title: Novel method for vestibular evoked myogenic potentials: technique and reproducibility.
abstract: OBJECTIVE
  A novel method was employed to control the sternocleidomastoid muscle contraction level during vestibular evoked myogenic potential (VEMP) measurement.
  
  
  METHODS
  A prospective study to measure the normal VEMP response.
  
  
  METHODS
  A pressure feedback device composed of a firm rubber bulb and a pressure gauge was employed to monitor the muscular contraction level during measurement.
  
  
  METHODS
  Nineteen normal-hearing subjects (12 males; mean age 34.0 ± 7.7 years) were tested. Subjects were instructed to position the chin on the rubber bulb and use the neck flexors to maintain a pressure of 120 mm Hg during the measurement.
  
  
  METHODS
  The P13 latencies, N23 latencies, and P13-N23 amplitudes were recorded. In nine subjects, the reproducibility of the technique was tested weekly for 3 consecutive weeks.
  
  
  RESULTS
  The average (± SD) latency of P13 was 13.97 ± 1.33 ms, and the latency of N23 was 24.03 ± 1.79 ms. The average amplitude was 66.89 ± 44.1 μV. There was no significant difference between right and left ears in P13 latencies, N23 latencies, and P13-N23 amplitudes. In nine subjects, the average measured interclass correlation coefficient was 0.97 in amplitude, 0.8 in P13 latency, and 0.93 in N23 latency in three consecutive weekly measurements.
  
  
  CONCLUSIONS
  The chin-rest pressure feedback method is easy to perform during VEMP testing. Subjects can maintain a constant level of sternocleidomastoid contraction and neck flexion to facilitate this response with a high degree of test-retest reliability. This technique provides a means to compare VEMPs across different clinical scenarios over time.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubai, P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Qian
authors.forename: David
authors.initials: D
authors.lastname: Houlden
authors.forename: Julija
authors.initials: J
authors.lastname: Adamonis
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Chen
authors.forename: Ze-Zhang
authors.initials: ZZ
authors.lastname: Tao
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods; D011446:Prospective Studies; D015203:Reproducibility of Results; D058585:Vestibular Evoked Myogenic Potentials; D014724:Vestibular Function Tests / Q000379:methods*; D014722:Vestibule, Labyrinth / Q000502:physiology*