I have same set of symptoms with improvement on Mestonin. All labs and nerve tests are negative per neuromuscular neurologist at Mayo. Suggested improvement on Mestonin is placebo effect, but told me not to stop med. Nothing he can do for me. No suggestions, nothing. Referring local neurologist diagnosed MG 5 mos ago, started Mestonin and increased dose with significant improvement. He does not deal with MG on regular basis so he recommended Mayo for their MG clinic. He is disappointed in dr's conclusion as well. Discouraging.

Also have CVID and adrenal insufficiency, so get oral steroids and IV Ig which are also treatments for MG. Tired of seeing drs, being put through tests and being told nothing. Ready to quit trying to get an answer and just put up with being sick more days than not. Has had an enormous impact on my life, my husband's, who has been through all the disappointments with me. We have had to stop doing most any social activities at least ones that require advance commitment because we never know how weak I will be tomorrow much less in a week.

Sorry to see others are in similar circumstances, but encouraging in that we are not alone.