Literature on Central Pain

[Prodigy]

Does anyone know of any scientific article on diagnosis of central pain?

So far all the literature I have read about this condition talks about lesions in the spinothalamic region. However, it was not clear if these lesions can be easily seen on an MRI scan.

The website Painonline.com (http://www.painonline.com/mt-archives/2004/07/the_five_ais_of.html (http://www.painonline.com/mt-archives/2004/07/the_five_ais_of.html)) refers to the fact that Central Pain Injury might not show up on MRI. I have quoted that line below:

"Your CP injury may not show up on MRI, since the spinothalamic tracts are smaller than MRI can resolve, and if you do have bright spots or lesions on MRI, they may not be the ones responsible for your pain."

Do you know of any scientific peer reviewed article that discusses the diagnosis of Central Pain. I am particularly interested in any case study or literature that discuss Central Pain where no lesions were found in MRI scans. Any information you could provide in this regard would be highly appreciated.

Thank you for your help.

Prodigy

[firesmurf]

I just wanted to mention something regarding central pain.while i know mine was triggered by spinal cord damage when i had to have a lesion(cavernous hemangioma)removed from the actual spinothalamic tract within my cord.there is absolutely no real sign of anything showing up on my MRIs now,post op since 2003.if you suffered some level of trauma to that tract with either a direct spinal cord injury,or at one time had part of a disc,bone spurs.... affecting that area or some level of what would have been causing some affectation of it in some way,you would still possibly end up with CP.you DO NOT have to actually "see' anything upon an MRI in order to have had the CP trigger itself.there are just alot of things that will not actually show up on an MRI either.if you are having actual central pain syndrome,something has either at one time actually affected or directly damaged the spinothalamic tract OR has damaged the actual thalamus inside the brain.stroke patients can also get central pain when there has been an event that effects the thalamus too.or even a traumatic brain type injury.both the tract and the thalamus,when affected in some way CAN trigger CP in some people.

there are also other vascular malformations that when are affecting the thalamus within the brain can also trigger CP.AVMs,cavernous hemangiomas and brain aneurysms are just a few.some people will never really obtain any hard evidence of what actually triggered their CP.of course that makes getting a doc to believe you just that much harder.but it can and does happen unfortunetly.

sorry i couldn't help with any real factual documantation of all this.maybe someone else has some better possibilitys for you,DAVE??WISE??DEJERINE??

do you actually have CP or are you just researching it for some reason?marcia

[David Berg]

Prodigy,

I recommend you speak to any doctor with a decent knowledge of neuroanatomy and they will confirm that the spinothalamic tract is too small for the resolution available on MRI machines. A formal diagnosis of central pain must be made from clinical exam and patient history, not from imaging. Insurance companies and others would love it if it were this simple, but unfortunately it isn't.

As for literature, here's a brief entry by Dr David Bowsher on the diagnosis of central pain.
http://www.pubmedcentral.nih.gov/pagerender.fcgi?artid=1663246&pageindex=1

[Prodigy]

I am a patient of central pain, looking for literature on the same. About 5 years ago, I met with an accident (hit by a car) in which I suffered a dissection of the internal carotid artery. About 2 months after the accident I started getting left sided pain, numbness, tingling, burning feeling etc that extended to the whole left side (head to toe). Initially almost all neurologists I went to kept telling me "You should not be in pain!!!" Some treated me for migraine, some sent me to psychiatrists. Finally (2 years later) I did find a neurologist who diagnosed Central Post Stroke Pain. However unfortunately, now my good neurologist is no more and I am with a new neurologist who thinks that since they do not see any lesions in the brain it is not Central Pain and wants to treat me for somatoform disorder. I am a bit tired to start another two year search for a neurologist who knows Central Pain.

Before the accident I was a postdoctoral researcher in the field of Chemical Biology. After the accident I could no longer continue the work. So I work as a freelance science writer from home. I was thinking of writing an article on Central Pain that addresses the issue of diagnosis of Central Pain. Hence the search for literature.

Other than the website Painonline.com, I do not see the issue of imaging in Cenral Pain addressed anywhere. And doctors do not usually accept anything that was just found on a website as literature/proof/information. So I thought it would help if I could put together something with proper reference.

