Thanks, Abby. We sound similar in some respects. I think when I challenged my doctor he mentioned something similar. That is, the ocular muscles are super sensitive to problems in the nueromuscular junction. Therefore the test could be positive in that area well before the test is positive in other areas, even though the weakness predominates elsewhere. I guess for that to make sense, he is saying the test is more sensitive to abnormalities in the ocular muscles than elsewhere.

My problem is fatigue and not functional weakness per se (that is nothing literally stops working) in my arms and legs. Made worse by chronic low level exercise or acute one off exercise. Chronic Magnesium caused slow moving limbs

Incidentally I just tried supplementing with Manganese and it seems to of helped. I appreciate that sounds a bit quacky, but I did a google search and there are some references to it being an effective treatment for MG. At least one, albeit very very old and not RBC, published piece of research also suggests it's effective