The Basics of
by Linda Crabtree, CM, O.Ont., O.M.C., B.A., LL.D., Founder CMT International
Questions answered about the basics of CMT
and what you need to know to look after yourself
SUMMARY - The author looks at Charcot-Marie-Tooth disease, a fairly common but little understood neuromuscular disorder also known as hereditary motor and sensory neuropathy (HMSN), and addresses the questions most often asked of her by people about their CMT. The answers have come through many years of working with people who have CMT and coping with it herself since age one. - Thanks to Dr. Greg Carter for vetting this article. - This article was updated in 2001 and 1997 and replaces Charcot-Marie-Tooth as a Disabling Disorder written by the same author and published in the Canada Family Physician Vol. 35: Feb. 1989
When I began working with my fellow CMT people in 1984, little was known about CMT, and most doctors considered it an extremely rare syndrome that affected us only from the knees and elbows down. Now, many years later, we are beginning to know otherwise. Not only is considerable research being done on the genetics of the disease but those in the various medical specialities are seriously looking at symptoms such as pain, gastrointestinal problems, hearing, eyesight and other symptoms that are being seen more often as more people with CMT are being diagnosed and step forward to be counted.
I am not a doctor but we here at CMT International work with many doctors, all interested in CMT, and I have met, talked with, and interviewed thousands of people who have CMT. What I am going to try to do here is to give you an eight page overview of CMT by answering the most frequent questions put to me throughout the years. I hope this format will give you answers to some of the things you want to know.
I'll provide you with enough information to seek out appropriate health care and to begin to understand what is going on in your own body so you can look after yourself. What I don't want to do is frighten you so that you do not want to carry on in your search for more information and a positive way of coping with your own particular case of CMT.
Remember, PLEASE, that very few of us have ALL of the symptoms I will speak about, most have two or three, and ALL of us experience CMT differently within the boundaries of the disorder.
I'm going to quote Dr. Sherwin B. Nuland who wrote in his book The Wisdom of the Body.
"...the only certainty I have ever known in my long clinical career in medicine: A disease presents itself in a unique form in each person it attacks, and it pursues a unique course. A good or a bad prognosis is a statement of probability, not of fact. Every individual responds to treatment differently than every other. Statistics and a physician's experience are useful only as general guidelines. Whether the numbers appear fair or foul, the outcome of your or my sickness is ultimately decided by unknowable factors within us. They will probably remain unknowable for decades or perhaps even centuries to come, or forever. The objectifications of biomedical science lead us ever closer to the real sources of healing, but long distances are still to be travelled."
Remember the above, please, because all through this article I will ask you to remember that the symptoms I refer to have affected the overall mass of people I have spoken to and seen but no one has all and most have only two or three. The treatments I am talking about work for some and do not work for others. Each and every one of us is unique with our CMT, there is no overall prognosis, there is no cure, but there are things you can do for yourself to make your life better, more productive and longer.
First the name. Charcot- (pronounced Sharko - he was French) Marie-Tooth disease or syndrome was named almost simultaneously by French neurologists Jean M. Charcot (1825-1893) and his student, Pierre Marie (1853-1940), and by Howard H. Tooth (1856-1926), an English physician.
If we were to lean on the side of research these days, I'd say the other name for CMT, hereditary motor and sensory neuropathy (HMSN) would be more correct, but, because so much research is going on, the entire classification for these diseases may change, so we'll stick with CMT for the time being. More than 100 years later, we know that Charcot-Marie-Tooth disease is much more complicated than was once thought. Of the entire classification of hereditary motor and sensory neuropathies (HMSN), CMT types are only a few of more than 20 types so far classified, and classifications are changing as geneticists find more variations all the time.
How did I get CMT?
In most instances CMT is inherited. Chances are good someone in your immediate family, your mother or father, has CMT. If you have the most common type, CMT type1A, you would have had to inherit it directly from a parent who has it. That parent, however, may have it so lightly they don't even realize they have it. In CMT type1A, there is a 50 per cent chance at each conception that the child will inherit CMT. CMT can also be inherited in a recessive and an X-linked form and the odds of passing it on vary.
CMT can also be a spontaneous mutation. So there may not be anyone in your family who has it. You may be the first and you may pass it on. (Please see GENETICS -- The genetics of CMT and the present state of DNA testing, explaining the various types of CMT and the ways you can inherit CMT as well as the available tests involved to find out what type you have.) As research finds more types, it is a race to develop the tests to let people find out if they have that type or not. There are, to date, blood tests for five of the many types known and HNPP.
