Vestibular evoked myogenic potentials are intact after sudden deafness

OBJECTIVE: To evaluate vestibular evoked myogenic potentials (VEMPs) in cases of sudden deafness, and to confirm the noncochlear origin of the VEMPs. STUDY DESIGN: Prospective study. VEMPs, which were evoked by short tone burst (95 dB nHL) stimulation, were recorded in 20 patients with unilateral, idiopathic sudden deafness. The results of the deaf ears were compared with those of the contralateral healthy ears and the normal control ears. The relations between VEMPs and the hearing level or caloric response were then investigated. RESULTS: All 20 of the deaf ears displayed normal biphasic VEMPs. The mean latencies of p13 and n23, as well as mean amplitude p13-n23, were 15.1 +/- 2.8 msec, 20.7 +/- 3.3 msec and 25.2 +/- 12.6 microV, respectively, not significantly different to either the contralateral healthy ears (p > 0.05) or the normal control ears (p > 0.05). Five deaf ears displayed canal paresis or absent caloric response, whereas the remaining 15 ears revealed normal caloric response. CONCLUSION: All the lesioned ears of patients with idiopathic sudden deafness exhibit normal biphasic VEMPs. Neither the hearing level nor the caloric response correlated to the VEMPs.