Axons are the only part of nerves in the PNS that regenerate. CNS nerves don't regenerate at all, well I did read they try, but fail miserably, and if they ever do heal its minimal and takes years. However, in the PNS, if the nerve cell is alive, then axons can regenerate off that cell and heal neuronal pathways. If you lost all your axons, but have the cell body, expect a painful and long recovery, but a recovery.