FREE SHIPPING over $40
OVER 9000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Home / Equine Research Bank / J Vet Intern Med / Pathological classification of equine recurrent laryngeal ne...
Journal of veterinary internal medicine2018; 32(4); 1397-1409; doi: 10.1111/jvim.15142

Pathological classification of equine recurrent laryngeal neuropathy.

Abstract: Recurrent Laryngeal Neuropathy (RLN) is a highly prevalent and predominantly left-sided, degenerative disorder of the recurrent laryngeal nerves (RLn) of tall horses, that causes inspiratory stridor at exercise because of intrinsic laryngeal muscle paresis. The associated laryngeal dysfunction and exercise intolerance in athletic horses commonly leads to surgical intervention, retirement or euthanasia with associated financial and welfare implications. Despite speculation, there is a lack of consensus and conflicting evidence supporting the primary classification of RLN, as either a distal ("dying back") axonopathy or as a primary myelinopathy and as either a (bilateral) mononeuropathy or a polyneuropathy; this uncertainty hinders etiological and pathophysiological research. In this review, we discuss the neuropathological changes and electrophysiological deficits reported in the RLn of affected horses, and the evidence for correct classification of the disorder. In so doing, we summarize and reveal the limitations of much historical research on RLN and propose future directions that might best help identify the etiology and pathophysiology of this enigmatic disorder.
Copyright © 2018 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.
Get Full Text
Publication Date: 2018-04-24 PubMed ID: 29691904PubMed Central: PMC6060325DOI: 10.1111/jvim.15142Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
LinkedInCopy
  • Journal Article
  • Review

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 research article explores the pathological classification of Recurrent Laryngeal Neuropathy (RLN), a common degenerative disorder in tall horses which affects their laryngeal nerves and ultimately their performance and welfare. The study examines the neuropathological changes and electrophysiological deficits in affected horses, aiming to clarify the classification and thereby facilitate further research into its cause and treatment.

Recurrent Laryngeal Neuropathy (RLN)

  • RLN is a degenerative disorder prevalent in tall horses, specifically impacting their recurrent laryngeal nerves (RLn). This disorder leads to inspiratory stridor at exercise because of intrinsic laryngeal muscle paresis – a condition where muscles become weak or paralyzed.
  • Impact of this disorder on the affected horses is significant, leading not only to exercise intolerance and laryngeal dysfunction but often to serious outcomes such as surgical intervention, retirement, or euthanasia. There are also financial and welfare implications associated with the disorder.

Classification of RLN

  • Despite speculation, there is no clear consensus on RLN’s primary classification due to conflicting evidence. It is uncertain whether RLN is a distal axonopathy – a disease affecting the nerve axons, a primary myelinopathy – a disease affecting the protective layer around nerve fibers, or whether it’s a mononeuropathy affecting one nerve or a polyneuropathy affecting many nerves.
  • This lack of defined classification impedes not only the understanding of the disorder but also hampers etiological (causal) and pathophysiological research.

Neuropathological Changes and Electrophysiological Deficits

  • The study examines the changes at a cellular level (neuropathological changes) and the impact of these changes on the electrical functioning of the nerves (electrophysiological deficits) within the RLNs of horses affected by RLN.

Future Directions for RLN Research

  • The paper also critically evaluates the historical research on RLN, highlighting its limitations and proposing new directions for future research. Better understanding of the disorder’s pathological classification could help identify its etiology (causation) and pathophysiology (disease mechanisms), ultimately aiding in its treatment and prevention.

Cite This Article

APA
Draper ACE, Piercy RJ. (2018). Pathological classification of equine recurrent laryngeal neuropathy. J Vet Intern Med, 32(4), 1397-1409. https://doi.org/10.1111/jvim.15142

Publication

Journal of veterinary internal medicine
ISSN: 1939-1676
NlmUniqueID: 8708660
Country: United States
Language: English
Volume: 32
Issue: 4
Pages: 1397-1409

Researcher Affiliations

Draper, Alexandra C E
  • Comparative Neuromuscular Disease Laboratory, Department is Clinical Science and Services, Royal Veterinary College, London, United Kingdom.
Piercy, Richard J
  • Comparative Neuromuscular Disease Laboratory, Department is Clinical Science and Services, Royal Veterinary College, London, United Kingdom.

MeSH Terms

  • Animals
  • Cranial Nerve Diseases / classification
  • Cranial Nerve Diseases / pathology
  • Cranial Nerve Diseases / veterinary
  • Horse Diseases / classification
  • Horse Diseases / pathology
  • Horses
  • Recurrent Laryngeal Nerve / pathology

