Considerations for pacing of the cricoarytenoid dorsalis muscle by neuroprosthesis in horses.
Abstract: The success rate of prosthetic laryngoplasty is limited and may be associated with significant sequelae. Nerve muscle pedicle transplantation has been attempted but requires a year before function is restored. Objective: To determine the optimal parameters for functional electrical stimulation of the recurrent laryngeal nerve in horses. Methods: An experimental in vivo study was performed on 7 mature horses (2-21 years). A nerve cuff was placed on the distal end of the common trunk of the recurrent laryngeal nerve (RLN). In 6 horses the ipsilateral adductor branch of RLN was also transected. The electrodes were connected to programmable internal stimulator. Stimulation was performed using cathodic phase and then biphasic pulses at 24 Hz with a 0.427 ms pulse duration. Stimulation-response experiments were performed at monthly intervals, from one week following implantation. The study continued until unit failure or the end of project (12 months). Two of the horses were stimulated continuously for 60 min to assess onset of fatigue. Results: Excellent arytenoid cartilage abduction (mean arytenoid angle of 52.7 degrees, range 48.5-56.2 degrees) was obtained in 6 horses (laryngeal grades I or II (n = 3) and III (n = 2). Poor abduction was obtained in grade IV horses (n = 2). Arytenoid abduction was maintained for up to a year in one horse. Technical implant failure resulted in loss of abduction in 6 horses at one week to 11 months post operatively. Mean tissue impedance was 1.06 kOhm (range 0.64-1.67 kOhm) at one week, twice this value at 2 months (mean 2.32, range 1.11-3.75 kOhm) and was stable thereafter. Maximal abduction was achieved at a stimulation range of 0.65-7.2 mA. No electrical leakage was observed. Constant stimulation of the recurrent laryngeal nerve for 60 min led to full abduction without evidence of muscle fatigue. Conclusions: Functional electrical stimulation of the recurrent laryngeal nerve leading to full arytenoid abduction can be achieved. The minimal stimulation amplitude for maximal abduction angle is slightly higher than those for man and dogs. Conclusions: This treatment modality could eventually be applicable to horses with recurrent laryngeal neuropathy.
Publication Date: 2010-08-19 PubMed ID: 20716194DOI: 10.1111/j.2042-3306.2010.00115.xGoogle Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research aims to define the optimal parameters for effectively using electrical stimulation on the recurrent laryngeal nerve in horses in order to improve laryngeal movement. The study found that such stimulation could lead to the full abduction of the arytenoid cartilage in horses, potentially providing a treatment modality for horses with recurrent laryngeal neuropathy.
Study Objective
- The goal of the study was to identify the best parameters for functional electrical stimulation of the recurrent laryngeal nerve (RLN) in horses. This was carried out with a view to improve prosthetic laryngoplasty outcomes in horses and repair impaired laryngeal function.
Methodology
- The research was conducted on 7 mature horses, with an age range from 2 to 21 years. Each animal had a nerve cuff placed on the distal end of the RLN’s common trunk.
- In order to evaluate the effectiveness of the electrical nerve stimulation, the ipsilateral adductor branch of RLN in six horses was transected. The electrodes from the nerve cuff were connected to an internal programmable stimulator.
- The optimal parameters of stimulation were explored by using cathodic phase and biphasic pulses at 24 Hz with a specific pulse duration (0.427 ms).
- Experiments to observe the response from this stimulation were performed at monthly intervals, starting from one week after the implantation, and continued for up to one year.
Results
- The researchers found that excellent movement of arytenoid cartilage (with an average angle of abduction of 52.7 degrees) was achieved in six horses. However, two of the horses which had grade IV laryngeal function exhibited poor abduction.
- Successful arytenoid abduction was maintained for up to a year in one horse, while technical difficulties with the implant resulted in loss of abduction in six horses at varying stages post-operation.
- The study also revealed the minimal amount of stimulation required for achieving maximum abduction, and uncovered no electrical leakage during the experiment process. Importally, continuous electrical stimulation of the RLN for 60 minutes did not lead to muscle fatigue.
Conclusion
- The study concluded that functional electrical stimulation of the RLN can lead to full arytenoid abduction in horses.
- Furthermore, the study suggested that this type of treatment could be applicable for horses suffering from recurrent laryngeal neuropathy – a condition characterized by the gradual damage of the RLN that leads to voice changes and difficulty in breathing.
Cite This Article
APA
Ducharme NG, Cheetham J, Sanders I, Hermanson JW, Hackett RP, Soderholm LV, Mitchell LM.
(2010).
Considerations for pacing of the cricoarytenoid dorsalis muscle by neuroprosthesis in horses.
Equine Vet J, 42(6), 534-540.
https://doi.org/10.1111/j.2042-3306.2010.00115.x Publication
Researcher Affiliations
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, New York, USA. ngd1@cornell.edu
MeSH Terms
- Animals
- Female
- Horse Diseases / surgery
- Horses
- Laryngectomy / veterinary
- Larynx / surgery
- Male
- Postoperative Complications / veterinary
- Prostheses and Implants / veterinary
- Vocal Cord Paralysis / surgery
- Vocal Cord Paralysis / veterinary
Citations
This article has been cited 3 times.- Otto S, Michler JK, Dhein S, Mülling CKW. Development of a constant pressure perfused ex vivo model of the equine larynx. PLoS One 2021;16(5):e0251530.
- Cheetham J, Regner A, Jarvis JC, Priest D, Sanders I, Soderholm LV, Mitchell LM, Ducharme NG. Functional electrical stimulation of intrinsic laryngeal muscles under varying loads in exercising horses. PLoS One 2011;6(8):e24258.
- Hardwick JL, Ahern BJ, Crawford KL, Allen KJ, Franklin SH. Yearling laryngeal function in Thoroughbreds that underwent a laryngoplasty differs from controls. Equine Vet J 2025 Mar;57(2):431-440.
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