THE DOCTOR SPEAKS

New research validates CMT pain

Linda here - How many times have I heard people tell me that their doctor has told them there can be no pain with CMT. How many calls have I had asking what they can do for the shooting pains, the muscle spasms or the terrible deep aches that their doctors say have to be something else because they couldn't have anything to do with CMT, and how many people have I sent to Dr. Harvey Rose in California who not only feels passionately about the treatment of pain but works with so many of us to do what he can. It is clear that CMT pain is not understood, simply dismissed and not treated. We suffer in part because there was no available literature on the topic, until now, that is. Thanks to several years of hard work by some dedicated professionals, we have a journal article that anyone with CMT can take to their doctor to show that pain can indeed be a very real part of CMT. This is not the first, as a paper on pain and CMT was done many years ago by Dr. Paul Hardy in Scotland. However, because the people who worked on this one are in North America and because they are prominent in their field, and the methods used were somewhat more modern, the paper is likely to get more attention and to serve us further in searching for better treatment for our pain. The title of the paper is Neuropathic Pain in Charcot-Marie-Tooth Disease and it was put together by Gregory T. Carter, MD; Mark P. Jensen, PhD, Bradley S. Galer, MD; George H. Kraft, MD; Linda Crabtree, CM, O.Ont.; Ruth Beardsley, BA; Richard T. Abresch, MS; and Thomas D. Bird, MD and published in the Archives of Physical Medicine Rehabilitation in the December 1998 issue; Volume 79 pages 1560-4. I asked Dr. Carter for an interview about the research and reasoning behind the paper and he agreed.

CMTI: Dr. Carter, what first encouraged you to look into CMT and reported pain? Dr. Carter: Drs. Bird, Kraft and myself had all noticed that a lot of our CMT patients had significant pain problems. CMTI: We all know that research like this costs money. How did you manage to fund the work?

Dr. Carter: The study was funded from several sources. CMT International took care of our mailing and distribution costs and the remainder of the study was funded by the Providence Healthcare Foundation CMT Research Fund and the National Institutes of Disability and Rehabilitation Research, Research and Training Center at the University of California, Davis. Anyone interested in donating to the CMT Research Fund can contact the Providence Healthcare Foundation, CMT Research Fund at 914 S. Scheuber Rd., Centralia, WA 98531, U.S.A. This is non-profit tax-exempt foundation: donations are tax deductible to those in the U.S.A.

CMTI: Was it difficult to find people to work with you, to see that the study was valid and needed, or had the many professionals you worked with seen people with CMT pain as well?

Dr. Carter: It was not difficult at all, thanks to CMTI. My colleagues, including Drs. Bird and Kraft are very knowledgeable in CMT. The project was truly a collaborative effort.

CMTI: Your objectives "to determine the frequency and extent to which subjects with Charcot-Marie-Tooth (CMT) disease reported pain and to compare quantities of pain in CMT to other painful neuropathic conditions" may seem like a make-work project to those who experience so much pain they just want help. An you explain why this type of reporting must be done?

Dr. Carter: In science and medicine you cannot simply make assumptions. In other words, just because you think people with CMT have pain problems based on your clinical experience, that is anecdotal evidence only. The scientific method of formulating an hypothesis (i.e. people with CMT have neuropathic pain) and then designing a study to prove or disprove your hypothesis is the only way to arrive at valid conclusions. Believe me, it sometimes is a pain in the neck, but that's the way it has to be done.

CMTI: Can you tell us how you went about gathering the information. We all know here that we filled out a big form a couple of years ago on our pain and sent them in. How was the information that we supplied on that form used?

Dr. Carter: We sent out a mailing through CMTI and then we sat down and entered information into a computer and ran various statistical analyses on the data. Dr. Mark Jensen, an expert on pain research, and Ted Abresch, a statistics expert, were invaluable resources to us in this regard.

CMTI: Can you tell us about the Neuropathic Pain Scale you used and what it had been previously used to study? Did you have an expert on measuring pain working with you? Who was it and can you tell us about him?

Dr. Carter: The Neuropathic Pain Scale was developed by two of the authors on the paper, Dr. M. Jensen and Dr. Brad Galer. It was specifically designed to evaluate neuropathic pain, i.e. pain that is generated directly by abnormal nerve. The scale has been previously validated and used to study neuropthic pain in other diseases including diabetes. Dr. Jensen is a psychologist and Dr. Galer is a neurologist and both are internationally known pain researchers.

CMTI: When all the data was in, who went through it all and what did they look for? How long did it take?

Dr. Carter: It took hours and hours of tedious work sorting through the surveys and doing data entry and statistical analysis. We are very grateful to Ruth Beardsley who did the majority of the data entry work. Ruth, Dr. Jensen and Ted Abresch did most of the statistical analysis.

CMTI: Can you compare the results you got to the results from other people with other forms of pain answering the same Neuropathic Pain Scale (NPS). How did we with CMT pain compare?

Dr. Carter: About 70% of respondents had significant pain problems, and specifically ‘neuropathic' pain (i.e. burning, shooting, electrical, cold/hot intense type pain). Remarkably, the frequency and intensity of pain reported in CMT was similar to the other neuropathic conditions we studied, which included patients with diabetic neuropathy, post-herpetic neuralgia, peripheral nerve injury and reflex sympathetic dystrophy who were attending the University of Washington Multidisciplinary Pain Treatment Center. In summary, pain in CMT is reported as being very severe, interrupting activities of daily living and requiring strong pain medication for about 40% of the respondents who reported pain.

