-
I would say that “objective” tests like SFEMG are not really that important for determining MG, and a neurologist who is WELL TRAINED should see the symptoms of MG immediately without any need for these tests. There are two explanations for your case: either the neuro is really not very good at it and tries to do it by “the book” or your case is really not that clear.
If you have clear-cut improvement with Mestinon after 1 hour, that speaks with very high probability that you have MG.
if you come to see a doctor with your symptoms controlled (by Mestinon), than it is quite possible that the doctor will not find MG symptoms. My doctor sometimes was not able to see any symptoms except for double vision (when looking to one side and following the finger).
Now the second part is whether you need or not to have immunosupressant treatment, even as simple as prednisone is another issue.
If Mestinon controls most of your symptoms and you can tolerate it well, it is wise to stay just on Mestinon and increase the dosage/frequency of it (I was taking up to 10-12 60 mg pills daily). 3 pills per day is a good starter, but you have a lot of leeway for higher dosage. You must understand that Mestinon is acting only about 45 minutes after taking and for no more than 3 – 4 hours, so the effect disappears completely after that.
What surprises me somewhat that you have low oxygen in blood. With MG, that is usually the case only if you are in crisis or close to it, and can not really breathe; it is one of the last symptoms to appear, and then it goes bad very quickly. Blurry vision, if it is double vision or “heavy eye” feeling (i.e. your eyes feel like they can not follow well moving objects, but without having double vision), is a classic thing of MG.
If you should try prednisone or not, is a difficult question, but if you do try it, you can expect relatively quick improvement starting from about 10 days and certainly after 30 days.
But remember, in general, the need for treatment for MG is mostly determined by how you feel and cope and not by objective tests. What is important is to exclude other possible conditions.