I asked my neurologist if my twitching meant that I had motor nerve involvement now in addition to sensory and autonomic SFN. She said, "not necessarily; twitches can be from lots of things." My nerve conduction velocity was normal but the EMG showed chronic reinnervation, which she explained was nerve damage followed by "sprouting" of fibers from nearby nerves to compensate for the deficit. Later she mentioned that there are just a limited number of muscles and nerves that are large enough and close enough to the skin for testing, and that there could be motor nerve damage in other inaccessible areas. So, a little more information but not really a definitive answer to the question.