CMTI: Was anyone surprised at the results?

Dr. Carter: Frankly, I was a bit surprised at how bad the pain problems are in CMT. I knew intuitively that folks with CMT had pain problems but I had no idea it was that bad.

CMTI: Can you tell us about the conclusion you cam to when it all was done.

Dr. Carter: Our ‘bottom line' conclusions are that neuropathic pain is a significant problem for the majority of folks with CMT. The pain is often severe enough to cause interruption of activities of daily living and require pain medication. Clearly, more research is needed in this area, including looking at ways to treat pain in CMT.

CMTI: Do we know what actually causes pain in people with CMT or is that work in the future?

Dr. Carter: There are likely many pain generators in CMT. First of all, I think the damaged nerves themselves generate abnormal signals which can cause the ‘neuropathic' type pain I previously described. However, I also think that the bones and joints themselves are sources of pain in CMT since the muscles that support these structures are weak causing abnormal wear and tear.

CMTI: Even though the fact that pain can be a very real part of our lives with CMT, how do we get away from the fact that many doctors remain extremely reticent to prescribe the right drugs and enough quantity of them to relieve our pain and that laws are still slanted against truly effective treatment of chronic pain. Can you talk about this and is there anything we can do?

Dr. Carter: Have you tried screaming, ranting, and raving? Seriously through, doctors in North America probably greatly under-recognize pain problems and under-prescribe or inappropriately prescribe pain medication (i.e. too little, too late). However, we could go on forever on that topic. I would advise folks with CMT who have pain problems to see a doctor who specializes in pain management, rather than hounding their probably already overworked family physician. If you have trouble getting a referral to a pain specialist, show your family physician a copy of our paper and also take a copy of the paper to the pain physician who will be an expert in treating pain but may not know much about CMT.

CMTI: We'd like to thank you and all the other wonderful physicians and health-care workers who made this paper possible. Would you like to mention your colleagues, where they work and what part they had in the paper.

Dr. Carter: Sure, First of all I would like to acknowledge you as an author and take this opportunity to thank you and all the folks in CMTI. Without this organization this study could not have been done. Dr. Mark Jensen is an internationally known pain research psychologist at the University of Washington who played an integral part in the design and carry through of this study (in other words, we couldn't have done it without him!). Dr. Brad Galer is a neurologist who is also an internationally known pain researcher now at Beth Israel Hospital in New York. As noted, Drs. Jensen and Galer created the Neuropathic Pain Scale, which was the foundation of this study. Of course most of your readers likely know who Dr. Tom Bird is, but for those who don't, he is one of the world's foremost authorities on CMT and is an internationally famous neurogeneticist. Dr. George Kraft is also an internationally known and famous physician. He is a physiatrist and is Director of the Neuromuscular Disease Clinic at U.W. Ted Abresch is Director of Research and Training at the University of California, Davis Neuromuscular Disease Research and Training Center funded by the National Institute of Disability and Rehabilitation Research (NIDRR). Ted and I have worked together for many years and he is a co-author on most of the papers I have published. He has helped me greatly through the years and I have learned a lot from him about how to do research. Ruth Beardsley is a research associate at the U.W. and gets a sainthood nomination for all her hours of data entry work.

CMTI: What's next for you? Are you continuing to study pain and CMT? Are you working with anyone on anything about CMT pain? How is it being funded? Do we have your interest for a while?

Dr. Carter: You will always have my interest, for this is the area of medicine I have chosen to specialize in and you have been incredibly supportive of my work. I am currently continuing pain research in neuromuscular disease with this same group of researchers. The studies are being funded by the same agency (NIDRR).

CMTI: All of us with CMT and pain would dearly like to see the treatment of pain come into the 21st century. We can send a man to the moon but we can't relieve pain in a person. Do you think the understanding of the treatment of pain will progress rapidly in the next century or are we in for a continuation of the status quo? What has to happen to allow physicians to know more about the treatment of pain and the ability to actually relieve it?

Dr. Carter: Sending a man to the moon required tremendous amounts of technology but it was all involving Newtonian physics, which is predictable and follows certain "laws." Human pain and suffering is unpredictable and follows no such laws and thus is, and will remain, an incredibly challenging entity to study, diagnose and treat. Only a better understanding of our conscience and very souls, not just our bodies, will, in my opinion, produce any true breakthroughs in the treatment of pain.

CMTI: All of us with CMT thank you and your colleagues. If we don't have pain now, we very well could have it at any time. What you and your colleagues have done is to open the door for further research on pain in CMT and to give us the means whereby we may be seen as credible when we approach a physician for pain relief. The support this paper gives us will help many of us in our search for pain relief. We urge you and your colleagues to continue this important work. Anyone who lives with chronic pain will tell you there is nothing more dear to their hearts than finding a way to relieve that pain, and you are actually working on it. We will continue to support you, just tell us how.

Dr. Carter: You have already helped tremendously and I am sure I will be calling on you for more help in the future. People with CMT can further their own cause by participating in any research project they can get involved in. I am very appreciative to all the people with CMT who have been research subjects for me in the past.