--when the nerve cell body, with the nucleus, dies, than the nerve cell is gone, and since nerve cells do not under normal circumstances reproduce, anything that kills off nerve cells will be detrimental.

Nerve cells DO grow new axonal connections and links to other nerve cells, though--that is how we consolidate memories and learning, and develop motor skills that do not require our conscious attention. The fibers, under the right conditions, absolutely re-enervate body parts.

Exhibit A in this are my comparative skin biopsy results over time--I have slowly, over the years, recovered some of the intraepidermal small-fiber nerve density that I lost during my acute neuropathic attack in 2003. Don't know if I'll get back to whatever my original density numbers were--and of course almost no one knows those original numbers, as skin biopsy is not done on asymptomatic people except very rarely for research purposes--but I've gone from 3rd percentile to 5th percentile in some sports to 16th to 20th percentile in those spots over several years, absolutely indicating some re-enervation, with a corresponding reduction in symptoms.

Of course, I am unusual--my neuropathy, primarily small-fiber and involving a highly acute (hours/days) full body presentation, is not the most common scenario. Acute neuropathies often result in at least partial recovery if the neuropathic process can be arrested, though recovery is often incomplete and patchy.