My wife has tingling limbs and her test results (nerve conduction, bloodwork, MRI, etc) all came back without any problems. Is this normal to have all tests come back ok, but still have PN symptoms? I thought that even with idiopathic neuropathy that at least some test results would show something abnormal, that the "idiopathic neuropathy" simply meant that they don't know what's causing the abnormal test results.

How common is it to have PN symptoms with no abnormal test results? Is it worthwhile to get a second opinion, or is it best to forget about trying to find the cause and just start treating the symptoms?