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Re: Waiting for Diagnosis

Thank you so much for your quick reply and lots of information! This has been very scary, especially because it is taking soooo long to get any answers. He has not had an EMG yet. The neurologist we plan to see in Cincinnati stated that she rarely does them on children because they are too traumatic for kids. She is planning to do a muscle biopsy to diagnose him, so we are now getting numerous heart exams done to make sure it's safe for him to undergo anethesia for the biopsy.
Thank you again for your help- I'll let you know what we find out.
-Shea

Type of Myotonia: Becker's ?

Country: USA

Re: Waiting for Diagnosis

If you ask anyone who has had a muscle biopsy, they will tell you that it is far more traumatic than an EMG. Hardly anyone does that any more unless they are trying to confirm a dystrophy or mitochondrial disease.

See if you can get a referral to a physiatrist in your area to do an EMG. They are much more gentle in my experience and I have sent several parents to them with good feedback. You can always premedicate with a small dose of a tranquilizer that your doctor prescribes and feels safe using, but most kids do just fine as long as they know it's over quickly. The EMG itself is not very painful...it's the nerve conduction study that is more uncomfortable because they actually send small shocks into the muscles.

I have never seen a biopsy report for myotonia congenita that wasn't inconclusive. I would really encourage you to hold off on that if you can. It leaves a scar which may not be as much of an issue for a boy, but it still is not usually needed. The protocol is usually EMG, DNA testing, and then if nothing shows up, consider a muscle biopsy. If you do decide to go ahead with it, we are fine with local anesthesia that does not contain vasoconstricters. So we avoid Lidocaine/Novacaine but are fine with Marcaine and Carbocaine.

Here's the protocol for general anesthesia:
http://myotoniacongenita.org/anesthesiaprotocol.doc

You can also get to it from the website link above. Normal heart function tests will not tell you if he will react to anesthesia from myotonia congenita.

Jan





Type of Myotonia: Thomsen's

Country: US

Re: Waiting for Diagnosis

Forgot to mention that the cost of an EMG is about $1500 and a muscle biopsy is about twice that (even more if it's done with general anesthesia or IV sedation) plus the pathology fee. You can see which is the better money-maker for the hospitals. I'm getting cynical in my old age :-)

Jan

Type of Myotonia: Thomsen's

Country: US

Re: Waiting for Diagnosis

Hi,
In support of what Jan said about biopsy; The reason muscle biopsy is rarely used outside of research is that an MRI can reveal most muscle abnormalities. Second, as she said they are most often inconclusive in CLCN1 defects. On the other hand they are more useful in Sodium Channel diseases (SCN4a), but here again an MRI is just as useful as a biopsy.

I am sorry but I must add more complexity to the picture. A nerve EMG makes a positive finding in 90% of Ion Channelopathies. I am among the 10% without electrical myotonia. Some who do not exhibit electrical myotonia on initial testing may still have it inferred from a test that includes muscle that is stressed by an exercise routine and cold. So if one is not prepared to test for the rarest occurance then one is not prepared to do a complete test.

If you feel in the least frustrated or insecure about your doctors, may I suggest that you make arrangements to be seen at the Neuromuscular Clinic at the University of Rochester, they are among the top three clinics in the US. Prof. Robert Griggs M.D. will respond to email sent directly to him. His address is to a staff member:
Patricia_Hopkins@urmc.rochester.edu
Good Luck, Joe

Type of Myotonia: SCN4a

Country: US