Objective: The labyrinthitis poses inferior quality of life with prolonged vestibular symptoms in patients with sudden sensorineural hearing loss with vertigo (SSNHLV). This study utilized a novel coherence analysis in video head impulse test (vHIT) to investigate vertigo outcomes in SSNHLV patients.
Methods: A retrospective review included 48 SSNHLV patients completing high-dose steroid treatment between December 2016 and April 2023, and 38 healthy volunteers were prospectively enrolled between November 2022 and April 2023 in our academic tertiary referral center. Magnitude-squared wavelet coherence was measured between eye and head velocities in vHIT to represent the degree of correlation across different frequency bands. Vertigo recovery, assessed by visual analog scale equal to zero at 2 weeks and 2 months, was analyzed using a multivariable Cox regression model.
Results: The VAS among patients with SSNHLV was 5.73 ± 2.45 (mean ± standard deviation). Higher coherent frequencies in the horizontal semicircular canal (SCC), posterior SCC, mean, and minimal coherent frequencies of all three SCCs combined were significantly associated with early complete vertigo remission at two weeks post-treatment. In the multivariate analysis, the minimal coherent frequency among the three SCCs emerged as an independent factor (hazard ratio [HR] 2.040, 95% confidence interval [CI] 1.776-2.304). At two months post-treatment, in addition to the previously significant parameters, vestibulo-ocular reflex (VOR) abnormality in the posterior SCC, gains in the horizontal and posterior SCCs, total and overt saccades in the horizontal SCC, coherent frequency in the anterior SCC, and mean VOR gain of all three SCCs combined were also statistically significantly related to total vertigo relief.
Conclusion: The greater minimal coherent frequency among the three SCCs was a strong factor contributing to earlier relief of vertigo in patients with SSNHLV. Coherence analysis in vHIT may be more sensitive than time series analysis for evaluating vertigo prognosis prediction.
Keywords: Sudden sensorineural hearing loss; vertigo; video head impulse test; wavelet coherence.