title: Influence of head acceleration on ocular vestibular-evoked myogenic potentials via skull vibration at Fz versus Fpz sites.
abstract: OBJECTIVE
  This study applied bone vibration (BV) stimulation to the Fz and Fpz sites to investigate the influence of head acceleration on the ocular vestibular-evoked myogenic potentials (oVEMPs).
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Fourteen healthy subjects underwent oVEMP tests combined with real-time triaxial accelerometry.
  
  
  RESULTS
  Under BV stimulation from a vibrator to the Fz and Fpz sites, acceleration magnitudes along x-, y- or z-axis did not significantly differ between the two sites. The mean nI and pI latencies of the oVEMPs stimulated at Fz were significantly earlier than those at Fpz. However, no statistical differences existed in the nI-pI interval and amplitude between the two sites. A blunt or double peak nI configuration was noted in three subjects (22%) when tapping at Fpz, but not at Fz, likely because different muscles contributing to the oVEMPs.
  
  
  CONCLUSIONS
  While both Fz and Fpz are effective sites for generating an oVEMP, the variation in human skull shapes and properties will lead to different acceleration profiles being transmitted to the vestibular apparatus. These differing stimuli may lead to different oVEMP profiles, so if one site does not produce the expected response, the clinician should try the other site.
authors.affiliation: Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Kuei-You
authors.initials: KY
authors.lastname: Lin
authors.forename: Shou-Jen
authors.initials: SJ
authors.lastname: Wang
authors.forename: Yi-Ho
authors.initials: YH
authors.lastname: Young
mesh_terms: D000054:Acceleration; D000328:Adult; D000704:Analysis of Variance; D004576:Electromyography; D005260:Female; D019416:Head Movements; D006801:Humans; D008297:Male; D040542:Mechanotransduction, Cellular; D011446:Prospective Studies; D012886:Skull / Q000033:anatomy & histology / Q000502:physiology*; D013624:Taiwan; D013997:Time Factors; D058585:Vestibular Evoked Myogenic Potentials; D014724:Vestibular Function Tests; D014732:Vibration; D055815:Young Adult