Correlations between click-ABR / PTA outcomes and temporal bone malformation characteristics in patients with congenital aural atresia.

OBJECTIVE

To evaluate correlations between click auditory brainstem response (c-ABR) / pure tone audiometry (PTA) hearing thresholds and high-resolution computed tomography (HRCT) temporal bone abnormalities in congenital aural atresia (CAA) patients and identify key anatomical predictors of hearing loss.

METHODS

This retrospective study included 64 CAA patients (74 ears). Auditory assessments comprised c-ABR (performed in infancy) and PTA (conducted in school-aged children), with temporal bone HRCT completed during the same period as PTA. Patients with prior surgical interventions were excluded. Anatomical parameters (oval window height, middle ear cavity dimensions, stapes height, etc.) were quantified via HRCT multiplanar reconstruction and 3D analysis.

RESULTS

Oval window height exhibited the strongest correlation with c-ABR air conduction thresholds (r = -0.518, p < 0.001) and PTA4-AC thresholds (r = -0.459, p < 0.001). Middle cranial fossa depression was associated with higher c-ABR AC thresholds (r = -0.276, p = 0.017), while Jahrsdoerfer scores inversely correlated with PTA4-AC (r = -0.350, p = 0.002). Pneumatized atresia plates were more frequent in the low-threshold c-ABR group (57.8% compared to 24.1%, p = 0.004). Middle ear cavity width and height, alongside stapes height, significantly influenced PTA outcomes (p < 0.05).

CONCLUSION

Hearing loss severity in CAA patients strongly correlates with temporal bone malformations, particularly oval window height, which critically impacts both subjective and objective hearing outcomes.