High-frequency conductive hearing loss as a diagnostic test for incomplete ossicular discontinuity in non-cholesteatomatous chronic suppurative otitis media.

Chronic suppurative otitis media, with or without cholesteatoma, may lead to erosion of the ossicles and discontinuity of the ossicular chain. In incomplete ossicular discontinuity (IOD), partial erosion of the ossicles occurs, but some sound transmission is noted throughout the ossicular chain. High-frequency conductive hearing loss (HfCHL) has been considered a hallmark of incomplete ossicular discontinuity. This study aims to evaluate the use of HfCHL as a preoperative predictor of IOD in patients with non-cholesteatomatous chronic suppurative otitis media. The HfCHL test was defined as the preoperative air-bone gap (ABG) at 4 kHz minus the average of the ABG at 0.25 and 0.5 kHz. The test was applied in 328 patients before surgery and compared to intraoperative findings as the gold standard. At surgery, 201 (61.3%) patients had an intact ossicular chain, 44 (13.4%) had a complete ossicular discontinuity, and 83 (25.3%) exhibited an IOD. The best cutoff level was calculated as 10 dB. The HfCHL test to diagnose IOD had a sensitivity of 83% and a specificity of 92% with a post-test probability of 78% and a likelihood ratio of 10.2. We concluded that the HfCHL test is highly effective in predicting IOD in patients with non-cholesteatomatous chronic suppurative otitis media and that it should be used routinely as a screening test prior to surgery

HfCHL test properties.

<p>HfCHL test properties.</p

Incomplete ossicular discontinuity.

<p>A: IOD type 1. There is erosion of the long process of the incus but still bony contact between incus and stapes. (I) incus, (M) malleus and (S) stapes. B: IOD Type 2. Incus and stapes are connected mainly by soft tissue.</p

ROC curves for scenarios 1 and 2.

<p>Receiver operating characteristics curves (n = 328) for the HfCHL test. Scenario 1 (in black): Target group for the test (disease group) included all patients with incomplete ossicular discontinuity. Scenario 2 (in red): Target group for the test (disease group) exclusively included patients with type 2 IOD.</p