References

This article includes 150 references
  1. Boyko AR. Genomic analysis establishes correlation between growth and laryngeal neuropathy in Thoroughbreds.. BMC Genomics 2014;15:259.
    pmc: PMC4051171pubmed: 24707981
  2. Goulden BE, Anderson LJ, Cahill JI. Roaring in Clydesdales.. N Z Vet J 1985;33:73–76.
    pubmed: 16031164
  3. Cahill JI, Goulden BE. Equine laryngeal hemiplegia. Part I. A light microscopic study of peripheral nerves.. N Z Vet J 1986;34:161–169.
    pubmed: 16031224
  4. Duncan ID, Griffiths IR, Madrid RE. A light and electron microscopic study of the neuropathy of equine idiopathic laryngeal hemiplegia.. Neuropathol Appl Neurobiol 1978;4:483–501.
    pubmed: 745676
  5. Taylor SE, Barakzai SZ, Dixon P. Ventriculocordectomy as the sole treatment for recurrent laryngeal neuropathy: long‐term results from ninety‐two horses.. Vet Surg 2006;35:653–657.
    pubmed: 17026550
  6. Duncan ID, Griffiths IR. Pathological changes in equine laryngeal muscles and nerves. In: Proceedings of the 19th Annual Convention of the American Association of Equine Practitioners, Atlanta, Georgia. 1973;97–223.
  7. Cahill JI, Goulden BE. Equine laryngeal hemiplegia. Part II. An electron microscopic study of peripheral nerves.. N Z Vet J 1986;34:161–165.
    pubmed: 16031225
  8. Cook WR. The diagnosis of respiratory unsoundness in the horse.. Vet Rec 1965;77:516–528.
    pubmed: 14331430
  9. Takayuki IBI, Takeshi M, Seiji H, Hironori O, Nobushige I, Yoshiyuki S. Estimation of heritability of laryngeal hemiplegia in the thoroughbred horse by Gibbs sampling.. J Equine Sci 2003;14:81–86.
  10. Barakzai S. Heritability of Recurrent Laryngeal Neuropathy.. In: 4th World Equine Airways Symposium (WEAS 09); 2009; Berne, Switzerland.
  11. Dupuis MC, Zhang Z, Durkin K, Charlier C, Lekeux P, Georges M. Detection of copy number variants in the horse genome and examination of their association with recurrent laryngeal neuropathy.. Anim Genet 2013;44:206–208.
    pubmed: 22582820
  12. Dupuis MC, Zhang Z, Druet T. Results of a haplotype‐based GWAS for recurrent laryngeal neuropathy in the horse.. Mamm Genome 2011;22:613–620.
    pubmed: 21698472
  13. Cahill JI, Goulden BE. The pathogenesis of equine laryngeal hemiplegia–a review.. N Z Vet J 1987;35:82–90.
    pubmed: 16031387
  14. Rooney JR, Delaney FM. An hypothesis on the causation of laryngeal hemiplegia in horses.. Equine Vet J 1970;2:35–37.
  15. Loew FM. Thiamine and equine laryngeal hemiplegia.. Vet Rec 1973;92:372–373.
    pubmed: 4720649
  16. Cavanagh JB. The problems of neurons with long axons.. Lancet 1984;1:1284–1287.
    pubmed: 6144984
  17. Burrows GE. Lead poisoning in the horse.. Equine Prac 1982;4.
  18. Duncan ID, Brook D. Bilateral laryngeal paralysis in the horse.. Equine Vet J 1985;17:228–233.
    pubmed: 4076131
  19. Fleming G. Roaring in horses.. London: Balliere, Tindall & Cox; 1889.
  20. Hahn CN, Matiasek K, Dixon PM, Molony V, Rodenacker K, Mayhew IG. Histological and ultrastructural evidence that recurrent laryngeal neuropathy is a bilateral mononeuropathy limited to recurrent laryngeal nerves.. Equine Vet J 2008;40:666–672.
    pubmed: 19165936
  21. Griffiths IR. The pathogenesis of equine laryngeal hemiplegia.. Equine Vet J 1991;23:75–76.
    pubmed: 2044512
  22. Cahill JI, Goulden BE. Further evidence for a central nervous system component in equine laryngeal hemiplegia.. N Z Vet J 1989;37:89–90.
    pubmed: 16031531
  23. Cahill JI, Goulden BE. Equine laryngeal hemiplegia. Part III. A teased fibre study of peripheral nerves.. N Z Vet J 1986;34:181–185.
    pubmed: 16031232
  24. Duncan ID. Determination of the early age of onset of equine recurrent laryngeal neuropathy. 2. Nerve pathology.. Acta Neuropathol 1992;84:316–321.
    pubmed: 1329430
  25. Ekins S, Litterman NK, Arnold RJG. A brief review of recent Charcot‐Marie‐Tooth research and priorities.. F1000Res 2015;4:53.
    pmc: PMC4392824pubmed: 25901280
  26. de Lahunta A, Glass E, Kent M. Veterinary Neuroanatomy and Clinical Neurology.. St Louis, Missouri, USA: Saunders Elsevier; 2009:134–167.
  27. McGeady TA, Quinn PJ, Fitzpatrick ES, Ryan MT, Kilroy D, Lonergan P. Veterinary Embryology.. Oxford: Blackwell Publishing; 2008:120–122.
  28. Mason JE. Laryngeal Hemiplegia: a further look at Haslam's anomaly of the left recurrent nerve.. Equine Vet J 1973;5:150–155.
    pubmed: 4766688
