I do not know if evoked potentials are similar to nerve conduction studies. I certainly have abnormal NCS as well as EMG's. I also feel almost nothing during the tests, even after hours of it, but I will have zapping and buzzing for weeks afterwards. Both legs are similarly insensitive,but i have no feeling in either leg now to above the knee. I hope you are not as affected. Small fiber neuropathies commonly do not show up on the tests, the skin biopsy is the preferred method of diagnosis, so that will give you more info.

I have both small and large fiber hereditary neuropathy, so it shows up on both tests. Nerve conduction studies are only useful to diagnose large fiber types, as far as I know.