What is the different testing vs. Paramyotonia and Thomsen's. I know the Thomsen's...what do they do for testing of Paramyotonia? Very curious and thanks Jan.

Usually the initial screening is an EMG to look for myotonic discharges. But with PMC you may not see those discharges unless the muscles are iced.

From there the best approach is to rule out myotonic muscular dystrophy and the myotonia congenita disorders (both Thomsen's and Becker's) with DNA testing. DNA testing for PMC is much less developed at this time.

Another difference would be that with MC the stiffness is worse after exercise and actually improves as you work the muscles, but with PMC the stiffness progresses AS you exercise.

Again, these are two totally different disorders caused by mutations in different ion channels. While there are some similarities, there are some important distinctions and the treatment approach can be quite different.

Jan

Jan, I am sorry for picking your brain again. I gave you the data comments that I reread from the doctor's. I got confused and that is why I asked you as I saw the same clumping of paramyotonia and Thomsen's. It was like it was in the same sentence but I knew it was two different Myotonias. You had taught me that in the past. I just wanted to keep my brain on the right page for my child. Jan, any word on the insurance changes yet? I really want to send the blood to Fullerton. I did go to the links you gave and paramyotonia is definitely out of the picture. No similar signs.

The new coding changes went into effect October 1st. That doesn't guarantee that an underwriter for a health insurance company will automatically approve someone for private insurance that has myotonia congenita. However it does give us a platform for an appeal since MC is now distinguished from myotonic muscular dystrophy. That was the problem in the past.

I would go ahead and send off the sample and ask that the results be kept confidential. Since your son wouldn't be taking any medications there's no need for it to be on his chart as a diagnosis at this time. If your doctor has a problem with that, ask him to fill out the requisition and request that the results be sent only to you. I've had DNA tests done where no doctor's order was even needed (celiac disease for example) but I do think Fullerton requires a doctor's signature.

Jan

Jan - I notice what seems to be a slight change in your term for Becker's. I have only heard Myotonia Congenita, Thomsen's or Becker's type, but here you have called Becker's "Becker's Generalized Myotonia"... I haven't heard that before, and wonder if it has anything to do with either the new coding, or perhaps with the "other" Becker's, which seems to confuse people. Also, is Thomsen's not generalized? I thought they were almost identical. Thanks - lois

Lois, terminology is a real problem with our condition. Doctors and researchers seem to use different names for the same thing. I guess officially Becker's MC is either Becker's Generalized Myotonia or Recessive Generalized Myotonia.

Some use the term Myotonia Congenital (with an "l") when they mean Thomsen's (dominant) and others still think that all myotonia congenita is called Thomsen's Disease.

I tried to get more of a consensus when I petitioned for coding changes, but they basically ignored me :-)

So just to make it easier to understand on this site I use Thomsen's MC for the dominantly inherited form and Becker's MC for the recessive form. I think the reason the word "generalized" is used for Becker's is because the skeletal muscle stiffness seems to be all throughout the body at once rather than with various areas being more stiff than others.

Of course then you still have the issue of Becker's Muscular Dystrophy, etc. Ugh! Couldn't they have been a little more specific and creative?

Jan

I agree Jan, doctor's do tend to use different terms and are confusing. However, they "the doctor's" I think are trying the best they can to understand. You just have one up on all of them:):):) We love the doctor we have...while he is not a myotonia specialist, he embraces and is willing to learn...that is so key to us.