Hi Rach,
I'm sorry I haven't been around until now. I noticed you said 3 doctors mentioned myasthenic syndrome. There is a form of Myasthenia with this name that does the same things to you, but not because of autoimmune problems - it's hereditary - called Congenital Myasthenic Syndrome. Here is a link:

http://en.wikipedia.org/wiki/Congeni...henic_syndrome

Your parents don't have to have shown serious symptoms, you can inherit it because of one parent having a recessive gene. It may be what they were talking about, and since a form responds to acetylcholine but not other MG treatments, it may be worth checking out. Also, it's possible to have had very mild unnoticable symptoms as a child, which get worse later in life.

Best of luck to you. I sure hope you get help soon.

P.S. My positive Tensilon test lasted very few (long time ago, can't exactly remember) minutes as well - I was able to stand out of a chair without using my hands and walk a little bit. I'm sorry you are dealing with such seeming ignorance! Since you have i-net access, try googling some of these things and printing them out. That way, you can put the information in their face when necessary. Just make sure you are printing from a reputable site, like Mayo, Johns Hopkins, or Wikipedia. If it's printed from a forum, you're asking for even more scorn!