[David Berg]

Prodigy,

Unfortunately, the ignorance you've faced with your doctors isn't exactly uncommon. I recommend you educate yourself as well as you can AND keep hunting for a doctor until you find someone knowledgable about this condition. It may be a neurologist, a physiatrist (rehab specialist) or someone else. I've even heard that rheumatologist often are a good choice for a diagonsis, but that probably wouldn't be my first pick. Do you live near a teaching hospital with a pain clinic?

My website, painonline.org, and the "sort-of-sister-site" painonline.com run by someone else have quite a bit of info. If you can afford it and you really want a comprehensive review of the literature on central pain I **HIGHLY** recommend you buy "Central Pain Syndrome" by Dr Sergio Canavero. It just came out in the last couple of months and it's an excellent resource. It cost $90.
http://www.amazon.com/Central-Pain-Syndrome-Pathophysiology-management/dp/0521866928/ref=sr_1_1/103-8845777-8446213?ie=UTF8&s=books&qid=1176927687&sr=8-1

It's a much easier read that I expected, but at the same time is very informative and complete.

[dejerine]

Many years ago, Triggs and Wall in Brain showed that those with lesions on MRI were more likely to have NO sensation than to have pain. Maybe 90% of radiologists still believe you can see cord lesions on MRI, or even CT which are capable of causing CP, but it just ain't so. The ST tract is like phone wire. It winds in and around other tracts and it is a convenient fiction to say it is one tract. It is many tracts and even if you put all of them together they woudl still be smaller than MRI resolution.

You will have to look at a good university pain clinic if you want expertise. Since almost no pain clinics have neurosurgeons, you are not going to find what you want with a neurosurgeon either, UNLESS you go to Western Toronto or perhaps Johns Hopkins or one of the programs where neurosurgeons get involved with central pain. At painonline.org, there is a reference to an article published by IASP on central pain. I am sorry I cannot remember the citation, but look through articles from the literature at David's site and you will find it. I located it using Google one time. Try looking at it this way. It is not your job to convince anyone of anything. If they haven't read the literature, to heck with them. Where is the article that says you CAN see pain, central or otherwise, on MRI??? Central pain is a metabolic disorder characterized by proliferation of glia and the products they make such as BNDF, which cranks up MAPK and ERK. Do you know of any MRI which can visualize genetic upregulation? Of course not. So why would MRI show pain? You cannot see pain. You cannot see pain with an MRI machine. You cannot see it with PET unless you are really really good. All they can do is give CP to rats and then measure the amount of pain chemical in the rat using immunologic methods. We have to presume humans act the same way.

What state do you live in?

[firesmurf]

Considering your mechanism of injury and what the resulting damage was,have you ever had a stellate block done to make certain that your CP is not actually RSD or complex regional pain syndrome caused by a damage sympathetic nervous system instead?I am only asking because i unfortuently have both CP in my upper torso and the RSD in the lower.the RSD is most definitley being sympathetically generated but i did not react to the block they did on my stellate ganglion and i did not have the other RSD indicators up there like i did in my knee with RSD,so that was ruled out for certain and was given the CP Dx but only in my left arm and up over both shoulderblades.with the symp blocks,basically,if you do not actually feel any relief what so ever but you did get whats called a horners syndrome eye,it would be ruled out as being SNS generated.but if you get any relief at all even slight with this type of block,there is a very very strong chance that what you have is actually being from a damaged sympathetic that believe me,could have very easily occured given the mechanism of and your actual resulting injuries.the symp stellate ganglion is up right in the area where your injury took place and could have very easily become damaged with your type of incident,thats all.

