Equis ISSN 2398-2977

Electrodiagnostic testing

Synonym(s): Electromyography EMG, electroencephalography EEG, auditory brainstem testing ABR

Contributor(s): Graham Munroe, Michael Porter

Introduction

  • The changes in cell electrical activity which occur during neurologic disease can be measured using specialist electronic equipment.
  • Such measurements can be useful in localizing, diagnosing and prognosing neurologic disease.
  • The techniques should be used as an extension of the neurological examination   Neurology: examination - adult    Neurology: examination - foal  and other diagnostic procedures, eg cerebrospinal fluid (CSF) evaluation   CSF: collection  , radiography   Head: radiography    Spine: radiography  , ultrasound   Ultrasonography: overview  , to provide a more complete picture of the disease process and assist in obtaining a distinct diagnosis. 
  • Because of recent advances made in magnetic resonance imaging (MRI)   Magnetic resonance imaging  , scintigraphy   Brain: scintigraphy  and computed tomography (CT)   Computed tomography  electrodiagnostic testing is used less frequently today. 
  • It is far more common to perform an MRI on horses with CNS disease.
  • techniques include:
    • Electromyography (EMG)useful for defining diseases of: 
      • Lower motor neuron.
      • Motor unit:
        • Nerve cell body.
        • Myoneural junction.
        • Muscle fibers.
    • Nerve conduction studiesuseful for defining diseases of: 
      • Lower motor neuron.
      • Motor unit.
    • Auditory brainstem response (ABR)useful for defining diseases of:
      • Cranial nerve VIII.
      • Auditory pathways through the brainstem.
    • Electroencephalography (EEG)useful for defining: 
      • Focal and diffuse intracranial lesions.

Advantages

Disadvantages

  • Expensive equipment required.
  • High degree of specialist expertise required to perform procedures and interpret results.

Electromyography (EMG)

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Nerve conduction studies

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Auditory brainstem evoked response (ABR testing)

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Electroencephalography (EEG)

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Other

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Further Reading

Publications

Refereed papers
  • Recent references fromPubMedpublished during the last 12 months.

Other sources of information

  • Andrews F M (2004)Electrodiagnostic Aids and Selected Neurologic diseases.In: Equine Internal Medicine. Eds: Reed S M, Bayly W M & Sellon D C. Saunders, Missouri. pp 546-560. ISBN: 0721697771.
  • Byrne B A (1992)Nervous System Diagnostic Procedures.In: Equine Surgery. Eds: Auer J A & Stick J A. W B Saunders, Philadelphia. pp 412-423. ISBN: 0721677339.


ADDED