The diagnostic value of vestibular-evoked myogenic potential in patients with vestibular schwannoma

Objective: This study examined the diagnostic value of the vestibular-evoked myogenic potential (VEMP) in comparison with the caloric test in patients with vestibular schwannoma (VS). Methods: Data were retrospectively collected from 803 consecutive patients who visited Our vertigo clinic and underwent vestibular tests. Amongst them, 78 patients were diagnosed as having untreated unilateral VS. VEMP was performed using click and short-tone burst stimulation. The caloric test was performed using ice water. The sensitivity and specificity of each test were evaluated. Results: Of the 78 patients with VS, 63 had abnormal VEMPs as well as abnormal caloric responses. Of the 725 patients without VS, 382 had normal VEMPs and 416 had normal caloric responses. The sensitivity and specificity of VEMP were 80.8% (95% Cl: 72.0-89.5%) and 52.7% (95% Cl: 49.1-56.3%), respectively; those of the caloric test were 80.8% (95% Cl: 72.0-89.5%) and 57.4% (95% Cl: 53.8-61.0%), respectively. Conclusions: The sensitivity and specificity of VEMP and the caloric test showed no significant differences. Significance: In patients with VS, although the specificity of VEMP was not very high, its sensitivity was high and comparable to that of the caloric test. (C) 2009 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.