Vestibular evoked myogenic potentials show altered tuning in patients with Ménière's disease.
OBJECTIVE
Acoustic stimulation of the saccule gives rise to a vestibulocollic reflex, the output of which can be measured in the neck as inhibition of activity in the ipsilateral sternocleidomastoid muscle. This vestibular evoked myogenic potential has been promoted as a means of assessing integrity of saccular function. In this study, we test the hypothesis that the cochleosaccular hydrops of Ménière's syndrome leads to alterations in saccular motion that change the dynamics of the vestibular evoked myogenic potential.


METHODS
Prospective cohort study.


METHODS
Large specialty hospital, department of otolaryngology.


METHODS
Fourteen normal adult volunteers and 34 consecutive consenting adult patients with unilateral Ménière's disease by American Academy of Otolaryngology-Head and Neck Surgery diagnostic criteria.


METHODS
All subjects underwent vestibular evoked myogenic potential testing using ipsilateral broadband click and short tone-burst stimuli at 250, 500, 1,000, 2,000, and 4,000 Hz.


METHODS
Threshold, amplitude, and latency of vestibular evoked myogenic potential responses in normal and Ménière's affected and unaffected ears.


RESULTS
Vestibular evoked myogenic potential was present in all ears tested. Normal subjects show a frequency-dependent vestibular evoked myogenic potential threshold, with best response ("frequency tuning") at 500 Hz. Compared with normal subjects and unaffected ears of Ménière's subjects, affected Ménière's ears had significantly increased vestibular evoked myogenic potential thresholds. Affected Ménière's ears showed threshold shifts at all frequencies and there was less tuning apparent at 500 Hz. Unaffected ears of Ménière's subjects also showed significantly elevated vestibular evoked myogenic potential thresholds compared with normal subjects. Analyses of vestibular evoked myogenic potential thresholds for effects of age, hearing loss, and audiometric configuration showed no significant differences.


CONCLUSIONS
Ménière's ears display alterations in vestibular evoked myogenic potential threshold and tuning, supporting our hypothesis of altered saccular motion mechanics arising from hydropic distention. Unaffected ears of unilateral Ménière's subjects show similar changes, though to a lesser degree. This finding may be because of occult saccular hydrops in the asymptomatic ear or binaural interactions in the vestibular evoked myogenic potential otolith-cervical reflex arc.
Rauch
Steven D
SD
Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts 02114, USA. sdr@epl.meei.harvard.edu
Zhou
Guangwei
G
Kujawa
Sharon G
SG
Guinan
John J
JJ
Herrmann
Barbara S
BS
D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D015331:Cohort Studies; D004576:Electromyography / Q000379:methods; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008575:Meniere Disease / Q000503:physiopathology*; D008875:Middle Aged; D009334:Neck Muscles / Q000502:physiology / Q000503:physiopathology; D011446:Prospective Studies; D012444:Saccule and Utricle / Q000502:physiology / Q000503:physiopathology*