Window Coverage and Liquid Biopsy in the First-Line Therapy of Severe Sudden Sensorineural Hearing Loss

Abstract

Introduction: Based on clinical practice guidelines, the application of corticosteroids as a first-line therapy is common. Although sudden sensorineural hearing loss (SSHL) etiology is primarily idiopathic, hearing loss can result from a perilymphatic fistula (PLF). Recent findings show evidence of a specific rate of PLF based on a cochlin-tomoprotein (CTP) detection test. Based on this rate of PLF treatment, the concepts of SSNHL need to be re-evaluated. The present study aimed to evaluate CTP in SSNHL patients and compare pre-surgical and post-surgical pure tone hearing thresholds after round and oval window sealing as first-line treatment.

Material and methods: A total of 30 patients with unilateral SSNHL with a pure tone average (PTA) (4 Freq. of 60 dB or more were enrolled in a prospective study. All patients underwent tympanoscopy for middle ear exploration as a first-line treatment. After intraoperative observation of a possible PLF, all patients obtained middle ear lavage to gain CTP samples for following ELISA-based CTP detection tests. All patients received round window and oval window sealing with fascia. PTA hearing thresholds were analyzed post-surgically 3 weeks after treatment based on 4-frequency bone conduction (BC).

Results: The average preoperative pure tone BC threshold was 97.7 dB compared with the 69 dB postoperative BC threshold. Mean BC improved by 20.3 dB after middle ear exploration and window sealing. A total of 56% (17 of 30) of patients recovered at least 10 dB. The middle ear cochlin-tomoprotein detection rate was 70% positive.

Conclusions: The combination of early tympanoscopy and inner ear-specific cochlin-tomoprotein as a detection tool for suspected PLF showed evidence of PLF as a key causative in SSNHL.

Keywords: cochlin-tomoprotein (CTP); perilymphatic fistula (PLF); sudden sensorineural hearing loss (SSNHL); tympanoscopy.

Figure 1

Relationship between time to treatment (in days) and mean postoperative difference in pure tone audiometry (PTA). Statistical analysis revealed no statistically significant association (Pearson’s correlation coefficient r = −0.05).

Figure 2

Comparison of bone conduction (BC) improvement in the three most affected contiguous frequencies between 0.5 and 4 kHz (Max 3 Freq ^{0 = 110 dB}, maximum hearing loss set 0 = 110 dB) and the CTP category.

Figure 3

Comparison of bone conduction (BC) improvement in 4-frequency bone conduction at 0.5, 1, 1.5, and 4 kHz (4 Freq ^{0 = 130 dB}, maximum hearing loss set 0 = 130 dB) and the CTP category.

Figure 4

2 × 2 contingency table. Relationship between CTP categories (positive/intermediate) and postoperative PTA improvement. The association between CTP categories and postoperative PTA improvement was not statistically significant (Fisher’s exact test, p = 0.6828).

Figure 5

Correlation test of the individual CTP value (dots) and pre-treatment PTA. Statistical analysis showed no correlation between the CTP value and pre-treatment PTA (Pearson correlation).