  29. Cahill JI. The Pathology of Laryngeal Hemiplegia in Horses.. New Zealand: Massey University; 1985.
  30. Duncan ID. The Pathology of Equine Laryngeal Hemiplegia.. United Kingdom: University of Glasgow; 1975.
  31. Dyer KR, Duncan ID. The intraneural distribution of myelinated fibres in the equine recurrent laryngeal nerve.. Brain 1987;110:1531–1543.
    pubmed: 3427399
  32. Lopez‐Plana C, Sautet JY, Ruberte J. Muscular pathology in equine laryngeal neuropathy.. Equine Vet J 1993;25:510–513.
    pubmed: 8275997
  33. Murray JG. Innervation of the intrinsic muscles of the cat's larynx by the recurrent laryngeal nerve: a unimodal nerve.. J Physiol 1957;135:206–212.
    pmc: PMC1358922pubmed: 13398975
  34. Shin T, Rabuzzi DD. Conduction studies of the canine recurrent laryngeal nerve.. Laryngoscope 1971;81:586–596.
    pubmed: 5553125
  35. Tomasch J, Britton WA. A fibre analysis of the laryngeal nerve‐supply in man.. Acta Anat (Basel) 1955;23:386–398.
    pubmed: 14387413
  36. Gacek RR, Lyon MJ. Fiber components of the recurrent laryngeal nerve in the cat.. Ann Otol Rhinol Laryngol 1976;85:460–471.
    pubmed: 949153
  37. Dahlqvist A, Carlsoo B, Hellstrom S. Fiber components of the recurrent laryngeal nerve of the rat: a study by light and electron microscopy.. Anat Rec 1982;204:365–370.
    pubmed: 7181142
  38. Harrison DF. Fibre size frequency in the recurrent laryngeal nerves of man and giraffe.. Acta Otolaryngol 1981;91:383–389.
    pubmed: 7023176
  39. Lang IM, Medda BK, Jadcherla SR, Shaker R. Characterization and mechanisms of the pharyngeal swallow activated by stimulation of the esophagus.. Am J Physiol Gastrointest Liver Physiol 2016;311:G827–G837.
    pmc: PMC5130554pubmed: 27634013
  40. Pascual‐Font A, Hernández‐Morato I, McHanwell S. The central projections of the laryngeal nerves in the rat.. J Anat 2011;219:217–228.
    pmc: PMC3162241pubmed: 21599662
  41. Love S, Louis DN, Ellison DW. Greenfield's Neuropathology.. London, UK: Edward Arnold Publishers Ltd; 2008:1609–1725.
  42. Pareyson D, Marchesi C. Diagnosis, natural history, and management of Charcot‐Marie‐Tooth disease.. Lancet Neurol 2009;8:654–667.
    pubmed: 19539237
  43. Rossor AM, Evans MR, Reilly MM. A practical approach to the genetic neuropathies.. Pract Neurol 2015;15:187–198.
    pubmed: 25898997
  44. Kimura J. Electrodiagnosis in diseases of Nerve and Muscle: Principles and Practice.. Oxford: Oxford University Press; 2013:74–92.
  45. Matsunami N, Smith B, Ballard L. Peripheral myelin protein‐22 gene maps in the duplication in chromosome 17p11.2 associated with Charcot‐Marie‐Tooth 1A.. Nat Genet 1992;1:176–179.
    pubmed: 1303231
  46. Patel PI, Roa BB, Welcher AA. The gene for the peripheral myelin protein PMP‐22 is a candidate for Charcot‐Marie‐Tooth disease type 1A.. Nat Genet 1992;1:159–165.
    pubmed: 1303228
  47. Timmerman V, Nelis E, Van Hul W. The peripheral myelin protein gene PMP‐22 is contained within the Charcot‐Marie‐Tooth disease type 1A duplication.. Nat Genet 1992;1:171–175.
    pubmed: 1303230
  48. Züchner S, Mersiyanova IV, Muglia M. Mutations in the mitochondrial GTPase mitofusin 2 cause Charcot‐Marie‐Tooth neuropathy type 2A.. Nat Genet 2004;36:449–451.
    pubmed: 15064763
  49. Hahn AF, Ainsworth PJ, Bolton CF, Bilbao JM, Vallat JM. Pathological findings in the x‐linked form of Charcot‐Marie‐Tooth disease: a morphometric and ultrastructural analysis.. Acta Neuropathol 2001;101:129–139.
    pubmed: 11271367
  50. Birouk N, LeGuern E, Maisonobe T. X‐linked Charcot‐Marie‐tooth disease with connexin 32 mutations: clinical and electrophysiologic study.. Neurology 1998;50:1074–1082.
    pubmed: 9566397
  51. Dubourg O. Clinical, electrophysiological and molecular genetic characteristics of 93 patients with X‐linked Charcot‐Marie‐Tooth disease.. Brain 2001;124:1958–1967.
    pubmed: 11571214
  52. Duncan ID, Griffths IR, McQueen A, Baker GO. The pathology of equine laryngeal hemiplegia.. Acta Neuropathol 1974;27:337–348.
    pubmed: 4407536
  53. Duncan ID, Hammang JP. Ultrastructural observations of organelle accumulation in the equine recurrent laryngeal nerve.. J Neurocytol 1987;16:269–280.
    pubmed: 3625241
  54. Harrison GD, Duncan ID, Clayton MK. Determination of the early age of onset of equine recurrent laryngeal neuropathy. 1. Muscle pathology.. Acta Neuropathol 1992;84:307–315.
    pubmed: 1384268
