Nerve conduction velocity tests

[Tuzza]

Second post in a day......I found out I had CMT in 1999. I had some nerve conduction velocity tests done then and then for a second time this year, 16 years after. They are exactly the same. Can anyone tell me if this is good, normal or makes no difference to what CMT does. Thanks again, Sean.

[DawnD]

Hi Sean. I'm not sure, to be honest. CMT is a progressive disease, but the speed at which it progresses, if it progresses noticeably, varies from person to person. I have only had the nerve conduction velocity tests done once (I was only diagnosed in 2013 after my Dad was diagnosed in his late 70s - he was adopted so there was no family history to look to) and my results showed the electrical impulses were roughly half the speed they should be, and the consultant actually said that if he woke up the next day with the same result as me, he wouldn't be able to walk! So I would say that if yours are the same as they were 16 years ago then that is good - whether it is normal I have no idea. Plus it might also depend on the actual sub-group of CMT that you have (I have the most common - CMT1A). Hope you get some more replies

[chicodex]

Over the past 14 years I have had no less than four nerve conduction tests - quite uncomfortable procedures... jabbing & stabbing and electric shocks and such - there has been little variance in the results over the years apparently because I have axonal nerve damage rather than demyelisation, I had it explained to me by my neurologist and I think I got the gist of what was said but I must confess I am as yet a little sketchy, knowledge-wise on what the results actually mean...

[Amanita in reply to chicodex]

I felt virtually nothing when I had my nerve conductivity tests done three years ago. I understand the neurophysiologist who did the tests found them hard to interpret as most of the responses were absent. The little information she obtained suggested a demyelinating peripheral neuropathy with secondary axonal damage - later confirmed (with a genetic analysis ) as CMT 1A

[chicodex in reply to Amanita]

I have CMT type 2 axonal and the last N.C. test I had was 2 years ago, I have to say that after 15 minutes of testing and I couldn't feel anything she turned the gizmo up to full blast and stuck the needles into my leg muscle fibre as far as they would go eventually it did hurt a little and only when she stuck them into my upper shin muscle very close to the bone.

[Lickylicky]

Your story sounds exactly like mine! Five years ago I was diagnosed with CMT. This past December I went back to the neurologist to ask him could he do a nerve biopsy to confirm that I indeed did have CMT. He explained that the genetic test was the way to confirm CMT. he went ahead and did the nerve conduction velocity tests and concluded that my results were the same as they were five years ago. He looked at me and said I don't think you have CMT. He then says to me so for the last five years you've been thinking you have CMT? I told him yes but I forgive and I gave him the biggest hug.

For sure I have peripheral neuropathy and I presume that you do as well. I think you've got the best news in your life! As you know CMT gets progressively worse over one's lifetime. In my opinion it sounds to me like you were misdiagnosed maybe your doctor is not being honest about it I guess I'm lucky my doctor is a Christian so he was honest about it

[Amanita]

Lickylicky -

I think the only way to prove whether you have CMT or not to is to have a genetic test (based on a blood sample) . This is expensive for the NHS and the results take several months to come back. I think in a very small number of rare cases it may not be conclusive, but understand that for the majority of us it shows which faulty gene (therefore which type of CMT) is responsible for our problems.

As I understand it, nerve conduction studies show broadly whether the neuropathy affects primarily the axons ("electric wiring") or the myelin ("insulation"), as well as indicating the degree of damage.

If neither of your parents has/had CMT, it is less likely that you will have it, as most cases are inherited.

I am very happy for you that your original CMT diagnosis has been overturned.

[Shazza65]

Nerve conduction tests are not normally expected to give results that have changed over a period of time and just because yours haven't changed doesn't

mean you have or have not got CMT. My results were 16m/s as a child, the same when I had my children and the same last September aged 49. My CMT has got progressively worse over those years. I have CMT type 4 auto recessive.