Useful chronic pain terms to know

In my blog, I talk a lot about central sensitization, which describes the changes that can take place in a person’s nervous system and make her more sensitive to pain. However, there are many other pain-related terms you will most likely come across, whether you’re doing your own research or simply trying to understand your medical records.

So here is a list of some of the most common terms I have come across in my own reading.  I hope you find it helpful.

Pain Amplification: means pretty much the same thing as central sensitization– that your nervous system is “amplifying” pain signals.

Allodynia: When the nervous system perceives what should be harmless physical sensations as extremely painful.  A friend once told me there were times she couldn’t stand to feel the fabric of shirt she was wearing against her chest.  Tears came to her eyes just describing it to me.  The fabric was not damaging her skin in any way, but her nervous system processed the touch sensations as though it was. 

Hyperalgesia: When the nervous system perceives what would be a harmful stimulus to anyone, but in an exaggerated way.  It’s as though it “turns up the volume” on the pain signal (or gets a little “hyper” with it).

For a really interesting explanation of allodynia and hyperalgesia from a scientific researcher, check it out  Juniorprof’s site.

Chronic Neuropathic Pain.  Neuropathic means having to do with the nerves, originating from the nervous system.  This word also describes nerve pain from other causes than central sensitization, such as nerve damage or pinched nerves.

Idiopathic Pain, Chronic Idiopathic Pain Syndrome.  Idiopathic has to be one of my least favorite words, but it simply means that the cause of a particular health issue is unknown.

Not-so-helpful terms for chronic pain:

The following are terms that convey a more psychological, or even psychoanalytical, meaning for pain.  At least one of these diagnoses stems directly from Freud, whose other theories have been almost unanimously discredited.  If your doctor goes straight to these quasi-explanations for pain without discussing the role of central sensitization of the nervous system at all, you need a second opinion, STAT.

Psychogenic Pain:  Pain that has a psychological cause.  In my experience, there is a big difference in explanations for pain that focus on the nervous system as a pain alarm system, and explanations that focus on someone’s mood or mental state.  There is also a big difference in the types of people who use each explanation.

The peer-reviewed articles I have read that discuss psychogenic pain tend to be written by psychologists and psychiatrists, as 0pposed to the neuroscientists who write about central sensitization.  Years ago I was happy to find these articles because they represented the closest thing I had gotten to an explanation.  Now that I know about how central sensitization occurs, I consider all the time I spent reading those articles to have been wasted.  Sure, mood and stress level can affect your level of pain, but I think most people who haven’t experienced chronic pain tend to make too much of it.  There have been plenty of times where I’ve been having a great day and all of a sudden, I’ve walked too far or I’m sitting in an uncomfortable chair and it all goes to hell in a hand-basket. Try to explain that to someone who subscribes to the mood-pain theory and its like you’re suddenly speaking to them in a foreign language.

Depressive Disorder or Mood Disorder, otherwise unspecified:
This diagnosis is basically the same thing as psychogenic pain, and I have many of the same issues with it.  I believe the public’s perception that depression can cause pain is being strengthened by all the TV commercials for anti-depressants like Cymbalta and Lyrica, which can also supposedly help to reduce feelings of chronic pain.  Some anti-depressants have been shown to reduce the severity of chronic pain, but this doesn’t necessarily mean that depression causes chronic pain.  Most of the research I’ve seen finds that there is a correlation between depression and chronic pain, but as anyone who’s ever taken a statistics class knows, correlation does not imply causation.  Just because depression and chronic pain tend to occur together does not mean that depression causes chronic pain.   In many people’s cases, it’s perhaps more likely to be the other way around.

Functional Somatic Syndrome: basically, a problem with how your body functions when everything appears to be normal by all objective measures.  A classic example would be Irritable Bowel Syndrome– your intestines look fine during a colonoscopy, the doctors can’t find anything wrong, but in your actual day to day life, you’re uncomfortable.  Or let’s say you have pain in your arm, so much pain that you don’t use that arm, but the doctor can’t find anything wrong with it.  That’s what makes it functional, supposedly.

To me this is another waste of a diagnosis.  I have no patience for explanations of chronic pain that do not acknowledge the concept of neuroplasticity.  It’s like handing someone a novel that you’ve ripped the last six chapters out of.

Somatoform Disorder: If someone tells you you have this, just walk away.  Seriously.  This is the term psychologists use for someone who has physical pain in multiple parts of their bodies “with no physical cause that doctors can find.”  This is also the exact definition for someone with central sensitization syndrome.  Read this article on somatoform disorder and note how not a single mention is made of central sensitization or the nervous system in general.

Somatoform disorder is reported to be higher among victims of abuse, and I’m not trying to argue that emotions/traumatic memories/PTSD can’t lead to the experience of pain.  But I do think any explanation of chronic pain that doesn’t discuss the nervous system at all is completely worthless.

Conversion Disorder: This diagnosis stems directly from Sigmund Freud.  In a nutshell, it is used to describe someone who went through some kind of traumatic experience and now has thoughts in his or her unconscious mind that pose a “threat” to mental stability.  Supposedly these unconscious threats are so horrible that the person can’t process them in his or her conscious mind without going insane.  Instead, the person’s unconscious mind somehow transforms his or her emotional pain into physical pain, because that doesn’t have any obvious meaning to it so it isn’t a threat to mental stability.

I first learned about conversion disorder from a neurologist (Dr. B.) who told me a story about a patient he met while doing his residency in neurology.  This patient was unable to walk and used a wheelchair even though doctors couldn’t figure out any reason why.  The woman’s elderly mother was also confined to a wheelchair and when she passed away, her daughter was suddenly able to walk again.  Apparently she told Dr. B. that, after her mother passed away, she realized that a part of her had wanted to kill her mother.  She believed that her unconscious mind rendered her immobile to stop herself from actually committing the murder.

Based on anecdotes like this one, I don’t think it would be fair of me to dismiss the ideas behind conversion disorder altogether.  But again, this is a story that I heard second-hand, and that you have now heard third-hand, so please don’t read this and wonder if maybe you could be crazy, too.  I only told this anecdote to give people an idea of the kind of situation that “conversion disorder” is meant to describe, whether or not it’s actually possible.

The bottom line is that the nervous system is able to do crazy things, and we have no way of knowing if that woman’s realizing she wanted to kill her mother really did have anything to do with her regaining mobility.  Personally, I think it’s more likely that there were other things going on.  If you watch the online lectures from Neil Pearson that I talk about all over this blog, you will see that there are other possible explanations for why someone with no obvious injury would be unable to walk.

Conclusion

The fact that different disciplines offer such widely different labels for pain says to me that there is not enough cross-over between psychology/psychiatry and neuroscience.  I think what happens is, because it takes so many years for someone to earn their M.D. or Ph.D, people who become advanced in their fields don’t often talk to others outside of their own discipline.  They spend the majority of their time interacting with others in their same graduate departments, all using the same “lingo,” and work and go to conferences with others who’ve had training in the same area.  This is not something that ends up creating the best care possible care for patients because people become “experts” at a very narrow range of things.

If you see a doctor who tells you you might have conversion disorder on the very first office visit, I would take it as a sign that he or she has been reading way too much old-school Freud and not enough neuroscience.  I would urge you not to waste time wondering if you’re crazy and seek out a second opinion from someone whose views are a little less off the beaten path.

I’ve included all of the terms that I can think of right now for chronic pain, but I may have left some out.  Feel free to add any to my list!