There is also Lems (Lambert Eaton Myasthenic Syndrome). It behaves a lot like myasthenia gravis, but has a few additional symptoms. I have Lems but was told at first I had mg. A lot of the treatment is the same. In Lems there are antibodies to voltage gated calcium channels (VGCC)s.
My disease was not diagnosed with EMGs or single fiber EMG, but only with antibodies and clinical presentation or symptoms.