Hi, derosie.
I'm confused too! It said it was a normal RNS but there was significant decrement? Wuh?

The more a muscle is "zapped" in MG, the more decrement there is. So, yeah, their statements are quite contradictory.
I think it means that a Single Fiber EMG is in your future. You should call the doctor who ordered the test and get some answers!
Have you had the MG antibody tests, both AChR and MuSK?
I can't tell you what the results mean for sure. They have to be analyzed by your doctor, in combination with your clinical exam and any other tests that have been done.
I really hope you can get some answers soon. Do you have symptoms that look like MG? Is there anything else you need help with? Thanks.

Annie