I can tell you what I know of the Tensilon test. I had one in 2001.
MG experts like to do a "double blind" one, where the doctor performing the test doesn't know if they're injecting saline or Tensilon. That's kind of funny since many patients can actually taste saline (if they've had it injected before) when it's injected and know the difference!
Some doctors—which I think is fairly reprehensible—even throw Atropine into the mix (which makes MG worse). Yes, doctors have Atropine on hand to counteract an adverse reaction to Tensilon, but giving it
during a test skews the results!
They can inject anywhere from 1 to 10 mg. of the drug. My diagnosing neurologist, who is a MDA director and MG expert, only had to inject 2 mg. of the drug to see results.
They should do a clinical exam of the muscles with the most obvious weakness (i.e., ptosis) before the injection, during, and after.
The drug is fast-acting and wears off quickly. A dramatic change in muscle strength is pretty telling. I felt my eyelids pop up in under one minute. I even looked in a mirror to prove it to myself!
Since the drug is stronger than Mestinon, you can have side effects from the injection (depending upon how much they inject). Bradycardia is a common one. You can also have other overdose symptoms such as increased saliva, increased weakness, etc. Make sure that the doctor performing the test knows of ALL your medical conditions and other drugs you're taking, even over-the-counter ones.
I became even weaker after the test than I was before, so watch out for that reaction, too.
Will they be doing the test in a hospital or clinic setting?
Have you had the CPK test? Have you seen a rheumatologist (they're the inflammatory docs)? Have you had your vitamin D tested (that can cause pain)?
I hope that information helps. Good luck with the test. BTW, I felt so awesome for those few minutes—I wanted it to last forever!
Annie
http://neuromuscular.wustl.edu/mtime/mgdx.html
http://www.youtube.com/watch?v=CifH6_Uj2uE
http://pn.bmj.com/content/2/3/173.full.pdf