Equis ISSN 2398-2977

Larynx: slap test

Synonym(s): Thoraco-laryngeal adductor test

Contributor(s): Tim Brazil, Christopher Brown, Paddy Dixon

Introduction

  • Slapping one hemithorax causes a reflex adduction of the muscular process of the arytenoid cartilage on the contralateral side.
  • This reflex is absent in animals with lesions of the ascending cervical spinal cord tracts, CNS and the motor nerve supply to the larynx hence its use in the diagnosis of cervical vertebral stenotic myelopathy   Spine: cervical vertebral malformation (CVM)  and other spinal cord lesions and idiopathic left laryngeal hemiplegia   Larynx: hemiplegia  .

Uses

  • Diagnosis of idopathic left laryngeal hemiplegia   Larynx: hemiplegia  .
  • Diagnosis of cervical spinal cord and CNS disorders.

Advantages

  • Easy test to perform.

Disadvantages

  • Unreliable - reflex can be superceded by CNS influence, eg excitement, inspiration, and may be absent/reduced in some 'normal' horses.

Procedure

  • 15 min.

Requirements

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Preparation

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Outcomes

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Prognosis

  • Critical studies including by electronic assessment of this reflex by electrolaryngeogram have shown that this test can be unreliable.

Further Reading

Publications

Refereed papers

Other sources of information

  • Hawe C, Dixon P M & Mayhew I G (2001)A study of an electrodiagnostic technique for the evaluation of equine recurrent laryngeal neuropathy.Equine Vet J33(5), 459-465.


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