Hi Fred @goetf4997, I have no experience or knowledge of Prolotherapy but did find a few links that may provide a little more information.

Platelet-rich plasma and the elimination of neuropathic pain.
-- https://www.ncbi.nlm.nih.gov/pubmed/23832571

Sugar Coated Nerves: The Pseudo-Science of Neural Prolotherapy
-- http://nationalpainreport.com/sugar-coated-nerves-pseudo-science-neural-prolotherapy-8822875.html

Mayo Clinic -- Is prolotherapy an effective treatment for chronic low back pain?
-- https://www.mayoclinic.org/prolotherapy/expert-answers/faq-20058347

There has been some success with Platelet Rich Plama (PRP) but I'm not sure about neuropathic pain. Mayo Clinic Regenerative Medicine has some information here:
-- https://www.mayo.edu/research/centers-programs/center-regenerative-medicine

Hope this helps...
John