Detailed vestibular subtyping and prognostic implications in idiopathic sudden sensorineural hearing loss

Idiopathic sudden sensorineural hearing loss (ISSNHL) is often accompanied by vertigo and vestibular dysfunction; however, the characteristics and prognostic significance of different vestibular dysfunction patterns remain unclear. The aim of this study was to evaluate vestibular dysfunction patterns in patients with ISSNHL and explore their associations with clinical characteristics and hearing prognosis.

Clinical data from 130 participants with ISSNHL were retrospectively analyzed. All participants underwent comprehensive audiological and vestibular assessments and received standardized treatment including systemic and intratympanic corticosteroid therapy combined with hyperbaric oxygen therapy. Vestibular dysfunction subtypes were classified according to the combined nomenclature proposed by Fujimoto et al. Group comparisons were performed using appropriate statistical tests with the Holm‒Bonferroni correction for multiple comparisons. Logistic regression analyses were conducted to identify independent prognostic factors for hearing recovery.

Fourteen vestibular dysfunction subtypes were identified, and nine subtypes with sufficient sample sizes were included in further statistical comparisons. After the Holm‒Bonferroni correction was performed, significant differences remained in vertigo incidence (adjusted P = 0.041) and short-term hearing recovery (adjusted P = 0.018) among the vestibular subgroups. Patients with more extensive vestibular dysfunction presented a greater incidence of vertigo and poorer short-term hearing recovery. Multivariable logistic regression analysis demonstrated that air-conducted sound-cervical vestibular evoked myogenic potential (ACS-cVEMP) abnormalities were an independent predictor of poor hearing recovery (OR=3.23, 95% CI: 1.24‒8.44; P = 0.017).

Distinct vestibular dysfunction patterns are present in ISSNHL patients, and the extent of vestibular impairment is closely related to vertigo and hearing prognosis. ACS-cVEMP abnormalities independently predict unfavorable short-term hearing outcomes, suggesting that comprehensive vestibular assessment may help evaluate inner ear damage and improve prognostic prediction in patients with ISSNHL.