the one thing about CP and RSD is they both generally will present with horrid burning and stinging,but they eventually will start to seperate themselves with more vasomotor type symptoms stemming from SNS generated pain,unlike the CP.you have a definite temp difference with RSD(while my normal body temp is now at 96.7 most of the time,my knee is always around 101-102 degrees,just the knee area alone) and the swelling,and possible mottling or full extremity color changes to the affected areas.it can be pretty dramatic in some people.but one thing they both have in common is horrid levels of deep and surface agony

do you feel any temp differences in the CP affected areas at all,either always cold or hot?is there any indication of swelling at all in those areas?If you actually tried a sympatheic block,you could possibley at least rule out any RSD or SNS generated pain,it would at the very least,give the central pain much more wieght and certainty.By just ruling other possibilitys out will help lead to a more difinitive Dx of the CP anyways and could help you in actually being believed by some ignorant docs.just a suggestion for you.i do wish you luck with trying to find the documentation you need.There IS a central pain site on yahoo that i have popped onto from time to time,it is really a huge source of CP info.just another thought if you have not been there already.Marcia

[dejerine]

Prodigy,

Do you ever pull out in front of a cement truck. No. Does anyone argue with someone who has a four million dollar magnet. No. The mistakes of today are precisely the mistakes of yesterday. Doctors have known for years, decades, that the spinal cord narrows with flexion and extension. This simple piece of information would mandate taking that into account. However, back in the CT stone ages, they did their spinal canal measurements with the patient in the neutral position. It gets worse. The literature are absolutely clear that the compression is worse with the patient sitting up. You would again think radiologists would include a series with the patient sitting or standing. Nothing of the kind. EVERYTHING is done with the patient on his/her back. The interpretations roll out. The insurer pays the 4500 dollars and everyone is happy, except the patient. You can no more reverse tradition in radiology than use the ISS to go to Mars. Tables are flat. You lay on them. And the radiologist can easily take in millions of dollars/year.

I may be wrong, but i believe the real culprit is managed care. They are bottom line business people, not doctors. As long as the public takes the reaming, they will get reamed. Managed care suppresses competition. the antitrust laws are NOT enforced by the justice department, and the crummy, amateurish MRI's keep rolling out. The public is so brainwashed by TV that they think this is medicine. it is not. Medicine is a clinician taking care of a patient. Remember this. Radiologists are NOT clinicians. They are technicians. They have NO idea what symptoms mean. They do not know they are being bush league and amateurish. And even if the literature make clear they should evaluate the cord sitting up, they have never done it and are not going to start. Not while the public and insurers will pay for worthless studies. It all gets lumped under MRI. And the public thinks it is all the same. There is a world, a universe of difference between a first rate, high grade, research neuroradiologist and what the public typically gets. However, nothing the really smart radiologists say, such as lets slow down and include a sequence in the sitting position in every spine case is going to resonate with their managers. Radiology today is about FASTER image acquisition. Spin angles and acquisition techniques which move FASTER, are what sells to hospitals. No one is talking about BETTER imaging. Why should they. They are cleaning up with rapid sequencing. This is supposedly better for us, because we have to lay still for a shorter period. However, the bill does not get cheaper, even if the acquisition time drops from 20 minutes to 1 1/2 minutes. There is no incentive to keep the costs down. NONE. It is medicine gone mad with profits. Hospitals credential doctors not on training but on economic credentialing which means how much MONEY do they make. Nonreimbursable tests are not run. Reimbursable tests like MRI are run 24/7. Where is the radiologist who can accurately read spine films? I have had mine read by five neuroradiologists and only found one who was even close to being correct. Most dictations are done before the film is even read. You can buy a CD with the interpretations already there or make your own and just dictate to the typist, "Number four" which spits out two pages of garbage with no helpful infomration for the clinician. At Hopkins they used to make every doctor do his own radiology to avoid this kind of problem. When high tech things like CT and then MRI arrived, this was no longer possible. The pressure is on to make things go faster, which means ever evolving acquisitions, which are more and more mysterious to untrained clinicians, who don't want to admit they cannot read MRI. Since the clinician has been kicked out of the imaging process, you really cannot win. They need to revamp the whole thing. Even if they did, you could still not see pain. You would perhaps be able to pick it up with electrophysiologic testing, EEG, and PET, SPECT or functional MRI, but they haven't taken the trouble to design programs to recognize pain. You will waste a lot of money if you get the study and listen ot a lot of nonsense if you rely on an interpretation. Can you fly to the moon in a cigar? No, and you cannot see PAIN on an MRI. You cannot see any other signal so why should you be able to see pain?????