The most common type of CMT is caused by a duplication on the peripheral myelin protein (PMP) gene locus on chromosome 17; however, this accounts for only some of CMT 1 (i.e. 1A). Instead of a pair, we have three. The deletion of this gene causes hereditary neuropathy with liability to pressure palsies (HNPP), a disease with many of the symptoms of CMT but in addition severe numbness in sites where pressure is placed, such as when you lean on one arm or cross your legs. (Please see HNPP)
Will CMT kill me?
A lot of people are afraid to ask. Let's get it out of the way. CMT will not kill you but, I must add, because some people with CMT experience paralysis of the diaphragm muscles that help our lungs function and allow us to breathe, CMT can weaken us to the point where it becomes a secondary factor in our death. When our diaphragm becomes paralyzed, our breathing is impaired, and we have a difficult time recovering from pneumonia. Sometimes our cough reflex is also impaired or lost, so CMT can indirectly be the cause of death if your breathing is impaired in a major way and you get pneumonia or develop emphysema from smoking. Other than that, most of us wear out from work rather than rust out from sitting on our duffs. We're an intelligent, busy, active crowd who don't feel sorry for ourselves in any way and just keep plugging.
What can I expect down the road?
That all depends on how much your CMT affects you now. Remember that quote I asked you to digest. All of us are different. Some of us play tennis into our 60s and 70s, while others are having surgery to simply allow them to walk at 15, and others are in a wheelchair by 40. We are all so different that no one can tell you exactly what to expect and don't believe them if they do.
What can I do to help myself?
You can make sure you know that there is a list of drugs you should not be taking when you have CMT. These drugs alone can make you much worse. (Please see DRUGS for information about drugs and vitamin B6 which you also shouldn't take. Most people don't think of vitamins as harmful but vitamin B6 and, indeed, massive doses of some other vitamins can harm us.
Smoking is very hard on the nervous system and alcohol is toxic, so why mess with something that is already struggling to survive. You'll be better off if you don't smoke or drink or drink very little.
What about taking vitamins?
There is some evidence that the vitamin CoQ10 can help us a little. It is preliminary work, and nothing much else has been reported on it, but some of us take CoQ10 and we seem to breathe more easily and have a little more energy. The literature says 120 mgs a day were given research subjects. Some of us take a little less with good results over time. It is available at health food stores. Research is ongoing.
Is there anything else I can do?
Yes, you can learn to pace yourself. The basics of CMT is that it is a genetically inherited problem of the nerves. It affects the peripheral nerves (the ones that serve the muscles of the legs and arms and just about everything else except the brain and spinal cord ) and we are finding that it affects all kinds of muscle groups. I'll explain how it works. When the brain sends out a message, say to your toe to move, the message zots through all kinds of nerve pathways to finally hit the toe muscles, which contract, and your toes move. If you picture the nerve as having insulation on it, like an electric wire (and we all know a wire doesn't work if the insulation is shot), and the insulation or myelin on the nerve is there in patches but not in a continuous cover, the message can't get through to the muscle correctly, and no matter how hard you try, that muscle will not work. If you keep pushing that message down those nerves with impaired myelin on them the nerves eventually say, "To heck with you, I'm not going to take any of the message anymore," and the nerve, and thus the muscle, just stops working. When the nerves die or are severely impaired, you can only get a flicker of movement and sometimes you can't move it by thinking about it at all. That's what happens if you overwork a muscle served by a CMT affected nerve. It can just give up. So, learning to pace yourself is very important.
Running a marathon because you can do it, isn't smart; working until 11 every night isn't smart; trying to be a super mom is just plain nuts. You last a lot longer if you learn to pace yourself. Your body needs rest not punishment. No amount of exercise or pushing will make up for the torture you've put it through trying to prove that you can lick this thing. You can't lick it but you sure can learn to live well with it. (Please see WELLNESS which points out the signs and symptoms of CMT and helps you cope.)
Exercise: isn't there something I can do?
Absolutely. There isn't any reason why you can't exercise within reason. If you are swimming, don't get exhausted until you shake. If you are bicycling, don't go until everything you have burns. With CMT, pain does not make gain; it means we are harming ourselves, and we are going to have to cut back.
