title: Reliability and comparison of gain values with occurrence of saccades in the EyeSeeCam video head impulse test (vHIT).
abstract: The vHIT (video head impulse test) investigates the vestibular function in two ways: a VOR (vestibulo-ocular reflex) gain value and a head impulse diagram. From the diagram covert and overt saccades can be detected. Evaluation of the vestibular function based on vHIT depends on both parameters. There is a lack of knowledge regarding the reliability of the two parameters. The objective was to investigate the reliability of vHIT by comparing gain values between examiners on the same subjects, and to see how differences affected the occurrence of saccades.
  
  
  METHODS
  25 subjects who had undergone cochlear implant (CI) surgery. Subjects were tested using the vHIT by two of four different examiners. Two judges interpreted the occurrence of saccades in the diagram.
  
  
  METHODS
  VOR gain values and the occurrence of saccades in the diagram. Differences in gain values between examiners varied from 0.2 to 0.58 with an average of 0.14 (95 % CI 0.12-0.16) on the right ear and 0.17 (95 % CI 0.15-0.19) on the left ear. Occurrences of saccades in the same patient were reproduced in 93 % of the cases by all examiners. Kappa's coefficient on the occurrence of saccades was 0.83. Interclass correlation coefficient (ICC) of the gain values between examiners ranged from 0.62 to 0.70. Differences in gain values amongst examiners did not seem to affect the occurrence of saccades in the same patient. The occurrence of saccades, therefore, seems to be more reliable than the gain value in the evaluation of the vestibular function. Interpretation of vHIT results should, therefore, first depend on the occurrence of saccades and second on the gain value.
authors.affiliation: Department of ENT Head and Neck Surgery, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense C, Denmark. lekor11@student.sdu.dk.
authors.forename: Leise Elisabeth Hviid
authors.initials: LEH
authors.lastname: Korsager
authors.affiliation: Department of ENT Head and Neck Surgery, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense C, Denmark.|Department of Audiology, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense C, Denmark.|Department of Clinical Research, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense C, Denmark.
authors.forename: Jesper Hvass
authors.initials: JH
authors.lastname: Schmidt
authors.affiliation: Department of ENT Head and Neck Surgery, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense C, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Faber
authors.affiliation: Department of ENT Head and Neck Surgery, Odense University Hospital, Sdr. Boulevard 29, 5000, Odense C, Denmark.
authors.forename: Jens Højberg
authors.initials: JH
authors.lastname: Wanscher
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019929:Cochlear Implantation; D005260:Female; D064087:Head Impulse Test / Q000379:methods / Q000592:standards*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D015203:Reproducibility of Results; D012438:Saccades / Q000502:physiology*; D014722:Vestibule, Labyrinth
keywords: EyeSeeCam; Saccades; VOR; Vestibulo-ocular reflex; Vestibulopathy; Video head impulse test; vHIT