[Prodigy]

David,

Thank you for your reference to the book "Central Pain Syndrome" by Dr Sergio Canavero. I will take a look at it.

------------------------------------------------------------------------

Marcia,

I have never got a a stellate block done. Infact, this is the first itme I heard about it. I will look into this. Thanks for letting me know.

I do feel hot on my left side of the body, but never measured the temprature. How do you measure the temprature of your knee?

My understanding is that RSD is more localized. In my case, the whole left side face, neck, trunk, arms, leg) is affected. However, I do get this intense pain (that feels different from the pain in the rest of the body) on my left thigh. So it could be possible that I do have both RSD and CP. I also do get swelling of my left hand and feet, but that happens only when my all other symptoms are bad too. On other forums I have seen other CP patients mentioning the swelling.

My problem right now is getting the doctor to even look at any of these possibilities because they do not see any lesions in the MRI.

--------------------------------------------------------------------------
Dejerine,

I can see where your frustration is coming from. Believe me I have also exploded with frustration several times!! But I got no where, just got really upset.
-------------------------------------------------------------------------------

All,

I know that people on this forum and other central pain forums are doing a lot to raise awareness about central pain, RSD, and other neuropathic pain. But in terms of actully getting anything done (I mean improving the situation), thats not happening.

I do agree with dejerine that the medical community, wether it is the doctors, insurance company, pharma and biotech, they are all in it for the business/money, not becuase they care or want to do something for fellow human beings. (My sincere apologies to the few who actually do this with the intension of helping people.) The one thing they all respond to is numbers. There is more research on Cancer today because the market for cancer drugs is huge and the health care community can make a lot of money on it.

If we make an effort to focus research and/or accumulate literature on the diagnosis of CP/RSD that the general medial community cannot deny, then there will be many more people diagnosed with CP.

I believe that the number of people suffering from CP is way more that what is reported. I suspect that no more than 10% (and that is an optimistic number) of the CP patients are being actually diagnosed with CP. In 4 years I have been to almost 15-20 neurologists, stroke specialists, neurovascular surgoens and neurosurgeons. And I am talking about the premier educational medical facilities in California. All these "well known, highly respected" doctors I went to had the same response - "Well you are lucky to be alive after such a bad dissection. But I do not see any lesions in your brain, so you should not be having the pain you are complaining of or we do not know why you are having this pain." The only place I got diagnosis is at the pain clinic. (Initially since this was a vascular/neurological injury I was not looking at pain clinic.) I was persistant and had access to people since I was myself a researcher at one of these premier institutions. But I always wonder how many people out there have the access to facilities that I had?

What I am trying to get at is, if we can somehow focus more on getting the diagnosis of CP more defined, there will be many more people diagnosed with CP, then the drug companies and the healthcare facilities/companies will have more incentives for doing further research for treatment of this condition.

But for this effort, we need to have someone from the medical community to help us. Because in general docotrs are snobish (again, I apologise to the few who are not) and they do not listen to patients, only fellow doctors. They only believe peer reviewed articles, not what is written on forums and on other sites by patients. So if there is literature out there that shows that central pain does not always show up on MRI, it would help to bring that to genral awareness. If there is no such literature, then may be we could find the few doctors who are open minded and willing to work in this area to come up with some literature about this.

This is what I think. I would like to know your response.

Have a Pain Free Day.

JR

[David Berg]

Prodigy,

Man, it sounds like you have a great reason to be so frustrated!!! Trust me, there really are doctors out there who understand all of this better.

You're correct that many more people have central pain than is commonly recognized. Central pain is caused by any condition that damages sensory nerves in the CNS. I compiled a list of some of the conditions that may lead to central pain.
http://painonline.org/WhoGets.htm

Just curious, have you seen a physiatrist? I've come across a few that have a good understanding of central pain. Certainly not all, but that's an option to consider.

I'm also sending you a PM.

[adi chicago]

my opinion regarding central pain .a person who doesnt feel this kind of pain cannot understand what pain means.
word.

