title: Difference of diagnostic rates and analytical methods in the test positions of vestibular evoked myogenic potentials.
abstract: OBJECTIVE
  To compare the differences of diagnostic rates, of the two widely used test positions, in measuring vestibular evoked myogenic potentials (VEMP) and selecting the most appropriate analytical method for diagnostic criteria for the patients with vertigo.
  
  
  METHODS
  Thirty-two patients with vertigo were tested in two comparative testing positions: turning the head to the opposite side of the evaluating side and bowing while in seated position, and bowing while in supine positions. Abnormalities were determined by prolonged latency of p13 or n23, shortening of the interpeak latency, and absence of VEMP formation.
  
  
  RESULTS
  Using the three criteria above for determining abnormalities, both the seated and supine positions showed no significant differences in diagnostic rates, however, the concordance correlation of the two positions was low. When using only the prolonged latency of p13 or n23 in the two positions, diagnostic rates were not significantly different and their concordance correlation was high. On the other hand, using only the shortened interpeak latency in both positions showed no significant difference of diagnostic rates, and the degree of agreement between two positions was low.
  
  
  CONCLUSIONS
  Bowing while in seated position with the head turned in the opposite direction to the area being evaluated is found to be the best VEMP test position due to the consistent level of sternocleidomastoid muscle tension and the high level of compliance. Also, among other diagnostic analysis methods, using prolonged latency of p13 or n23 as the criterion is found to be the most appropriate method of analysis for the VEMP test.
authors.affiliation: Department of Rehabilitation Medicine, Wonju Severance Christian Hospital, Wonju, Korea.
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Rehabilitation Medicine, Wonju Severance Christian Hospital, Wonju, Korea.
authors.forename: Jeong Mee
authors.initials: JM
authors.lastname: Park
authors.affiliation: Department of Rehabilitation Medicine, Wonju Severance Christian Hospital, Wonju, Korea.
authors.forename: Sang Yeol
authors.initials: SY
authors.lastname: Yong
authors.affiliation: Department of Rehabilitation Medicine, Wonju Severance Christian Hospital, Wonju, Korea.
authors.forename: Jong Heon
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Occupational Therapy, Graduate School, Yonsei University; Department of Occupational Therapy, Wonju Medical Center, Wonju, Korea.
authors.forename: Hee
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors.forename: Sang-Yoo
authors.initials: SY
authors.lastname: Park
keywords: Data interpretation; Patient positioning; Vestibular evoked myogenic potentials (VEMP)