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Neuropathology and applied neurobiology1978; 4(6); 483-501; doi: 10.1111/j.1365-2990.1978.tb01358.x

A light and electron microscopic study of the neuropathy of equine idiopathic laryngeal hemiplegia.

Abstract: A study has been made of the pathological changes in the recurrent laryngeal nerves from horses with clinical and sub-clinical idiopathic laryngeal hemiplegia. Qualitative and quantitative studies showed in clinical cases there was a progressive distal loss of large myelinated fibres in the left recurrent nerve. Regenerating clusters and onion bulbs were frequently seen in affected nerves both at proximal and distal levels. Degenerating axons were characterized by collections of organelles, and denervated bands of Bungner were common. Similar but less severe changes were seen in the left recurrent nerve of sub-clinical cases, and in both the clinical and sub-clinical cases the distal right recurrent nerve was also affected. Teased fibre studies showed evidence of chronic demyelination and remyelination. The aetiology of this chronic neuropathy remains uncertain but the possibility of nerve compression is discussed.
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Publication Date: 1978-11-01 PubMed ID: 745676DOI: 10.1111/j.1365-2990.1978.tb01358.xGoogle Scholar: Lookup
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  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This study investigates the pathological changes observed in the recurrent laryngeal nerves of horses affected by idiopathic laryngeal hemiplegia—a condition of unknown cause that impairs the function of the larynx. The research reveals a pattern of progressive nerve damage, along with signs of nerve regeneration and chronic demyelination. The exact cause of this condition is still unknown but nerve compression is being considered.

Objective of the Research

  • The research primarily aims to understand the pathological changes occurring in horses suffering from idiopathic laryngeal hemiplegia, a condition that affects the function of the larynx and potentially causing difficulty in breathing and changes in voice – a condition of clinical and veterinary importance. The causes of this condition remain unclear.

Methodology

  • The laryngeal nerves from affected horses were studied both through light and electron microscopy to analyze the structural and morphological alterations.
  • Both qualitative and quantitative studies were performed on these nerves. The research focused on progressive distal loss of large myelinated fibres, a distinct feature of degenerative nerve disorders.
  • Teased fibre studies, a method that enables researchers to examine individual nerve fibres, were also conducted to assess the extent of chronic demyelination and remyelination.

Findings

  • Significant pathological changes were observed in the left recurrent nerves in clinical cases, including progressive loss of large myelinated fibres—this essentially means the protective layering around nerve fibres was eroding over time.
  • Regenerating clusters and onion bulbs, which are formations seen during the process of nerve healing after damage, were often noticed not only at proximal but also distal levels. This indicates the nerves’ attempts to repair themselves.
  • Degeneration of the nerves was characterized by visible collections of organelles—a sign of neuronal injury or disease.
  • Denervated bands of Bungner, which occur once a peripheral nerve has been injured, were common. These structures support axonal regrowth after an injury.
  • Similar, yet less severe, changes were seen in the left recurrent nerve in subclinical cases and the distal right recurrent nerve in both clinical and subclinical cases—this suggests the condition isn’t exclusive to one side.
  • Teased fibre studies presented strong evidence for chronic demyelination and remyelination, suggesting a prolonged and ongoing damage-repair process in these nerves.

Conclusions

  • The cause of this chronic nerve condition remains uncertain. However, the researchers discuss the possibility of nerve compression playing a role, which might provide a direction for further studies.

Cite This Article

APA
Duncan ID, Griffiths IR, Madrid RE. (1978). A light and electron microscopic study of the neuropathy of equine idiopathic laryngeal hemiplegia. Neuropathol Appl Neurobiol, 4(6), 483-501. https://doi.org/10.1111/j.1365-2990.1978.tb01358.x

Publication

Neuropathology and applied neurobiology
ISSN: 0305-1846
NlmUniqueID: 7609829
Country: England
Language: English
Volume: 4
Issue: 6
Pages: 483-501

Researcher Affiliations

Duncan, I D
    Griffiths, I R
      Madrid, R E

        MeSH Terms

        • Animals
        • Cell Count
        • Horse Diseases / pathology
        • Horses
        • Laryngeal Nerves / pathology
        • Microscopy, Electron
        • Myelin Sheath / pathology
        • Nerve Degeneration
        • Nerve Fibers, Myelinated
        • Recurrent Laryngeal Nerve / pathology
        • Vocal Cord Paralysis / pathology
        • Vocal Cord Paralysis / veterinary

        Citations

        This article has been cited 17 times.
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