This is a monograph on axonal neuropathies:

http://emedicine.medscape.com/article/1175276-overview

This explains the differences too:
http://www.ninds.nih.gov/disorders/p...neuropathy.htm

Axonal damage can come from demyelinating the insulation on the axon, or by damaging the cell that owns the axon from within. Some demyelinating can be repaired, as in GBS if caught in time. If the cell interior dies however, it is gone.

The repair of myelin can be enhanced with B12, fish oil (essential fatty acids) and B6, magnesium.

Be aware that there are some studies coming out that Statins damage remyelination repair, mostly in the CNS so far. I would think they also do this elsewhere too in the periphery. (the studies used imaging only in the CNS using MRIs.)
http://www.newsinferno.com/product-r...r-ms-patients/
Previously high dose statins (the kind that cross easily into the brain) were suggested and tried on MS patients. Then this effect became obvious. Zocor, is one that is very lipofilic and Lipitor which is moderately so.