Many people with CMT exercise, and they do everything from bicycling (actual or stationary), walking is a favorite, to stretching or working out, sitting down if their legs and knees won't hold them. (Please see EXERCISE which explains how you can tell if a muscle is served by a CMT affected nerve. If you work those muscles, you can do damage; however, if you take the time and effort to find out which muscles you have that are NOT served by CMT affected nerves, you can likely strengthen them to help the ones that are affected carry on longer.
You talked about balance - is it always affected?
In many of us, the inability to balance is one of the first things we notice. We just have to reach out and touch something for that little bit of balance we need to stay standing still. I'll talk about balance more when I talk about bracing and surgery. Please see WHEN YOU FALL for information that helps you avoid a fall and cope with the ones you have.
If lack of balance is one of the first signs of CMT, what are the others?
We notice young children who have CMT sometimes walk on their toes and complain of being tired often. Indeed, fatigue is one of the prime symptoms of CMT. One of our advisors put the fatigue problem well when she said that people with CMT are trying, with vastly impaired nerve function and atrophied muscles, to do in the same time and at the same pace what normal people are doing. No wonder they are tired! That doesn't mean we are looking for pity or asking for help, we just have to think smarter and learn to pace ourselves...do as much as we can with what we have.
Some of us first notice that we are beginning to trip a lot. This is because the peroneal muscle down the front of our lower leg is often the first muscle to go. CMT was once called peroneal muscular atrophy (PMA). The peroneal is the muscle that helps us lift or dorsiflex our feet. If we don't lift our toes properly, we trip. Stairs become difficult as we lose muscles in the feet and ankles, we trip up steps and up curbs, and ankle sprains become common.
Some people also notice that their knees begin to give out for seemingly no reason.
Our hands can also become weak, and many of us lose some of the strength in our thumbs, which means we cannot pinch to do up buttons or pick up coins or small objects, and holding a pen for any length of time can be impossible...it just falls away.
Some of us who have had symptoms of CMT since we were a young child have severe foot, leg, hand and arm involvement and total paralysis is possible, although you'd be surprised what you can do with totally paralyzed feet or hands. With bracing or surgical fusing, and the determination along with the smarts to think things out, most of us manage to be pretty independent even if we are badly affected. The ability to stoop, bend and squat can be impaired if and when the leg, thigh and lower back muscles become affected. With weakness can come considerable cramping.
Some people lose the feeling and the movement in these areas, some just the feeling but retain the movement, and some just the movement so, again, we are a diverse lot.
You mentioned breathing, what else can CMT affect?
Breathing can be affected in some of us and so can hearing, vision, the neck and shoulder muscles; we can have scoliosis or what we used to call curvature of the spine; hip sockets can be malformed; gastrointestinal problems can be part of CMT, as can chewing, swallowing, speaking (our vocal cords can atrophy); and a tremor can develop so we have a little shake in some areas. But I must stress again that we are all different and not many of us have all of these symptoms; in fact, most of us have only two or three. Again, see WELLNESS for more on this topic.
If breathing can be affected, what about anesthetics?
A lot of people who experience breathing problems with their CMT know they have dysfunctional breathing and are being treated for it. Often CMT breathing problems are misdiagnosed as asthma. One sign of breathing problems is being winded for seemingly no reason or having a very bad headache first thing in the morning. This will go away as you go about your business but sometimes leaves you feeling tired and foggy all day. This is a buildup of CO2 in your bloodstream that should have been exhaled during the night but because you weren't breathing out very well, you were lying down and didn't have the benefit of gravity to help you, the buildup occurred and the headache. Elevating the legs at the head of your bed a couple of inches can often help this. CoQ10 helps too (see WELLNESS). A good respirologist can check out your breathing for you. (Please see BREATHING for information that will help you understand what CMT breathing problems are all about, and also ANESTHETICS because it is so important that your doctors know you have CMT before you have surgery that requires an anesthetic.
People with CMT should be kept warm before, during and after surgery to preserve precious energy, thus hasten their recovery. Some of us use so much energy trying to keep our body warm during surgery that we are physically exhausted after surgery.
What about pain?
I'm not going to say that people with CMT do not experience pain because we know very well that we do, and it is sometimes very debilitating muscle or nerve pain. A group of research doctors have done a large pain survey on our members and the results say that, for some, pain is one of the most debilitating symptoms of CMT.
