====== Neurolytic block ======

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The deliberate temporary [[degeneration]] of [[nerve fiber]]s through the application of chemicals, heat or freezing, produces a [[block]] that may persist for weeks, months or indefinitely.

A neurolytic [[block]] is a form of [[nerve block]] involving the deliberate injury of a [[nerve]] by freezing or heating ("[[neurotomy]]") or the application of chemicals ("[[neurolysis]]").

These interventions cause degeneration of the nerve's fibers and temporary (a few months, usually) interference with the transmission of nerve [[signal]]s. In these procedures, the thin protective layer around the [[nerve fiber]], the basal lamina, is preserved so that, as a damaged fiber regrows, it travels within its basal lamina tube and connects with the correct loose end, and function may be restored. Surgical cutting of a nerve ([[neurectomy]]), severs these basal lamina tubes, and without them to channel the regrowing fibers to their lost connections, over time a painful [[neuroma]] or deafferentation pain may develop. This is why the neurolytic is usually preferred over the surgical block.
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Frequently, the term [[neuroablation]] is used to also describe the physical interruption of pain either chemically, thermally, or surgically. All neurolytic techniques cause [[Wallerian degeneration]] of the nerve axon distal to the lesion.

Chemicals were extensively utilized in the past for neurolysis in the early 20 century. 

The first report of chemical [[neurolysis]] was made in [[1863]] by Luton who delivered irritant chemicals subcutaneously in patients with [[sciatica]], offering them significant alleviation of pain. [Luton A, generales de medecin, 1863] The advent of newer and safer modalities have been introduced into pain practice including [[radiofrequency]] [[ablation]] (RFA), [[cryoablation]], and neurosurgical procedures.

The advancements in imaging modalities such as [[fluoroscopy]] have improved the precision and efficiency of targeted [[neurolysis]]
((D'Souza RS, Hooten WM. [[Neurolytic Block]]s. 2018 Dec 28. StatPearls [Internet]. 
Treasure Island (FL): StatPearls Publishing; 2018 Jan-. Available from
http://www.ncbi.nlm.nih.gov/books/NBK537360/
PubMed PMID: 30726045.
)).