Kevin McHenry and his blog, www.painonline.com

[Diane]

I've raved on about this site (http://painonline.com) in the past, have read every single article on there, and go there every day to see if there's anything new. It's very drug oriented, and I won't claim to understand every word of all the bewildering physiological terminology that is there, but at least it is somewhere, and somebody who does understand it and who tracks it closely is trying to put it into English for regular people.

This latest essay (http://www.painonline.com/mt-archives/2006/03/central_pain_we.html#more) discusses recent research on Type C fibres. It refers to ordinary persistent pain and not "just" central pain..
Some wonderful news. Liu and other scientists at Merck have figured out a way to grow and assay the Nav1.8 channel. We have already stated that sensitization in NORMAL adults comes via the Nav1.8 channel. Nav1.8 is sometimes also called the "Tetrodotoxin resistant" ion channel, but testing with tetrodotoxin is clumsy and time consuming. Nav1.8 is typically found in the small C fiber type of neuron, in other words, the sensitizer fibers. These channels are also found wherever small diameter sensory neurons are found, including the heart. Maybe, some day in the far far distant future, research in manual therapy will include some sort of way to examine these channels pre and post treatment. Wouldn't that be fun?

[Diane]

I just have to bring McHenry's latest blog (http://www.painonline.com/mt-archives/2006/06/what_is_inflamm.html#more) here, because he is impersonating Dr. House. :D
The essay is titled "How similar is regular pain and central pain?"

Question:

Dear Dr. House. What is inflammation?

Answer:

Deep in the jungles of Java, is a mysterious species of animal which manufactures acid as a defense against just about everything. We call this species, "Man", although actually we should call it "Man and Woman". You know, Homo Sapiens, the link that all the missing links supposedly hooked UP to, once they got tired of the sun beating down on the African Rift Valley and got rid of most of the hair that was REALLY, REALLY, HOT, and not very attractive either. Pain was not just a warning, it was a stiff dose of acid for whatever tried to get inside us. This was back when primates discovered that heaving feces and biting might not be the very best way to kill, so they evolved to develop better methods (unless you include the Jerry Springer show, where they prove evolution never succeeded as an experiment). Not that I am sold on the whole story as given, since medical statistics show a clear and ongoing DE-volution in the gene pool (sperm counts are down from four hundred million to the sissy level of about 20 million and fifty percent of the populatio now gets diabetes as opposed to 5% in 1920, but I do like monkeys, and teaching evolution, while omitting the facts about complex unused gene libraries in the simplest of blue green algae, which were the earliest life forms, gives jobs to thousands of guys who didn't make it into medical school and do not feel any need to explain the declining SAT scores, so why not. Actually, evolution cannot be supported scientifically, since the DNA of Humans is 97% the same as apes, while our behavior is 100% the same. Any idiot can see there is a problem there.

He goes into some detail describing the immune system and how it interacts with central pain, how glia are involved (they make a lot of the drippy things that irritate nerves) and ends with this: Yes, I do limp and am addicted to Vicodin because of pain. I'm still right.

[Diane]

Here is the latest blog, Can Central Pain be separated from peripheral activity? (http://www.painonline.com/mt-archives/2007/05/post_7.html#more).

If I were a betting woman I'd say, no. Maybe pain is a teeter totter, one end central and the other peripheral, and the fulcrum is good genetically determined adjustment to internal conditions (homeostasis) and external conditions (allostasis).

Maybe the fulcrum isn't fixed, like teeter totters we used to build at home - a simple plank over a barrel. If the fulcrum shifts, one end will tip down by itself, even with perfectly balanced loads. Maybe good treatment involves helping the brain move its own fulcrum around, help it be more "centroverted."

[Diane]

Here is a great entry on fMRI (http://www.painonline.com/mt-archives/2007/08/good_news_on_fu.html#more).

Most of it is about the test itself, technical aspects, what the impact may be once the test equipment gets into ordinary radiology departments, etc. But this part really caught my eye -
We have suggested before that the mere sound of the magnet clacking is enough to change the fMRI. The realization that scanning is dynamic (changing) has been very hard to put across to radiologists who are used to a one shot deal.

Also sufficient to change things is the monotone voice that suddenly comes through some five dollar speaker into the five million dollar human pencil sharpener shaped cocoon and says, "It is very important that you hold absolutely still and do not swallow or cough for the next fifteen minutes"--a statement that never fails to make your nose itch like crazy, your throat to become incredibly irritated, and your salivary glands to shift to full throttle and fill your mouth with spit until you desperately want to swallow before you choke. There are lots of things they don't mention that you also figure you better not do.

I think it really speaks to the shortage of downregulation (of anything interoceptive) available to central pain sufferers. I don't think he was exaggerating, using hyperbole for effect. At least I'm going to give him the benefit of the doubt.