--known as NEURONOPATHY, which is associated with Sjogren's an someother autoimmune situations, in which the primary atttack is on the dorsal root ganglia and the cell bodies there, rather than on the axonal fibers:

http://neuromuscular.wustl.edu/antibody/sneuron.html

In these cases, if the cell bodies are destroyed, they are gone, and that entire nerve is gone, so healingis muchmore difficult than with condtions in which only myelin of the axon is damaged; recovery of function depends on how much other nerve cells nearby that res till functioning can sprout additional connecting axons to take over some of the functions. (Possible, but difficult.)