--predominantly small-fiber neuropathy would not result in muscular problems--fasciculations, twitching, weakness, cramping--as these nerves do not connect to muscle. It is possible to have "mixed" types, however, or for there to be damage that is causing symptoms that is "subclinical"--not (yet) showing up on the EMG or nerve conduction studies.

There are other things that can cause such things, though--and there are a lot of electrolyte/mineral deficiencies on that list.

Sudomotor axon reflex testing is a small-fiber autonomic test designed to evaluate how well the small sweat glands n the skin are functioning--abnormal sweat response to stimulation can point to problems with small-fiber nerves:

http://peripheralneuropathycenter.uc...ic/qsart.shtml

http://my.clevelandclinic.org/servic..._overview.aspx