Canis ISSN: 2398-2942

Brachial plexus: avulsion

Synonym(s): Brachial plexopathy

Contributor(s): Kyle Braund, Prof Mark Rochat,

Introduction

  • See brachial plexus root avulsion Brachial plexus: root avulsion.
  • Clinical signs more severe than partial avulsions.
  • Cause: result of trauma, usually road traffic accidents (RTA).
  • Signs: neurological deficits apparent immediately following injury.
  • Neurogenic muscle atrophy takes 7-10 days to develop.
  • Prognosis: for recovery poor.

Pathogenesis

Etiology

  • Traumatic traction of spinal nerve roots at their origin inside the dura mater.

Predisposing factors

General
  • Lack of leash laws and/or irresponsible pet ownership.
  • Intact dog.
  • Bitch in heat.
Environmental
  • Dog lives on busy road or in city.
Management
  • Dog allowed to exercise unsupervised.
  • Old or faulty extending lead.
  • Dog exercised off the lead.

Pathophysiology

  • Traumatic.
  • Limb forcibly abducted or rotated at its attachment to the body → traumatic traction on the spinal nerve roots at their origin inside the dura mater → disruption of the neural elements → interruption of spinal reflexes. Ventral roots are especially susceptible.
  • Skin desensitization → decrease in muscle tone → onset of neurogenic muscle atrophy.
  • Some shrinkage of the areas of skin desensitization as nerves grow in from neighboring innervated areas.

Timecourse

  • Neurological deficits apparent immediately after injury.
  • Neurogenic muscle atrophy from 7-10 days after injury.

Diagnosis

Treatment

Prevention

Outcomes

Further Reading

Publications

Refereed papers

  • Recent references fromPubMed.
  • Forterre Fet al(1998)Myelography by computer tomography for the diagnosis of brachial plexus avulsion in small animals.Tierarzt Praxis26(5), 322-329PubMed.
  • Steinberg H S (1988)Brachial plexus injuries and dysfunctions.Vet Clin North Am18, 565-580PubMed.
  • Wheeler S Jet al(1986)The diagnosis of brachial plexus disorders in dogs - a review of twenty-two cases.JSAP27(3), 147-157.
  • Bailey C S (1984)Patterns of cutaneous anesthesia associated with brachial plexus avulsions in the dog.JAVMA185(8), 889-899PubMed.


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