  55. Cahill JI, Goulden BE. Equine laryngeal hemiplegia. Part V. Central nervous system pathology.. N Z Vet J 1986;34:191–193.
    pubmed: 16031234
  56. Cahill JI, Goulden BE. Equine laryngeal hemiplegia. Part IV. Muscle pathology.. N Z Vet J 1986;34:186–190.
    pubmed: 16031233
  57. Cavanagh JB. The ‘dying back' process. A common denominator in many naturally occurring and toxic neuropathies.. Arch Pathol Lab Med 1979;103:659–664.
    pubmed: 389195
  58. Kamholz J, Menichella D, Jani A. Charcot‐Marie‐Tooth disease type 1: molecular pathogenesis to gene therapy.. Brain 2000;123:222–233.
    pubmed: 10648431
  59. Scherer S. Axonal pathology in demyelinating diseases.. Ann Neurol 1999;45:6–7.
    pubmed: 9894870
  60. Krajewski KM. Neurological dysfunction and axonal degeneration in Charcot‐Marie‐Tooth disease type 1A.. Brain 2000;123:1516–1527.
    pubmed: 10869062
  61. Dixon PM, Robinson NE, Wade J. Proceedings of a workshop on equine recurrent laryngeal neuropathy Havemeyer Foundation Monograph Series No 11.. Newmarket: R&W Publications; 2003.
  62. Vandevelde M, Higgins RJ, Oevermann A. General Neuropathology.. West Sussex, UK: Wiley; 2012:1–37.
  63. Griffin JW, Price DL. Demyelination in experimental beta, beta'‐iminodipropionitrile and hexacarbon neuropathies. Evidence for an axonal influence.. Lab Invest 1981;45:130–141.
    pubmed: 7265914
  64. Bosboom WM. Diagnostic value of sural nerve demyelination in chronic inflammatory demyelinating polyneuropathy.. Brain 2001;124:2427–2438.
    pubmed: 11701597
  65. Dyck PJ, Johnson WJ, Lambert EH, O'Brien PC. Segmental demyelination secondary to axonal degeneration in uremic neuropathy.. Mayo Clin Proc 1971;46:400–431.
    pubmed: 4326086
  66. Midroni G, Bilbao JM. Biopsy Diagnosis of Peripheral Neuropathies.. Boston: Butterworth‐Heinemann; 1995.
  67. Bertram M, Schröder JM. Developmental changes at the node and paranode in human sural nerves: morphometric and fine‐structural evaluation.. Cell Tissue Res 1993;273:499–509.
    pubmed: 8402830
  68. Schroder JM. Developmental and pathological changes at the node and paranode in human sural nerves.. Microsc Res Tech 1996;34:422–435.
    pubmed: 8837018
  69. Schroder JM. Structure of the nodes and paranodes in peripheral nerves, Part I. Introduction.. Microsc Res Tech 1996;34:397–398.
    pubmed: 8837016
  70. Bilbao JM, Schmidt RE. Biopsy Diagnosis of Peripheral Neuropathy.. Switzerland: Springer; 2015:144–145.
  71. Jones HB, Cavanagh JB. Distortions of the nodes of Ranvier from axonal distension by filamentous masses in hexacarbon intoxication.. J Neurocytol 1983;12:439–458.
    pubmed: 6683751
  72. Millecamps S, Julien JP. Axonal transport deficits and neurodegenerative diseases.. Nat Rev Neurosci 2013;14:161–176.
    pubmed: 23361386
  73. Jones HB, Cavanagh JB. The evolution of intracellular responses to acrylamide in rat spinal ganglion neurons.. Neuropathol Appl Neurobiol 1984;10:101–121.
    pubmed: 6539426
  74. Brismar T, Hildebrand C, Tegner R. Nodes of Ranvier in acrylamide neuropathy: voltage clamp and electron microscopic analysis of rat sciatic nerve fibres at proximal levels.. Brain Res 1987;423:135–143.
    pubmed: 3676803
  75. Simonati A, Cavanagh JB. Changes in terminal sprout formation in rat sternocostalis muscle during chronic intoxication with 2,5 hexanedione.. Muscle Nerve 1984;7:355–361.
    pubmed: 6738573
  76. Brismar T, Hildebrand C, Berglund S. Nodes of Ranvier above a neuroma in the rat sciatic nerve: voltage clamp analysis and electron microscopy.. Brain Res 1986;378:347–356.
    pubmed: 2425905
  77. Sayre LM, Autilio‐Gambetti L, Gambetti P. Pathogenesis of experimental giant neurofilamentous axonopathies: a unified hypothesis based on chemical modification of neurofilaments.. Brain Res 1985;10:69–83.
    pubmed: 2412663
  78. Cavanagh JB, Bennetts RJ. On the pattern of changes in the rat nervous system produced by 2,5 hexanediol. A topographical study by light microscopy.. Brain 1981;104:297–318.
    pubmed: 7237096
  79. Sickles DW, Stone JD, Friedman MA. Fast axonal transport: a site of acrylamide neurotoxicity?. Neurotoxicology 2002;23:223–251.
    pubmed: 12224764
  80. Jones HB, Cavanagh JB. Cytochemical staining characteristics of peripheral nodes of Ranvier in hexacarbon intoxication.. J Neurocytol 1983;12:459–473.
    pubmed: 6192221
