Exploring the Burgeoning Question: “What is CMT?”
“Why are you wearing shin guards? You play soccer?”
“What’s wrong with your hands?”
“What’s wrong with your legs?”
Etc., Etc., Etc.
We all know the drill. The answer to the seemingly never-ending questions involves those three lovely letters, C-M-T. And then, the proverbial follow-up, whether it’s a random person in public or even a healthcare provider, requires us to dig deep in hopes of giving them a straight-to-the-point answer that’ll leave them knowing just enough about our disease to remember the name should they hear it again, all the while hoping we give them enough information to know it’s not a tooth disease and that it has nothing to do with sharks.
What is CMT?
“What is CMT?” I’m always trying to improve on how I answer this question. I can easily rattle off some quick factoids, such as CMT is a heterogeneous group of inheritable peripheral polyneuropathies whose name comes from the three doctors who first described it in 1886: Drs. Charcot, Marie, and Tooth; and this name, CMT, has since become an umbrella term that refers to many different inheritable sensory and/or motor neuropathies. Quick and to the point, right? This doesn’t say much about what the disease is though.
Medically, CMT is a genetically caused neuromuscular disease—neuro because peripheral nerve, muscular because the disease in the peripheral nerves causes symptoms in muscles. Genetically caused because each subtype is caused by a mutation in any one of many different genes.
Medically, CMT is an inheritable multisystem neuromuscular peripheral polyneuropathy. Inheritable because each of the genetic mutations that cause CMT are inheritable. Peripheral because CMT is a disease of the peripheral nerves. Polyneuropathy because CMT affects more than one peripheral nerve at a time (poly), as opposed to only one peripheral nerve (mononeuropathy). Neuropathy because peripheral nerve disease. Then, multisystem because CMT can affect hearing, vision, breathing, genitourinary, and much more, in addition to feet/legs/hands.
Statistically, CMT is the most commonly inherited neuromuscular disease nobody has ever heard of. This one is a weird dichotomy unto itself. CMT is a rare disease by every statistical and modeling measure. At the same time, when it comes to inheritable neuromuscular diseases, in totality, CMT is the most commonly inherited. In this context, common and rare can peacefully coexist even if it seems like they shouldn’t.
These above are just a select few examples of how CMT can be described. All of these descriptions are fine and dandy, but not only are these difficult to remember, firing off any of them to Jane Q. Public tends to render confusion about a disease they’ve never heard of. Is there a viable solution—a grand unifying answer, so to speak?
The Elevator Speech
I’m often asked to give my “45-second elevator speech” on what CMT is. My response typically hits several talking points and is usually along the lines of “CMT stands for Charcot-Marie-Tooth disease and is a rare inheritable neuromuscular peripheral neuropathy named after the three doctors who first described it more than 130 years ago. Although rare by definition, affecting only 1 in every 2,500 people, and totaling about 3 million people worldwide, CMT is the most commonly inherited peripheral nervous system disease. CMT causes the peripheral nerves to stop working correctly; and this leads to muscle weakness and atrophy, joint changes, difficulty with walking, and hand issues. Some who have CMT have breathing issues, hearing impairment, vision problems, bladder issues, and GI issues. The disease progressively worsens over one’s lifetime, there is currently no treatment, the disease can’t be cured, and it affects everybody very differently from one another.” Sometimes, people will ask follow-up questions. Other times, we part ways with only a, “whoa,” and maybe they’ll recognize the name the next time they hear it.
My “elevator speech” has been a go-to for many years, having evolved only slightly since my initial CMT diagnosis. It’s very easy for me to throw it out there anytime I’m asked. Does it say enough about what CMT is as a whole that it could be adopted by anybody who needs a quick go-to description? Until a week ago, I thought it did and I thought it could. What changed?
Bicyclists as a Catalyst
For the first time, I attended the Charcot-Marie-Tooth Association’s Cycle 4 CMT fundraising event held annually the last weekend of August in Charlotte, Vermont. This event is huge and people from all over the place, not just locals, attend and/or participate. I met and spoke with many CMTers. Some CMTers were cycling participants riding a treacherous 40-mile course through the western Vermont mountains even though there were shorter less-challenging routes. Some CMTers were there to participate in non-cycling activities. Some were event volunteers. Some were parents who do not have CMT, but their child does (or children do). Some were members of the CMTA leadership and social media teams.
