title: Differing response properties of cervical and ocular vestibular evoked myogenic potentials evoked by air-conducted stimulation.
abstract: OBJECTIVE
  To determine the amplitude changes of vestibular evoked myogenic potentials (VEMPs) recorded simultaneously from the neck (cVEMPs) and eyes (oVEMPs) in response to 500 Hz, 2 ms air-conducted sound pips over a 30 dB range.
  
  
  METHODS
  Fifteen healthy volunteers (mean age 29, range 18-57 years old) and one patient with unilateral superior canal dehiscence (SCD) were studied. The stimulus was reduced in increments to 105 dB pSPL for the normals (81 dB pSPL for the SCD patient). A statistical criterion was used to detect responses.
  
  
  RESULTS
  Ipsilateral (i-p13/n23) and contralateral (c-n12/p24/n30) peaks for the cVEMP montage and contralateral (c-n10/p16/n21) and ipsilateral (i-n13) peaks for the oVEMP montage were present for the baseline intensity. For the lowest intensity, 6/15 subjects had responses for the i-p13 cVEMP potential and 4/15 had c-n10 oVEMP responses. The SCD patient showed larger responses for nearly all intensities. The cVEMP potentials were generally well fitted by a power law relationship, but the oVEMP c-n10, p16 and n21 potentials showed a significant increase in gradient for the higher intensities.
  
  
  CONCLUSIONS
  Most oVEMP and cVEMP responses follow a power law relationship but crossed oVEMP responses showed a change in gradient above a threshold.
  
  
  CONCLUSIONS
  The pattern of response to AC stimulation may be a property of the pathways underlying the potentials.
authors.affiliation: Prince of Wales Clinical School and Neuroscience Research Australia, University of New South Wales, Randwick, Sydney, NSW 2031, Australia.
authors.forename: Danielle L
authors.initials: DL
authors.lastname: Dennis
authors.affiliation: Prince of Wales Clinical School and Neuroscience Research Australia, University of New South Wales, Randwick, Sydney, NSW 2031, Australia.
authors.forename: Sendhil
authors.initials: S
authors.lastname: Govender
authors.affiliation: Prince of Wales Clinical School and Neuroscience Research Australia, University of New South Wales, Randwick, Sydney, NSW 2031, Australia.
authors.forename: Peggy
authors.initials: P
authors.lastname: Chen
authors.affiliation: Faculty of Life Science, University of Manchester, Manchester M13 9PL, UK.
authors.forename: Neil P McAngus
authors.initials: NP
authors.lastname: Todd
authors.affiliation: Prince of Wales Clinical School and Neuroscience Research Australia, University of New South Wales, Randwick, Sydney, NSW 2031, Australia. Electronic address: j.colebatch@unsw.edu.au.
authors.forename: James G
authors.initials: JG
authors.lastname: Colebatch
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000388:Air; D000704:Analysis of Variance; D004576:Electromyography; D005123:Eye; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009333:Neck; D010812:Physical Stimulation; D011930:Reaction Time; D013115:Spinal Canal; D015837:Vestibular Diseases / Q000175:diagnosis* / Q000503:physiopathology*; D058585:Vestibular Evoked Myogenic Potentials; D014724:Vestibular Function Tests / Q000379:methods*; D055815:Young Adult
keywords: Myogenic potentials; Superior canal dehiscence; Vestibular reflexes; cVEMP; oVEMP