  81. Tshala‐Katumbay D, Monterroso V, Kayton R, Lasarev M, Sabri M, Spencer P. Probing mechanisms of axonopathy. Part II: protein targets of 2,5‐hexanedione, the neurotoxic metabolite of the aliphatic solvent n‐hexane.. Toxicol Sci 2009;107:482–489.
    pmc: PMC2639756pubmed: 19033394
  82. LoPachin RM, Gavin T. Toxic neuropathies: mechanistic insights based on a chemical perspective.. Neurosci Lett 2015;596:78–83.
    pmc: PMC4362956pubmed: 25218479
  83. Harris CH, Wrenn RW, Friedman MA, Sickles DW. Acrylamide effects on cAMP‐dependent MAP phosphorylation and microtubule disassembly.. Toxicologist 1994;14:206.
  84. Sickles DW, Brady ST, Testino A, Friedman MA, Wrenn RW. Direct effect of the neurotoxicant acrylamide on kinesin‐based microtubule motility.. J Neurosci Res 1996;46:7–17.
    pubmed: 8892100
  85. Stone JD, Peterson AP, Eyer J, Oblak TG, Sickles DW. Axonal neurofilaments are nonessential elements of toxicant‐induced reductions in fast axonal transport: video‐enhanced differential interference microscopy in peripheral nervous system axons.. Toxicol Appl Pharmacol 1999;161:50–58.
    pubmed: 10558923
  86. Martenson CH, Sheetz MP, Graham DG. A quantitation of fast axonal transport in cultured chick dorsal root ganglion (DRG) explants following exposure to acrylamide (ACR), methacrylamide (M‐ACR) and cyanide.. Toxicologist 1992;12:191.
  87. Schmidt RE. Neuropathology of human sympathetic autonomic ganglia.. Microsc Res Tech 1996;35:107–121.
    pubmed: 8923446
  88. Schmidt RE. Synaptic dysplasia in sympathetic autonomic ganglia.. J Neurocytol 1996;25:777–791.
    pubmed: 9023724
  89. Coleman M. Axon degeneration mechanisms: commonality amid diversity.. Nat Rev Neurosci 2005;6:889–898.
    pubmed: 16224497
  90. Raff MC, Whitmore AV, Finn JT. Axonal self‐destruction and neurodegeneration.. Science 2002;296:868–871.
    pubmed: 11988563
  91. Yang H, He X, Yang J. Activation of cAMP‐response element‐binding protein is positively regulated by PKA and calcium‐sensitive calcineurin and negatively by PKC in insect.. Insect Biochem Mol Biol 2013;43:1028–1036.
    pubmed: 24018109
  92. Kurant E. Keeping the CNS clear: glial phagocytic functions in Drosophila.. Glia 2011;59:1304–1311.
    pubmed: 21136555
  93. Yang J, Weimer RM, Kallop D. Regulation of axon degeneration after injury and in development by the endogenous calpain inhibitor calpastatin.. Neuron 2013;80:1175–1189.
    pubmed: 24210906
  94. Finn JT, Weil M, Archer F, Siman R, Srinivasan A, Raff MC. Evidence that Wallerian degeneration and localized axon degeneration induced by local neurotrophin deprivation do not involve caspases.. J Neurosci 2000;20:1333–1341.
    pmc: PMC6772375pubmed: 10662823
  95. Hackett SM. The equine nucleus ambiguus: Myotopic and neurotopic representations of motor and sensory components of the recurrent laryngeal nerve.. Ithaca, NY, USA: Cornell University; 2000.
  96. Gerdts J, Summers DW, Milbrandt J, DiAntonio A. Axon self‐destruction: new links among SARM1, MAPKs, and NAD+ metabolism.. Neuron 2016;89:449–460.
    pmc: PMC4742785pubmed: 26844829
  97. Conforti L, Gilley J, Coleman MP. Wallerian degeneration: an emerging axon death pathway linking injury and disease.. Nat Rev Neurosci 2014;15:394–409.
    pubmed: 24840802
  98. Osterloh JM, Yang J, Rooney TM. dSarm/Sarm1 is required for activation of an injury‐induced axon death pathway.. Science 2012;337:481–484.
    pmc: PMC5225956pubmed: 22678360
  99. Henninger N, Bouley J, Sikoglu EM. Attenuated traumatic axonal injury and improved functional outcome after traumatic brain injury in mice lacking Sarm1.. Brain 2016;139:1094–1105.
    pmc: PMC5006226pubmed: 26912636
  100. Summers DW, DiAntonio A, Milbrandt J. Mitochondrial dysfunction induces Sarm1‐dependent cell death in sensory neurons.. J Neurosci 2014;34:9338–9350.
    pmc: PMC4087211pubmed: 25009267
  101. Massoll C, Mando W, Chintala SK. Excitotoxicity upregulates SARM1 protein expression and promotes Wallerian‐like degeneration of retinal ganglion cells and their axons.. Invest Ophthalmol Vis Sci 2013;54:2771–2780.
    pmc: PMC3632266pubmed: 23518770
  102. Yang J, Wu Z, Renier N. Pathological axonal death through a MAPK cascade that triggers a local energy deficit.. Cell 2015;160:161–176.
    pmc: PMC4306654pubmed: 25594179
  103. Shin JE, Miller BR, Babetto E. SCG10 is a JNK target in the axonal degeneration pathway.. Proc Natl Acad Sci USA 2012;109:E3696–E3705.
