title: Effects of stimulus and recording parameters on the air conduction ocular vestibular evoked myogenic potential.
abstract: BACKGROUND
  Vestibular evoked myogenic potentials (VEMPs) have been recorded from the sternocleidomastoid muscle (cervical VEMP or cVEMP) and more recently from the eye muscles (ocular VEMP or oVEMP) in response to air conduction and bone conduction stimuli. Both cVEMPs and oVEMPs are mediated by the otoliths and thereby provide diagnostic information that is complementary to videonystagmography and rotational chair tests. In contrast to the air conduction cVEMP, which originates from the saccule/inferior vestibular nerve, recent evidence suggests the possibility that the air conduction oVEMP may be mediated by the utricle/superior vestibular nerve. The oVEMP, therefore, may provide complementary diagnostic information relative to the cVEMP. There are relatively few studies, however, that have quantified the effects of stimulus and recording parameters on the air conduction oVEMP, and there is a paucity of normative data.
  
  
  OBJECTIVE
  To evaluate the effects of several stimulus and recording parameters on the air conduction oVEMP and to establish normative data for clinical use.
  
  
  METHODS
  A prospective repeated measures design was utilized.
  
  
  METHODS
  Forty-seven young adults with no history of neurologic disease, hearing loss, middle ear pathology, open or closed head injury, cervical injury, or audiovestibular disorder participated in the study.
  
  
  METHODS
  The effects of stimulus frequency, stimulus level, gaze elevation, and recording electrode location on the amplitude and latency of the oVEMP for monaural air conduction stimuli were assessed using repeated measures analyses of variance in an initial group of 17 participants. The optimal stimulus and recording parameters obtained in the initial group were used subsequently to obtain oVEMPs from 30 additional participants.
  
  
  RESULTS
  The effects of stimulus frequency, stimulus level, gaze elevation, and electrode location on the response prevalence, amplitude, and latency of the oVEMP for monaural air conduction stimuli were significant. The maximum N1-P1 amplitude and response prevalence were obtained for contralateral oVEMPs using a 500 Hz tone burst presented at 125 dB peak SPL during upward gaze at an elevation of 30°.
  
  
  CONCLUSIONS
  The optimal stimulus and recording parameters quantified in this study were used to establish normative data that may be useful for the clinical application of the air conduction oVEMP.
authors: James H. Quillen VA Medical Center, Mountain Home, TN, USA. owen.murnane@va.gov
authors: Owen D
authors: OD
authors: Murnane
authors: Faith W
authors: FW
authors: Akin
authors: Kip J
authors: KJ
authors: Kelly
authors: Stephanie
authors: S
authors: Byrd
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000293:Adolescent; D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology; D006801:Humans; D008297:Male; D010037:Otolithic Membrane / Q000502:physiology*; D011446:Prospective Studies; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D012444:Saccule and Utricle / Q000502:physiology; D013018:Sound Spectrography; D058585:Vestibular Evoked Myogenic Potentials / Q000502:physiology*; D014725:Vestibular Nerve / Q000502:physiology; D055815:Young Adult