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Pathologic Remodeling of Endoneurial Tubules in Human Neuromas

Background: Laminins are extracellular matrix proteins that participate in endoneurial tubule formation and are important in the regeneration of nerves after injury. They act as scaffolds to guide nerves to distal targets and play a key role in neurite outgrowth. Because there is evidence that lamin...

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Autores principales: Karsy, Michael, Palmer, Cheryl A, Mahan, Mark A
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Cureus 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5856420/
https://www.ncbi.nlm.nih.gov/pubmed/29560300
http://dx.doi.org/10.7759/cureus.2087
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author Karsy, Michael
Palmer, Cheryl A
Mahan, Mark A
author_facet Karsy, Michael
Palmer, Cheryl A
Mahan, Mark A
author_sort Karsy, Michael
collection PubMed
description Background: Laminins are extracellular matrix proteins that participate in endoneurial tubule formation and are important in the regeneration of nerves after injury. They act as scaffolds to guide nerves to distal targets and play a key role in neurite outgrowth. Because there is evidence that laminin architecture affects nerve regeneration, we evaluated endoneurial tubules by examining the laminin structure in clinical samples from patients with nerve injuries. Methods: In a retrospective review of eight nerve injury cases, we evaluated nerve histology in relation to clinical history and injury type. The immunohistochemical delineation of the laminin structure in relationship with the neuroma type was performed. Results: Five cases of upper-trunk stretch injuries—four from childbirth injury and one from a motorcycle accident—and three cases of nerve laceration leading to neuroma formation were examined. In the upper-trunk stretch injuries, avulsed nerves demonstrated no neuroma formation with a linear laminin architecture and a regular Schwann cell arrangement, but increased fibrous tissue deposition. For neuromas-in-continuity after a stretch injury, laminin immunohistochemistry demonstrated a double-lumen laminin tubule, with encapsulation of the Schwann cells and axonal processes. Nerve laceration leading to stump neuroma formation had a similar double-lumen laminin tubule, but less severe fibrosis. Conclusions: In nerve injuries with regenerative capacity, endoneurial tubules become pathologically disorganized. A double-lumen endoneurial tubule of unclear significance develops. The consistency of this pattern potentially suggests a reproducible pathophysiologic process. Further exploration of this pathophysiologic healing may provide insight into the failure of programmed peripheral nerve regeneration after injury.
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spelling pubmed-58564202018-03-20 Pathologic Remodeling of Endoneurial Tubules in Human Neuromas Karsy, Michael Palmer, Cheryl A Mahan, Mark A Cureus Pathology Background: Laminins are extracellular matrix proteins that participate in endoneurial tubule formation and are important in the regeneration of nerves after injury. They act as scaffolds to guide nerves to distal targets and play a key role in neurite outgrowth. Because there is evidence that laminin architecture affects nerve regeneration, we evaluated endoneurial tubules by examining the laminin structure in clinical samples from patients with nerve injuries. Methods: In a retrospective review of eight nerve injury cases, we evaluated nerve histology in relation to clinical history and injury type. The immunohistochemical delineation of the laminin structure in relationship with the neuroma type was performed. Results: Five cases of upper-trunk stretch injuries—four from childbirth injury and one from a motorcycle accident—and three cases of nerve laceration leading to neuroma formation were examined. In the upper-trunk stretch injuries, avulsed nerves demonstrated no neuroma formation with a linear laminin architecture and a regular Schwann cell arrangement, but increased fibrous tissue deposition. For neuromas-in-continuity after a stretch injury, laminin immunohistochemistry demonstrated a double-lumen laminin tubule, with encapsulation of the Schwann cells and axonal processes. Nerve laceration leading to stump neuroma formation had a similar double-lumen laminin tubule, but less severe fibrosis. Conclusions: In nerve injuries with regenerative capacity, endoneurial tubules become pathologically disorganized. A double-lumen endoneurial tubule of unclear significance develops. The consistency of this pattern potentially suggests a reproducible pathophysiologic process. Further exploration of this pathophysiologic healing may provide insight into the failure of programmed peripheral nerve regeneration after injury. Cureus 2018-01-18 /pmc/articles/PMC5856420/ /pubmed/29560300 http://dx.doi.org/10.7759/cureus.2087 Text en Copyright © 2018, Karsy et al. http://creativecommons.org/licenses/by/3.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Pathology
Karsy, Michael
Palmer, Cheryl A
Mahan, Mark A
Pathologic Remodeling of Endoneurial Tubules in Human Neuromas
title Pathologic Remodeling of Endoneurial Tubules in Human Neuromas
title_full Pathologic Remodeling of Endoneurial Tubules in Human Neuromas
title_fullStr Pathologic Remodeling of Endoneurial Tubules in Human Neuromas
title_full_unstemmed Pathologic Remodeling of Endoneurial Tubules in Human Neuromas
title_short Pathologic Remodeling of Endoneurial Tubules in Human Neuromas
title_sort pathologic remodeling of endoneurial tubules in human neuromas
topic Pathology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5856420/
https://www.ncbi.nlm.nih.gov/pubmed/29560300
http://dx.doi.org/10.7759/cureus.2087
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