    pmc: PMC3535671pubmed: 23188802
  104. Gerdts J, Summers DW, Sasaki Y, DiAntonio A, Milbrandt J. Sarm1‐mediated axon degeneration requires both SAM and TIR interactions.. J Neurosci 2013;33:13569–13580.
    pmc: PMC3742939pubmed: 23946415
  105. Gilley J, Coleman MP. Endogenous NMNAT2 is an essential survival factor for maintenance of healthy axons.. PLoS Biol 2010;8:e1000300.
    pmc: PMC2811159pubmed: 20126265
  106. Gilley J, Adalbert R, Yu G, Coleman MP. Rescue of peripheral and CNS axon defects in mice lacking NMNAT2.. J Neurosci 2013;33:13410–13424.
    pmc: PMC6705152pubmed: 23946398
  107. Marangoni M, Adalbert R, Janeckova L. Age‐related axonal swellings precede other neuropathological hallmarks in a knock‐in mouse model of Huntington's disease.. Neurobiol Aging 2014;35:2382–2393.
    pubmed: 24906892
  108. Mack TG, Reiner M, Beirowski B. Wallerian degeneration of injured axons and synapses is delayed by a Ube4b/Nmnat chimeric gene.. Nat Neurosci 2001;4:1199–1206.
    pubmed: 11770485
  109. Araki T, Sasaki Y, Milbrandt J. Increased nuclear NAD biosynthesis and SIRT1 activation prevent axonal degeneration.. Science 2004;305:1010–1013.
    pubmed: 15310905
  110. Ma M, Ferguson TA, Schoch KM. Calpains mediate axonal cytoskeleton disintegration during Wallerian degeneration.. Neurobiol Dis 2013;56:34–46.
    pmc: PMC3721029pubmed: 23542511
  111. George EB, Glass JD, Griffin JW. Axotomy‐induced axonal degeneration is mediated by calcium influx through ion‐specific channels.. J Neurosci 1995;15:6445–6452.
    pmc: PMC6577979pubmed: 7472407
  112. Vallat J‐M, Ouvrier RA, Pollard JD. Histopathological findings in hereditary motor and sensory neuropathy of axonal type with onset in early childhood associated with mitofusin 2 mutations.. J Neuropathol Exp Neurol 2008;67:1097–1102.
    pubmed: 18957892
  113. Duncan ID, Baker GJ, Heffron CJ, Griffiths IR. A correlation of the endoscopic and pathological changes in subclinical pathology of the horse's larynx.. Equine Vet J 1977;9:220–225.
    pubmed: 923556
  114. Duncan ID, Reifenrath P, Jackson KF, Clayton M. Preferential denervation of the adductor muscles of the equine larynx. II: nerve pathology.. Equine Vet J 1991;23:99–103.
    pubmed: 2044517
  115. Dixon PM, McGorum BC, Railton DI. Clinical and endoscopic evidence of progression in 152 cases of equine recurrent laryngeal neuropathy (RLN).. Equine Vet J 2010;34:29–34.
    pubmed: 11817549
  116. Dixon PM, McGorum BC, Railton DI. Laryngeal paralysis: a study of 375 cases in a mixed‐breed population of horses.. Equine Vet J 2010;33:452–458.
    pubmed: 11558739
  117. Bilbao JM, Schmidt RE. Biopsy Diagnosis of Peripheral Neuropathy.. Switzerland: Springer International; 2015:246–247.
  118. Scherer SS, Wrabetz L. Molecular mechanisms of inherited demyelinating neuropathies.. Glia 2008;56:1578–1589.
    pmc: PMC2570024pubmed: 18803325
  119. Kazamel M, Dyck PJ. Sensory manifestations of diabetic neuropathies: anatomical and clinical correlations.. Prosthet Orthot Int 2015;39:7–16.
    pubmed: 25614497
  120. Faissler D, Jurina K, Cauzinille L, Gaschen F, Adama F, Jaggy A. Peripheral Nervous System and Musculature, in Small Animal Neurology: An Illustrated Text.. In: Platt SR, ed. Hannover: Schlutersche; 2010.
  121. Aronson AL. Lead poisoning in cattle and horses following long‐term exposure to lead.. Am J Vet Res 1972;33:627–629.
    pubmed: 4552303
  122. Liu ZP. Lead poisoning combined with cadmium in sheep and horses in the vicinity of non‐ferrous metal smelters.. Sci Total Environ 2003;309:117–126.
    pubmed: 12798097
  123. Sojka JE, Hope W, Pearson D. Lead toxicosis in 2 horses: similarity to equine degenerative lower motor neuron disease.. J Vet Intern Med 1996;10:420–423.
    pubmed: 8947877
  124. Willoughby R, Macdonald E, Mcsherry B, Brown G. The interaction of toxic amounts of lead and zinc fed to young growing horses.. Vet Rec 1972;91:382–383.
    pubmed: 4635159
  125. Willoughby RA, MacDonald E, McSherry BJ, Brown G. Lead and zinc poisoning and the interaction between Pb and Zn poisoning in the foal.. Can J Comp Med 1972;36:348–359.
    pmc: PMC1319698pubmed: 4263914
  126. Huntington PJ, Jeffcott LB, Friend SC, Luff AR, Finkelstein DI, Flynn RJ. Australian Stringhalt–epidemiological, clinical and neurological investigations.. Equine Vet J 1989;21:266–273.
    pubmed: 2767028