Everything possible is being done to recognize CMT pain, to figure out how to treat it and to make sure people who have CMT get that treatment, but it is going to be a long hard road. Because you can't see pain, can't feel it in someone else, and can't register it on anything, you have to go by the report of the person who has it. Research has always based its conclusions on things they can measure. Anecdotal reports or the hearsay of patients isn't something hard research can trust but, when it comes to pain, they are beginning to realize that the words of the person actually experiencing the pain is all they are going to get.
Treating CMT pain is a long and sometimes difficult thing. Drug therapy such as neurontin works for some but some cannot tolerate the sedating effects of many pain killers; heat and/or cold will sometimes help; some people have had success with acupuncture and others with a TENS or transcutaneous electrical nerve stimulation device.
There are many different kinds of pain and as many ways to treat it.
You can learn to live with CMT pain. I say that from experience. It isn't easy, and the pain is always with you, but you do go on. BUT, and it is a big but, it is far better to treat your body well so you do not end up in a lot of pain. However, in many cases, nothing the person could have done would have prevented it in the first place, so no one with CMT pain should ever blame themselves. And, don't forget, not everything we'll experience healthwise will be caused or be part of our CMT. Look elsewhere when you are searching for a cause and cure for pain and other symptoms. Blaming everything on CMT can mean you could miss something that is treatable.
Again, I have to say, we are all different. Most of us don't have pain or you might not have any pain for years. Then, as you begin to "wear out," so to speak, with simple aging, you develop pain from just living. (Please see PAIN for information that will give you further insight into the treatment of CMT pain.)
What about bracing?
When ankles and knees and feet and hands weaken, they can be braced. Even your neck and spine can be braced, but most of us live all our lives without any bracing, except for the simple light plastic ankle/foot orthoses that many of us wear to help prevent footdrop. I don't know how many calls and letters I've had from people who were absolutely delighted with their newfound ability to walk quickly and smoothly wearing their new AFOs. Custom-made ones are best, and expect alterations until they feel right for you and don't hurt.
Some people don't even need AFOs but manage very well with sensible flat shoes, probably lace-ups, and some only need in-shoe orthotics that can't even be seen. A lot of people with CMT wear athletic walking shoes all the time, and high-tops can really help stabilize the ankle if you're into sports. (Please see BRACING, also FEET.)
Simple wrist braces can help a person work longer, but getting away from the type of work that puts undue stress on any part of your body is the smartest way to go when something is weakened. Figure out why it's weak, and then don't do it. That's fine advice if the activity isn't one you must do, like walking, breathing or eating. If you stand on your feet all day, or your job demands that you walk many miles a day, and your legs, ankles and feet are suffering, try to find another job somewhere with the same company that doesn't demand you do this. For instance, if you keypunch all day long and your fingers are getting so weak you are making mistakes, try to develop further skills so you'll be eligible for another job where keypunching isn't the main activity. Your fingers won't get stronger keypunching but will continue to weaken, and that weakness will carry over into your personal life and include everything from preparing meals to making beds and wiping your behind. This is serious stuff; you have to be aware of what is happening to you and beware of occupational hazards. Even a hobby can weaken you if it is repetitive and you are continuously working muscles that are served by CMT nerves.
What about surgery instead of bracing?
That's a big question and one each individual has to answer for himself. There are surgical procedures that will fuse your ankles, feet and toes and wrists, hands and fingers, but do you want it done. It is permanent in most instances and means you have to compensate for something that won't bend for the rest of your life. I've lived with fused feet, ankles and toes for more than 40 years and walked pretty well for 30 years because of these surgical procedures. Now my knees have gone and I can no longer hold myself up. Rather than go to full bracing from my hips down, I have opted to use an electric scooter or a wheelchair when I'm outside. These mobility devices get me around just fine. In my heart, I simply could not go to a full-length brace; so, you see, it's up to you what you do for your CMT. Know your options and make your choice. Just know that if you neglect parts that with bracing would remain viable for years, you are, in fact, damaging your body through neglect and not realizing your full potential.
Like those people who said no to AFOs for years because they didn't like the look of them and then found out they could out-shop their daughters when they wore them...orthotics and all of these helping aids are there to make us better not to push us down. When they call a scooter a mobility device, I laugh; I call mine Freedom! (Please see HELPING AIDS for information that gives you ideas to help yourself and addresses for catalogues. It also includes toileting aids and driving aids and where to get them.)
