I haven't had any issues with my speech since getting on the Mestinon. But prior, I would get the feeling of a knot in the back of my throat that would prevent me from speaking properly. I'd start to slur and get a real nasal sound to my voice. And then there would be the occasional word I just couldn't get out. It would feel like a combination of not being able to get my mouth/lips/tongue into the right positioning to form the word correctly, and that feeling in the back of my throat preventing me from getting any sounds out.