title: Repetitive stimulation of the common peroneal nerve as a diagnostic aid for botulism in foals.
abstract: BACKGROUND
  Botulism is a potentially fatal paralytic disorder for which definitive diagnosis is difficult.
  
  
  OBJECTIVE
  To determine if repetitive stimulation of the common peroneal nerve will aid in the diagnosis of botulism in foals.
  
  
  METHODS
  Four control and 3 affected foals.
  
  
  METHODS
  Validation of the test in healthy foals for its comparison in foals with suspected botulism. Controls were anesthetized and affected foals were sedated to avoid risks of anesthesia. The common peroneal nerve was chosen for its superficial location and easy access. Stimulating electrodes were placed along the common peroneal nerve. For recording, the active and reference electrodes were positioned over the midpoint and distal end of the extensor digitorum longus muscle, respectively. Repeated supramaximal stimulation of the nerve was performed utilizing a range of frequencies (1-50 Hz). Data analysis consisted of measuring the amplitude and area under the curve for each M wave and converting these values into percentages of decrement or increment based on the comparison of subsequent potentials to the initial one (baseline) within each set.
  
  
  RESULTS
  A decremental response was seen at all frequencies in control foals. Decremental responses also were observed in affected foals at low frequencies. An incremental response was seen in all affected foals at 50 Hz.
  
  
  CONCLUSIONS
  Decreased baseline M wave amplitudes with incremental responses at high rates are supportive of botulism. Repetitive nerve stimulation is a safe, simple, fast, and noninvasive technique that can aid in the diagnosis of suspected botulism in foals.
authors.affiliation: William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA. mraleman@ucdavis.edu
authors.forename: M
authors.initials: M
authors.lastname: Aleman
authors.forename: D C
authors.initials: DC
authors.lastname: Williams
authors.forename: N E
authors.initials: NE
authors.lastname: Jorge
authors.forename: K G
authors.initials: KG
authors.lastname: Magdesian
authors.forename: R J
authors.initials: RJ
authors.lastname: Brosnan
authors.forename: D J
authors.initials: DJ
authors.lastname: Feary
authors.forename: H G
authors.initials: HG
authors.lastname: Hilton
authors.forename: T A
authors.initials: TA
authors.lastname: Kozikowski
authors.forename: J K
authors.initials: JK
authors.lastname: Higgins
authors.forename: J E
authors.initials: JE
authors.lastname: Madigan
authors.forename: R A
authors.initials: RA
authors.lastname: Lecouteur
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D019540:Area Under Curve; D001906:Botulism / Q000175:diagnosis / Q000662:veterinary*; D004568:Electrodiagnosis / Q000379:methods / Q000662:veterinary*; D005260:Female; D006734:Horse Diseases / Q000175:diagnosis*; D006736:Horses; D008297:Male; D009431:Neural Conduction / Q000502:physiology*; D010543:Peroneal Nerve / Q000502:physiology*