Prevalence and clinical significance of spontaneous low-frequency air-bone gap in Meniere's disease

Abstract

Objectives: This study was performed to identify the prevalence and clinical significance of spontaneous low-frequency air-bone gap (LFABG) in Meniere’s disease.Study design: A retrospective study.Methods: Three hundred and thirty-seven definite Meniere’s disease patients were included. The prevalence of LFABG in this population was calculated and the following parameters were analyzed to identify the clinical significance of LFABG: 1) changes of hearing threshold after the resolution of LFABG; 2) correlation between LFABG and the result of electrocochleography; 3) changes in the number of vertigo spells after the resolution of LFABG; 4) correlation between LFABG and canal paresis values in caloric test; and 5) the difference in the prognosis between patients with and without LFABG.Results: The prevalence of LFABG was 12.6%. Cochlear function was correlated with LFABG; the patients’ hearing threshold was significantly decreased after the resolution of LFABG (from 48.9 ± 17.0 to 39.7 ± 19.6 dBnHL) and the SP/AP ratio showed a tendency to increase as LFABG increased (R2 = 0.09, P = 0.03). The mean number of vertigo spells was significantly reduced after the resolution of LFABG (from 5.2 ± 8.5 to 0.5 ± 0.01, P = 0.02). However, the prognosis was not different between patients with and without LFABG.Conclusion: The prevalence of LFABG in Meniere’s disease was 12.6%. Although the prognostic importance of LFABG was not significant, it is likely to reflect the aggravation of endolymphatic hydrops in the cochlear and vestibular compartments and may be useful for evaluating and treating patients with Meniere’s disease.