Corrective orthotics built into regular shoes, custom-made shoes, ankle/foot orthotics, canes, crutches (mainly the Canadian style that do not go under the arm), walkers, manual wheelchairs, electric scooters and electric wheelchairs cover the range of aids to help mobility that most people with CMT will try during the progress of the disease. Some will need one or two as they live with the disease, some none, and some will use almost all during a life span.
How do I know if I really have CMT or could it be something else?
Blood tests have been developed that will pinpoint the location of five types of CMT and HNPP. Geneticists are working on describing the locus of other forms of CMT and more blood tests are actually in the works. As soon as the locus is found, a test can be designed to find that particular type in a person's genetic makeup. No truly reliable prenatal test has been established yet but it is also being worked on.
Physicians also commonly use several other tests to make the CMT diagnosis. An electromyogram (EMG) tests the irritability and function of muscles, while tests of motor-nerve conduction velocities (MNCV) establish the ability of nerves to send and receive impulses. MNCVs are tested using surface electrodes, following standard techniques. Reflexes are also examined, and muscle strength is tested. A detailed family history also helps establish which type of CMT is present. Sometimes, a nerve biopsy is taken but, with all the other tests available now, nerve biopsies are not really needed. (Please see DIAGNOSING for information that explains the complete diagnostic procedure for CMT.
I didn't know I had CMT, it is a complete surprise for me and some of the other members of my family. Is this common?
It sure is. I don't know how many times I've had people call me to say they've always known something was wrong but they didn't find out what it was until their grandchild was diagnosed at two or three years of age. It was only then that their daughter found out she had it, and they took a good look at themselves and back to their mother or father and grandparents. Sure enough, Grandma Jones had a funny walk and didn't some of her sisters and brothers also have problems, and now look at us. A lot of lightbulbs go on when one person in a large CMT family is finally diagnosed. Often, it is with relief that everyone finally knows what the problems are...affirmation can be a wonderful thing; you aren't crazy after all.
Science doesn't really have a handle on CMT yet. They are still finding and learning but they are a lot further along than they were 50 years ago and even five years ago. The answer is coming, and when we have the answer, we'll have treatments and maybe even a cure. But, we must live well in the meantime.
A few other quick questions that are often asked of me:
My doctor told me that 50 per cent of my children will have CMT, is that true? I mean if I only have one child, what will happen?
What the doctor means is that with conception there is a 50 per cent chance of any child you may have having CMT. This applies to the autosomal dominant type only. All or none or some of your children could have CMT if you have it, depending on the type you have. (Please see GENETICS.)
Is there any special diet I can eat that will help?
No, not really, but not drinking alcoholic beverages, smoking or becoming overweight will help
Will electrical stimulation treatments help me?
There has been no evidence that electric shock therapy to the nerves and muscles helps over time. Some of our members have paid for long sessions of this type of therapy and have unfortunately experienced no long-lasting benefits.
Will CMT affect my ability to drive?
The ability to use your feet when driving can be lost when and if we can no longer lift our foot from gas to brake fast enough to pass the tests of the Motor Vehicles Board of Examiners. Hand controls are the answer in this situation. I've been able to drive for more than 30 years with hand controls. If you can pat your head and rub your belly, believe me, driving with hand controls is a cinch. A grip you can place your hand in, mounted on the steering wheel, means you can steer safely no matter how weak your hands. (Please see HELPING AIDS.)
Is there a doctor near me who knows about CMT?
We have a list of doctors all over the world who know about CMT but they are generally found in big cities and are specialists. Most general practitioners in most towns and cities in North America and, indeed, the rest of the world will know virtually nothing about CMT. It is going to be up to you to educate him or her, and you can do it by learning all you can about yourself and your CMT.
Neurologists can diagnose, and some will treat you for pain; anesthetists often treat for pain; orthopedic surgeons can fuse and do muscle, tendon and ligament work on your hands and feet, spine and hips, orthopedic surgeons can also suggest bracing; orthotists can make braces; respirologists can diagnose breathing problems; physiotherapists can help keep you flexible and suggest ways to let you work out without harming yourself; an occupational therapist can help you adapt your living and working conditions to your changing capabilities; a physiatrist, who is a specialist in physical and rehabilitation medicine, can help with many aspects of your CMT because he knows the body and what we need to cope with the changes; your general practitioner should be able to help keep your everyday concerns under control and refer you to the specialists you may need from time to time.
