I think so many people don't have concrete diagnoses, since it seems nothing in medicine (especially neuromuscular disorders it seems) follows text books.... no one case is alike.. and there are so many varients and ranges out there! Combine that with dr's are just humans, and it really is hard to find a GREAT one, one that can think outside the box when the simple tests aren't positive... then that makes coming to a firm diagnosis difficult.. As long as you are with a dr who listens to you and understands though you may not be dragging a limb or in a wheelchair that YOU dont' feel YOUR normal and to investigate that, that's whats so important...
I have sensory issues too- though I have at times questioned maybe it was all in my head, until a skin biopsy came back abnormal.. I Have burning, numbness etc at times, and almost no sensory issues at other times..
My twitching is also exacerbated by exercise or fatigue.. I noticed it first 4 years ago after going for a long walk when pregnant with my daughter (i was throwing up a ton, so figured it was malnutrition/electrolyte abnormalities).. turns not wasn't the case!!! Good luck!!