Difference of Cervical Vestibular Evoked Myogenic Potentials between Bone-Conduction and Air-Conduction in Patients with Nonspecific Dizziness

Objectives: This study was performed to evaluate the difference of the cervical vestibular evoked myogenic potentials (cVEMP) stimulated by bone-conduction (BC) and air-conduction (AC) in patients with nonspecific dizziness.Methods: Twenty-eight dizzy patients (56 ears) and 15 subjects (30 ears) as normal control was enrolled. Responses of BC- and AC-cVEMP were recorded sequentially in both groups. cVEMP parameters including latencies, inter-latencies intervals, amplitudes, and interaural amplitude asymmetry were analyzed and compared.Results: Among the patients with nonspecific dizziness, AC-cVEMP responses were clearly detected in all 56 ears while BC-cVEMP responses were detected in 32 ears (57.1%). Amplitudes of BC-cVEMP were significantly smaller than those of AC-cVEMP in all patients with BC-cVEMP response. There was no difference in latencies, inter-latencies intervals, and interaural amplitude asymmetry ratios between BC- and AC-cVEMP. There was no significant difference in BCand AC-cVEMP between the dizzy and control groups.Conclusions: BC-cVEMP is not clinically useful in comparison to AC-cVEMP for the evaluation of nonspecific dizziness. An effective stimulation tool for BC is necessary to provoke more reliable responses of BC-cVEMP.