Tatia, Cold will momentarily make MG weakness better. Extremes of heat or cold for any extended period of time will decline it. The Tensilon test will do that too. I got better with Tensilon but then got worse after the test than I was before it.

A lot of meds can have rebound effects too. Sort of like when you drink coffee one day and then don't the next you can get a headache from the lack of continual effects on your CNS (dopamine, acetylcholine, etc.).

Heat and cold can also be relative terms. If you get heated up in the summer, getting cold in the air conditioning of your car, for example, will help but it may not help enough to counteract how bad the heat made your MG. If you hit your knee on a desk, the thing that caused the pain is no longer hitting you but you still feel the pain afterwards.

If you have MG, weakness will not be evenly distributed all of the time. You can have really weak legs, especially if you use them more, and not have weak arms. The neurologist who diagnosed me said that you think your legs are weaker because you don't walk on your arms. Sometimes you can predict what muscles will be weak by the activity you do. Sometimes MG can be highly unpredictable and you can get weak anywhere.

It's the same with taking Mestinon. If you have sort of weak legs and really weak arms, it may make the legs better but not so much the arms. But that too can depend upon how someone's MG is doing in general. There's no easy algorithm for MG, sorry.

I hope that helps explain it.

Are you any closer to a diagnosis?

Annie