I was told CMT can't affect the very young so why has my two-year-old granddaughter just been diagnosed?
CMT can show up in the very young, and there is something called CMT Plus that actually seems to reverse the development of a young child. Thankfully, it is rare. CMT can show up in teenagers, in the middle-aged or in persons nearing retirement. There seems to be no set time when it manifests itself. It does not seem to affect longevity, although I have to qualify that by referring back to the ‘but' I wrote on pneumonia and breathing problems. If your breathing is affected and you get pneumonia and are not treated, or you are given improper anesthetics and your breathing is affected, CMT can contribute to your death.
Can I stop my CMT?
No, but people with CMT have been known to reach a plateau. It's a strange word meaning to stay the same for a period of time...some 15 or 20 years.
What happens to make you worse again?
Sometimes nothing, it is just time for your body to change. Sometimes the aging process can start things up again, menopause, childbirth, major stressors like the death of a loved one, a bad case of the flu, a car accident, losing your job or a divorce. Stress is a hard thing to measure because no one but you ever knows what you were like before the stressor occurred. There isn't any literature on stress making CMT worse but we have heard from hundreds of people who have experienced an exacerbation of their CMT after a major stressful event in their lives.
A visit to the family doctor with symptoms of chronic fatigue, sleeplessness, aches and pains, constant falls, and problems with feet and hands can be the beginning of a search for an easier, less demanding lifestyle. Part-time work is the answer for some, while others retire from work earlier than usual, and still others take a disability pension if the extent of the disability makes working entirely impossible.
Those most severely affected emotionally seem to be persons who, for many years, thought that there was nothing wrong with them and suddenly experienced loss of function in either hands or feet and were thrown into the world of disability completely unexpectedly. (Please see STRESS.)
Can CMT affect my sex life?
In some cases - yes. Some of us lose the ability to feel touch in our genitalia, some women cannot experience orgasm, some men cannot maintain an erection. We have a publication expressly written for people who have CMT who want to know the possibilities regarding their sex life, but remember what I said at the beginning about all of us being different. (Please see SEXUALITY & SEX for information about many of these problems.) Don't count yourself out until it happens and even then there is help. We also have information in WOMEN with CMT, directed specifically at women's personal problems.
What about having children?
This concern has been debated over and over for years in the CMT Newsletter. There are always arguments, pro and con, but the answer always comes out the same: you must follow your heart in these very personal matters. None of us would be here if our mothers had all said they were not going to have children because her child could have CMT. I, for one, am very glad I am here, and I know some terrific people with CMT including doctors, lawyers, judges, pilots, nurses, writers, researchers, even a rocket scientist, who have made wonderful contributions to this world. It's what's in the heart and mind that counts. (Please see PREGNANCY for information that will reassure new mothers but it doesn't debate the question of whether you personally should have children or not.) We discuss the question of testing in TESTING/TELLING. Testing to determine if an unborn child has CMT is available providing the mother has been diagnosed with CMT1A or HNPP. Also, preimplantation genetic diagnosis (PGD) is being developed so a child can be born without CMT. We also have information in CHILDREN & YOUTH that addresses some of the problems we face when raising a child with CMT.
Can I live a quality life with CMT?
You bet you can, but it takes a lot of coping. You have to learn to listen to your body and not abuse it, and learning to pace yourself may be one of the hardest things you ever do. You may lose your job because of your CMT and have to retrain in mid-life or go on pension. However, when I look at the many thousands of people I have talked to and written about who have CMT, in spite of the fact that for all there are undeniable periods of grieving, depression, confusion, frustration and anger, I have no doubt that the majority feel their lives worthwhile, and most have a smile on their face. Life goes on, CMT or not; the ones who survive are the ones who accept their CMT, do what they can, with help, to make the best of it and learn to live well with it. We're here to help.
We have information in GRIEVING that could help you get through the initial periods of adjusting to CMT and on to the fast track of living with it.
To the best of our knowledge the information contained herein is correct and up to date but we cannot be held liable for errors or omissions. Please contact your doctor for more information and know that there are many sites on the WWW featuring more information on CMT and HNPP.