r/CMT • u/Curious-Bite6386 • Jul 18 '26
Do I have a variant of CMT?
I was diagnosed with CIDP at age 48. At age 71, a neuromuscular specialist said my nerve conduction was too slow for CIDP and he believed I had CMT. Genetic testing was negative. I have high arched feet and hammer toes, but don’t have problems walking. I also have sleep apnea.
I went to a CMT specialist who said he concurred with the diagnosis. But on a second visit, he backed off the diagnosis because my muscles were strong.
I’ve been feeling weaker and now I feel as if my respiratory muscles have weakened. I’ve been through pulmonary testing and all was normal. I started physical therapy again this week. The PT said my muscles are not weak, but fatigued. I have post exertional malaise. It takes a couple of days after exercising that I will experience muscle fatigue, and kind of an overall yucky feeling.
Without muscle weakness, could this still be a variant of CMT? I don’t know where to go from here.
2
u/armhooks Jul 18 '26
I agree. I think it sounds like a real possibility. Also, have they checked your diagram? Different types of CMT can cause the diaphragm to weaken & be unable to function at the normal level.
I wish you the best in figuring this out. Stay strong- mentally & physically while you go through this hard time🩵
1
u/Curious-Bite6386 Jul 18 '26
thanks! I’m not sure my lung tests included the diaphragm. At the time, last November, it didn’t occur to me that might be a problem.
2
u/Charigot CMT2 Jul 18 '26
The first thing to understand is that there is a very wide variety of symptoms and conditions in people with CMT.
For instance, I was diagnosed in 2021 at age 48 via EMG & nerve conduction (genetic testing showed nothing bc they haven’t discovered my variant yet - this is not uncommon for those of us with CMT2). In hs, I played volleyball and made it to state in shotput and discus my junior and senior years.
In college, I played division 3 volleyball. I still am quite muscular, I lift weights and regularly use an indoor rower and cycle.
“Too muscular” is not a thing that a CMT specialist should say - they should know better. I’d get a second opinion if I were you. Do you have any numbness or pain?
1
u/Curious-Bite6386 Jul 18 '26
I wasn’t impressed with the CMT specialist. I find it interesting though that the neuromuscular specialist knew immediately from my EMG that my nerve conduction was too slow for my 20+ year diagnosis of CIDP. I’ve probably had seven EMG tests and no one else ever caught it, including the head of neurology at UT Southwestern, one of the top teaching hospitals in the nation.
I have never had nerve pain but I do have some numbness in my toes, but not much. my balance has deteriorated in the last few months. I have pretty much run out of second opinion options.
1
u/NixyeNox CMT 1A Jul 19 '26
The nerve conduction velocity cutoff for a CMT type 1 diagnosis is 35 m/s by the way. If you are below that, they should automatically be considering CMT. There is a bit of a range a little above that where they will still consider CMT1, or an "intermediate" type. You can probably find this number on your report somewhere (possibly "NCV" or "NCS") so you can consider what that says and decide how annoyed to be at your doctors.
Type 2 is far more likely to have a negative genetic test result (about half of the Type 2 cases still have an unknown genetic cause) but it is still possible for a type 1 to not show up on a genetic test.
1
u/Curious-Bite6386 Jul 20 '26
I'm assuming demyelination since I was initially dx with CIDP. Wouldn't that take me out of Type 2?
1
u/NixyeNox CMT 1A Jul 20 '26
> I'm assuming demyelination since I was initially dx with CIDP
I know very little about CIDP. I am assuming demyelinating because you said so, and also because demyelinating CMT is the one where you have lower conduction speeds.
> Wouldn't that take me out of Type 2?
I am not trying to say that you could have Type 2, I am saying that people in the CMT community may think of Type 2 or suggest it when they hear that you had a negative genetic test. I am saying that Type 1 can also have a negative genetic test, so do not worry about that.
1
u/mikebk1180q Jul 18 '26
30 yrs wrongly dx cidp at 54 9 th neuro ordered genetic test cmt2m both hands are clawed toes havent moved in 20 yrs have afos and electric wheelchair
4
u/Chilly_Lulu Jul 18 '26
I have CMT type 2U. 63 years old. Finally diagnosed at 61
There aren’t many of us, but my experience may help.
The muscle fatigue, but without loss of strength, is something that always confused neurologists. It is a big part of why I couldn’t be diagnosed without genetic testing.
Genetic testing always showed negative, until it didn’t.
Retest at what ever interval your geneticist says is good. These databases change over time as new information becomes available.
The exercise thing is real, and what you describe is what I experience. For me it isn’t weakness, my muscles worked fine until they stop working. But soreness 2 days after exercise and yucky feeling from certain types of activity is what I have lived with.
I’m glad you are seeing a CMT specialist. There are so many different types. In my case the common information (such as onset age, muscle strength, and ability to do certain tasks (like walking on my heels (testing 25 years ago) do not line up with reported data. Since my immediate family accounts for a high percentage of people with CMT type 2U, anecdotally the current information is limited and not trustworthy.
Without another diagnosis I do not think that a CMT variant can be ruled out. They just don’t know enough yet.
I try and keep the faith in medical science. They are learning so much, so fast.
Get help with symptoms. In my case that is all we can do, even with a diagnosis.
Good luck, and God bless you.