Sudden sensorineural hearing loss: Recovery rates according to audiometric patterns

The aim of this study was to evaluate the different audiometric patterns in sudden sensorineural hearing loss (SSNHL), assess recovery rates based on the initial pattern and also, analyse the impact on speech discrimination scores (SDS).

A retrospective, descriptive, study was completed for patients with SSNHL from January 2010 until June 2020. Outcome measures included audiometric patterns, recovery rates, improvements over time for hearing loss as well as for SDS at 14 days and 3 months follow-up. The Kruskal-Wallis test and Mann-Whitney U test were used to compare differences between the different groups. Post-hoc testing involved the Wilcoxon signed-rank test. A P<0.05 was considered statistically significant.

We included 211 patients, 64.3% showed downward-sloping or flat audiometric curves. Overall, 40% of the patients had recovered 50% or more of their hearing by day 14. We observed that hearing did improve over time, and this was more common for the upward-sloping cases, with 65% recovering to at least 50% of the maximum possible recovery by 3 months follow-up. Thirty percent had concomitant vertigo and/or dizziness; these patients had worse initial speech PTAs (pure tone average) (P≤0.0001) and inferior recovery rates (P=0.0007) as compared to patients without vertigo and/or dizziness.

SSNHL is still a controversial topic. Variability was observed with regards to audiometric curves, recovery rates and SDS recovery. We provide a table with recovery rates based on audiometric patterns that may help guide clinicians when explaining this condition to their patients.