Ana,

Mestinon is a fast-acting drug. Whatever results it's going to have should show up right away. It doesn't have to build up in your system or anything like that.

Most people with MG are helped by Mestinon, but not all of us.

I hope that you will get a single-fiber EMG next (SFEMG). A lot of us here who have negative blood tests were diagnosed by SFEMG. Also, there are three different kinds of antibodies that they commonly test for (and more that they know about). The most common one is the AChR-antibody, but they should also test you for the MuSK anitbody and for LEMS.

Abby

Abby, I respectfully disagree. Mestinon did nothing for me until about day 3. Maybe I'm an oddity???? If I recall correctly, my neuro said to give it up to a week to see if I had a good response. I am, of course, sero-positive for AChR.

Thanks, Jana! I really appreciate having other people read and chime in, so that if I post something wrong it won't mislead anyone.

Abby

Is it true that a sfemg cannot be done on the quadricep/thigh? That's what my new neuro told me last week. He wants to do a sfemg on the face, but I told him that my greatest weakness is in my legs and ability to walk.

On a related note, the mestonin I started a couple of weeks ago was something I felt a huge improvement on, after taking one dose. (input for the original poster for this thread)

I had a SFEMG on my thigh and on my arms, both twice. The results were inconclusive. Then I had one on my face (by a different doctor) even though I was not having any facial or eye symptoms. The facial SFEMG got me diagnosed. That still seems weird to me (the neuro who did it said "myasthenia gravis affects every muscle in your body even if you can't feel it").

Did anyone tell you yet to make sure you're off the Mestinon for the test? Doctors will tell you to be off it for 24 hours, but there's some evidence that you should be off it longer--at least for several days. The reason you should be off it is that you might get a false negative if it's in your system. Also, don't be too well rested, and don't be cold. If the air-conditioning in the office is too high and you're chilly, ask to have the muscle warmed with a heat pack. Again, the reason is to avoid a false negative.

I hope you get answers. It's so scary and frustrating to be undiagnosed.

Abby

Thanks everyone!