VMD - yes, I do experience weakness. Unfortunately, I am not sure if it is a perceived weakness or if I am truly weaker than I used to be. I am able to pass the neuro test by squeezing the docs hand, pushing my leg against his hand....you know the routine. But, does that mean I am doing it as well as I could have last year? That I don't know. I think the neuros call it clinical weakness when you can't push at all or get up from a squat. Then they know it is weakness. Go figure.
I notice my weakness because I get the feeling I am a rubber band, like I can't walk a step. Most recently my hands haven't been working well and get spasticity (some of my fingers are straight and are difficult to bend, I have to "snap" them down). It gives me a feeling of utter exhaustion, I have to sit straight to get a good breath.
It has progressed to other parts of the body. I started with weakness only in my legs, then my ribs and back (I am very thin, but the muscle and skin on my ribs and back has "fallen"). Sometimes this weakness will last for a couple of weeks and then I feel like the weakness that overcame me is gone, but I am not strong like I was.
I think my cramping started at the same time as my weakness, but now I get periodic muscle pains all over, even ribs. My back has been excruciating at times and it is definitely muscle cramping, even from sitting up too long. Once I couldn't stand up straight for 2 weeks from a back spasm. The docs thought nothing of it.
The fasciculation thing is a killer to answer. If I use my legs, let's say for a walk, I will get unrelenting fasciculations, but not just in my legs. No matter what part of my body that I exercise they will be all over, face, ribs, stomach, legs, bottom of feet, everywhere. The neuro who did my biopsy today told me that he started fasciculations the first time he "tried" to surf and they haven't gone away, and they are everywhere.
And yes, I experience muscular fatigue with the weakness. Folding a towel in front of me causes my arm muscles to burn in muscular pain, like I just did 10 reps with 100 pound weights, and they are also weak.
I hope these answers help you to realize that we are all pretty much sailing in the same boat! I also had a clean EMG, so time is all we have to help us. I hope you are doing okay. Leslie