Differentiating hidden meniere's disease from typical sudden sensorineural hearing loss: clinical significance of acute low-tone hearing loss.

PURPOSE: This study aimed to elucidate the clinical heterogeneity of sudden sensorineural hearing loss (SSNHL) by analyzing audiometric profiles over a 12-year period. Specifically, the study sought to identify a subgroup with acute low-tone hearing loss (ALHL) as a potential manifestation of hidden Meniere's disease (MD) and to differentiate its pathophysiological characteristics from typical SSNHL.

METHODS

A retrospective review was conducted on 620 patients treated for SSNHL at a tertiary referral center between 2004 and 2016. Patients were stratified into an ALHL group (n = 80), suspected of hidden MD, and a typical SSNHL group (n = 540) based on frequency-specific audiometric configurations. Clinical characteristics, hearing recovery outcomes, and the prevalence of vertigo and metabolic comorbidities (diabetes and hypertension) were compared between groups.

RESULTS

The ALHL group exhibited significantly milder initial low-tone hearing loss (50.5 ± 15.1 dBHL) and superior recovery (27.9 ± 17.2 dBHL) compared with the severe pan-frequency loss in typical SSNHL (initial: 83.0 ± 23.6 dBHL; post-treatment: 48.7 ± 27.9 dBHL). A marked divergence in comorbidities was observed. The ALHL group demonstrated a high prevalence of vertigo (87.5%) but significantly lower metabolic risk (diabetes, 12.5%; hypertension, 28.8%). Conversely, typical SSNHL displayed higher metabolic risk (diabetes, 26.5%; hypertension, 41.1%) with less frequent vertigo (29.1%).

CONCLUSION

Sudden hearing loss associated with MD represents a distinct clinical entity within SSNHL: low-frequency impairment, high vertigo prevalence, and low risk of metabolic diseases. These findings suggest a hydropic etiology for this ALHL pattern, distinct from the viral or vascular causes of typical SSNHL. Therefore, clinical differentiation is imperative to implement targeted therapeutic strategies addressing endolymphatic hydrops in patients with ALHL in MD within SSNHL.