[firesmurf]

SOOOOO true adi!!! no one really understands what hell this really is until they feel it for themselves.its just so over the top,i really don't think the average person could possible even relate to it or even believe the human body is actually capable of creating this.i know that what i keep feeling and thinking.how in the hell can this be soo flippin bad and real,and just BE there ya know?

prodigy,i DO feel for you and everything you have had to endure.it all just plain sucks.just sucks to have to live with this hell.one thing you need to consider here is that the other people who you have chatted with on other sites who reportted having the swelling,is that THEY may also be misdiagnosed as well.I know for sure with mine,there is no swelling what so ever in the CP areas,absolutely noe.the skin "looks' absolutely normal on the surface but there is hell in it ans under it.but it looks normal from all appearances.tho it would be a possibility that other underlying problems could be responsible for actually having CP and swelling in the same extremity or areas,RSD should at the very least be ruled out since the treatment is a bit different and you can,if caught early enough in some people get some of the RSD crap to actually remit.i don't think you can do that with CP.

You really do need to do some research on RSD as there are other treatments if this is what you actually have.or you can also have a bit of both.thats why the stellate or sympathetic blocks are really crucial in dxing this in someone.i went and bought one of those little skin surface/strip type thermometers at walgreens one day.just happened to see one of those hanging there while i was waiting for my rxes.since i knew my knee was always hot,just always hotter than the rest of my body,i was just curious as to what the difference in the main body temp and the temp of my other knee actually was when compared.my very first reading was right around that 102 mark.i was a bit shocked since i knew it was hotter,just not that much hotter ya know?but the really bizarre thing now is that since i tried lyrica about almost a year ago,the swelling has reduced and the heat it was also generating there.now that knee is always colder than the rest of my body now.i had to stop the lyrica after about three weeks(really bad bad side effects for me) but all of this stuff that changed is still that way now,after an entire year after trying lyrica.i don't understand it either and neither does my PM doc.she saw it and felt it and just shakes her head when she looks at it now.she baffled too.but my SNS and the thalamic is also damaged so who the hell knows.

this is just stuff you really do need to look into.RSD can spread.some unfortunate souls actually have full body RSD.it can pop up in any area that connects it to the sympathetic chain.i do wish you luck with all of what you are dealing with.please stick around awhile.marcia

[dejerine]

Prodigy, I am sorry. IASP now requires membership to access the peer reviewed article. I think it is interesting that you have the research background and are now in a position to benefit others and to spread the word. I add that I am very sorry you have central pain.

I once knew a believer who was trying to debate an atheist on the existence of God and the rules of the debate were that it had to be kept on a scientific level. The believer lost the debate. After it was over, the professor chided the believer for "arguing out of context". He meant that you cannot prove the existence of a being who is outside time and space by arguing in the context of science.

Keeping that thought, consider this. MRI is about STRUCTURES. That is its context. PAIN is not a structure. It is a construct of the nervous system. Using blood oxgyen level diminishment (BOLD) on PET/SPECT? FUNCTIONAL MRI, you can measure a change in oxygen level in certain structures. No two studies ever fully agree, including in the same patient. Pain always has a context, the emotional state of the patient. What BOLD is measuring is the reaction to pain plus whatever else is going on, not pain itself. What he wanted to do was to change BOLD so it was done dynamically, ie. while a painful stimulus was being applied. This has not been done in central pain, and is very spotty and incomplete in ordinary pain. There are many different kinds of central pain, thalamus, posterior cord, anterior cord etc. So you are still going to get a spread of reaction. That is what BOLD measures, reaction to pain in the brain. It does not see pain. .

You can have someone with terrible central pain right in front of you and you cannot see it because pain does not emit photons. Your eye, the MRI magnet, the xray penetrating CT cannot see central pain. It has to be derived from the patient history. If they don't teach that history in medical training, then you will not be diagnosed. . When i got central pain, Adams and Victor, the leading neurology text did not even mention central pain. I conclude that any neurologist training with Adams and Victor as text would know nothing of it For me, I finally found someone at USC who knew what CP was. It was at a spine hospital rehab doc. You were probably not treated at a spine hospital, where they seem to be more familiar with it.

MRI cannot see pain--it can only see STRUCTURES. Pain is not a structural matter. Big lesion, little lesion, NO visible lesion and you can still have it. I think Dr. Young's comment here is authoritative. Sometimes neuropathic pain just happens.

