Equis ISSN 2398-2977

Neurology: Horner's syndrome

Introduction

  • Loss of sympathetic innervation to head and specifically to the eye; often unilateral.
  • Cause: secondary to other disease process, eg perivascular injections, periorbital masses, cervical neck trauma, thoracic masses and guttural pouch abnormalities   Guttural pouch: empyema    Guttural pouch: mycosis  .
  • Signs: ptosis , miosis, enophthalmos   Eyeball: enophthalmos - prolapsed third eyelid  , patchy head/neck sweating.
  • Diagnosis: history, clinical signs.
  • Treatment: directed at primary problem.
  • Prognosis: guarded - related to primary problem.

Pathogenesis

Etiology

Pathophysiology

  • The sympathetic tract arises at T1-T3, it passes cranially through the cervicothoracic ganglion. The sympathetic fibers join the vagosympathetic tract following the path of the jugular vein to ascent up the neck to the cranial cervical ganglion situated just beneath the guttural pouch. These anatomical associations explain why just a diverse range of diseases can result in Horner's syndrome.
  • Loss of sympathetic innervation to the head results in a combination of lesions, including abnormalities of the eye.
  • Damage to the sympathetic innervation of the head   →   denervation of the dilator iris muscles, tarsal and orbital muscles and increased sensitivity of the skin blood vessels and neck sweat glands to circulating catecholamines.

Diagnosis

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Treatment

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Furr M (2011)Horner's syndrome.Equine Vet Educ23(9), 453-454 Wiley Online Library.
  • Palumbo M I P, Moreira J J, Olivo G, Neto C R & Pyles M D (2011)Right-sided laryngeal hemiplegia and Horner's syndrome in a horse.Equine Vet Educ23(9), 448-452 VetMedResource.
  • Firshman A M, Hayden D W, Valberg S J & McKenzie E C (2003)Horner's syndrome associated with fungal mediastinitis in a horse.Equine Vet Educ15(2), 82-85 VetMedResource.
  • Hahn C N (2003)Horner's syndrome in horses.Equine Vet Educ15(2), 86-90 VetMedResource.
  • Bacon C Let al(1996)Bilateral Horner's syndrome secondary to metastatic squamous cell carcinoma in a horse.Equine Vet J28(6), 500-503 PubMed.
  • Simoens Pet al(1990)Horner's syndrome in the horse - a clinical, experimental and morphologic study.Equine Vet J Suppl10, 62-65 PubMed.
  • Milne J C (1986)Malignant melanomas causing Horner's syndrome in a horse.Equine Vet J18(1), 74-75 PubMed.


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