to the experience of pain, there are many additional factors.

Normally we think about the nervous system as a one way street, where signals are only travelling to the brain. But what I learned from Tim is that the experience of pain is a lot more complicated.  Our brains are constantly evaluating input from our nervous system, trying to sort out which signals are important for us to know about, and which aren’t.

Our brains are filtering our experiences all the time, determining what is and what isn’t important for us to know about.  After all, it wouldn’t make sense for us to be aware, on a conscious level, of every little thing that’s going on in our bodies.  We don’t need to feel, at all times, the sensation of clothing on our backs.  We don’t need to wake up out of a deep sleep just because there is a blanket touching our legs.  Our brains filter out information all the time, so that we can focus on more important things.

On the other side of this equation, the brain can actually “turn up the signal” on something it thinks we need to know about.  If a part of your body hurts and you try to ignore the pain and go about business as usual, your brain will make that pain louder.  It isn’t doing that to be annoying; it’s trying to protect you.

Lorimer Moseley tells a revealing story about the time he was walking in a nature preserve when a stick brushed against his ankle.  He had once been bitten by a poisonous snake in that same nature preserve, also on his ankle.  He freaked out and fell to the ground, writhing in excruciating pain.  He told his friends to call for help, thinking he needed to get to a hospital as soon as possible.

A few moments later he looked at his ankle and realized there were no bite marks.  There was, instead, a stick lying on the ground next to him with a sharp point.  He was then faced with the awkward task of telling his friends he was wrong, that there was no snake, that he’d freaked out over nothing.

This is how the nervous system works.  It is not meant to be “accurate.”  It is meant to protect us.

When Moseley’s nervous system felt the stick scrape his skin, it knew that the last time it felt those sensations, there had been great danger.  It also knew that not only was he outside, but he was walking in the exact same nature preserve where that same danger lurked.  His nervous system decided to tell him about the dangerous thing that had just happened to his ankle, and it told him about it loudly.  This is how the nervous system works; it decides how much danger we are in based not only on physical sensations but also on context.

Normally when we notice these little idiosyncracies of the nervous system, we are embarrassed.   These little errors in judgment can make it seem like we’re crazy, or overly anxious or neurotic.  But this is how the nervous system works.  It is not meant to be “accurate,” it is meant to protect us.   Even when our nervous system doesn’t have the whole story, it fills in blanks as much as possible, taking our fears and beliefs about the situation into account.

In people with chronic pain, the body’s protective response has gone haywire.  It’s as though the nervous system’s threshold for action has been lowered, and things that didn’t seem dangerous before now seem very dangerous.

It’s like we’re Lorimer Moseley walking through the nature preserve, all the time.  The difference is that Moseley’s case was a singular event based on coincidence: the stick brushed up against him in the same place that the snake had bit him, and he was walking in the exact same park where he had encountered the snake before.  While Moseley’s experience had a concrete end, every day chronic pain patients encounter “sticks” that our bodies interpret as “snake bites.”

The good news is that, because the nervous system takes our conscious beliefs about pain into account when making judgments, we can actually affect how it reacts to various stimuli.  (I want to be very clear here: we do not cause chronic pain with our thoughts and beliefs.  This is an oversimplification, and it’s also insulting).  But the nervous system does pay attention to context when deciding how dangerous something is.

In his lectures, Neil Pearson says that when your pain starts to get worse, you should ask yourself “Is this really dangerous?”  An increase in pain is a sign that your nervous system has decided whatever you’re doing is dangerous.  But is that really the case?  If you’ve been living with pain for a long time, it might not be.

This is where your conscious thoughts and beliefs can play a role in breaking the cycle of pain.

I had lived with pain for so long that my view of what my body could and couldn’t do had gotten very warped.  I felt pain every time I tried to walk, or lift something, or go up and down stairs.  I thought my body was weak, that there was something fundamentally wrong with it, and every time I pushed myself it seemed to get worse.

Tim helped me to recognize that the pain I felt was not necessarily an accurate barometer for what was wrong in my body.  The reason I had a setback every time I exerted myself, he said, had more to do with my nervous system freaking out than the fact that I had actually pushed my healthy twenty-five year-old body to its limits.  When my body began to hurt, I was to say to myself, “There’s my nervous system again.  Freaking out.  But that doesn’t mean anything is wrong in my body.”

Tim and I talked a lot about how the body works, and how I wasn’t going to hurt my back, or my legs, or my ankle just by doing basic things.  Because one of my major complaints was back pain, we talked about the anatomy of the back, and how my MRI showed I didn’t have any serious pathology.  Tim promised me that my body was so much more capable than I thought it was, and that once I could help my nervous system calm down a little bit, I would see that.

We also talked about what kinds of things would produce pain in a person whose nervous system wasn’t freaking out.  It honestly really helped me to have a trained physical therapist to bounce ideas off of.  I trusted Tim.  If he told me the pain I felt was likely coming from my freaking-out nervous system, rather than any physical damage, I believed him.

We talked about my leg surgery several years before, and how I was afraid my compartment syndrome was going to come back if I pushed my legs too much.  We sat down and had a rational discussion about this; how unlikely it was, but what the worst case scenario really would be if it came back.  This helped to reduce some of my fear, and give back a sense of control.

We also talked about my ankle, which I had sprained a few months earlier.  It still hurt a lot of the time, and I had a lot of trouble walking and driving.  Tim explained that I wasn’t going to re-sprain my ankle just by performing normal activities.  Since it had been a few months, he said, the majority of the healing had already occurred.  As long as I kept my ankle within the normal range of motion, I wouldn’t be doing anything to make the sprain worse.

This actually made a striking difference in the amount of pain I felt in my ankle.   My nervous system had been interpreting the sensations in my ankle as very dangerous, and as a result it was very painful.  But once my brain understood that my ankle wasn’t in any real danger anymore, my nervous system no longer saw the need to tell me about it all the time. Over the course of the next few weeks, the pain in my ankle gradually melted away.

It’s almost embarrassing to admit something like this– that my ankle, which had been bothering me for months, stopped hurting as soon as someone explained to me that it wasn’t really dangerous.  But it shouldn’t be embarrassing.  This is how our nervous systems work: they take into account both physical signals as well as our mental interpretation of events.

If you’ve undergone the process of central sensitization, your nerves, spinal cord, and brain have changed in ways that cause you to be more sensitive to pain.  Scientists don’t yet know whether or not these physical changes are actually reversible.  But the good news is that whether or not you can undo the effects of central sensitization, you can still break the cycle of pain by changing how you react to pain on a conscious level.

Continued in Part 5.

**The top picture was taken in the Australian Outback, which is where many of Lorimer Moseley’s stories take place.  Published by Mark Veerhart under a Creative Commons license.**

**Mulberry sticks picture courtesy of JodiGreen**