Until they begin to evoke the central pain DURING the PET, BOLD, MEG, or whatever, they aren't going to see through the emotional noise which will be present in any chronic pain state. None of this has anything to do with MRI, which can ONLY see structures, not pain.

Best wishes to you and non illegitimus carborundum.

One of my doctors said this, "You have to know the difference between a bull riding artist and a b___s___ artist. The bull rider tries to see how long he can stay on the bull--the radiology technician usually tries to see how fast she can get you off the table".

Now you know why I have a bad attitude--it is my pain clinic doctor's fault.

His other quote, "The fastest way to put an audience of neurologists to sleep is to talk about central pain--they prefer to hear terms they actually recognize. That is why I always start my speech with the word "synapse", seque over to "calcium" and then hope they are still with me when I get to gene upregulation, glial proliferation and BDNF".

Radiologists are not trained to be clinicians and there is an unfortunate gap between imaging and clinical care. Generally speaking doctors like to read their own films. They do not have the option of telling the radiologist they don't need his interpretation. Especially now that the studies are changing with new flip angles and new acquisition sequences the clinical docs are dependant on radiologists to tell them what is going on anatomically. If the problem is not structural they aren't going to be able to rely on the radiologist.

[alan]

my opinion regarding central pain .a person who doesnt feel this kind of pain cannot understand what pain means.
word.

This had be repeated because it is exactly right. Heck, we can't even adequately describe the sensations we feel!

[David Berg]

Prodigy, I am sorry. IASP now requires membership to access the peer reviewed article.
One way around this is go to a library at a medical school and see if you can get access on the computers there. I've done that more than once. There's a chance that a "regular" university might have access as well if they have significant offerings in life sciences.

[Prodigy]

We now have two pages of debate on "Literature on Central Pain", but not a single reference of any kind of scientific article on the diagnosis of CP.

Some of you have been dealing with this for a long time and have evidently read about it in detail. Since no one has come forward with any kind of reference, does this mean that there are NO scientific article on diagnosis of CP?

[David Berg]

Well, my copy of Canavero's "Central Pain" is loaned out to a friend who's a spinal surgeon, so I can't refer to it right now. Have you tried searching on pubmed.com? I presume you're looking for something more than the brief reference I posted from Bowsher in the the BMJ.

Ultimately, the diagnosis does have to be from clinical examination, not imaging. Imaging *may* be able to rule CP in, but it cannot rule CP out. This is especially true when the cause is from something such as MS or chemical exposure.

Edit: I viewed the TOC for Canavero's book on Amazon. The section on diagnosis runs from 133-137. If anyone has the book on hand, please take a peek and see if it has a better answer to Prodigy's question. I'll see if I can get my copy of the book back in the next several days.

[dejerine]

Prodigy, that is the very point. Until this year, there was not even a medicare code number for the central pain. I personally wrote to Harold Merskey and asked his help in getting the IASP to create terminology for central pain. They have done so and published an article, but I cannot find the online URL, because it is member confined. I used to have a copy, but have no located it. If you will post an address, if I find one, I will mail you the IASP article.

The emptiness of your search reflects the emptiness of literature on the subject. However, if you can set aside any pressure to find it in the medical literature, you will find the PhD's are doing a fine job with it in experimental animal models. Canavero's book is replete with references, such as exist, in the medical literature. Central Pain usually travels under other names, such as post stroke pain, post SCI pain, MS pain etc and you will find plenty on it there. The sad part is that many clinicians do not realize these are all one disease; ie. gene upregulation of the pain kinases and proteins. The lack of literature is to be regretted, but this is due mainly to a lack of vocabulary. You cannot expect much literature where there are not words. The problem is not lack of a reference in two pages on a chat room. The problem is lack of references in the many volumes of neurology in the medical library. The Textbook of Pain, all editions, ed by Wall, Patrick has some good material. Ron Tasker has over 150 articles on central pain in the literature. David Bowsher, Howard Rowbotham and others have articles. However, what you want is to be found in the PhD literature, and for that you have to search using very specific terms, such as MAPK and pain, or insular cortex and pain.