Some of the CMTers at Cycle 4 CMT used wheelchairs, canes, walkers, etc. Some CMTers wore leg braces. Some CMTers had breathing issues. Some CMTers had severely twisted and deformed feet. Some CMTers had hearing loss. Some CMTers had speech impairment. Some CMTers had <fill in the blank>. I’m confident there were many hidden symptoms that went unmentioned and unnoticed. Without a doubt, it was the most diverse single-source representation of what CMT is that I have experienced in-person. As I spoke with CMTers and as I looked around, it became apparent that my go-to elevator speech is grossly inadequate and under-represents what CMT is.
It's well established that CMT can and does affect everybody differently, and even within the same family. CMT can cause many things. Not everybody who has CMT will experience all symptoms of CMT. The mix of symptoms, the severity of individual symptoms, the rate of disease progression, and the overall disease severity can be quite different for every CMTer. What one CMTer experiences cannot be used to gauge or to predict what the disease will be for the next CMTer, regardless of subtype. It’s one thing for me to read it, and another for me to witness these concepts firsthand.
Is There a Solution for the Question?
What is CMT? The answer to that question, as it turns out, is quite different for every CMTer. My CMT is different than somebody else’s CMT. CMT, for me, looks quite different than does CMT for another. CMT, for me, is twisted, contorted, crooked feet that have led to tendons tearing requiring corrective reconstruction surgery of my right foot (and upcoming surgery for my left foot). CMT, for me, is weakened hands that easily cramp, a knee that used to dislocate before corrective surgery, bilateral hearing loss, unrelenting fatigue, chronic whole-body pain, progressively weakening upper leg muscles, spine changes (kyphoscoliosis), premature degenerative joint changes, speech/vocal difficulties, and for me, CMT is breathing issues. For another CMTer, CMT is wheelchair dependency, is an inability to hold and use a pen or pencil, is 24/7 mechanical ventilation via tracheostomy, and is total deafness. Yet, for another, CMT is none of these things, or a is a combination of these.
What is CMT? True to CMT, there isn’t a one-size-fits-all answer. The answer to the proverbial question is unique to the CMTer who is asked. The answer is even unique to the healthcare provider and to the scientific investigator. There are wrong answers to the question, such as a suggestion that CMT is an autoimmune disease. While CMT might share symptoms with some autoimmune diseases, such as Multiple Sclerosis (MS) and Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) for example, CMT is decidedly not an autoimmune disease. Nonetheless, the answer to the burgeoning question is dependent on what CMT looks like for the one who’s giving the answer.
If you were to line up ten random CMTers—somebody who has CMT or somebody whose loved one has CMT, and ask each, “what is CMT?” each of the ten answers are likely going to be very different from one another. The differences are not born of inaccuracy or of a misunderstanding of their disease. The differences instead come from how differently CMT looks for each individual and from how each person individually experiences CMT.
What is CMT? For me, CMT is a cruel and often debilitating neuromuscular disease that looks very different from person-to-person. For me, what was once an easy answer to a complex question, or what was a complex answer to an easy question, has become exponentially more difficult to answer. As a CMTer, it’s easy to answer the question by simply describing what CMT looks like for me. As an advocate, however, I’ve learned my “45-second elevator speech,” while it gives a lot of information, is a disservice to the CMT community as a whole. The solution? I resolve to do better. I have to do better. I will do better.
About the Author
Kenneth Raymond was first diagnosed clinically with CMT1 in late 2002, at the age of 29. He was genetically confirmed to have CMT1A a year later. Kenneth has since devoted his life to studying, researching, and learning all things CMT, with an emphasis on the genetics of CMT as they relate to everyday CMTers. As a member of the Charcot-Marie-Tooth Association’s Advisory Board, Kenneth serves as a CMT genetics expert, a CMT-related respiratory impairment expert, and as a CMT advocate who is committed to raising CMT awareness through fact-based information rooted in the latest understandings of CMT.