  127. Rose RJ, Hartley WJ, Baker W. Laryngeal paralysis in Arabian foals associated with oral haloxon administration.. Equine Vet J 1981;13:171–176.
    pubmed: 7297547
  128. Step DL, Cummings JF, de Lahunta A. Motor neuron degeneration in a horse.. J Am Vet Med Assoc 1993;202:86–88.
    pubmed: 8420912
  129. Brakenhoff J, Holcombe S, Hauptman J, Smith HK, Nickels FA, Caron JP. The prevalence of laryngeal disease in a large population of competition draft horses.. Vet Surg 2006;35:579–583.
    pubmed: 16911159
  130. Griffiths IR, Duncan ID. Age changes in the dorsal and ventral lumbar nerve roots of dogs.. Acta Neuropathol 1975;32:75–85.
    pubmed: 1146507
  131. Arnold N, Harriman DG. The incidence of abnormality in control human peripheral nerves studied by single axon dissection.. J Neurol Neurosurg Psychiatry 1970;33:55–61.
    pmc: PMC493407pubmed: 5418180
  132. Dyck PJ, Karnes J, O'Brien P, Nukada H, Lais A, Low P. Spatial pattern of nerve fiber abnormality indicative of pathologic mechanism.. Am J Pathol 1984;117:225–238.
    pmc: PMC1900442pubmed: 6333825
  133. Wheeler SJ. Structure and function of equine peripheral nerves: morphology, morphometry and clinical electrophysiology.. London: Royal Veterinary College, University of London; 1988:209.
  134. Boillée S, Vande Velde C, Cleveland DW. ALS: a disease of motor neurons and their nonneuronal neighbors.. Neuron 2006;52:39–59.
    pubmed: 17015226
  135. Beech J. Neuroaxonal dystrophy of the accessory cuneate nucleus in horses.. Vet Pathol 1984;21:384–393.
    pubmed: 6464300
  136. Kenny M, Cercone M, Rawlinson JJ. Transoesophageal ultrasound and computer tomographic assessment of the equine cricoarytenoid dorsalis muscle: Relationship between muscle geometry and exercising laryngeal function.. Equine Vet J 2017;49:395–400.
    pubmed: 26709115
  137. Cheetham J, Pigott JJ, Leal MT, Soderholm LV, Mitchell LM, Ducharme NG. Nerve conduction in horses with normal arytenoid function.. In: Proceedings of the 47th British Equine Veterinary Association Congress; 2008; Liverpool, UK.
  138. Hawe C, Dixon PM, Mayhew IG. A study of an electrodiagnostic technique for the evaluation of equine recurrent laryngeal neuropathy.. Equine Vet J 2010;33:459–465.
    pubmed: 11558740
  139. Steiss JE, Marshall AE, Humburg JM. Electromyographic evaluation of conduction time of the recurrent laryngeal nerve: findings in clinically normal horses and ponies.. Equine Vet J 1989;21:218–220.
    pubmed: 2731511
  140. Bilbao J, Schmidt RE. Biopsy Diagnosis of Peripheral Neuropathy.. London: Springer; 2015:7.
  141. Kokubun N, Nishibayashi M, Uncini A. Conduction block in acute motor axonal neuropathy.. Brain 2010;133:2897–2908.
    pubmed: 20855419
  142. Blythe LL, Engel HN Jr., Rowe KE. Comparison of sensory nerve conduction velocities in horses versus ponies.. Am J Vet Res 1988;49:2138–2142.
    pubmed: 3266450
  143. Stetson DS, Albers JW, Silverstein BA, Wolfe RA. Effects of age, sex, and anthropometric factors on nerve conduction measures.. Muscle Nerve 1992;15:1095–1104.
    pubmed: 1406766
  144. J. Kim S, G. Lee D, Kwon JY. Development of a nerve conduction technique for the recurrent laryngeal nerve.. Laryngoscope 2014;124:2779–2784.
    pubmed: 25042932
  145. Campbell WW Jr., Ward LC, Swift TR. Nerve conduction velocity varies inversely with height.. Muscle Nerve 1981;4:520–523.
    pubmed: 7311991
  146. Simpson AH, Gillingwater TH, Anderson H. Effect of limb lengthening on internodal length and conduction velocity of peripheral nerve.. J Neurosci 2013;33:4536–4539.
    pmc: PMC4335134pubmed: 23467369
  147. Williams PL, Wendell‐Smith CP. Some additional parametric variations between peripheral nerve fibre populations.. J Anat 1971;109:505–526.
    pmc: PMC1270992pubmed: 4949292
  148. Steiss JE, Marshall AE. Electromyographic evaluation of conduction time and velocity of the recurrent laryngeal nerves of clinically normal dogs.. Am J Vet Res 1988;49:1533–1536.
    pubmed: 3223662
  149. Lopez JM, Alvarez‐Uria M. A morphometric and fine structural study of the myoepithelial cells in the hamster Harderian gland.. J Submicrosc Cytol Pathol 1993;25:223–232.
    pubmed: 8324726
  150. Cook WR, Thalhammer JG. Electrodiagnostic Test for the Objective Grading of Recurrent Laryngeal Neuropathy in the Horse. In: Proceedings of the Annual Convention of the American Association of Equine Practitioners; 1991; AAEP.

