Hey, 2Fatigued.

I think there is a spectrum of what people like to talk about here, which makes things interesting. As far as I'm concerned, I enjoy medical research and have done that since 1995. Alice used to post here, and is a doctor who has MG. Some people like to share coping strategies. Others like to talk about what food to eat with bad bulbar muscles. There are plenty of "boffins" here and you'll find that people are very savvy about MG.

Acetylcholine, for example, is essential for mood (and brain function). Too much and someone can feel depressed. Too little, and someone with MG is weaker. Acetylcholine is also essential for producing stomach acid, which is why some people with MG have such bad GI issues when they take Mestinon. If you ever want to know how a drug affects MG, just search "acetylcholine +drug name."

New evidence suggests that there is an underestimated inflammatory reaction in MG (look up HMGB1).

In 2007, I uncovered that caffeine, also a cholinesterase inhibitor, has similar effects to Mestinon. If someone drinks too much caffeine, they could have overdose symptoms if also on Mestinon. Drinking too much can make them feel more tired or weak.

As far as that mental fatigue question, I haven't seen definitive answers as to why MGers have that component when they become weaker. Researchers are fairly sure that it has to do with the overall demand of acetylcholine. MG can literally put someone without enough ACh to sleep.

If we use only a few muscles during the day, for example, the fatigue may not be as great. Activities such as socializing use nearly all muscle groups. The mental fatigue (and weakness) is far greater then. Add heat to all of that (an outdoor event) and we don't stand a chance!

Heat increases acetylcholinesterase (AChE), an enzyme in the body that mops up after ACh does its job. Extremes of heat and cold increase that enzyme and, therefore, decrease ACh.

I have personally always wanted to know why something is happening in the body, not only that it is happening. Some people find that interesting and others can't stand hearing about it! I share what information I know anyway, in case that might help someone.

Consider yourself validated. There are heaps of medical articles and other sources (biochemistry) on what happens in the body with MG. And how ACh affects other neurotransmitters.

MGers aren't lazy, or whatever label those who don't understand MG want to put on us. We literally can't move at times. Or think, swallow, or breathe well. And the only things that will help that are rest/naps/sleep, cooling down or warming up, and having better treatments.

People can live a "relatively" normal life with MG, if they can find the best balance of drugs and managing activities with rest. There are some of us (like me) who aren't on drugs other than Mestinon (complicated) and need to be extra careful every day of what they do. I can't work. But I know people who do. So there's always hope of a fairly normal life.

And some people with MG take Provigil, which essentially has the same effect as caffeine but with a predictable dosing. Studies have been done comparing those two things, stating that they are basically the same but that one is natural and one is a drug.

This is probably more than you asked for! I hope that it helps.

Annie

Search in PubMed with "myasthenia gravis cognitive fatigue."

Fatigue in myasthenia gravis: risk factors and impact on quality of life. - PubMed - NCBI

Fatigue in myasthenia gravis: is it more than muscular weakness? - PubMed - NCBI

Effects of napping on neuromuscular fatigue in myasthenia gravis. - PubMed - NCBI

Clinical neurophysiology of fatigue. - PubMed - NCBI

On the early fatigue of ocular muscles.

Neuromuscular transmission failure in myasthenia gravis: decrement of safety factor and susceptibility of extraocular muscles. - PubMed - NCBI