title: Development of a nerve conduction technique for the recurrent laryngeal nerve.
abstract: OBJECTIVE
  To develop a reliable and safe laryngeal nerve conduction technique and to obtain consistent parameters as normal reference values.
  
  
  METHODS
  A prospective single-arm study.
  
  
  METHODS
  A nerve conduction test was performed on the contralateral normal side in 42 patients with unilateral vocal fold palsy. The recording was performed in the intact thyroarytenoid muscle using a monopolar needle. The electrical stimulation using a 37-mm monopolar needle was applied 3 cm below the lower margin of the cricoid cartilage, just lateral to the trachea and medial to the carotid artery, and its intensity was gradually increased until the amplitude of the electrical response reached the maximum level. The latency of the evoked muscle response was acquired at the first evoked waveform deflection from the baseline.
  
  
  RESULTS
  The average latency of the recurrent laryngeal nerves was 1.98 ± 0.26 ms. The latencies showed normal distribution according to the quantile-quantile plot and Kolmogorov-Smirnov test (P = .098). There was no significant difference in latencies between the right and left recurrent laryngeal nerves. Anthropometric factors including height and weight did not show any correlation with the latencies.
  
  
  CONCLUSIONS
  We developed a reliable and safe laryngeal nerve conduction technique and obtained normal reference values for the recurrent laryngeal nerve conduction study. This laryngeal nerve conduction study can be an additional tool for detecting recurrent laryngeal nerve injury if it is performed in combination with the conventional laryngeal electromyography.
  
  
  METHODS
  4.
authors.affiliation: Department of Physical and Rehabilitation Medicine, Samsung Medical Center, Seoul, South Korea.
authors.forename: Sang
authors.initials: S
authors.lastname: J Kim
authors.forename: Dae
authors.initials: D
authors.lastname: G Lee
authors.forename: Jeong-Yi
authors.initials: JY
authors.lastname: Kwon
mesh_terms: D004599:Electric Stimulation Therapy / Q000379:methods*; D004576:Electromyography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology*; D011446:Prospective Studies; D012009:Recurrent Laryngeal Nerve / Q000503:physiopathology*; D061226:Recurrent Laryngeal Nerve Injuries / Q000150:complications* / Q000503:physiopathology / Q000628:therapy; D016896:Treatment Outcome; D014826:Vocal Cord Paralysis / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*
keywords: Laryngeal nerve conduction; evoked potential; hoarseness; recurrent laryngeal nerve; vocal fold palsy