Abstract
The potentials evoked by acoustic stimuli in the cervical muscle are called vestibular evoked myogenic potentials (VEMP). Study results suggested that VEMP reflect the vestibular function, particularly that of the saccule and inferior vestibular nerve. In the present study we measured VEMP in the cases of sudden deafness and studied its relation with hearing at the first clinic visit, vestibular findings and hearing prognosis.
The subjects included 49 cases who were diagnosed as sudden deafness at our department between April, 1998 and June, 1999, in whom VEMP were measured. According to the hearing level at the first presentation and the results of VEMP measurements, the more profound the hearing impairment was, the higher was the percetage of abnormal VEMP cases. This result suggested that the vestibular system close to the cochlea might be impaired in the profoundly deaf cases. From this result the authors postulated that the vestibular lesion in sudden deafness could be evaluated.
The presence or absence of the vestibular findings (subjective dizziness, nystagmus and CP on the caloric test) is well correlated with the results of VEMP measurement in that both reflect the vestibular impairment. Many cases of good prognosis were found in the normal VEMP cases, while many cases of poor prognosis were noted in the abnormal VEMP cases.
These results suggested that examination of VEMP can serve as a useful factor in estimating the hearing prognosis in sudden deafness.
