Canis ISSN: 2398-2942

Vestibulocochlear neuritides

Synonym(s): Peripheral vestibular syndrome

Contributor(s): Paul Cuddon, Laurent Garosi

Introduction

  • Pathological processes in the peripheral receptors in the inner ear and of the vestibular branch of the VIII cranial nerve.
  • Cause: includes otitis interna, canine geriatric vestibular disease, aminoglycoside toxicity, topical iodophors or chlorhexidine, hypothyroidism, neoplasia, trauma (especially iatrogenic) and congenital peripheral vestibular disease.
  • Signs:
    • Head tilt.
    • Wide base stance.
    • Ataxia with a tendency to lean to one side.
    • Circling and nystagmus.
    • Deafness and disturbances of balance occur together.
    • Important to differentiate these disorders from central vestibular disturbances.
  • Diagnosis: signs.
  • Treatment: none
  • Prognosis: good to guarded.

Pathogenesis

Etiology

  • Autosomal inheritance in congenital peripheral vestibular disease.
  • Immune-mediated disease.
  • Transitory labyrinthitis.
  • Endolymphatic fluid dynamic abnormality within labyrinthine organ.
  • Neuritis of the vestibular portion of facial nerve VIII.
  • Metabolic, ie hypothyroidism.
  • Foreign body related.
  • Secondary to nasopharyngeal polyps.
  • Extension of opportunistic infection byStaphylococcusspp,Streptococcusspp,P. canis,Clostridium welchiiand especiallyPseudomonas aeruginosa.
  • Neoplasia.
  • Head trauma (rare).

Geriatric vestibular disease

  • Results from abnormal flow of endolymphatic fluid in the semicircular canals of the inner ear secondary to either:
    • Disturbance in production, circulation or absorption of the fluid.
    • Intoxication of vestibular receptors and inflammation of the vestibular nerve.

Iatrogenic damage during the treatment of middle ear disease

  • Trauma from excessive pressure from overzealous irrigation.
  • Use of ototoxic compounds in irrigation of middle ear.

Sudden onset idiopathic otitis interna

  • Extension of an infection of the external ear through either the tympanic membrane or the oral and nasopharyngeal cavities via the eustachian tubes.
  • Hematogenous spread of infectious agent, possibly a virus.
  • Hematogenous spread of a systemic infection.
  • See under otitis interna Otitis interna , canine geriatric vestibular disease, metronidazole toxicity, aminoglycoside toxicity, neoplasia, trauma (especially iatrogenic) and congenital peripheral vestibular disease.

Predisposing factors

General
  • Old dogs.
  • Dogs which are prone to otitis externa, ie the German Shepherd dog, dogs with pendulous or hairy ears, dogs with generalized skin conditions (especially atopy).
  • Hypothyroidism.
  • Inhalant anesthesia may change the pressure of the middle ear and predispose to infection.

Specific

  • Otitis media.
  • Bulla irrigation or bulla osteotomy.

Pathophysiology

  • See under otitis interna Otitis interna , canine geriatric vestibular disease, metronidazole toxicity, aminoglycoside toxicity.
Neoplasia
  • Space occupying lesion → pressure on surrounding nervous tissue → compromised blood supply and anoxia of nervous tissue or direct pressure trauma to nervous tissue → loss of function.
Congenital peripheral vestibular disease in Dobermann, Japanese Akita and Beagle
  • Autosomal recessive inheritance → non-inflammatory neuroepithelial degeneration of the cochlea with a progressive loss of auditory sensory hair cells → almost complete loss of organ of Corti by 11 weeks of age → bilateral, severe, permanent deafness and vestibular signs which improve as dog learns to compensate.
Congenital peripheral vestibular disease in Dobermann/lymphocytic labyrinthitis
  • Lymphocytic labyrinthitis (otitis interna) → multiple lymphocytic aggregates in the lamina.
  • Multiple lymphocytic aggregates in the lamina propria underneath the ciliated columnar epithelium of the inner ear → loss of function, deafness and vestibular signs.

Timecourse

  • Usually acute onset - may occur over several hours.

Diagnosis

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Treatment

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Prevention

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Rossmeisl Jr J H (2010) Vestibular disease in dogs and cats. Vet Clin North Am Small Anim Pract 40 (1), 81-100 PubMed.
  • Thomas W B (2000) Vestibular dysfunction. Vet Clin North Am Small Anim Pract 30 (1), 227-249 PubMed.
  • Forbes S, Cook J R (1991) Congenital peripheral vestibular disease attributed to lymphocytic labyrinthitis in two related litters of doberman pinscher pups. JAVMA 198 (3), 447-449 PubMed.
  • Schunk K L (1990) Diseases of the vestibular system. Prog Vet Neur (3), 247-54 VetMedResource.
  • Schunk K L, Averill D R Jr. (1983) Peripheral vestibular syndrome in the dog - a review of 83 cases. JAVMA 182 (12), 1354-1357 PubMed.
  • Blauch B, Martin C L (1974) A vestibular syndrome in aged dogs. JAAHA 10 (1), 37-40 VetMedResource.

Other sources of information

  • de Lahunta A, Glass E (2009)Vestibular system - special proprioception.Veterinary Neuroanatomy and Clinical Neurology.3rd edn. W B Saunders, Elsevier, St Louis, Missouri. pp 319-347.
  • Munana K R (2004)Head tilt and nystagmus.In:BSAVA Manual of Canine and Feline Neurology. S R Platt & Olby N J (eds). pp 155-171.
  • Merck Veterinary Manual(1998)8. pp 375-377.
  • Cochrane S M (1997)Head tilt (vestibular disease).The 5 minute veterinary consult - canine and feline.pp 74-75.
  • Joseph S M (1997)Otitis media and internaThe 5 minute veterinary consult - canine and feline. pp 896-897.
  • Cochrane S M (1997)Vestibular disease, geriatric dogs.The 5 minute veterinary consult - canine and feline. pp 1150-1151.


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