Calculated versus measured pure tone bone conduction 3 kHz thresholds in sudden sensorineural hearing loss

Could the Audiometric Criteria for Sudden Sensorineural Hearing Loss Miss Vestibular Schwannomas?

OBJECTIVE

To investigate the likelihood of missing a vestibular schwannoma (VS) diagnosis in patients who present with a sudden hearing loss (SHL) that does not meet the most accepted audiometric criteria for sudden sensorineural hearing loss (SSNHL) (a decrease of ≥30 dB at three consecutive frequencies).

METHODS

All adult patients (>18 years) diagnosed with SHL of any severity in a tertiary care referral medical center between 2015 and 2020 and who underwent an MRI scan to rule out VS were included. Statistical analyses were conducted to evaluate the difference between the rate of VS among patients with an initial audiogram, which met the abovementioned criteria, and those who did not. Other audiometric criteria for SNHL were also evaluated (≥10 dB at ≥2 frequencies and ≥ 15 dB at one frequency).

RESULTS

Of the 332 patients included in the study, 152 met the audiometric criteria for SSNHL, and 180 did not. Both groups had a similar VS rate (8.6% vs. 8.9%, p = 0.914). Similar results were found when other audiometric criteria for asymmetric SNHL were analyzed. In a subgroup analysis of patients with VS-associated SSNHL, neither the tumor size nor the Koos classification was associated with any of the audiometric criteria systems.

CONCLUSION

There should be a high index of suspicion for the presence of VS in patients with an SHL of any severity.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:670-675, 2023.