Clinical features and prognosis of severe-to-profound sudden sensorineural hearing loss

Sudden sensorineural hearing loss (SSNHL) is an otologic emergency. Despite multiple efforts to clarify the factors affecting the prognosis of severe-to-profound SSNHL, various studies showed inconsistent results and lack of clinical significance. Therefore, we examined the clinical features and outcomes of severe-to-profound SSNHL.

We included patients who experienced SSNHL between 2018 and 2021 and were diagnosed according to the American Academy of Otolaryngology-Head and Neck Surgery criteria; hearing loss over 70 dB on initial pure tone audiometry (PTA) was used to define severe-to-profound SSNHL. We retrospectively examine the demographic, laboratory, radiologic, and audiometric data of SSNHL patients. We also evaluated the final hearing gain of these patients by assessing their PTA findings and word-recognition scores.

Of the 178 patients, 94 (52.81%) and 84 (47.19%) showed profound (>90 dB) and severe (>70 to 90 dB) hearing loss, respectively. The presence of vertigo and hypertension differed significantly between the severe and profound groups (p < 0.001 and p = 0.012, respectively), as did the initial serum creatinine level (p = 0.043). Recovery in PTA showed a reliable correlation with the interval between onset and treatment in the severe group and periventricular white-matter findings in the profound group (p < 0.001 and p = 0.011, respectively). The presence of hypertension was related to recovery of low tone (p = 0.023 for 250 Hz; p = 0.034 for 500 Hz), while glycated hemoglobin level was related to recovery of high tone in the severe group (p = 0.049 for 4000 Hz; p = 0.047 for 8000 Hz).

Severe-to-profound SSNHL showed poor prognosis for hearing gain. The interval from onset to treatment was a significant prognostic factor for severe SSNHL, while the presence of vertigo, estimated glomerular filtration rate, and periventricular white-matter findings were significant prognostic factors for profound SSNHL.