Citations

This article has been cited 11 times.
  1. Al Shehab G, Naji R, Alali F, Alali A, Allowaim A, Almohammed A, Aljasim D, Alkhalifah A, Alhammad YMA, Marzok M, Mohamad ZA, Almuhanna AH. Laryngoscopic evaluation of arytenoid movements in pure Arabian horses. Open Vet J 2025 Jun;15(6):2875-2881.
    doi: 10.5455/OVJ.2025.v15.i6.56pubmed: 41069487google scholar: lookup
  2. McGivney CL, McGivney BA, Farries G, Gough KF, Han H, Holtby AR, MacHugh DE, Katz LM, Hill EW. A genome-wide association study for recurrent laryngeal neuropathy in the Thoroughbred horse identifies a candidate gene that regulates myelin structure. Equine Vet J 2025 Jul;57(4):943-952.
    doi: 10.1111/evj.14461pubmed: 39791379google scholar: lookup
  3. Hardwick JL, Ahern BJ, Crawford KL, Allen KJ, Franklin SH. Yearling laryngeal function in Thoroughbreds that underwent a laryngoplasty differs from controls. Equine Vet J 2025 Mar;57(2):431-440.
    doi: 10.1111/evj.14110pubmed: 38847239google scholar: lookup
  4. Lean NE, Franklin SH, Steel C, Woolford L, White J, Ahern BJ. Evaluation of recurrent laryngeal neuropathy in domestic and feral horse populations in Australia using histologic and immunohistochemical analysis: A pilot study. Vet Med Sci 2023 Jul;9(4):1610-1617.
    doi: 10.1002/vms3.1186pubmed: 37317987google scholar: lookup
  5. Cahalan SD, Perkins JD, Boehm I, Jones RA, Gillingwater TH, Piercy RJ. A method to identify, dissect and stain equine neuromuscular junctions for morphological analysis. J Anat 2022 Nov;241(5):1133-1147.
    doi: 10.1111/joa.13747pubmed: 36087283google scholar: lookup
  6. Cahalan SD, Boehm I, Jones RA, Piercy RJ. Recognising the potential of large animals for modelling neuromuscular junction physiology and disease. J Anat 2022 Nov;241(5):1120-1132.
    doi: 10.1111/joa.13749pubmed: 36056593google scholar: lookup
  7. Adalbert R, Cahalan S, Hopkins EL, Almuhanna A, Loreto A, Pór E, Körmöczy L, Perkins J, Coleman MP, Piercy RJ. Cultured dissociated primary dorsal root ganglion neurons from adult horses enable study of axonal transport. J Anat 2022 Nov;241(5):1211-1218.
    doi: 10.1111/joa.13719pubmed: 35728923google scholar: lookup
  8. Otto S, Michler JK, Dhein S, Mülling CKW. Development of a constant pressure perfused ex vivo model of the equine larynx. PLoS One 2021;16(5):e0251530.
    doi: 10.1371/journal.pone.0251530pubmed: 34014952google scholar: lookup
  9. Cequier A, Sanz C, Rodellar C, Barrachina L. The Usefulness of Mesenchymal Stem Cells beyond the Musculoskeletal System in Horses. Animals (Basel) 2021 Mar 25;11(4).
    doi: 10.3390/ani11040931pubmed: 33805967google scholar: lookup
  10. D Alvites R, V Branquinho M, Sousa AC, Zen F, Maurina M, Raimondo S, Mendonça C, Atayde L, Geuna S, Varejão ASP, Maurício AC. Establishment of a Sheep Model for Hind Limb Peripheral Nerve Injury: Common Peroneal Nerve. Int J Mol Sci 2021 Jan 30;22(3).
    doi: 10.3390/ijms22031401pubmed: 33573310google scholar: lookup
  11. Cercone M, Hokanson CM, Olsen E, Ducharme NG, Mitchell LM, Piercy RJ, Cheetham J. Asymmetric recurrent laryngeal nerve conduction velocities and dorsal cricoarytenoid muscle electromyographic characteristics in clinically normal horses. Sci Rep 2019 Feb 25;9(1):2713.
    doi: 10.1038/s41598-019-39189-zpubmed: 30804428google scholar: lookup
Subscribe to our newsletter
Join 99,344 horse owners like you who receive our email updates on horse health and nutrition.