Is there a cure for nerve pain in the back and legs?

May be: You could cure nerve pain if no scar in the nerve or what we call permanent change in the structure of the nerve, if you have changes in the nerve i doubt you could. In this situation we resort to a lot of methods of pain relief. (pain management).

Yes: Have you had a recent MRI to diagnose nerve impingement? If not having weakness in legs or incontinence, try conservative treatments such as: rest, hot/cold compresses to lower back even if the pain radiates to butt or leg, nsaids, physical therapy and activity modification. If you have tried these, there are prescription nerve medications out their that your pcp or spine specialist can recommend.