Lit Love,
You're correct that a nerve conduction tests can be more harmful than good. I had one done but my neurologist targeted specific nerves and she had some program in her computer that registered my pain signals to the brain. She was unable to find exactly were the disconnect was but she stopped after it became evident that the search was leading her to my cerebellum area.
Since I don't want anybody drilling holes into my skull I'll except the mystery and treat the pain...

P.S.: Roy, she's right on about getting your blood sugar checked. If nothing else to rule diabetes out...