Sensitivity, Specificity, and Reproducibility of 2 kHz cVEMP and 4 kHz oVEMP Tone Burst in Superior Semicircular Canal Dehiscence Syndrome

Introduction Superior semicircular canal dehiscence (SSCD) creates a pathological "third window" in the inner ear, leading to characteristic auditory and vestibular symptoms. Although 0.5 kHz vestibular evoked myogenic potential (VEMPs) are commonly used, we aimed to evaluate the sensitivity, specificity, and reproducibility of VEMPs elicited with high-frequency tone bursts. Methods This prospective, multicenter, observational, longitudinal study included adults with strictly unilateral SSCD confirmed by high-resolution CT, using the contralateral ear as an intra-individual control. Participants attended three visits over four weeks. Cervical (2 kHz) and ocular (4 kHz) VEMPs were recorded with two traces per ear per session using standard electrode placement and 95 dB nHL tone bursts. Sensitivity, specificity, ROC/AUC, and reproducibility (intra- and inter-visit) were assessed. Results Twenty-eight patients with strictly unilateral SSCD were included (mean age 57.6 ± 12.5 years; 17 women). No VEMP responses were observed in unaffected ears, yielding a specificity of 100% for both 2 kHz cVEMPs and 4 kHz oVEMPs. Sensitivity in dehiscent ears ranged from 71.4% to 60.7% for cVEMPs and from 60.7% to 50.0% for oVEMPs across the three visits. Overall, the analyzed electrophysiological markers demonstrated good to excellent intra- and inter-visit reproducibility. Conclusions In conclusion, high-frequency VEMPs, including 2 kHz cVEMPs and 4 kHz oVEMPs, show perfect specificity for detecting ears with SSCD and good to excellent intra- and inter-visit reproducibility. A fixed stimulation intensity of 95 dB nHL provides a balance between patient comfort and test duration.